Patent Application
20230358128
The present disclosure generally relates to resource extraction, and in particular to processes and configurations for subterranean resource extraction.
The following paragraphs are provided by way of background to the present disclosure. They are not however an admission that anything discussed therein is prior art or part of the knowledge of persons skilled in the art.
Various techniques have evolved to extract and recover valuable subterranean resources, including mineral resources, such as potash, for example, from geological formations. One such technique, commonly referred to as in situ leaching, involves the drilling of boreholes from the surface into a subterranean resource deposit, and the subsequent injection of a fluid from surface into the borehole to in situ leach the resource material from the deposit into the fluid for recovery at the surface. Significant benefits can be said to be provided by resource extraction based on in situ leaching relative to more traditional subterranean mining practices. Thus, for example, resource extraction involving in situ leaching does not require the deployment of an underground workforce, only a limited amount of underground rock material needs to be removed, and the capital costs associated with resource extraction based on in situ leaching are generally lower than those associated with conventional mining or resource extraction operations.
For example, the performance of known primary potash solution mining techniques commonly initially involves the formation of a subterranean cavern at the distal end of a vertically oriented borehole. Thereafter primary resource extraction can be initiated starting from the subterranean cavern. This may involve breaking layers of the resource deposit, which is a process commonly referred to as rubblizing, to create rubblized resource material which has an enlarged surface area, and then injecting a fluid, such as an unsaturated fresh water solvent, to dissolve the soluble resource material. The solvent fluid may be slowly pumped downwards from the surface into the borehole, for example, through a liner in the borehole, towards the cavern. Dissolution of resource material in the cavern in the solvent generally results in the formation of a brine. Once the concentration of resource material in the brine is sufficiently high, further solvent is injected from surface and the brine is circulated up to surface, for example, through the annulus of the borehole. A fluid flow rate through the cavern can be established to discharge the brine at the surface on a continuous basis. At the surface the brine can then be processed to recover the resource material, and waste minerals such as salt, are disposed of, typically in a surface tailings area.
Thus, a typical resource extraction configuration for in situ leaching resource extraction involves a vertically extended borehole comprising a distally situated subterranean cavern from which the resource material is leached and extracted.
Primary potash solution mining resource extraction according to the known techniques and configurations generally requires large ground surface areas, for example, large scale in situ leaching resource extraction based operations can contain 40 wells spread over ten or more square kilometers, thus having a significant environmental impact. At the same time, large amounts of the total resource content of subterranean resource deposits remain unmined using the mining techniques known to those skilled in the art. Furthermore, as noted, waste minerals are brought to the surface using conventional potash extraction techniques. Thus, at the surface, separation of the resource material and waste minerals is required. Tailing areas require further surface space. In addition, under windy conditions waste mineral material can escape from the tailings area and cause environmental contamination.
Furthermore, many operational parameters and properties of the resource deposit effect the efficiency of an in situ leaching resource extraction operation, including, for example, solvent flow rate, solvent temperature, resource deposit temperature, brine salinity and cavern geometry. Using known systems and techniques for in situ leaching resource extraction it is challenging to monitor or control these parameters and properties, thus resulting in a suboptimal recovery of minerals from the resource material from the subterranean resource deposit.
Thus, despite the availability of a variety of techniques for recovery of resource materials from subterranean resource deposits, the known techniques are insufficiently effective. There is an ongoing need in the art for improved processes for resource recovery from resource deposits, and in particular there is a need for improved techniques and configurations for in situ leaching resource recovery, including economic techniques and configurations which have a limited environmental impact.
The following paragraphs are intended to introduce the reader to the more detailed description that follows and not to define or limit the claimed subject matter of the present disclosure.
In one broad aspect, the present disclosure relates to processes and configurations for extracting resource materials from a subterranean resource deposit.
In another broad aspect, the present disclosure relates to processes and configurations for extracting resource materials from a subterranean resource deposit which may be applied over relatively small surface regions, thereby limiting environmental impact, and inputs, notably energy and water, and reducing costs, while still recovering substantial quantities of resource materials, similar to or even exceeding the quantities that may be extracted using traditional resource extraction processes. In at least one embodiment, the mining configurations may be applied over a surface region of one square mile or less.
Accordingly, in one aspect, in accordance with the teachings herein, the present disclosure provides, in at least one embodiment, a process for in situ subterranean resource extraction from subterranean space comprising a resource deposit by extracting a resource from the resource deposit using a borehole configuration that comprises:
wherein the process comprises:
In at least one embodiment, the first section of the first borehole string or the first section of the second borehole string can extend substantially vertically relative to the surface region.
In at least one embodiment, the second sections of the first and second borehole strings can extend generally in a horizontal direction relative to the surface region and the first planar region is situated substantially horizontal relative to the surface region.
In at least one embodiment, the circulating the carrier fluid can continue until the internal volumes of the first and second borehole strings have increased so that the average height along the lengths of the second sections of the first and second borehole strings have increased at least two-fold, while the average widths along the lengths of the second sections of the first and second borehole strings have increased at least as much as the increases in the heights.
In at least one embodiment, the circulating the carrier fluid can continue until the internal volumes of the first and second borehole strings have increased so that an average width along the lengths of the second sections of the first and second borehole strings have increased at least two-fold from initial widths of those sections, and thereafter, the process comprises stopping the carrier fluid circulation and maintaining the carrier fluid stagnant within the second sections of the first and second borehole strings for a period of at least one day, before recovering the carrier fluid through the first and/or the second borehole string.
In at least one embodiment, the borehole configuration can comprise first and second borehole strings comprising casing along a proximal portion of the first borehole string extension or the second borehole string extension.
In at least one embodiment, the process can comprise periodically injecting the carrier fluid in an alternating fashion through the first and the second borehole strings.
In at least one embodiment, the borehole configuration can comprise a third borehole string extending downward from the surface region, the third borehole string distally connecting at the nodal space in the resource deposit.
In at least one embodiment, the third borehole string can have a surface borehole string opening adjacent to the surface borehole string openings of the first and second borehole string.
In at least one embodiment, the third borehole string can have a surface borehole string opening spaced away from the surface borehole string openings of the first and second borehole string.
In at least one embodiment, the process can comprise assaying the subterranean resource deposit for the presence of the resource material by accessing the nodal space via the third borehole string with an assaying device prior to injecting the carrier fluid.
In at least one embodiment, the process can comprise injecting the carrier fluid from the surface region into the nodal space via the third borehole string and up to the surface region through the fluid path along the first borehole string or the second borehole string.
In at least one embodiment, the first borehole string can comprise:
the process further comprises:
In at least one embodiment, the first and second borehole strings can be a first borehole and a second borehole, respectively.
In at least one embodiment, the first section of the first borehole string can be a first tubular liner and the second section of the first borehole string is a first laterally extending borehole extending from the first tubular liner, the first section of the second borehole string is a second tubular liner and the second section of the second borehole string is a second laterally extending borehole extending from the second tubular liner, and the first sections of the first and second borehole strings together are installed in a first borehole extending from the surface region.
In at least one embodiment, the borehole configuration can comprise a fourth borehole string, the fourth borehole string extending downward from the surface region into the resource deposit, and distally connecting to the second nodal space.
In at least one embodiment, the third sections of the first and second borehole strings can be at the same depth so that the first and second planar regions are situated at approximately at the same depth relative to the surface region.
In at least one embodiment, the third sections of the first and second borehole strings can be at different depths so that the first and second planar regions are situated at two different depths relative to the surface region.
In at least one embodiment, the surface region below which the borehole configuration can be implemented is twenty five square mile or less.
In at least one embodiment, the surface region below which the borehole configuration is implemented can be one square mile or less.
In at least one embodiment,
In at least one embodiment, a plurality of additional borehole strings can extend downward from the surface region into the resource deposit, and each of the plurality of additional borehole strings distally connect to one of the plurality of nodal spaces.
In at least one embodiment, the plurality of additional borehole strings can be a plurality of boreholes.
In at least one embodiment, wherein the first section of a first plurality of the additional borehole strings can correspond with an equal first plurality of tubular liners and the second section of the first plurality of the additional borehole strings corresponds with an equal plurality of laterally extending boreholes extending from the first plurality of tubular liners, the first section of a second plurality of the additional borehole strings corresponds with an equal second plurality of tubular liners and the second section of the second plurality of the additional borehole strings corresponds with an equal plurality of laterally extending boreholes extending from the second plurality of tubular liners, and the first sections of the first and second plurality of the additional borehole strings are together installed in a first borehole extending from the surface region.
In at least one embodiment, the plurality of additional borehole strings can be spaced away from one another and from the first and second borehole strings.
In at least one embodiment, the plurality of additional borehole strings can be radially disposed relative to the first and second borehole strings.
In at least one embodiment, the first section of the first borehole string can be a first tubular liner 190a and the second section of the first borehole string is a first laterally extending borehole extending from the first tubular liner 190a, the first section of the second borehole string is a second tubular liner 190b and the second section of the second borehole string is a second laterally extending borehole extending from the second tubular liner 190b, and the first sections of the first and second borehole strings together are installed in a first borehole extending from the surface region.
In at least one embodiment, the process can comprise subsequently injecting the carrier fluid from the surface region into the nodal space via one or more of the plurality of additional borehole strings and up to the surface region through the fluid path along the first and second borehole strings.
In at least one embodiment, the resource material can comprise first and second chemical constituents, and the process comprises circulating the carrier fluid wherein the first chemical constituent in situ leaches into the carrier fluid, and the second chemical constituent is retained in situ and forms a porous matrix.
In at least one embodiment, the first chemical constituent can potassium chloride, and the second chemical constituent is sodium chloride.
In at least one embodiment, the resource material can be an evaporite.
In at least one embodiment, the carrier fluid can be a solvent and the resource material is an evaporite that is soluble in the solvent.
In at least one embodiment, the evaporite can be potash.
In another aspect, the present disclosure provides, in at least one embodiment, a process for constructing a mining configuration for subterranean resource extraction from a resource deposit, the process comprising:
In at least one embodiment, the process can comprise forming the first section of the second borehole string, and the first section of the second borehole string to extend substantially vertically relative to the surface region.
In at least one embodiment, the process can comprise forming the second sections of the first and second borehole strings to extend generally in a horizontal direction relative to the surface region and the first planar region is situated substantially horizontal relative to the surface region.
In at least one embodiment, the process can comprise casing the second section of the first and second borehole strings along a proximal portion of the first borehole string extension or the second borehole string extension.
In at least one embodiment, the process can comprise installing a third borehole string extending downward from the surface region, the third borehole string distally connecting at the nodal space in the resource deposit.
In at least one embodiment, the process can comprise installing the third borehole string to have a surface borehole string opening adjacent to the surface borehole string openings of the first and second borehole strings.
In at least one embodiment, a plurality of additional borehole strings 471, 472, 473, and 474 can extend downward from the surface region into the resource deposit, and each of the plurality of additional borehole strings distally connect to one of the plurality of nodal spaces.
In at least one embodiment, the first and second borehole strings can be boreholes and the installing comprises drilling each of the boreholes to form the boreholes.
In at least one embodiment, wherein the first sections 477a and 477b of a first plurality 475 of the additional borehole strings 471, 472, 473, and 474 can correspond with an equal first plurality 479 of tubular liners 478a and 478b and the second sections 105b and 105d of the first plurality 475 of the additional borehole strings 473 and 474 correspond with an equal plurality of laterally extending boreholes 105-1 and 105-2 extending from the first plurality 479 of tubular liners 478a and 478b, the first sections 477c and 477d of a second plurality 476 of the additional borehole strings 471 and 472 correspond with an equal second plurality 480 of tubular liners 478c and 478d and the second sections 105e and 105c of the second plurality 476 of the additional borehole strings 471, and 472 correspond with an equal plurality of laterally extending boreholes 105-3 and 105-4 extending from the second plurality 480 of tubular liners 478c and 478d, and the first sections 477a and 477b of the first plurality 475 and first sections 477c and 477d of the second plurality 476 of the additional borehole strings 471, 472, 473, and 474 are together installed in a first borehole 105 extending from the surface region.
In at least one embodiment, the surface region below which the borehole configuration can be implemented is twenty five square mile or less.
In at least one embodiment, the surface region below which the borehole configuration can be implemented is one square mile or less.
In at least one embodiment, the process further can comprise:
In at least one embodiment, wherein the process can comprise forming the third sections of the first and second borehole strings at the same depth so that the first and second planar regions are situated at the same depth relative to the surface region.
In at least one embodiment, the process can comprise forming the third sections of the first and second borehole strings at different depths so that the first and second planar regions are situated at two different depths relative to the surface region.
In at least one embodiment, the process can comprise
In at least one embodiment, the process can comprise installing a plurality of additional borehole strings that extend downward from the surface region into the resource deposit, and wherein each of the plurality of additional borehole strings distally connect to one of the plurality of nodal spaces.
In at least one embodiment, the process can comprise forming each of the additional borehole strings to be spaced away from one another and the first and second borehole strings.
In at least one embodiment, the process can comprise forming each of the plurality of additional borehole strings to be radially disposed relative to the first and second borehole strings.
In at least one embodiment, the resource material can be an evaporite.
In at least one embodiment, the carrier fluid can be a solvent and the resource material is an evaporite that is soluble in the solvent.
In at least one embodiment, the evaporite can be potash.
In another aspect, the present disclosure provides, in at least one embodiment, a process for subterranean resource extraction from a subterranean resource deposit, the process comprising:
In at least one embodiment, the process can comprise forming the first section of the second borehole string, and the first section of the second borehole string to extend substantially vertically relative to the surface region.
In at least one embodiment, the process can comprise forming the second sections of the first and second borehole string to extend generally in a horizontal direction relative to the surface region and the first planar region is situated substantially horizontal relative to the surface region.
In at least one embodiment, the process can comprise continuing circulation of the carrier fluid until the internal volumes of the first and second borehole strings have increased so that the average heights along the lengths of the second sections of the first and second borehole strings have increased at least two-fold, while the average widths along the lengths of the second sections of the first and second borehole strings have increased at least as much as the height increases.
In at least one embodiment, the process can comprise continuing circulation of the carrier fluid until the internal volumes of the first and second borehole strings have increased so that average widths along the lengths of the second sections of the first and second borehole strings have increased at least two-fold from initial widths of those sections, and thereafter, the process comprises stopping the carrier fluid circulation and maintaining the carrier fluid stagnant within the second sections of the first and second borehole strings for a period of at least one day, before recovering the carrier fluid through the first and/or the second borehole string.
In at least one embodiment, the process can comprise casing the second section of the first and second borehole strings along a proximal portion of the first borehole string extension or the second borehole string extension.
In at least one embodiment, the process can comprise installing a third borehole string extending downward from the surface region, the third borehole string distally connecting at the nodal space in the resource deposit.
In at least one embodiment, the process can comprise installing the third borehole string to have a surface borehole string opening adjacent to the surface borehole string openings of the first and second borehole strings.
In at least one embodiment, the process can comprise installing the third borehole string to have a surface borehole string opening spaced away from the surface borehole string openings of the first and second borehole strings.
In at least one embodiment, the first and second borehole strings can be boreholes and the installing comprises drilling a borehole to form each of the boreholes.
In at least one embodiment, the first, second and third borehole strings are boreholes and the installing comprises drilling a borehole to form each of the boreholes.
In at least one embodiment, the process can comprise assaying the subterranean resource deposit for the presence of the resource material by accessing the nodal space via the third borehole string with an assaying device.
In at least one embodiment, the process can comprise subsequently periodically injecting the carrier fluid in an alternating fashion through the first and the second borehole strings.
In at least one embodiment, the process can comprise subsequently injecting the carrier fluid from the surface region into the nodal space via the third borehole string and up to the surface region through the fluid path along the first borehole string or the second borehole string.
In at least one embodiment, the process can comprise
In at least one embodiment, the process can comprise forming the third sections of the first and second borehole strings at the same depth so that the first and second planar regions are situated at approximately the same depth relative to the surface region.
In at least one embodiment, the process can comprise forming the third sections of the first and second borehole strings at different depths so that the first and second planar regions are situated at two different depths relative to the surface region.
In at least one embodiment, the surface region below which the mining configuration is implemented can be twenty five square mile or less.
In at least one embodiment, the surface region below which the mining configuration is implemented can be one square mile or less.
In at least one embodiment, wherein the process can comprise
In at least one embodiment, the process can comprise installing a plurality of additional borehole strings that extend downward from the surface region into the resource deposit, and wherein each of the plurality of additional borehole strings distally connect to one of the plurality of nodal spaces.
In at least one embodiment, the process can comprise forming each of the additional borehole strings to be spaced away from one another and from the first, and second borehole strings.
In at least one embodiment, the process can comprise forming each of the plurality of additional borehole strings to be radially disposed relative to the first and second borehole strings.
In at least one embodiment, the process can comprise injecting the carrier fluid in an alternating fashion through the first borehole string and the second borehole string.
In at least one embodiment, the process can comprise subsequently injecting the carrier fluid from the surface region into the nodal space via one or more of the plurality of additional borehole strings and up to the surface region through the fluid path along the first and second borehole strings.
In at least one embodiment, the resource material can comprise first and second chemical constituents, and the process comprises circulating the carrier fluid wherein the first chemical constituent in situ leaches into the carrier fluid, and the second chemical constituent is retained in situ and forms a porous matrix.
In at least one embodiment, the first chemical constituent can be potassium chloride, and the second chemical constituent is sodium chloride.
In at least one embodiment, the resource material can be an evaporite.
In at least one embodiment, the carrier fluid can be a solvent and the resource material is an evaporite that is soluble in the solvent.
In at least one embodiment, the evaporite can be potash.
In another aspect, the present disclosure provides, in at least one embodiment, a resource extraction configuration for in situ resource extraction from a resource deposit in an underlying subterranean space associated with a surface region, wherein the resource extraction configuration comprises:
In at least one embodiment, the at least one borehole configuration can comprise a third borehole string extending downward from the surface region, the third borehole string having a distal end at the nodal space in the resource deposit.
In at least one embodiment, the first section of the first borehole string, or the first section of the second borehole string, or the third borehole string of the at least one borehole configuration can be positioned to extend substantially vertically relative to the surface region.
In at least one embodiment, the second sections of the first and second borehole strings of the at least one borehole configuration can be positioned to extend generally in a horizontal direction relative to the surface region.
In at least one embodiment, the resource extraction configuration can comprise a plurality of borehole configurations having a plurality of borehole strings, wherein fluid paths through each of laterally extending second sections of a first portion of the plurality of borehole strings extend substantially parallel and adjacent to corresponding fluid paths of a second portion of the plurality of borehole strings.
In at least one embodiment, the first borehole string of the at least one borehole configurations can comprise a third section extending laterally in a third lateral direction from the first section of the first borehole string into the resource deposit; and the second borehole string of the at least one borehole configurations comprise a third section extending laterally in a fourth lateral direction from the first section of the second borehole string into the resource deposit, where the third sections of the first and second borehole strings penannularly extend to form a second planar region, and the third sections of the first and second borehole strings distally connect to form a second nodal space and a second fluid path is formed from the surface region through the first borehole string to the second nodal space and from the second nodal space upward to the surface region through the second borehole string.
In at least one embodiment, the resource extraction configuration can comprise first and second borehole configurations that have first and second nodal spaces and are situated side by side so that a first imaginary straight line run from the first distal nodal space towards the first and second borehole string of the first borehole configuration and a second imaginary straight line run from the second distal nodal space towards the first and second borehole string of the second borehole configuration, wherein the first and second imaginary line run approximately parallel.
In at least one embodiment, the surface region below which the mining configuration is implemented can be twenty five square mile or less.
In at least one embodiment, the surface region below which the mining configuration is implemented can be one square mile or less.
In at least one embodiment, the distance between the parallel first and second lines can be 200 meters, or less.
In at least one embodiment, the first borehole string of the at least one borehole configuration can comprise a first plurality of sections extending laterally in a first plurality of different lateral directions from the first section of the first borehole string into the resource deposit; the second borehole string of the at least one borehole configuration comprises a second plurality of sections penannularly extending in a second plurality of lateral directions from the first section of the second borehole string into the resource deposit, the first plurality of sections being equal in number to the second plurality of sections, and each section of the first plurality of sections penannularly extends with one section of the second plurality of sections to collectively form a plurality of planar regions, and distally connects to collectively form a plurality of nodal spaces so that a plurality of fluid paths from the surface region through the first borehole string to each of the nodal spaces and from the plurality of nodal spaces upward to the surface through the second borehole string.
In at least one embodiment, the at least one borehole configuration can comprise a first plurality of additional borehole strings that extend downward from the surface region into the resource deposit, each of the additional borehole strings being spaced away from one another and from the first, second and third borehole string, and each of the plurality of additional borehole strings are distally connected to one of the plurality of nodal spaces.
In at least one embodiment, the plurality of additional borehole strings can be radially disposed relative to the first and second borehole strings.
In at least one embodiment, the at least one borehole configuration can comprise a second plurality of borehole strings comprising first, second and third boreholes extending in a same manner as the first, second and third borehole strings of the first plurality of borehole strings, the first plurality of borehole strings comprising second and third extensions oriented so as to be radially disposed relative to the second and third borehole strings, and the second plurality of borehole strings is oriented so as to be encircling and intercalating the first plurality of borehole strings.
In another aspect, the present disclosure provides, in at least one embodiment, a plurality of adjacent borehole configurations that each include a plurality of borehole strings and are associated with adjacent surface regions to facilitate resource extraction from a resource deposit in an underling subterranean space, each borehole configuration comprising:
In at least one embodiment, each borehole configuration can comprise a third borehole string extending downward from the surface region, the third borehole string having a distal end at the nodal space in the resource deposit.
In at least one embodiment, each borehole configuration in the plurality of adjacent borehole configurations the first borehole string can comprise a first plurality of sections extending laterally in a first plurality of different lateral directions from the first section of the first borehole string into the resource deposit; the second borehole string comprises a second plurality of sections extending laterally in a second plurality of lateral directions from the first section of the second borehole string into the resource deposit, the first plurality of sections being equal in number to the second plurality of sections, and each section of the first plurality of sections penannularly extends with one section of the second plurality of sections to collectively form a plurality of planar regions, and distally connects to collectively form a plurality of nodal spaces so that a plurality of fluid paths are formed from the surface region through the first borehole string to each of the nodal spaces and from the plurality of nodal spaces to the surface through the second borehole string.
In at least one embodiment, the plurality of adjacent borehole strings can comprise a plurality of additional borehole strings that extend downward from the adjacent surface regions into the resource deposit, where for each borehole configuration the additional borehole strings are spaced away from one another and from the first, second and third borehole strings, and each of the plurality of additional borehole strings are distally connected to one of the plurality of nodal spaces
Other features and advantages of the present disclosure will become apparent from the following detailed description. It should be understood, however, that the detailed description, while indicating preferred implementations of the present disclosure, is given by way of illustration only, since various changes and modification within the spirit and scope of the disclosure will become apparent to those of skill in the art from the detailed description.
The disclosure is in the hereinafter provided paragraphs described, by way of example, in relation to the attached figures. The figures provided herein are provided for a better understanding of the example embodiments and to show more clearly how the various embodiments may be carried into effect. Like numerals designate like or similar features throughout the several views possibly shown situated differently or from a different angle. Thus, by way of example only, part 115 in
The figures together with the following detailed description make apparent to those skilled in the art how the disclosure may be implemented in practice.
Various processes, systems and configurations will be described below to provide at least one example of at least one embodiment of the claimed subject matter. No embodiment described below limits any claimed subject matter and any claimed subject matter may cover processes, systems, or configurations that differ from those described below. The claimed subject matter is not limited to any process, system, or configurations having all of the features of processes, systems, or compositions described below, or to features common to multiple processes, systems, or configurations described below. It is possible that a process, system, or configurations described below is not an embodiment of any claimed subject matter. Any subject matter disclosed in processes, systems, or configurations described below that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors or owners do not intend to abandon, disclaim or dedicate to the public any such subject matter by its disclosure in this document.
As used herein and in the claims, the singular forms, such as “a”, “an” and “the” include the plural reference and vice versa unless the context clearly indicates otherwise. Throughout this specification, unless otherwise indicated, the terms “comprise,” “comprises” and “comprising” are used inclusively rather than exclusively, so that a stated integer or group of integers may include one or more other non-stated integers or groups of integers. The term “or” is inclusive unless modified, for example, by “either”. The term “and/or” is intended to represent an inclusive or. That is “X and/or Y” is intended to mean X or Y or both, for example. As a further example, X, Y and/or Z is intended to mean X or Y or Z or any combination thereof.
When ranges are used herein for geometric dimensions, physical properties, or chemical properties, such as chemical formulae, all combinations and sub-combinations of ranges and specific embodiments therein are intended to be included. Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions used herein should be understood as being modified in all instances by the term “about.” The term “about” when referring to a number or a numerical range means that the number or numerical range referred to is an approximation within experimental variability (or within statistical experimental error), and thus the number or numerical range may vary between 1% and 15% of the stated number or numerical range, as will be readily recognized by the context. Furthermore, any range of values described herein is intended to specifically include the limiting values of the range, and any intermediate value or sub-range within the given range, and all such intermediate values and sub-ranges are individually and specifically disclosed (e.g. a range of 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.90, 4, and 5). Similarly, other terms of degree such as “substantially” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree should be construed as including a deviation of the modified term, such as up to 15% for example, if this deviation would not negate the meaning of the term it modifies.
Several directional terms such as “above”, “below”, “lower”, “upper”, “vertical” and “horizontal” are used herein for convenience including for reference to the drawings. In general, the terms “upper”, “above”, “upward” and similar terms are used to refer to an upwards direction or upper portion in relation to the earth's surface, as shown, for example in
Unless otherwise defined, scientific and technical terms used in connection with the formulations described herein shall have the meanings that are commonly understood by those of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention, which is defined solely by the claims.
All publications, patents, and patent applications referred herein are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically indicated to be incorporated by reference in its entirety.
In general, the resource extraction configurations and processes of the present disclosure can be used for subterranean resource extraction. Implementation of the resource extraction configurations and processes of the present disclosure can result in the recovery at the surface of carrier fluids containing subterranean resource materials such as, but not limited to, minerals, and other resource materials.
In broad terms, the processes of the present disclosure involve constructing and installing at least two borehole strings into a subterranean area from a ground level region, which is referred to herein as a “surface region” to recover a resource material of interest. The term “borehole string”, as used herein, generally refers to a tubular subterranean extension allowing for the flow of fluid therethrough. The tubular subterranean extension of a borehole string may be formed by the subterranean formation naturally surrounding the tubular extension, and thus be a borehole, or a borehole string may be formed by a tubular device, for example, casing or a liner, installed to extend at least partially, for example through a first section, inside a borehole drilled and configured to receive the tubular device. Thus, it is to be understood that in general a borehole may be constructed to comprise a singular borehole string, or a borehole may be constructed to comprise multiple borehole strings by installing multiple subterraneously extending tubular devices therein. Thus, in broad terms, the present disclosure involves drilling into a subterranean area from a surface region to recover a resource material of interest using at least one borehole and installing at least two tubular devices therein to construct two borehole strings, or drilling at least two boreholes, to thereby establish two borehole strings.
Preferably, a first borehole string and a second borehole string are established. The first and second borehole strings may be first and second boreholes situated adjacent to each other, or a first borehole comprising a first and second tubular device extending into the first borehole. The tubular device can be any tubular body, including any liner, pipe, tubing, casing, or the like, that can serve as a fluid conduit. The tubular device may be manufactured using any suitable material, including, for example, steel or plastic. The two borehole strings are interconnected at a distal nodal space. A fluid path is formed downward from the surface through the first borehole string and upward via the distal nodal space and the second borehole string. Alternatively, a fluid path is formed downward from the surface region through the second borehole string and upward via the distal nodal space and the first borehole string. A carrier fluid is injected at the surface region along the fluid paths to thereby in situ leach resource material from the resource deposit into the carrier fluid and circulate the carrier fluid containing the resource material up to the surface for processing.
In another preferred embodiment, three borehole strings are installed, including a third borehole string which can be adjacent to or spaced away from the first and second borehole strings, which are situated adjacent to each other. The third borehole string can be used to survey and detect the subterranean resource material. All three borehole strings are interconnected at a distal nodal space. Fluid paths are formed downward from surface through the first or second borehole string and upward via the distal nodal space and the first or second borehole string that didn't provide the downward fluid path. A carrier fluid is injected at surface along the fluid paths to thereby in situ leach resource material from the resource deposit into the carrier fluid and circulate the carrier fluid containing resource material up to surface for processing.
A challenge of many known processes and configurations for resource extraction is that only a small fraction of the resource materials of a resource deposit is extracted. At the same time a large ground surface area is required for the resource extraction operation, and often vehicular transport or pipeline transport of fluids between injection and discharge points is involved.
A further challenge with known processes for resource extraction is that large amounts of contaminating materials are recovered at the surface together with the resource material. Thus, separation of the contaminating materials from the resource materials is required at surface. Furthermore, disposal of the contaminating material often negatively impacts the environment, and can be costly.
A further challenge with known processes for resource extraction is that they do insufficiently permit the monitoring of operational parameters and properties of the resource material which negatively effects the efficiency of a solution-based resource extraction operation, including, for example, carrier fluid flow rate, carrier fluid temperature, resource deposit temperature, brine salinity and geometry of the borehole configurations.
A yet further challenge with known processes for resource extraction is that they comprise a single flow path.
In one aspect, at least one of the processes and configurations for resource extraction of the present disclosure allow for the extraction of a more substantial amount of the total resource content of a resource deposit, while at the same time using a more limited surface region compared to that which is used for traditional subterranean resource extraction processes. Thus, for example, using the processes and configurations of the present disclosure, 1 square mile (2.6 square kilometers) or less of above ground surface region may be used for in situ extraction of a portion of a subterranean potash deposit, also about a square mile in size, and, surprisingly, all or substantially all of the total available potash may be extracted from the mined potash deposit. In view of the limited surface region used to implement the mining configurations of the present disclosure, the environmental impact associated with operating the mining configurations of the present disclosure is limited. Furthermore, fewer inputs, such as water and energy, are used when compared to the inputs required in traditional mining processes.
In another aspect, at least one of the processes of the present disclosure can limit the quantity of contaminating material that is brought to surface, and thus can limit disposal costs and reduce the environmental impact of extraction operations run according to the processes of the present disclosure.
In another aspect, at least one of the processes and configurations for resource extraction of the present disclosure further permit monitoring of many operational parameters and properties including such as, but not limited to, solvent flow rate, solvent temperature, resource deposit temperature, brine salinity and cavern geometry, for example.
Furthermore, in another aspect, at least one of the processes and configurations for resource extraction of the present disclosure allow for the development of several flow paths.
Furthermore, in another aspect, at least one of the processes and configurations for resource extraction of the present disclosure allow for the distribution of carrier fluid and processing of discharged carrier fluid at a single fluid housing, and therefore no vehicular transport, and limited pipeline transport above surface of carrier fluid is required.
In what follows, example embodiments of the present disclosure are described with reference to the drawings. It is noted, in particular, in this respect that the embodiments generally involve selecting processes and configurations for the extraction of mineral materials from a subterranean mineral deposit. The terms “mineral materials” and “minerals”, as used herein, refer to naturally occurring, substantially homogenous inorganic solid substances having a definite chemical composition and ordered atomic arrangement, commonly crystalline, and include, without limitation, silicates including tectosilicates, phyllosilicates, inosilicates, cyclosilicates, sorosilicates and orthosilicates, for example; oxides including aluminum oxide, titanium dioxide and uranium oxide, for example; halides including potassium chloride and sodium chloride, for example; sulfates including calcium sulfate and barium sulfate, for example; carbonates including sodium carbonate, for example; phosphates including phosphates belonging to the apatite group, fluorapatite, for example; chemical elements, including metallic elements such as gold and silver, for example, and semi-metallic elements, non-metallic elements, and metallic compounds, notably alloys, for example. In addition to mineral materials, non-mineral resource materials may also be extracted using the configurations and processes of the present disclosure. Non-mineral resources include, but are not limited to, hydrocarbon resources, such as petroleum, for example. It is understood that although the following example embodiments refer to mineral materials, the configurations of the present disclosure may also be used to extract non-mineral subterranean resource materials.
Implementation of the resource extraction configurations and processes of the present disclosure can result in the recovery at the surface of carrier fluids containing subterranean resource materials, such as one or more minerals, and other resource materials of interest.
The mineral of interest or resource of interest can be any mineral or resource which can be dissolved in a solvent fluid injected into boreholes. The mineral constituting a mineral deposit can, for example, be an evaporite, i.e. a geological mineral deposit formed following sea water evaporation. In specific example embodiments, the evaporite can be, but is not limited to, potash, trona, halite, or gypsum, for example.
The term “potash” as used herein, refers to a potassium containing mineral. Potassium may be present in various chemical forms including, for example, in the form of potassium chloride (KCl), also referred to in a commonly naturally occurring crystalized form as sylvite, potassium hydroxide (KOH), potassium carbonate (K2CO3), potassium nitrate (KNOB), potassium chlorate (KClO), potassium sulfate (K2SO4) potassium permanganate (KMnO4), carnallite (KMgCl-6·(H2O)), langbeinite (K2Mg2(SO4)3), and polyhalite, (K2Ca2Mg(SO4)4·2(H2O)), for example.
The mineral deposit besides one or more chemical forms of potassium, may contain other chemical compounds, including sodium chloride, (NaCl), also referred to in a common naturally occurring crystalized form as halite, for example.
In some embodiments, mineral deposits may comprise a mixture of minerals. Thus, for example, potash mineral deposits commonly comprise a mixture of KCl (sylvite) and NaCl (halite). Potash deposits may, for example, contain from about 30% to about 70% KCl, with the preponderance of the balance, up to almost 100%, containing NaCl. In embodiments in which a solvent saturated with NaCl is used, as brine migrates through mineral deposit, KCl may dissolve in the brine, while a porous matrix structure of NaCl may in remain in place.
In general, borehole openings maybe separated by any suitable distance. In certain preferred embodiments, a borehole opening may be separated from another borehole opening by 50 m or less, for example 45 m or less, 40 m or less, 35 m or less, 30 m or less, 25 m or less, 20 m or less, 15 m or less, 10 m or less, 5 m or less or 2 m or less and boreholes that are within 50 m of each other can be said to be adjacent to each other. It is noted that in embodiments, where a single bore hole includes first and second tubular devices the borehole strings may be particularly close, and the first and second tubular devices may be contacting one another. In other embodiments, any borehole opening of the borehole configurations described herein may be separated from another borehole opening by at least 75 m, at least 100 m, at least 200 m, at least 300 m, at least 400 m at least 500 m, at least 750 m, at least 1 km, at least 1.5 kms or at least 2 kms. Combinations of closer and farther boreholes may also be used.
Variations of borehole directions may be used in the present teachings. Boreholes are preferably substantially oriented in a vertical downward fashion (relative to the surface region). Vertical borehole extensions may further extend laterally into mineral deposit and generally in a horizontal direction relative to the surface region to form generally horizontal borehole extensions. Although borehole extensions preferably extend generally horizontally, some local deviations, for example, in the form of undulations, can occur along the length of borehole extensions.
As will readily be appreciated by those of skill in the art, the depth of a borehole depends on the geographical location of the surface region as well as the mineral deposit or subterranean resource of interest. In some locations it may be necessary to drill deeper to reach a mineral deposit or resource of interest, while in other locations, the mineral deposit may be situated closer to the surface region. In various embodiments, the length of vertical borehole extensions (depth) can range from approximately 200 meters to approximately 3,000 meters.
In a general overview,
Referring initially to
Surface region s can be any above ground land surface having an area of any size. In some embodiments, surface region s can, for example, be a section of land i.e. one square mile (2.6 square kilometers). It is noted that the processes of the present disclosure require a small surface region relative to more traditional mining operations. This limits the environmental impact and input requirements to operate the mining configurations of the present disclosure. In general, borehole openings 105o and 110o are separated from one another by 50 m or less, for example 45 m or less, 40 m or less, 35 m or less, 30 m or less, 25 m or less, 20 m or less, 15 m or less, 10 m or less, 5 m or less or 2 m or less and thus boreholes 105 and 110 can be said to be adjacent to each other. Boreholes openings 105o and 110o may be spaced away from borehole opening 115o, for example, spaced away at least 75 m, at least 100 m, at least 200 m, at least 300 m, at least 400 m at least 500 m, at least 750 m, at least 1 km, at least 1.5 kms or at least 2 kms, as shown in in resource extraction configuration 100. Boreholes 105 and 110 comprise substantially vertical downward (relative to surfaces) borehole extensions 105a and 110a each extending into mineral deposit 140. Vertical borehole extensions 105a and 110a at depth d and extension points 125a and 125b, respectively, further extend laterally into mineral deposit 140 and generally in a horizontal direction relative to surface region s to form generally horizontal borehole extensions 105b and 110b, respectively. It is noted that although borehole extensions 105b and 110b extend generally horizontally there may be some local deviations, for example, in the form of undulations, that can occur along the length of borehole extensions 105b and 110b. Depth d, as will readily be appreciated by those of skill in the art, depends on the geographical location of surface region s, as well as the mineral deposit 140. In some locations it may be necessary to drill deeper to reach mineral deposit 140, while in other locations, mineral deposit 140 may be situated closer to surface region s. In various embodiments, the length of vertical borehole extensions 105a and 110a (i.e. depth d) can range from approximately 300 meters to approximately 3,000 meters. Thus, for example, in Saskatchewan, potash deposits may be located at a depth d of approximately 1,000 meters, while in regions further south of Saskatchewan the depth d generally increases. It should also be noted that the term “laterally” generally means that a given borehole section that extends laterally from a particular borehole section means that the given borehole section generally has a directional axis that is different compared to the longitudinal axis of that particular borehole section.
It is further noted that the three dimensional shape of resource deposits may vary. Thus, a resource deposit may, for example, be present in a substantially horizontal layer, or a resource deposit may, for example, be present in a layer with a generally upward or downward sloping angle, relative to surface region s, or, for example, a resource deposit may be present in a layer forming one or more wave like shapes. The lateral directions of borehole extensions 105b and 110b may be selected depending to the shape of the resource deposit. Thus, for example, where the deposits are present in a substantial horizontal layer, borehole extensions 105b and 110b may be selected to be situated generally horizontal relative to surface region s. In embodiments in which deposits are present in a layer with a generally upward or downward sloping angle, for example, borehole extensions 105b and 110b may be selected to extend generally at the same angle. In embodiments in which the deposit may be present in a layer with one or more wave like shapes, for example, borehole extensions 105b and 110b be may be constructed below the trough of the wave(s), or so as to conform with contours of the wave(s). Thus, those of skill in the art will be able to select appropriate lateral directions for borehole extensions 105b and 110b based on the general three dimensional shape of mineral deposit 140.
As noted above, surface region s may be one square mile or less. Similarly, the subterranean horizontal surface region of the portion of mineral deposit 140 in which horizontal borehole extensions 105b and 110b extend may be one square mile or less, e.g. about three quarters of a square mile or less, one half of a square mile or less, or even one quarter of a square mile or less. In other embodiments, larger surface regions may be used, for example, a surface region ranging from about 25 square miles (5 by 5 miles) to about 4 square miles (2 by 2 miles), e.g. a surface region of about 25 square miles, about 16 square miles, about 9 square miles, or about 4 square miles. As will be readily apparent by those of skill in the art, in embodiments wherein the mineral deposit is situated on a non-horizontal angle relative to surface region s, and wherein borehole extensions 105b and 110b laterally extend in a non-horizontal direction, for example, at a 45 degree angle relative to surface region s, the subterranean horizontal surface region of the portion of mineral deposit 140 in which horizontal borehole extensions 105b and 110b extend is smaller than the horizontal surface region of the portion of mineral deposit 140 in which horizontal borehole extensions 105b and 110b of the same length are situated horizontally relative to surface region s.
Horizontal borehole extensions 105b and 110b connect at distal nodal space 120. Further, horizontal borehole extensions 105b and 110b are planarly situated between extension points 125a and 125b, and distal nodal space 120, in such a manner that they together form a penannular extension, and further, in such a manner that separating portion 145 of mineral deposit 140 separates horizontal borehole extensions 105b and 110b and is embraced therein. Separating portion 145, in general, can be said to be the portion of mineral deposit 140 which is situated in between, and surrounded by, horizontal borehole extensions 105b and 110b, and separating portion 145 extends from extension points 125a and 125b to distal nodal space 120. Separating portion 145 may separate horizontal borehole extensions 105b and 110b by, for example, 15 m, 25 m, 50 m, 100 m, 150 m, 200 m, or up to 1 km and may alter as extraction operations in accordance herewith are conducted, as hereinafter further explained.
The mineral of interest can be any mineral which can be dissolved in a solvent fluid injected into boreholes 105, 110, or 115, as hereinafter further explained. Thus, the mineral constituting mineral deposit 140 can, for example, include without limitation an evaporite, i.e. a geological mineral deposit formed following sea water evaporation. In specific example embodiments, the evaporite can be potash, trona, halite, or gypsum. The mineral deposit 140, besides one or more chemical forms of potassium, may contain other chemical compounds, including sodium chloride, (NaCl), also referred to in a common naturally occurring crystalized form as halite, for example.
In general, in order to construct resource extraction configuration 100 (
In general, in order to construct resource extraction configuration 101 (
In alternate resource extraction configuration 102 (
In general, in order to drill boreholes 105, 110 and 115 conventional drilling equipment and techniques may be used, including drilling rigs, and drilling tools such as down-hole mud-driven motor drilling equipment, and drill bits generally known to those of skill in the art. Thus, for example, conventional drilling equipment, such as the equipment used in oil well drilling can be used, for example, drag or fishtail bits to drill in soft rock, and rotary tricone or other suitable bits to drill in hard rock. Conventional water-based drilling fluid or mud systems can be used for drilling through clastic or carbonate sedimentary rock. When drilling through mineral deposits, non-water-based fluids, such as emulsion muds, mineral oil, or diesel oil, for example, can be used to avoid washing out the resource material, if the material is soluble in water, and to avoid enlarging the borehole. For directional drilling a downhole assembly using a steerable drill bit driven by mud pressure can be continuously controlled while its location and direction is recorded. Gyroscopic compasses contained in the drill pipe can be used to more or less constantly measure inclination and declination of the drill bit. Directional control can further be facilitated by measurement-while-drilling (MWD) or logging-while-drilling (LWD) equipment and techniques using, for example, gamma ray sensors and electromagnetic telemetry techniques, as will generally be known to those of skill in the art.
Drilling directions can be selected based on seismic data applicable to the surface region and underlying deposits. Furthermore, directional information and control commands can be transmitted digitally up or down through the mud column using pressure pulse coding through the mud. Furthermore, MWD and LWD techniques, known to those of skill in the art, allow continuous analysis of the rock without the need to take core samples. From LWD data, physical properties of the rock can be continuously monitored to allow driving the borehole through the desired stratigraphic location, and reach mineral deposit 140. More sophisticated well logging data collected after the drilling is finished can allow for more comprehensive geological interpretation. When drilling near or through mineral deposit 140 coring bits with core barrel collection systems can be used to collect samples of the rock for chemical and geological analysis as needed.
Borehole diameters when drilled may vary and can range, for example, from 0.2 m to 0.5 m, and generally decrease as the borehole extends downwards from surface.
Referring now to
Referring initially to
It is noted that borehole extension 105a and a first section of borehole extension 105b are cased with casing 206, with the cased section terminating at 206e. The remainder of borehole extension 105b is uncased, or cased with a permeable material, such as casing with a plurality of sidewall openings, for example slots forming a slotted liner, which may form a pattern. Similarly, borehole extension 110a and a first section of borehole extensions 110b are cased with casing 211, with the cased section terminating at 211e. (see: further
Further shown in
Referring now to
Referring now to
Horizontal cross-sectional views of the first, second and third states shown in
It is noted that in order to operate resource extraction configuration 200, at borehole opening apertures 105o, 110o and 115o, wellhead assemblies (not shown) may be installed to control fluid flow and pressure. Further equipment that may be installed at surface region s adjacent to borehole opening apertures 105o, 110o and 115o, which may be part of the wellhead assemblies, include but are not limited to, fluid pumps, fluid tanks, including fluid heating equipment, shut off valves, and flow measurement equipment.
Referring now to
It is noted that portions 105b and 110b represent portions of rock formation 140 that have been drilled, while leached portions 105′ and 110b′ represent portions of rock formation 140 that have been in situ leached. Portions 105b and 110b are substantially hollow. However, leached portions 105′ and 110b′ may be more or less porous. In particular, if rock formation 140 comprises different chemical constituents, for example, crystalline potassium chloride and sodium chloride, selective in situ leaching may result in removal of potassium chloride into the solvent, as the solvent circulates, and in situ retention of sodium chloride, for example, in the form of a porous sodium chloride matrix. In this manner, the processes of the present disclosure can limit the quantities of contaminating materials extracted at surface region s.
It is noted that, in general, borehole expansion in the lateral direction is expected to outpace borehole expansion in the vertical direction, so that as the resource extraction process proceeds, the width w of uncased portions of boreholes 105b and 110b increases more than their height h (indicated in
Referring now to
It is also noted that variations in width (w) within borehole extensions 105b and 110b may occur depending on whether a cross-section closer to the proximal end (i.e. closer to extension points 125a, 125b) of these borehole extensions is considered or whether a cross-section closer to the distal end (i.e. closer to distal nodal space 120) of these borehole extensions is considered. In some embodiments, following a period of in situ leaching, as e.g. illustrated by
Referring again to
Turning now to various conditions and parameters that may be selected to operate the resource extraction configurations and processes of the present disclosure, it is noted that carrier fluid F is selected depending on the resource material being extracted, as will be appreciated by those of skill in the art. In general, it is deemed beneficial that carrier fluid F is selected to be a solvent in which the resource material can dissolve. Thus, for example, when the resource material is a mineral, an aqueous solution in which the mineral dissolves can be selected for carrier fluid F. In one embodiment, a substantially pure solvent, for example, a substantially pure aqueous solution, such as water or steam, may be used for injection. The carrier fluid F can be injected in liquid form, however in other embodiments, the carrier fluid F may be heated and injected in the form a vapour or steam. In further embodiments, the carrier fluid F may be a gel or slurry.
In other embodiments, a sodium chloride (NaCl) solution, for example, a saturated NaCl solution, or a potassium chloride (KCL) solution, or a solution comprising NaCl and KCl may be used as a solvent. Possible additives that be included are NaOH and manganese salts. These solvents are particularly useful when the extracted resource is potash. It should be noted that solvent in which minerals are dissolved may be referred to by the term brine.
In embodiments, where non-mineral materials are extracted, other carrier fluids F may be selected. Thus, for example, when hydrocarbons are extracted it may be beneficial to use a less polar carrier fluid, or to add dispersants to the carrier fluid F to facilitate dissolving of the resource material.
It is further noted that in some embodiments the resource material may not dissolve or may poorly dissolve in the carrier fluid F, and instead the carrier fluid F may serve as a medium to transport the resource material in non-dissolved form, for example, in the form of particulate material suspended in the carrier fluid F.
In another aspect, the solvent temperature of the carrier fluid F may be varied, and preheated (or precooled) carrier fluid having a temperature in a range of, for example, from about 10° C. to about 110° C. may be used, or even higher when the carrier fluid F is injected in the form of vapour or steam. It is noted that in situ temperatures at depths, for example, from 1,000 m to 3,000 m from surface region s are generally higher than at surface region s and can range, for example, from about 25° C. to about 80° C. Thus, the carrier fluid temperature can gradually increase as it is injected from surface region s and migrates towards mineral deposit 140. In embodiments herein where potash in the form of KCl is mined, higher solvent temperatures, for example in excess of 50° C. are generally deemed beneficial, since the solubility of KCl in aqueous solutions generally increases. Thus, in some embodiments a heated solvent may be injected into borehole 105.
In general, the concentration of mineral dissolved in the solvent increases along fluid path 210. However, at the same time, the rate of mineral dissolution generally decreases as the brine becomes saturated with dissolved mineral material. A further decrease in the rate of dissolution, and a decrease in the maximum saturation concentration, also generally occurs as the temperature of the brine decreases. Thus, in embodiments where a heated solvent is used the rate of dissolution may decrease as the solvent migrates along flow path 210. Fluid flow rate may be controlled from surface region s using a pump system (not shown) operably installed at surface region s or a downhole pump system installed into borehole 105.
In some embodiments, mineral deposit 140 may comprise a mixture of minerals. Thus, for example, potash mineral deposits commonly comprise a mixture of KCl (sylvite) and NaCl (halite). Potash deposits may, for example, contain from about 30% to about 70% KCl, with the preponderance of the balance, up to almost 100%, containing NaCl. In embodiments in which a solvent saturated with NaCl is used, as brine migrates through mineral deposit 140, KCl may dissolve in the brine, while a porous matrix structure of NaCl may in remain in place.
In some embodiments, initially carrier fluid F is injected through surface bore aperture 105o and fluid flow is established to achieve a certain flow rate. Initially the transit time, i.e. the time required for carrier fluid F to migrate from borehole 105o to borehole 110o, is generally shorter and may be, for example, about 3-6 hours. The transit time gradually increases as the volumes of horizontal borehole extensions 105b and 110b increase, and can increase to, for example 24 hrs, 48 hrs, 60 hrs, 120 hrs, 240 hrs or more as the widths of the horizontal borehole extensions 105b and 110b increase.
In general, the width of horizontal borehole extensions 105b, 110b is developed so that a substantial portion of separating portion 145 can remain. Thus, for example, the processes described herein may be performed such that the distance d between substantially horizontal borehole extension 105b and 110b may be no less than 100 m, no less than 50 m or no less than 25 m during the processes. It is noted that the width of horizontal borehole extensions 105b, 110b may be monitored by accessing distal node 120. Once a certain width has been attained, fluid circulation may be stopped and thereafter fluid may be maintained stagnant for a period of time, for example, at least one day, several days (e.g. 2, 3, 4, 5, 6 or 7 days), at least one week, several weeks (e.g. 2, 3, or 4 weeks), at least one month, or several months (e.g. 2, 3, 4, 6, 9 or 12 months), along the flow path without arranging for an upward flow to soak and further facilitate in situ leaching of mineral material. Thereafter, fluid flow upwards through surface bore aperture 110o may be initiated from surface region s.
In some embodiments, boreholes 105, 110 or distal nodal space 120 are rubblized prior to injection of solvent, using, for example, explosives to break pieces of borehole extensions 105b, 110b, or distal nodal space 120.
Carrier fluid F discharged from borehole aperture 110o can be used to recover resource material at surface region s, for example, by crystallizing minerals present in the brine and separating the crystallized mineral material from the fluid, and/or to separate minerals from each other; for example, potash may be separated from sodium chloride. Thus, at surface region s mineral recovery operations may be set up, for example, in close proximity to borehole aperture 110o. Mineral recovery techniques are known to those of skill in the art, and include, for example, the use of brine crystallizers.
In some embodiments, borehole 115 is used to monitor one or more subterranean parameters relating to mineral deposit 140 by accessing nodal cavern 230 with a monitoring device through borehole 115, and situating a monitoring device within nodal cavern 230, for example, at sump 235. Various parameters may be monitored in this manner using certain types of sensors and equipment as is known by those skilled in the art. These include, for example, solvent salinity, undissolved sodium chloride in the solvent, solvent flow rate, solvent pressure, solvent temperature, electrical conductivity (as a measure of total dissolved salt), radioactivity (to measure KCl), photoelectric absorption and neutron absorption and borehole geometry. Resource extraction operations, such as fluid flow, for example, may be adjusted as a result of such monitoring.
It is noted that the various resource extraction configurations of the present disclosure allow for a variety of flow paths, as illustrated by the examples in
In a further embodiment, the fluid flow path may be reversed by using borehole opening 115o as a fluid entry point, and using borehole openings 105o and/or 110o as a fluid exit point, as illustrated in
Further example flow paths are illustrated in
It is noted that the adjacent positioning of boreholes 105 and 110 permits operation of the boreholes 105 and 110 from a single well pad at surface region s positioned at borehole openings 105o and 110o (see:
Referring now to
Referring now to
Referring now to
Referring now to
Referring now to
It is noted that a further alternate embodiment may be developed starting from state (I) by drilling a single additional horizontal borehole extension e.g. only 110b2 or only 105b2 through separating portion 145, or, only 105c2 or only 110c2 through separating portion 145b to connect with distal nodal cavities 120 and 310, respectively, and use such single additional horizontal borehole in conjunction with the existing horizontal borehole extension 105b and/or 110b; or 105c and/or 110c as a flow path (now shown). Flow-control valves installed within borehole extensions 105b, 110b, 105c or 110c or at surface region s may be used to close 105b or 110b, or 105c or 110c.
In order to develop state (III) from state (I), each of horizontal borehole extensions 105b, 110b, 105c and 110c are closed with a flow-control valve installed at within borehole extensions 105b, 110b, 105c or 110c or surface region s. New horizontal extensions 105b3, 110b3, 105c3 and 110c3, including extension points 125a3′, 125b3′, 125a3 and 125b3, located exterior relative to 105b, 110b, 105c and 110c, are drilled and operated, essentially as described before. States (II) and (III) allow for further extraction of mineral deposit 140 using existing vertical boreholes.
Referring now to
Referring now to
Referring now to
It is noted that the order in which the pairs of horizontal boreholes (405b-2, 410b-2), (405c-2, 410c-2), (405d-2, 410d-2), (405e-2, 410e-2), (405f-2, 410f-2), (405g-2, 410g-2), (405h-2410h-2), and (405i-2410h-2) are implemented, or operated may be varied. Thus, for example, all horizontal boreholes (405b-2, 410b-2), (405c-2, 410c-2), (405d-2, 410d-2), (405e-2, 410e-2), (405f-2, 410f-2), (405g-2, 410g-2), (405h-2410h-2), and (405i-2410h-2) may be constructed and then operation of all may follow more or less simultaneously, or some, but not all, of the pairs of horizontal borehole extensions (405b-2, 410b-2), (405c-2, 410c-2), (405d-2, 410d-2), (405e-2, 410e-2), (405f-2, 410f-2), (405g-2, 410g-2), (405h-2410h-2), and (405i-2410h-2) may initially be constructed and operated, and at a later stage additional borehole extensions may be constructed and operated. Accordingly, at different points in time, the pairs of horizontal borehole extensions (405b-2, 410b-2), (405c-2, 410c-2), (405d-2, 410d-2), (405e-2, 410e-2), (405f-2, 410f-2), (405g-2, 410g-2), (405h-2410h-2), and (405i-2410h-2), may be in different operational stages.
The inventors have determined that implementing resource extraction configuration 404 shown in
As hereinbefore noted, in other embodiments, resource extraction configuration 404 shown in
Referring now to
Resource extraction sub-configuration 402b comprises four distal nodal spaces 120b, 310b, 450b and 460b, each representing a contact point between a substantially horizontal borehole 105bb, 105cb, 105db and 105eb, respectively, extending from extension point 125ab, and a substantially horizontal borehole 110bb, 110cb, 110db and 110eb, respectively, extending from extension point 125bb. Resource extraction configuration 402b can accommodate solvent flows downward from surface region s2 through borehole extensions 105bb, 105cb, 105db and 105eb to distal nodal spaces 120b, 310b, 450b and 460b through borehole extensions 110bb, 110cb, 110db and 110eb and then upwards to surface region s2. It is noted that a first imaginary straight line l1b can be drawn from first distal nodal space 120b approximately through extension points extension points 125ab and 125bb to second distal nodal space 310b, and a second imaginary straight line l2b can be drawn from third distal nodal space 450b approximately through extension points extension points 125ab and 125bb to fourth distal nodal space 460b.
Resource extraction sub-configuration 402c comprises four distal nodal spaces 120c, 310c, 450c and 460c, each representing a contact point between a substantially horizontal borehole 105bc, 105cc, 105dc and 105ec, respectively, extending from extension point 125ac, and a substantially horizontal borehole 110bc, 110cc, 110dc and 110ec, respectively, extending from extension point 125bc. Resource extraction configuration 402c can accommodate solvent flows downward from surface region s3 through borehole extensions 105bc, 105cc, 105dc and 105ec to via distal nodal spaces 120c, 310c, 450c and 460c through borehole extensions 110bc, 110cc, 110dc and 110ec and then upwards to surface region s3. It is noted that a first imaginary straight line I1c can be drawn from first distal nodal space 120c approximately through extension points extension points 125ac and 125bc to second distal nodal space 310c, and a second imaginary straight line l2c can be drawn from third distal nodal space 450c approximately through extension points extension points 125ac and 125bc to fourth distal nodal space 460c.
Resource extraction sub-configuration 402d comprises four distal nodal spaces 120d, 310d, 450d and 460d, each representing a contact point between a substantially horizontal borehole 105bd, 105cd, 105dd and 105ed, respectively, extending from extension point 125ad, and a substantially horizontal borehole 110bd, 110cd, 110dd and 110ed, respectively, extending from extension point 125bd. Resource extraction configuration 402d can accommodate solvent flows downward from surface region s4 through borehole extensions 105bd, 105cd, 105dd and 105ed to distal nodal spaces 120d, 310d, 450d and 460d through borehole extensions 110bd, 110cd, 110dd and 110ed and then upwards to surface region s4. It is noted that a first imaginary straight line l1d can be drawn from first distal nodal space 120d approximately through extension points extension points 125ad and 125bd to second distal nodal space 310d, and a second imaginary straight line l2d can be drawn from third distal nodal space 450d approximately through extension points extension points 125ad and 125bd to fourth distal nodal space 460d.
Resource extraction sub-configuration 402e comprises four distal nodal spaces 120e, 310e, 450e and 460e, each representing a contact point between a substantially horizontal borehole 105be, 105ce, 105de and 105ee, respectively, extending from extension point 125ae, and a substantially horizontal borehole 110be, 110ce, 110de and 110ee, respectively, extending from extension point 125be. Resource extraction configuration 402e can accommodate solvent flows downward from surface region s5 through borehole extensions 105be, 105ce, 105de and 105ee to distal nodal spaces 120e, 310e, 450e and 460e through borehole extensions 110be, 110ce, 110de and 110ee and then upwards to surface region s5. It is noted that a first imaginary straight line l1e can be drawn from first distal nodal space 120e approximately through extension points extension points 125ae and 125be to second distal nodal space 310e, and a second imaginary straight line l2e can be drawn from third distal nodal space 450e approximately through extension points extension points 125ae and 125be to fourth distal nodal space 460e.
Resource extraction sub-configuration 402f comprises four distal nodal spaces 120f, 310f, 450f and 460f, each representing a contact point between a substantially horizontal borehole 105bf, 105cf, 105df and 105ef, respectively, extending from extension point 125af, and a substantially horizontal borehole 110bf, 110cf, 110df and 110ef, respectively, extending from extension point 125bf. Resource extraction configuration 402f can accommodate solvent flows downward from surface region s6 through both borehole extensions 105bf, 105cf, 105df and 105ef to distal nodal spaces 120f, 310f, 450f and 460f through borehole extensions to 110bf, 110cf, 110df and 110ef and then upwards to surface region s6. It is noted that a first imaginary straight line l1a can be drawn from first distal nodal space 120f approximately through extension points extension points 125af and 125bf to second distal nodal space 310f, and a second imaginary straight line l2f can be drawn from third distal nodal space 450f approximately through extension points extension points 125af and 125bf to fourth distal nodal space 460f.
Resource extraction sub-configuration 402g comprises four distal nodal spaces 120g, 310g, 450g and 460g, each representing a contact point between a substantially horizontal borehole 105bg, 105cg, 105dg and 105eg, respectively, extending from extension point 125ag, and a substantially horizontal boreholes 110bg, 110cg, 110dg and 110eg, respectively, extending from extension point 125bg. Resource extraction configuration 402g can accommodate solvent flows downward from surface region s7 through borehole extensions 105bg, 105cg, 105dg and 105eg to distal nodal spaces 120g, 310g, 450g and 460g through borehole extensions 110bg, 110cg, 110dg and 110eg and then upwards to surface region s7. It is noted that a first imaginary straight line I1g can be drawn from first distal nodal space 120g approximately through extension points extension points 125ag and 125bg to second distal nodal space 310g, and a second imaginary straight line I2g can be drawn from third distal nodal space 450g approximately through extension points extension points 125ag and 125bg to fourth distal nodal space 460g.
Resource extraction sub-configuration 402h comprises four distal nodal spaces 120h, 310h, 450h and 460h, each representing a contact point between a substantially horizontal borehole, 105bh, 105ch, 105dh and 105eh, respectively, extending from extension point 125ah, and a substantially horizontal borehole 110bh, 110ch, 110dh and 110eh, respectively, extending from extension point 125bh. Resource extraction configuration 402h can accommodate solvent flows downward from surface region s8 through borehole extensions 105bh, 105ch, 105dh and 105eh to distal nodal spaces 120h, 310h, 450h and 460h through borehole extensions 110bh, 110ch, 110dh and 110eh and then upwards to surface region s8. It is noted that a first imaginary straight line l1h can be drawn from first distal nodal space 120h approximately through extension points extension points 125ah and 125bh to second distal nodal space 310h, and a second imaginary straight line l2h can be drawn from third distal nodal space 450h approximately through extension points extension points 125ah and 125bh to fourth distal nodal space 460h.
Resource extraction sub-configuration 402i comprises four distal nodal space 120i, 310i, 450i and 460i, each representing a contact point between a substantially horizontal borehole, 105bi, 105ci, 105di and 105ei, respectively, extending from extension point 125ai, and a substantially horizontal borehole 110bi, 110ci, 110di and 110ei, respectively, extending from extension point 125bi. Resource extraction configuration 402i can accommodate solvent flows downward from surface region s9 through borehole extensions 105bi, 105ci, 105di and 105ei to distal nodal spaces 120i, 310i, 450i and 460i through borehole extensions 110bi, 110ci, 110di and 110ei and then upwards to surface region s9. It is noted that a first imaginary straight line I1i can be drawn from first distal nodal space 120i approximately through extension points extension points 125ai and 125bi to second distal nodal space 310i, and a second imaginary straight line l2i can be drawn from third distal nodal space 450i approximately through extension points extension points 125ai and 125bi to fourth distal nodal space 460i.
Referring now to
Referring now to
Resource extraction configurations 402o, 402p, 402q, and 402r can each individually accommodate solvent flows downward from surface region s11 and then through both borehole extensions (105bba, 105bbb), (105bbc, 105bbd), (105bbe, 105bbf) and, (105bbg, 105bbh) respectively to distal nodal spaces (120ba, 120bb), (120bc, 120bd), (120be, 120bf) and (120bg, 120bh), respectively, and back through boreholes (110bba, 110bbb), (110bbc, 110bbd), (110bbe, 110bbf) and, (110bbg, 110bbh), respectively, to extension points (125aba, 125bba), (125abb, 125bbb), (125abc, 125bbc) and (125abd, 125bbd) and then upwards to surface region s11. Each of resource extraction sub-configurations 402o, 402p, 402q, and 402r is spaced apart by a distance di to an adjacent neighbouring sub-configuration. In this respect the distance di between imaginary line L1 and L2 is for example about 200 m or less, or 1 km or less.
Referring now to
Resource extraction sub-configurations 402s, 402t, 402u, 402v and 402w can each individually accommodate solvent flows downward from surface region s12 via extension points 125aba2, 125abb2, 125abc2, 125abd2, and 125abe2, through borehole extensions 105bba2, 105bbb2, 105bbc2, 105bbd2, and 105bbe2, respectively, to distal nodal spaces 120ba2, 120bb2, 120bc2, 120bd2, and 120be2, respectively, and back through boreholes 110bba2, 110bbb2, 110bbc2, 110bbd2, and 110bbe2, respectively, to extension points 125bba2, 125bbb2, 125bbc2, 125bbd2, and 125bbe2 back up to surface region s12. Each of resource extraction sub-configurations 402s, 402t, 402u, 402v and 402w is spaced apart from adjacent neighbouring resource extraction sub-configurations. Furthermore, it is noted that resource extraction sub-configurations 402s, 402t, 402u, 402v, and 402w can be, but do not necessarily need to be, situated at the same depth relative to surface region s12, and thus some or all of resource extraction sub-configurations 402s, 402t, 402u, 402v, and 402w can be situated at the same or at different depths relative to surface region s12.
Further also shown in
It is noted that in order to establish boreholes 115ba2, 115bb2, 115bc2, 115bd2 and 115be2, an initial proximal section 115c is shared between all of boreholes 115ba2, 115bb2, 115bc2, 115bd2 and 115be2, and thus these boreholes share a single common borehole opening at well pad 160. By contrast, boreholes 105ba2, 105bb2, 105bc2, 105bd2 and 105be2, as well as boreholes 110ba2, 110bb2, 110bc2, 110bd2 and 110be2 are configured to each have a separate borehole opening at well pad 160. In other embodiments, resource extraction configurations may be constructed which are similar to resource extraction configuration 505, provided, however that different arrangements regarding shared borehole openings may be provided for, as can be readily further understood by referencing, comparatively, the resource extraction configurations shown in
The inventors have determined that implementing resource extraction configuration 505 shown in
Referring now to
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Of course, the above described example embodiments of the present disclosure are intended to be illustrative only and in no way limiting. The described embodiments are susceptible to many modifications of composition, details and order of operation. The claimed subject matter, rather, is intended to encompass all such modifications within its scope, as defined by the claims, which should be given a broad interpretation consistent with the description as a whole.
This application is a continuation of U.S. patent application Ser. No. 17/086,104, filed Oct. 30, 2020, which claims the benefit of U.S. Provisional Patent Application No. 62/929,705 filed Nov. 1, 2019; the entire contents of each of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62929705 | Nov 2019 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17086104 | Oct 2020 | US |
| Child | 18349579 | US |
