Borehole mining tool

BACKGROUND OF THE INVENTION

(a) Field of the Invention

This invention relates to a system for providing remote hydrojet borehole mining, and more specifically, but not by way of limitation, to a hydraulic borehole mining system with interchangeable components that allow the use of a single device for a plurality of tasks. Some of the tasks that the instant invention could be used for: extraction or the mining of a mineral resources; the creation of a subsurface cavity or void space; to stimulate liquid and/or gas production; clean lake bottoms; recover either liquid or solid environmental contaminates; or other related uses which require a remotely operated tool.

The Borehole Mining Tool (tool) is intended for mining of mineral resources, through boreholes. This tool may be applied from the Earth's surface, underground mines and ocean platforms. The tool also will find an application in geological exploration for bulk sampling, in building of subterranean storages, in-situ leaching, production stimulation for oil/gas and water, in custom foundations, underground collectors construction, environmental clean up of subterranean spills and more. The tool can be used to solve other environmental problems, such as cleaning of lake bottoms and removing ooze, cleaning of oil reservoirs, radioactive contamination (nuclear missile silos), and other applications requiring remote operating.

(b) Discussion of Known Art

Borehole mining (BHM) as a remote underground mining method is based on water jet cutting of rock material. This is accomplished by pumping high pressure water down to the working area from the Earth's surface (or underground mines, or floating platforms) to the borehole mining tools lowered into pre-drilled holes. The slurry created by the water jet is simultaneously pumped out by the same tool. By removing the broken materials, underground cavities (stopes) can be created.

The BHM approach has many recognized advantages, but the method has not gained acceptance commensurate with its potential due to several important issues that have yet to be finalized. One of the most significant problems has been the specialized tooling needed for mining of different type of material and specific geo-technical and environmental tasks to be performed, which requires that the user needs to carry and the use of different tools to the work site instead of a universal one. These tools are typically large and heavy units having a minimum number of joints, couplings, threads and other easy-and-quick connectors which complicates the tool's assembly, accessibility, serviceability and replacement. In case of a failure of some part of the tool, the replacement of this disabled unit(s) usually requires a replacement of most, if not all, of the tool.

Another problem is that borehole mining is a blind method; there is no data about the current cutting direction as well as the current configuration of the driving space (cavern/stopes). All geophysical measurements (logging) may be executed only after all operations are stopped and the BHM tool is removed from the hole. This typically equates to several hours of down time. Additionally, because borehole mining is carried out in friable, unconsolidated (unstable) material, the shape of the created stopes can be easily changed by collapsed rock masses. Thus, measurements, made after stopping of operation can not always be used for estimation of production. Best downhole measurements must be made while mining: or “logging-while-mining” (LWM). This instant tool will allow for the attachment of monitoring devices which will give “eyes” to borehole mining.

In certain circumstances it is necessary to build vertical slots using several boreholes and then connecting them to each other, for example to create an extended underground collecting ditch. In this task, information about orientation of the tool's nozzle down in a borehole becomes very critical. But, through assembling and lowering the tool in a hole, its bottom part (which contains the head and the hydromonitor's nozzle) is twisted relative to the upper portion of the tool. Thus, after the tool is assembled and lowered down in a hole, there is no further information about the current bottom head's nozzle orientation; as it is lost while assembling.

In borehole mining, a hole is first drilled from the surface to a depth where the mineral deposit or work area is located. A metal or plastic casing, which is nothing more than a heavy pipe, is then inserted into the hole to prevent sidewall caving or capsizing of the hole. The casing bottom end, called a casing shoe is placed immediately above the future working (production) interval. Then, the borehole mining tool is lowered into this casing until its bottom (working) end portion reaches the “open” hole, right bellow the casing shoe.

The BHM tool consists of three main parts: an upper head, an intermediate column and a bottom (working) head. The upper head includes stub-pipes for pumping in a working high-pressure fluid (usually water) and for discharge of production slurry; a swivel; a turn table; and a mechanism for raising/lowering the tool while mining. The intermediate column is comprised of two or more pipes assembled in “pipe-in-pipe” manner by numerous dual conduit sections. At the end of this column is the bottom head with its hydromonitor and eductor (also known as hydro-elevator, or jet-pump). In most cases, a drill bit can also be placed at the bottom end of the tool.

The inner and outer columns of the tool form an O-shape gap. Thus, the tool has at least two hydraulic channels: one is the inner pipe's channel (inner channel), and the other is the aforementioned ring gap, or outer channel. These channels are used for delivery of high pressure working fluid (water) to the bottom head and for elevating production slurry back to the surface. It is obvious that two channels are the minimum required in borehole mining. Therefore, in BHM two main schematics of water/slurry circulation are used: (1) the “direct”; water is pumped by inner pipe and slurry is received by the gap and (2) the “return”; opposite circulating. Because of its relative simplicity, over 90% of existing BHM tools are based on these two schematics. The schematic of fluids circulating is reflected on the configuration of the top head and other surface equipment.

The borehole mining tool functions as follows: The tool is lowered into a borehole until the hydromonitor (which is located in a bottom head) is placed below the casing shoe in an open hole to the depth that the actual mining is to take place. Next, the high pressure (working) water, approx 2000 psi at a flow rate of 1000 GPM, is pumped down to the tool through one of the two channels or annulus' contained in the intermediate pipe. In the bottom head one part of this water is split off to the hydromonitor which contains a nozzle directing the water to the area to be worked-out. As it passes through the nozzle, this flow accelerates to a water jet that is sufficiently powerful to break and scale away the material being mined. The loosened rock/ore material from the worked out area is fluidized through mixing with water to create a productive (pregnant) slurry.

The created slurry must be drawn to the surface to clean the working space (stope/cavern) and to recover the desired mineral(s) or create the desired cavity. For this purpose, the remaining portion of the working water continues flowing down until it reaches the eductor which forces it to turn which creates a vacuum in front of the Venturi pipe opening. This vacuum sucks the incoming slurry, drawing it into the slurry channel of the tool and then it is transported up the pipe until it reaches the surface.

On the surface, the water contained in the slurry is separated from heavy particles (rock/ore chunks and other solids)in a collecting pond or tank by gravity force (and/or other standard equipment, if needed). The clarified water is pumped down to the working interval again. This completes the BHM water re-circulating cycle. While operating, the tool is rotated and moved up and down in the hole within the production (working) interval. The borehole mining process usually creates underground caverns.

It can be appreciated that the effectiveness of the rock cutting and slurry recovery are of great importance in the overall performance of the whole BHM tool and operation. One method of causing the slurry to rise through the return (slurry) channel is by pressurizing the entire system, including the cavity where the mining operations are being carried out, thus forcing the slurry through the return pipe. Another method for drawing the slurry to the surface is to include an eductor near the lowest point on the tool in order to force draw the slurry into the return pipe.

The eductor type pump has been favored in borehole mining since the simplicity of the device results in high reliability. The need for high reliability is a critical element for borehole mining tools, since failure of a component at a great depth can result in long down times and expensive procedures for trying to retrieve the tool through the borehole. The Venturi effect that is used to draw the slurry into an orifice(s) (slurry intake port(s)) in the device is created at a region on the tool that lies below the cutting jet. This allows the tool to draw material from the lowest possible position in the cavity created by the tool. Often, however, the orifice used to draw material is not at the lowest point on the tool. Therefore, with these configurations additional portions of the tool are located at the lowest position within cavity being mined. This is a serious disadvantage since the solids of the slurry will tend to settle and fill this low area.

Examples of tools which include points that are below the slurry intake ports include U.S. Pat. No. 5,366,030 to Pool, U.S. Pat. No. 4,718,728, and 4,296,970 to Hodges, U.S. Pat. No. 4,212,353 to Hall, U.S. Pat. No. 4,140,346 to Barthel, U.S. Pat. No. 4,059,166 to Bunelle, and U.S. Pat. No. 3,747,696 to Winneborg et al. Known devices for borehole mining have suffered from limited applicability. For example, one known device taught in U.S. Pat. No. 5,181,578 to Lawler, is a borehole mining tool which uses a swing-away hydromonitor that collapses to allow extension or retraction of the nozzle. This extension and retraction of the nozzle allows the user to improve the reach of the nozzle within the cavity being mined.

Another device which addresses the problems associated with the reach of the cutting jet nozzle is taught in U.S. Pat. No. 4,915,452 to Dibble. The Dibble invention teaches the use of a cutting head nozzle which can be moved relative to the rest of the tool in order to manipulate the position of the cutting jet without affecting the position of the slurry or intake portion of the tool.

A known device for borehole mining is shown in U.S. Pat. No. 4,934,466 to Paveliev, which has the blast pipe going through the eductor nozzle. With the same rate of pumping water, it allows an increase in the suction of the eductor because the diameter of its nozzle and thus the diameter of the water jet is also increased. This tool is not free from disadvantages. The drill bit located below the eductor does not allow slurry to be recovered from the very lowest points of the working area. Thus, this tool can not be successfully used, for example in cleaning of oil (or any other) storage, vessel or tank. The other disadvantage of this invention is the usage of an external pipe as a slurry channel. It excludes the possibility of using an airlift because there is no simple method to place an air pipe in this gap due to its rotation. Further, the annulus channel has 2 to 3 times smaller cross section than the inner pipe. This limits the maximum possible size of slurry chunks to be transported through the external channel in comparison to the internal one. Finally, these “double” walls increase the slurry pressure loss nearly two-fold due to the doubled hydraulic friction. In other words, the usage of an inner column as a slurry line, as does the Paveliev tool, increases the maximum size of transported chunks, while decreasing slurry flow pressure loss. The above mentioned disadvantages narrow the area of this tool application.

U.S. Pat. No. 5,366,030 to Pool has a design similar to Paveliev construction and is suffering from the same problems. Additionally, both devices have only two hydraulic channels. In certain circumstances, a tool with three or even four individual channels is required. Also, structurally these two devices are based on using a casing column as an outer pipe of the tool. However, oftentimes, structural and hydro geological conditions of the deposit allow operation in a borehole without the requirement to stabilize the walls through the uses of a casing string. In this situation, a double wall tool is preferable as it saves operational time and capital cost, because the outer pipe is “traveling” together with the tool from hole to hole instead of remaining in each worked-out well.

Another known device for borehole mining is U.S. Pat. No. 4,059,166 to Bunnelle. This device is also based on the “pipe-in-pipe” double column construction. These two columns define two hydraulic channels: the inner—slurry channel, and a gap between inner and outer columns which is used as high pressure water channel. At the bottom of the tool, there is a working head with a hydromonitor and an eductor sections. This device works as follows: The high pressure water is pumped down through the gap between inner and outer columns. At the hydromonitor section, part of the flow is diverted to the hydromonitor and becomes a water jet directed toward the rock which it cuts. Broken parts of rock material are mixed with spent cutting water to create a pregnant (productive) slurry. Another portion of the working water continues its movement down and finally reaches the eductor which produces the vacuum. This vacuum sucks the coming-up slurry. The slurry enters the inner pipe, through with it reaches the surface. The hydromonitor which has a cylindrical barrel and a standard conical nozzle at its end crosses the inner (slurry) pipe, splits (bifurcates) the flow at that point, forming a slurry fork-pass around the hydromonitor. The eductor section of the Bunnelle tool has a needle in its nozzle. This needle controls the suction of slurry in the same manner as the tools mentioned above. It also has a distribution reservoir located below the eductor. A drill bit can be attached to the reservoir which is located at the lowest point of the tool. In addition to an Earth's surface application, this tool can be mounted on a sea/ocean platform or barge and used to develop an offshore mineral zone or create voids for foundation or other requirements.

The Bunnelle device has the most relative (closest) design to the instant invention.

Main disadvantages of the Bunnelle tool are following:

1. Limited area of application. The tool can not remove the slurry at the lowest point of the working area because below the suction area is located the distribution reservoir and the drill bit.

2. A high number of moving mechanisms, parts, springs, pistons and cylinders decrease the reliability of the device, while increasing hydraulic friction and water pressure loss.

3. The inlet to the hydromonitor is located very close to the outer pipe wall. Part of the high pressure water flow makes a sharp turn to come into the hydromonitor at this point. The very high velocity of the water flow (5-10 m/sec), along with the sharp turn and the narrow space where this turn occurs, creates a high grade turbulence in water flow right before the hydromonitor nozzle. As a result, it negatively reflects on the hydrodynamic characteristics of the water jet: it becomes an unfocused, spray-type flow. Obviously, it therefore, decreases the water-jet productivity and also decreases the tool's overall borehole mining effectiveness.

The main disadvantage of all the afore mentioned devices is their limited area of application. Each of these tools was developed for a specific borehole mining task of which it can successfully execute. At the same time, choosing of the type of the borehole mining tool is based on a combination of different types of various criteria such as a deposit's hydro-geological situation, hardness, specific gravity, granule distribution of the mining material(s), depth of operations, rock mechanic characteristics of cap and bed rocks and several additional criteria. This combination dictates the type and configuration of borehole mining tooling, equipment and methods of BHM operation. Thus, for example, a tool which can effectively develop a sand-type material may not be very successful at the mining a clay-type material. Another example: a device for borehole mining can not be effectively applied for the purpose of cleaning a metal reservoir, and for creating underground pillars. Thus, there still remains the need for a universal borehole mining tool which can be easily modified to suit varied operations and technical tasks.

Borehole mining practice requires that, in some circumstances, it is necessary to have a four channel BHM tool. In addition to (1) water and (2) slurry channels, there is often a need for a channel for (3) air lift and another (4) extra channel for injection of a secondary agent to the working area to improve the effectiveness of the mining or cleaning process. Thus, it is important to have a 4 channel tool.

Another important aspect of the borehole mining tool, is its weight. Borehole mining is typically conducted at depths in excess of 50 m (150 feet) to 200 m (600 feet), and even deeper to 1 Km (3,300 Ft). Since the tool must be rotated at such a great depth while being suspended in a hole, it must be able to support not only its own weight, but also weight of water and slurry columns in both channels and transmit the torque through the tool's body. As it was shown before, in general, BHM tools have doubled body (“pipe-in-pipe”) construction, which doubles the weight of the tool and limits the working depth because of the risk of the tool rupture and loss. It also increases the tool initial and operational cost. Thus, it is important to reduce the weight of the tool.

There remains a need for a borehole mining tool which reduces pressure losses while pumping the working water through the bottom head and returning slurry to the surface. Importantly, there remains a need for a borehole mining tool that allows the user to know the orientation of the water jet being delivered to the working area. Still further, there remains a need for a borehole mining tool that allows the user obtain an image of the shape of the excavated area while mining, and thus increase the effectiveness of the jet cutting, raise safety and, finally, improve borehole mining as a process.

SUMMARY

It has been discovered that the problems left unsolved by known art can be solved by providing a borehole mining tool with a bottom head with a universal connector that can accept various mechanical components and parts to easily modify the function of the whole device. Thus, a configuration of the tool for a specific task can be carried out by simple modification of the bottom portion, or by replacing of some components by the same-type components with a different technical or hydro-dynamical characteristics as explained below.

Another aspect of the instant invention, is that an improved hydromonitor section for use with the tool has been developed. The hydromonitor includes a conical barrel and a nozzle that is positioned slightly offset from the center area of the hydromonitor section. The offset positioning of the entry of the hydromonitor provides for a more smooth turning of the pressure water flow as it enters the hydromonitor. This decreases the turbulence in the working fluid flow and improves the availability of fluid to the nozzle, thereby, enhancing the water jet characteristics. This makes the jet more focused and thus more powerful. Finally, it increases the tool's working radius and productivity of the rock cutting and overall borehole mining effectiveness.

The orientation of the hydromonitor nozzle as well as the overall shape of the driving cavity being created in the strata as it is being developed can be obtained by including a radar device near the nozzle of the hydromonitor, along with a current generator to produce small currents and a device to measure current changes as the tool is moved through the Earth's natural magnetic field. The signals collected from the radar and the current generator can be used to derive the orientation of the nozzle relative to the Earth's magnetic field (survey) and an image of the cavity formed while mining. Developing this data allows for the creation of a current 3D image of the driving space (cavern) and also for the instant calculation of its volume and the current productivity of the Borehole Mining operation itself.

While the above and other advantages and results of the present invention will become apparent to those skilled in the art from a study of the following detailed description and accompanying drawings, which explain the contemplated novel construction, combinations and elements as herein described, and more particularly defined by the appended claims, it should be understood that changes in the precise embodiments of the herein disclosed invention are meant to be included within the scope of the claims, except insofar as they may be precluded by the prior art.

The main idea and the purpose of this instant invention is the development of a multi functional (universal/versatile) borehole mining tool. By the shifting of various parts, details and units this device changes its functional features which expands the area of its application, enabling it to work in different hydro-geological conditions and physical properties in the extraction of material(s). Additionally, this tool should present higher reliability, less water/slurry pressure loss, lower device total weight and a reduction in the cost of its manufacture and operation. This tool also should be able to solve different type of mining, environmental, building and other problems. In other words, this tool should be universal, with the ability to execute different types of jobs depending on the engineering task requirements by simple shifting of its working parts, details, and units.

To achieve this purpose this tool should have:

wider area of application,

increased reliability,

improved hydrodynamic characteristics of water and slurry channels,

possibility of control of the driving space (cavern),

four individual hydraulic channels,

possibility of decreasing the weight of the device,

lower initial and operational cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1

is a side view of one preferred embodiment of the invention illustrating four channel double wall tool embodiment with attached radar positioning system. Inset A is an enlarged and detailed computer screen view.

FIG. 2

is a side view of the invention taught herein describing its main units, parts, blocks, and details for (A) double wall four channel (heavy) and (B) single wall three channel (light)tool embodiment.

FIG. 3

is a side view of the top head and the multi-sectional intermediate column of: A—four channel and B—three channel tool.

FIG. 4

is a side sectional view of the bottom head; A four channel (double wall) tool, B—three channel, (single wall tool), and C, D and E—cross sections illustrating different embodiment of the eductor's suction area (images increased twice).

FIG. 5

is a side sectional view of the hydromonitor and eductor sections; A—is a front view of the hydromonitor nozzle area; B—cross section of the hydromonitor; C—side sectional view of eductor throat insertion; D and E—are cross sectional views of the hydromonitor section, illustrating its geometrical proportions and the cylindrical (D) and the oval (E) shape of the inner pipe.

FIG. 6

is an enlarged side sectional view of the hydromonitor and the eductor sections.

FIG. 7A

illustrates a ring eductor nozzle and a sucking aperture at the tool's bottom point.

FIG.

7

B—the same as

7

A but with the secondary working agent duct going through the eductor nozzle.

FIG.

7

BB is the eductor cross section as indicated on FIG.

7

B.

FIG. 7C

is the same as

7

A, but with an accelerating nozzle and a drill bit.

FIG. 7D

is the same as

7

A, but with the telescopic sucker.

FIG. 8

is the side sectional view of the bottom part of the tool with a draw tube-needle, extra slurry intake ports, a positioning system compartment and the drill bit, A, B and C are cross sections as indicated.

FIG. 9

is a plurality of side cross-section views of the tool;

FIG. 9A

is the upper portion of the eductor;

FIG. 9B

is the eductor's insertion throat;

FIG. 9C

presents the bottom part of the eductor with the eductor nozzle;

FIG. 9D

illustrates the bottom part of the eductor with the universal connector ready-to-accept additional equipment;

FIG. 9E

is the bottom end ring-type eductor;

FIG. 9F

the same as E but with the telescopic slurry sucker;

FIG. 9G

presents the auxiliary nozzle;

FIG. 9H

the bottom part of the tool with the draw needle, extra slurry inlets, electronic compartment and the drill bit;

FIG. 9I

illustrates assembling of the solid needle;

FIGS. 9J and K

illustrate two possible endings of the tool: with the drill bit and the blind end respectively;

FIG. 9L

illustrates possibility of attachment of the drill bit to the tool bottom having the ring-type eductor;

FIG. 9M

illustrates possibility of attachment of the electronic compartment to the ring-type eductor;

FIG.

10

—samples of different assembling of the tool to illustrate versatility of the invention:

FIG.

10

A—preferred light embodiment with straight hub and the conventional (central type) eductor;

FIG.

10

B—preferred light embodiment with the third channel duct (airlift);

FIG.

10

C—the same as

10

B, but without the hydromonitor section, air lift, and the drill bit;

FIG.

10

D—illustrates the ring-type eductor and the secondary agent duct going through the bottom head, ending below the tool's lowest point;

FIG.

10

E—the same as A, but with the reverse hub and reversal surface equipment connections;

FIG.

10

F—the same as A, but with the logging positioning system;

FIG.

10

G—illustrates two hydromonitor sections joined together serially.

FIG.

10

H—presents interchangeable protecting-calibrating grill-net screens.

FIG. 11

is a side and cross sectional views of the different hub embodiments:

FIG. 11A

straight hub;

FIG. 11B

reversal hub;

FIG. 11C

the same as

11

A, but with the secondary working agent duct connected to the space between the tool and the casing, D, E and F are cross sectional views as indicated;

FIG. 12

is a greater view of the packer zone of the straight hub.

FIG. 13

is an enlarged view of the hydromonitor area and the removable nozzle with a radar sending (transmitter) and receiving (receiver) unit(s) as used with the positioning system; A—side section view; B—cross section; C—3D view of the nozzle and electrical contact rings; D—is enlarged view of contacts.

FIG. 14

is a side (A) and a 3D (B) views of the electronic compartment and a conductive loop as used to obtain orientation information on the position of the nozzle and other components of the tool while in use.

FIG. 15

presents a computerized image of the driving space at the current moment: A—plan view; B—3D view.

FIG. 16

illustrates one possible configuration for wiring of the transmitter and receiver included in the hydromonitor nozzle shown on

FIG. 13

as well as electronic compartment enclosure shown on

FIG. 14

for carrying out the radar sending and receiving signals as well as the positioning for the whole tool in a borehole while operating.

FIG. 17

illustrates the principal working of the tool positioning system based on geographical coordinates: A—presents a tool and cavern plan cross section as (in) a Polar coordinates system; B—is an inducted current sinus graph and its interpretation.

FIG. 18

illustrates an embodiment of the invention applying from the water surface.

Note: The tool

10

has several details and parts, going through the whole device from the top to the bottom, (for example, outer

68

and inner

70

pipe columns). In order to decrease this parts numbering, they have the same number, but following indexes are added, to determine the location: “B”—Bottom head, “I”—Intermediate section, H—hydromonitor section and E—Eductor section.

Before explaining the disclosed embodiment of the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown, since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

While the invention will be described and disclosed here in conjunction with certain preferred embodiments, the description is not intended to limit the invention to the specific embodiments shown and described here, but rather the invention is intended to cover all alternative embodiments and modifications that fall within the spirit and scope of the invention as defined by the claims included herein as well as any equivalents of the disclosed and claimed invention.

FIG. 1

illustrates the preferred tool

10

embodiment including four individual channels and positioning radar system. As it seen, the borehole

12

is drilled from surface

38

to the production interval

11

. The casing

114

is installed from the surface

38

through the caprock

13

. The open hole is drilled bellow the casing shoe

115

with the sump area

250

at its lowest level.

The borehole mining tool

10

is lowered and suspended in a borehole

12

by drill rig tower

62

. The tool

10

includes 4 hydraulic channels: (1) inner duct

226

, (2) the gap

24

between the duct

226

and the inner drill pipe column

70

, (3) the gap

26

between pipe

70

and outer pipe column

68

, and finally, (4) the gap

27

between the pipe

68

and the casing

114

. These four

16

channels are respectively connected to: air compressor (not shown), collecting tank/pond

40

, water pump station

30

, and secondary agent source (not shown).

Tool

10

embodiment also includes the radar positioning system comprising of an electronic compartment

184

, radar gun

309

mounted inside of the hydromonitor

32

and the surface computer center

300

.

Turning now to

FIG. 2

where both: “heavy” (A) and “light” (B) modifications of the tool

10

shown with the main sections and parts more detailed. The tool

10

has a top head

52

, an intermediate section

64

and a bottom head

74

. In turn, the bottom head

74

includes a hub section

67

, extended section

75

, hydromonitor section

76

and an eductor section

120

.

FIG.3

illustrates the upper part of the tool

10

. Attached to the top head

52

are stub pipes

14

and

16

that are used for providing or withdrawing a high pressure working fluid

56

(mostly water) or productive (pregnant) slurry

58

, produced by the mining operations. The top head

52

also includes a swivel

20

, a Kelly pipe

22

, and a gland

21

. Gland

21

seals the upper end of outer column

68

, allowing it to slide up and down and rotate the Kelly pipe

22

. Swivel

20

has a gland

31

allowing suspension of a secondary agent duct

226

inside of the tool

10

. Finally, the upper head

52

may have an extra stub pipe

19

for a secondary agent. Tool

10

suspension includes also an elevating system

18

for lifting and lowering the tool

10

and a turntable

60

that is used to rotate the tool

10

while operating.

The construction of the tool

10

is based on traditional “pipe-in-pipe” schematic: it consists of at least two pipe columns: inner (internal)

70

, and outer (external)

68

. Thus, the tool

10

has at least two hydraulic channels: an inner

24

which is simply the internal

70

pipe inside space and a gap (annulus)

26

, formed by internal

70

and external

68

columns. These two channels (

24

and

26

) are used for pumping down the working water

56

and receiving-back (rising) the slurry

58

. The intermediate section

64

consists of numerous separate sections

134

which are used to extend the tool

10

to achieve a desired production interval

11

.

The borehole

12

may be fixed by a casing

114

column which is used to protect this hole

12

from collapsing. It gives an extra gap channel

27

defined by the casing

114

and the tool

10

. This channel

27

has access through the extra stub pipe

19

and can be used for injecting a secondary agent along the tool

10

to the working area

82

shown on FIG.

1

.

The cased borehole

12

allows the weight of the total tool

10

to be cut nearly in half as compared to the prior art devices. In this case, the construction of the top head

52

and the intermediate section

64

is based on using the casing

114

as the tool's

10

external (

70

) pipe. Thus, the bottom head

74

is suspended in the hole

12

from the inner pipe

70

only.

In addition to the inner pipe

70

, the tool

10

may contain at least one additional duct

226

which is used to carry a secondary working agent

138

such as an air, or any chemical reagent. Nitrogen, other gas, concrete, clay mud, foam and other material may be used to enhance the working

82

area environment and increase the tool

10

productivity.

As shown on

FIG. 4

, a bottom head

74

is attached to the lower end

78

of the intermediate section

64

by means of a hub

67

. The bottom head

74

includes the hydromonitor section

76

with a hydromonitor

32

which is used to create and deliver a high velocity stream (water jet)

80

of working fluid

56

to the material

308

located in production interval

11

being mined (FIG.

1

).

The bottom head

74

is illustrated on FIG.

5

. Below the hydromonitor section

76

is attached the eductor section

120

which includes a distribution reservoir

126

, a nozzle

164

, a Venturi pipe

124

and at least one slurry intake port

132

. At the end of the tool

10

there is a drill bit

152

.

It is preferred that the barrel portion

102

of the hydromonitor

32

be generally conical in shape, and will have round cross-section normal to the direction of the flow

56

. Due to the generally conical configuration of the barrel portion

102

, working fluid

56

entering the barrel portion

102

is accelerated through it as the flow

56

moves towards the nozzle

90

. Thus, the water flow

56

will encounter the hydromonitor

32

through the maximum possible entrance area

101

.

The acceleration of the water flow

56

trough the hydromonitor

32

occurs upon entering it and not only after flowing through the nozzle

90

, as it was in the previous case. In other words: the process of water jet

80

forming starts earlier and, thus, runs longer. It will positively effect the water jet

80

structure, make it more compact and focused. It increases the water jet

80

work ability.

From examination of

FIG. 5

it can be seen that the hydromonitor

32

extends through the slurry knee passage

86

of the hydromonitor section

76

. The Hydromonitor

32

bifurcates the knee

86

to define a fork

87

with equal sized channels

116

(FIGS.

5

D and E). Preferably, this fork

87

will be placed at the crest

98

part of the knee

86

(FIG.

5

A). The crest

98

is the part of the Hydromonitor section

76

at which the internal fluid (slurry) knee passage

86

is closest to the external conduit

68

H.

There are two smoother-stabilizers

104

, mounted on outside surface of the barrel

102

portion of Hydromonitor

32

shown on FIG.

5

B. The smoother-stabilizers

104

decrease the slurry turbulence range and, as a result, decrease the slurry pressure loss.

On

FIG. 5C

the eductor

120

throat insertion

130

is shown separately illustrating its main parts which are confuser

128

and diffusor

206

.

From the

FIGS. 5D and E

, it can be understood that the maximum offset “x” that can be incorporated in a hydromonitor section

76

having two conduits, an external conduit

68

H of diameter “D”, and an internal conduit

70

H of diameter “d”, is described by the mathematics formula:

x=

½(

D−d

).

In order to take full advantage of the ability to create a large area of concentrated flow

88

, the preferred embodiment of the invention includes a window cutout

89

in the external pipe

68

H to allow additional displacement of the internal pipe

70

H for a distance equal to the thickness of the wall of the external pipe

68

H, as show on FIG.

5

.

On

FIGS. 5D and E

the advantage of the oval shape of the inner pipe

86

in the slurry fork crest area is shown in comparison with the standard cylindrical

94

shape (dashed line). The oval shape of the inner pipe

86

allows it to transport bigger size slurry chunks

222

through the forked channels

116

.

Thus, the fork

87

incorporates a streamlined profile to produce smooth flows of both high pressure water

56

and slurry

58

through the Hydromonitor section

76

. By including this smooth, streamlined profile and by providing a fork

87

at the knee

86

, the slurry

58

bottom head (

74

) pressure losses are minimized, while increasing the overall efficiency of the whole tool

10

as explained above. This synergistic effect is largely due to the fact that the knee

86

provides a large exposure of the entrance

101

of the barrel

102

to the flow of working fluid

56

. This increased exposure is due in large part to the use of the knee

86

, which concentrates the flow of working fluid

56

at the entrance

101

of the barrel

102

in a smooth manner. Moreover, the smooth transition of the knee

86

reduces the head

74

losses caused by turbulence as found in traditional designs which simply place a Hydromonitor in fluid communication with a bent duct. All mentioned distinctive signatures: knee

86

, stabilizer

96

, conical barrel

102

and offset of the knee

86

decrease hydrodynamic turbulence and thus water pressure loss. In turn, it enhances the bottom head

74

and water jet

80

hydrodynamic characteristics (makes it more compact, focused) . As a result, it increases water jet pressure, the effective distance between the tool and the rock face and finally, it enhances efficiency of borehole mining.

The gap

26

(see

FIGS. 2 and 3

) is used to carry working fluid

56

down, or to carry slurry

58

up, depending on the general configuration of the tool

10

. The outer pipe

68

of the bottom head

74

defines a gap

27

with the casing

114

which is sealed by the packer

36

located on the hub

67

.

While borehole mining, the tool

10

is rotated in a hole

12

and moved up and down within the production interval

11

. While pumping out the created slurry

58

, underground cavities (caverns, stopes)

82

can be created. The bottom head

74

is assembled in such a manner that its length allows the pucker

36

always to stay above the casing's

114

shoe

115

while operating.

In

FIG. 6

bottom head main fluid flows are shown. In the Hydromonitor section

76

one portion of the flow

56

encounters to the hydromonitor

32

and going through it accelerates to a water jet

80

(see FIG.

1

). This jet

80

cuts the rock material

11

which becomes slurry

58

.

The other portion of the working water

56

continues flowing down and reaches the distributive reservoir

126

. Working water

56

then makes a 180° turn and encounters the eductor nozzle

164

which creates the water jet

80

E shown on FIG.

5

. This jet creates a vacuum that inducts the incoming slurry

58

which firs encounters to the venturi pipe

124

.

From the diffusor

206

, the slurry

58

then enters to the knee passage

86

and then to the slurry channel

24

by which it finally reaches the ground surface

38

(FIG.

1

). Here, in a collecting pond or tank

40

the slurry

58

is separated by itself or by any type special equipment (hydro cyclones, separators or other). The mined material

222

is then delivered to a customer of further development, and the clarified water

56

is pumped down to the hole

12

again, closing the tool

10

recirculating water supply system.

The internal conduit

70

H includes a fluid knee passage

86

that carries the slurry

58

being retrieved as part of the mining operations. Because of the knee

86

, working water flow

56

is diverted to one side of the Hydromonitor section

76

, to the area of “concentrated” flow

88

, where it will encounter a stabilization plate

96

and the entrance

101

to the hydromonitor

32

. The hydromonitor

32

has a barrel portion

102

that accepts the working fluid

56

before delivering it to an interchangeable or removable nozzle

90

.

The stabilizer plate

96

serves as a means for preserving low-turbulence (laminar type) flow through the Hydromonitor

32

. It decreases the level of turbulence in the working water flow

56

, which helps to produce more focused (and thus, more powerful) water jets

80

.

By examining

FIGS. 5

,

6

it will be understood that in order to concentrate the flow

56

at one side of the Hydromonitor section

76

, the internal fluid (slurry) knee-passage

86

is offset to produce a bent section. Knee

86

offsets in turn the Hydromonitor

32

towards its outlet (nozzle

90

). Thus, the distance between the outer pipe

68

H and the entrance

101

to the Hydromonitor

32

is increased. It laminates, or smooths the water flow

56

at this point, and together with the stabilizer

96

decreases the grade of turbulence and cavitation of the flow

56

going through the Hydromonitor

32

.

As explained above, the hydromonitor section

76

houses the barrel portion

102

, which in turn supports the nozzle

90

. Preferably, the nozzle

90

will be interchangeable, allowing its replacement to develop the necessary flow pattern and ratio between Hydromonitor nozzle

90

and eductor nozzle

164

, as required by the field conditions.

The hydromonitor section

76

has the same type and size connection devices on each end (FIG.

6

). It allows a user to assemble the tool

10

without the Hydromonitor section

76

. With this arrangement the user may draw fluid-like slurries or liquids from a borehole

12

or any another cavity, tank, vessel or reservoir. This shape of the tool

10

will perform the pump-out functions only, when no water jet cutting is required.

Having same type connection devices on both ends of the Hydromonitor section

76

allows a user to combine more than one Hydromonitor section

76

within the same bottom head

74

. There may be two Hydromonitor sections

76

, three of them, and so on. This embodiment of the bottom head

74

allows accelerate the rock cutting process and will find an application in building of storages in Salt domes, in creating of underground collectors or barriers and in a several more engineering and environmental projects.

Since the hydromonitor

32

receives only a fraction of the working fluid

56

flowing through the bottom head

74

, the balance of the working fluid

56

is allowed another portion of it (

56

) to exit the Hydromonitor section

76

through an annular exit

118

shown on

FIGS. 5 and 6

. From this exit

118

the working fluid

56

then travels to an annular entrance

122

of an eductor

120

section.

Analyzing the

FIGS. 5 and 6

it also can be understood that working fluid

56

flows from the Hydromonitor section

76

into the eductor section

120

. From here it flows through the connector

42

to any additional part attached to the bottom head

74

of the tool

10

.

The eductor section

120

allows modification of the tool

10

for specific operations to be carried out. Referring now to

FIGS. 1

,

2

,

4

,

5

, and

6

, it can be understood that the eductor section

120

also includes external

68

and internal

70

pipes. The relationship between these two pipes is maintained by stabilizer plates

196

.

The internal pipe

70

E of the eductor section

120

(

FIG. 6

) houses a Venturi pipe

124

which is used to create a vacuum to draw slurry

58

and to perform the various other functions of the borehole mining tool

10

. The Venturi pipe

124

includes a confuser

128

, a mixing chamber (throat)

202

, and a diffuser

206

. The confuser

128

, the mixing chamber

202

, and the diffuser

206

are incorporated into an interchangeable insertion

130

shown separately on FIG.

5

C. By varying the diameters of nozzles

90

,

164

and the insertion

130

, the proportion of the working water

56

volume going through the Hydromonitor

32

to the volume going through the eductor section

120

can be controlled.

The Venturi pipe

124

receives a maximum abrasive wearing while mining. Interchangeable embodiment of the insertion

130

allows simple replacement when necessary. In other words—replaceable embodiment of the Venturi

124

simplifies the maintenance of the eductor section

120

.

The eductor section

120

has a universal connector

42

, located at the bottom end of the Venturi pipe

124

. This connector

42

allows attachment of additional equipment to the bottom head

74

which makes wider an application area of the entire device. In other words, this connector

42

allows modification of the eductor section

120

in order to adopt the borehole mining tool

10

for a specific technique or technological task. Thus, the versatility of the instant device is achieved by providing the eductor section

120

by the universal connector

42

.

One useful embodiment of the universal connector

42

consists of a conventional thread on the outer pipe

68

E, and slide-in hermetic coupling

43

on the inner pipe

70

E.

FIGS. 7 and 8

illustrate different embodiments of the device bottom part allowing by universal connector

42

, where:

FIG. 7A

presents bottom face ring-type eductor with the lowest possible suction area and two faces eductor jet

177

;

FIG. 7B

presents the same as A but with the extra duct

226

ending below the tool

10

, BB is the cross section view through the venturi pipe

124

;

FIG. 7C

is the same as A, but with the auxiliary nozzle

224

;

FIG. 7D

the same as A, but with the telescopic sucker

166

.

FIG. 8

illustrates draw needle-stabilizer, extra slurry intake ports

132

and an electronic compartment installed between the distribution reservoir

126

and a drill bit

152

.

FIG. 9

illustrates sequence of the instance device bottom part assemblies which allow it perform different exploration, mining, environmental and other tasks. Analyzing

FIGS. 1 through 9

, it can be seen that whole plurality of different tool

10

bottom head

74

assemblies is based on two main embodiments of the eductor section

120

. They are: central (

FIG. 9C

) and ring (FIGS.

9

D/E) types. These eductors form respectively solid

80

E (

FIG. 5

) and annular

177

(

FIG. 4

) water jets which perform different hydrodynamic characteristics and found application in different areas.

Also, it should be mentioned that the positioning system compartment

184

can be attached to the tool

10

, regardless of the type of the eductor section

120

, as illustrated on

FIG. 9H and M

.

On

FIG. 10

are presented several different modifications of the tool

10

. They are: A—preferable “light” configuration including straight hub, hydromonitor and eductor sections; B—the same with additional (third pipe) air duct with aerator

180

at its end to create an airlift effect; C—the same as A but without the hydromonitor section, an airlift and a drill bit; D—the same as B but with the end-face (ring-type) eductor with the very bottom suction area and the secondary agent duct ending below the tool; E—the same as A but with the reverse hub and surface equipment communications, F—the same as A but with positioning system and G—illustrates two Hydromonitor sections joined serially. The tool embodiment presented on

FIG. 1

should also be counted as the most complete and thus most powerful configuration of the instant device.

As it was noted above, usually next to the Venturi pipe

124

a distribution reservoir

126

is located. At least one water pass duct

154

is installed between the Venturi

124

and the distribution reservoir

126

. The distribution reservoir

126

serves as an interchangeable or modifiable means for diverting the flow of the working fluid

56

to the desired passage. This allows the flow of working fluid

56

to enter different tool's

10

parts such as the eductors's nozzle

164

, drill bit

152

or any other implement attached to the bottom head

74

.

The area between the eductor nozzle

164

and confuser

128

has at least one hydraulic connection to the well

12

or stope

82

(see for example FIG.

1

). This connection defines at least one (single) slurry intake port (inlet)

132

. Thus, the vacuum sucks the slurry

58

through intake

132

from the driving cavern

82

and directs it into the eductor confuser

128

. From the confuser

128

the slurry/water mixture (

56

/

58

) then proceeds to the mixing chamber

202

where they are mixed together and than continue on to the diffusor

206

.

The aforementioned slurry intake port

132

may have interchangeable protecting-calibrating grill-net screens

133

presented on FIG.

10

H. The screens' dimensions are equal or less than slurry channel minimum cross section. Thus, the screen(s) sort slurry

58

material and protect the slurry channel

24

from plugging by unconditioned chunks

222

.

As shown on

FIGS. 1

,

2

,

4

,

6

and

10

A, C, E and F, the eductor nozzle

164

may include a fixed needle

136

, which is used to create an annular water jet

177

, shown on

FIGS. 4

,

5

and

8

. It has been discovered that the one of the most important characteristics which determine the eductor's vacuum (suction ability) is the diameter of the water jet. In borehole mining, this parameter is in turn limited by the diameter of the well. In other words, there is always the maximum (limit) of the water capacity which can be pumped through the tool with its instant (given) diameter. This problem can be solved, however, by inserting a pipe (U.S. Pat. No 4,934,466) or a needle (U.S. Pat. No 4,059,1066—Bunnelle device) inside the eductor nozzle. This inserted cylindrical body occupies the central area of the water jet and allows it increase its diameter. Thus, increased suction can be achieved while pumping the same volume of water. Thus, the needle

136

allows to increase the tool

10

work ability.

The instant invention also offers another eductor section

120

embodiment based on the above mentioned discovery. On

FIGS. 7 and 10D

the ring-type eductor is presented. Next to the universal connector

42

and the distribution reservoir

126

, an annular nozzle

176

is attached. Nozzle

176

is formed by the plug

28

and the needle-draw tube

178

. The plug

28

blocks the gap

26

E, and together with the draw tube

178

directs the whole working water flow

56

upward to the confuser

128

of the Venturi pipe

124

. Thus, the annular nozzle

176

creates an annular water jet

177

, the inner space of which is connected to the mining area

82

by the drawtube

178

. It is noteworthy that this drawtube

178

works the same as the needle

136

, shown for example on FIG.

4

. The only difference is—that the hole (intake port)

132

connects the confuser

128

to the stope

82

. In other words, the drawtube

178

is the same needle

136

but contains the hole-connecter (intake port)

132

. Finally, the draw pipe

178

locates in the middle of the bottom-end face of the tool

10

. This arrangement allows the tool

10

to draw material from the very lowest point of the working area

82

. The outer face of the plug

28

(tool

10

end-face) is armored by the rock-breaking material

29

. It enables a user to re-drill collapsed intervals while mining when necessary.

In practice some of slurry particles

222

flowing down under gravity can miss the standard eductor

120

vacuum area, reach the sump

250

and avoid extraction. This is even more likely as the diameter of the stope

82

increases and/or tool

10

is lifted while operating. On

FIG. 7D

the telescopic sucker

166

is presented. This sucker enables to keep the slurry

58

intake port

132

at the stope's

82

sump

250

area constantly while tool

10

is elevating and lowering in the hole

12

while operating. Thus, this extendable telescopic trunk-sucker

166

delivers one more extra (specific) operational property to the tool

10

: slurry sucking remote ability.

It has been also discovered that the double faced annular jet has greater suction ability than the single (solid) one. It is due to the double vacuum created by the both faces of this jet. On

FIG. 8

the doubled slurry intake

132

area is presented. As it shown, both faces of the water jet

177

are hydraulically connected now to the same working space

82

. The outside surface of the jet

177

is connected by the intake port

132

. The second connection is achieved by the needle-draw tube

178

placed coaxially inside the standard “central type” nozzle

164

. The bottom part of this needle

178

is connected to the stope

82

space by radial draw pipes

108

. After the distribution reservoir

126

, one portion of the high pressure water

56

flows upward to the annulus gap between the nozzle

164

and the needle-draw pipe

178

. The other portion of water

56

continues flow down around the radial draw pipes

108

and through the channel

144

reaches the drill bit

152

. It should be mentioned that the drill bit

152

can be attached directly to the distribution reservoir

126

. The slurry

58

now encounters the tool

10

not only through the slurry intake port(s)

132

, but through the end faces of the radial draw pipes

108

, as well. In other words, now both faces of the water jet

132

draw slurry

58

from the stope

82

. This arrangement allows the eductor to increase its sucking ability, while enhancing the whole BHM process productivity.

Referring again to

FIG. 7C

, it can be appreciated that the gap plug

28

is able to accept additional components that will cooperate with the distribution reservoir

126

. For example, an annular nozzle

176

has been combined with an auxiliary-accelerative nozzle

224

. The auxiliary nozzle

224

provides a propulsion boost to help move slurry

58

up past the annular nozzle

176

and towards the Venturi

124

.

FIGS. 7B and 10D

illustrate the use of a flexible secondary agent (

138

) delivery tube

226

in use with the annular nozzle

176

. The tube

226

may be used to deliver fluids and mixtures, such as concrete, leaching agents, air, Nitrogen or another gases, foam, clay mud and other secondary agents needed for a specific task to be carried out with the tool

10

.

Thus, with the variations of the distribution reservoir

126

it has been taught herein a variety of tool

10

modifications may be assembled.

As was mentioned earlier, borehole mining is carried out through pre-drilled and cased holes. Usually, the pre-drilled borehole already has some above-the-earth equipment, especially in the oil and gas industry. This equipment, known in the field as a “Christmas tree”, prevents oil/gas leakage and explosion, and at the same time allowing operation in the hole “under pressure”. The trees construction allows it to be connected to the borehole mining tool by either direct or reverse schematic, as described earlier. Thus, the BHM tool, which construction is based on direct schematic, may not be applied on the hole with reverse Christmas tree, and opposite. In such cases, the tool requires either the additional equipment, or a complete reconfiguration, or a different type BHM tool. Thus, another distinguishing feature of this invention can be achieved by variation of embodiment of the hub

67

presented in great on

FIG. 11

, allowing assembly the tool

10

for direct or reverse fluid circulation.

On

FIG. 11

the direct (A) and the reverse (B) hub

228

modifications are shown. The construction of the reverse hub

228

is described as follows. The main part of the hub

228

is a truncated cone

168

, hydraulically connecting the inner column

70

of the intermediate section

64

to the gap between the bottom head's

74

external pipe

68

B and internal pipe

70

B. This detail not only pertains to the hydraulic connector between said parts, but also a main detail of the bottom head

74

suspension suspending it (

74

) on the inner column

70

I. Also, it is the one of main detail, transmitting a torque from the turntable

60

to the drill bit

152

. Inside of this cone

168

the slurry-pass stub pipe

174

is mounted connecting the bottom head

74

inner pipe

70

B to the intermediate section

64

gap

26

I between the casing

114

and the inner column

70

.

This hub

228

and port

175

allows to switch (replace) fluids

56

and

58

in the tool

10

main fluid channels (

24

and

26

) and reverse these fluids flow directions in these mentioned channels (

24

and

26

) within top head

52

and intermediate section

64

. Now, (see

FIG. 11B

) the water

56

goes down to the bottom head

74

by the inner pipe

70

and the slurry

58

is raising-up by the gap

26

. It should be noted that the reverse hub

228

does not cause any changes in the bottom head

74

fluids circulation. Thus, the reverse hub

228

solves only the tool

10

surface equipment connection problems. Both direct (

FIG. 11A

) and reverse (

FIG. 11B

) hubs have said pucker

36

.

Casing surface usually is very rough, covered by rust, oil, paraffin and other sediments. Because of the constant rotation and sliding up and down of the tool

10

in the hole

12

while borehole mining, the packer

36

contacting surface is subjected to severe wear. To decrease this, the packer

36

is embodied with possibility of rotation relative to the tool

10

. The hub

67

surface under the packer

36

(

FIG. 12

) is polished and sealed by rubber rings

92

. Because the friction force between packer

67

and the tool

10

(actually—the hub

67

) is much less than between the rusted casing

114

and said packer

36

, the last (

36

) will rotate relative to the tool

10

rather inside of the casing

114

. In other words, the packer

36

will remain stationary relative to the rough casing

114

and will rotate relative to the polished hub

67

. It will increase the packer

36

life and work ability.

Also, to prevent wearing of plastic or rubber packers and increase their life, below the packer

36

some cleaning elements are mounted, for example metal brush

44

(FIG.

12

). While lowering the tool

10

, its rotation in a hole

12

and moving it up and down while operating, these cleaning elements

44

clean the casing

114

face to help mitigate the packer

36

wear.

Some hydro geological and technological conditions require a secondary working agent

138

to be injected into the driving space

82

. For example nitrogen—to prevent Methane explosion, or compressed air—to create an extra pressure (pressurizing) above the slurry level

142

in a stope

82

, to help for eductor

120

to pump up the slurry

58

. On

FIG. 11C

a secondary agent bi-pass channel

146

is presented installed inside of the hub

67

. This channel

146

has a hold box

148

at its upper end to accept the secondary agent duct

226

. The bottom end of this channel

146

is connected to the gap

27

between the bottom head

74

and the casing

114

by means of an outlet slot

150

located below the packer

36

.

The secondary agent duct

226

is lowered down inside of the inner pipe column

70

after the tool

10

is assembled in a hole

12

until the duct

226

bottom end reaches the hold box

148

. The secondary agent

138

being pumped from the surface is going by the bi-pass channel

146

and through the outlet slot

150

encounters the annulus gap

27

. From here (

27

), the secondary agent

138

reaches the working space (stope)

82

and effects the borehole mining process. It should be mentioned that this shape of the tool

10

allows not only a user to pump-in a secondary agent but also recover any type of bi-product (such as a liquid or gas) if necessary.

A preferred embodiment (

FIG. 1

) of the universal borehole mining tool

10

will be capable of collecting data as to the geographical orientation of the hydromonitor

32

as well as the distance between the nozzle

90

and any solid ore face

308

(radius of cutting).

FIG. 13

illustrates mounting of radar elements inside of the hydromonitor section

76

. These radar elements include: transmitter

310

, receiver

312

, wiring

218

and ring contacts

314

.

Referring now to

FIG. 14

it will be understood that the distribution reservoir

126

of the eductor section

120

may accept an attachment such as an instrument enclosure

184

. The instrument enclosure

184

has been adapted for receiving a battery pack

186

and a positioning system

188

.

The positioning system

188

uses a conductive loop (or coil)

190

which is preferably placed within the instrument enclosure

184

. Since the conductive loop

190

is held within the instrument enclosure

184

, and the instrument enclosure

184

is rotated together with the rest of the tool

10

, the conductive loop

190

will be rotated together with the tool

10

. This rotation of the loop

190

will vary the orientation of the conductive loop

190

relative to the earth's magnetic field

191

. By rotating the conductive loop

190

into the earth's natural magnetic field

191

one can induce (generate) a current

185

to flow through the conductive loop

190

. This current

185

will be in a sinusoidal

286

wave form (see FIG.

17

). Thus, by detecting these waveforms

185

one can determine the orientation of the entire tool

10

assembly relative to the earth's magnetic field

191

or its geographical orientation.

The positioning or determination of the direction of the nozzle

90

is explained in details on

FIGS.14

,

15

,

16

and

17

and occurs as follows. As the conductive coil

190

rotates in the Earth natural magnetic field

191

, a current (alternating current—AC)

185

is produced. The force and direction of this current

185

depends on the instant angle (orientation) of the coil

190

relative to magnetic field force lines

191

. At the same time, the frequency of the current

185

is equal or proportional to the tool

10

rotation speed.

The coil

190

is mounted in a such a manner, that its axis

187

is parallel to the nozzle

90

axis

197

and oriented to the same direction as the nozzle

90

(FIG.

14

A). During a single rotation (360 degrees phase) of the tool

10

in the well

12

the force of current

185

reaches extremes (positive and negative) twice following sin

286

graph Y=SinX (FIG.

17

B). According to the theory [

1

], the maximum of current

185

force (see

FIG. 17B

) corresponds to the nozzle

90

direction (azimuth) to the East, minimum—to the West, first (after minimum) “zero” corresponds to the direction to the North, and second “zero” (after maximum)—to the South. All intermediate points (the points that are located between “zeros” and extremum) on the sinus curve (each) determines/belongs to a certain and only azimuth or tool

10

orientation. In other words, each point on a sine curve

286

gives the information about the current direction, in which the coil

190

is oriented in the instant moment. Because the coil axis

187

, the nozzle

90

and entire Hydromonitor

32

are parallel to each other, the Sinus line

185

gives an information about the instant direction of the water jet

80

or direction of cutting in the instant moment.

From the conductive coil

190

the current

185

arrives to the amplifying transformer

193

. Then, amplified signals from the transformer

193

arrive to the radio transmitter

195

with antenna

212

. From there it arrives to the earth's surface

38

in a kind of a radio signal. Here, in the decoder

201

this radio signal is transformed into computer signal (signal, accepted by a computer) and being developed by a computer

205

arrives on the monitor screen

207

(FIGS.

1

and

15

).

The transmitter

310

is periodically activated by impulses produced by an impulse generator

214

which is controlled by radio from the earth's surface

38

.

Practically, the speed of rotation of the tool

10

in a hole

12

is never equal to the frequency, generated by generator

214

. Thus, the transmitter

310

sends a signal (penetrates the stope

82

or makes a measurements in it) each turn in a new direction (geographical azimuth). Additionally, the tool

10

is moved along the well

12

up and down, so that the direction of each new gauging differs from the previous one not only by the azimuth A, but also by the depth (distance from the Earth's surface

38

). All this data enables more complete information about the instant configuration of the cavern

82

, to develop its 3D computerized image (FIG.

15

B).

The received information about the radius of the cavern

82

arrives to the computer

205

in the same manner as the orientation signal. On its screen

207

this signal gives a point on the line R of the azimuth vector, equal to the distance between the tool

10

and the rock face

308

(instant radius of the cavern

82

). The consecutive connecting (joining) of this points (R) gives a plane configuration (structure, contour) of the cavern

82

(

FIG. 15A

) on this given depth (elevation). Thus, each gauging (penetration) of the cavern

82

gives the R—radius of the cavern

82

and the A—azimuth, that are complete linear and angular positioning information. Thus, the tool

10

orientation (positioning) system works in a Polar Coordinates System illustrated by FIG.

15

A.

In addition to the information about the radius R and azimuth A, the information about the relative (distance from the earth surface

38

) or absolute (distance from the level of the ocean) depth, marked by Z, of the each gauging also comes to the computer

205

. This information comes from any device, based, as a rule, on the control of the length of a rope, reeling out from a rig

62

tower drum, on which the tool

10

is suspended in a hole

12

. The sum all incoming data (R, A and Z) is used to generate the 3D image of the stope

82

(

FIG. 15B

) on the computer screen

205

or a system printer when necessary.

The periodic (systematic) processing/development of up-coming data allows a user to conduct operative control of the BHM processes. So, the formula πR

2

* (Z

2

−Z

1

) determines the volume of the cavern. The formula ([πR

2

2

* Z

2

]−[πR

1

2

* Z

1

])/T, determines the current productivity of borehole mining, where: Z

2

and Z

1

—the lowest and upper elevations of the cavern; R

1

—the radius of the cavern at the current time T

1

l; R

2

—the radius at the current time T

2

; T—the difference in time between T

2

and T

1

, π=3.14. This current information may be displayed on the screen

207

, too (FIG.

15

B).

The preferred embodiment of the nozzle

90

will include a radar system including transmitter

310

and a receiver

312

or the same in one miniature block as, for example, a finger ring transmitter/receiver [

2

]. Power is delivered to the radar through connectors

314

(

FIG. 13

) attached to a wiring

218

which connects them to the electronic enclosure

209

which is held within the instrument compartment

184

. Thus, to detect the distance from the nozzle

90

and a rock face

308

, the transmitter

310

sends a direct signal

313

which bounces off or is reflected off of the face

308

. The reflected signal

315

is detected by the receiver

312

which in turn delivers this signal to the system circuitry which accepts and processes it to create data relating to the instant radius of the cavern

82

and cutting orientation.

In an alternate embodiment, an ultrasonic transmitter and receiver will replace the radar transmitter

310

and the receiver

312

. The image of the stope or borehole will be developed by use of the ultrasonic sound waves, instead of EM waves. The data will be transmitted to the surface as described above for the radar embodiment.

Following are several samples of other embodiments of the instant invention illustrating its versatility:

1—a miniature radar block

309

can be installed coaxial to the nozzle

90

in front of its entering

101

(see FIG.

14

A). This embodiment will improve reflected signal(s)

315

receiving process. It will happened because only straight from the rock face

308

signals

315

will come inside to the nozzle

90

and reach the radar

309

.

2—a hydro-turbine

302

may be installed in the water supply channel

144

to recharge the battery

186

(FIG.

14

A). It will allow for an increase in the tool's

10

running time without recharging of the battery

186

.

3—tool

10

may be used to develop offshore zone from sea/ocean platforms (FIG.

18

). It will increase this invention application area. As it can be seen from the illustration, the casing

114

must be extended through the whole depth of the reservoir. Mined material is loaded to any type of vessel

204

. Because the drill rig

62

and personal are now on a platform

270

, floating on the water surface

46

, there is no more a danger of subsidence while borehole mining.

Offered invention also can be used from existing underground mines or open pit's floor.

Thus, it can be appreciated that the above described embodiments of the invention are illustrative of just a few of the numerous variations of arrangements of the disclosed elements used to carry out the patenting idea. Moreover, while the invention has been particularly shown, described and illustrated in detail with reference to preferred embodiments and modifications thereof, it should be understood by that the foregoing and other modifications are exemplary only, and that equivalent changes in form and detail may be made without departing from the true spirit and scope of the invention as claimed, except as precluded by the prior art.

The offered borehole mining tool is a universal instrument: by shifting of units and parts of its bottom head the tool receives a new quality demonstrating new features and allowing effective use in various geological and hydro-geological conditions and mining of different types of mineral resources (including industrial minerals) as well as applying it in other types of industries, such as environment, building (construction), exploration and others. This tool has following advantages:

wider area of application,

simplified serviceability,

increased reliability and productivity,

improved hydrodynamic characteristics of water and slurry channels,

decreased fluids pressure loss,

increased water-jet cutting radius,

provides a possibility of control of the driving space (cavern).

Except the bottom head, all tool's details, units and parts (pumps, compressors, drilling equipment, pipes, fixtures, gauges and so on)—are standard, using oil and gas drilling industry standard pipes, threads and fittings. This allows for a decrease in the cost of tool manufacturing and operation. It also allows for the attachment of the tool to the customer's existing equipment.

All mentioned advantages guarantee wide application of this device in the mining industry, as well as in-situ leaching, oil/gas/water production stimulation, construction of subterranean storages, building of foundations, underground barriers and collectors, cleaning of tanks, radioactive contamination, nuclear missile shafts and lake bottoms and many other applications. All above mentioned actions can be executed by this tool from ground surface, water surface and underground mines.

Although the present invention has been described with reference to preferred or specific embodiments, numerous modifications and variations can be made and still remain within the scope of the invention. No limitation with respect to the specific embodiments disclosed herein is intended or should be inferred.

Number	Name	Date	Kind
3065807	Wells	Nov 1962	A
3286163	Holser et al.	Nov 1966	A
3638970	Sandquist et al.	Feb 1972	A
3747696	Wenneborg et al.	Jul 1973	A
4059166	Bunnelle	Nov 1977	A
4077481	Bunnelle	Mar 1978	A
4095655	Still	Jun 1978	A
4140346	Barthel	Feb 1979	A
4149739	Morris	Apr 1979	A
4212353	Hall	Jul 1980	A
4296970	Hodges	Oct 1981	A
4336564	Wisniewski et al.	Jun 1982	A
4381610	Kramer	May 1983	A
4708395	Petry et al.	Nov 1987	A
4718728	Hodges	Jan 1988	A
4814768	Chang	Mar 1989	A
4915452	Dibble	Apr 1990	A
4934466	Paveliev et al.	Jun 1990	A
5181578	Lawler	Jan 1993	A
5197783	Theimer et al.	Mar 1993	A
5366030	Pool, II et al.	Nov 1994	A

Borehole mining tool

Information

Patent Number

Date Filed

Date Issued

Inventors

Examiners

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

US Referenced Citations (21)