Patent Application
20160047199
All of the material in this patent application is subject to copyright protection under the copyright laws of the United States and of other countries. As of the first effective filing date of the present application, this material is protected as unpublished material.
However, permission to copy this material is hereby granted to the extent that the copyright owner has no objection to the facsimile reproduction by anyone of the patent documentation or patent disclosure, as it appears in the United States Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
Not Applicable
Not Applicable
The present invention generally relates to oil and gas extraction. Specifically, the invention attempts to isolate fracture zones through selectively positioning restriction elements within a wellbore casing. More specifically, it relates to restriction plug elements that are insoluble in well fluid but have properties such as phase or strength that vary with temperature so as to change shape to pass through restrictions during production.
The process of extracting oil and gas typically consists of operations that include preparation, drilling, completion, production and abandonment.
Preparing a drilling site involves ensuring that it can be properly accessed and that the area where the rig and other equipment will be placed has been properly graded. Drilling pads and roads must be built and maintained which includes the spreading of stone on an impermeable liner to prevent impacts from any spills but also to allow any rain to drain properly.
In the drilling of oil and gas wells, a wellbore is formed using a drill bit that is urged downwardly at a lower end of a drill string. After drilling the wellbore is lined with a string of casing. An annular area is thus formed between the string of casing and the wellbore. A cementing operation is then conducted in order to fill the annular area with cement. The combination of cement and casing strengthens the wellbore and facilitates the isolation of certain areas of the formation behind the casing for the production of hydrocarbons.
The first step in completing a well is to create a connection between the final casing and the rock which is holding the oil and gas. There are various operations in which it may become necessary to isolate particular zones within the well. This is typically accomplished by temporarily plugging off the well casing at a given point or points with a plug.
A special tool, called a perforating gun, is lowered to the rock layer. This perforating gun is then fired, creating holes through the casing and the cement and into the targeted rock. These perforated holes connect the rock holding the oil and gas and the wellbore.
Since these perforations are only a few inches long and are performed more than a mile underground, no activity is detectable on the surface. The perforation gun is then removed before the next step, hydraulic fracturing stimulation fluid, which is a mixture of over 90% water and sand, plus a few chemical additives, is pumped under controlled conditions into deep, underground reservoir formations. The chemicals are used for lubrication and to keep bacteria from forming and to carry the sand. These chemicals are typically non-hazardous and range in concentrations from 0.1% to 0.5% by volume and are needed to help improve the performance and efficiency of the hydraulic fracturing. This stimulation fluid is pumped at high pressure out through the perforations made by the perforating gun. This process creates fractures in the shale rock which contains the oil and natural gas.
In many instances a single wellbore may traverse multiple hydrocarbon formations that are otherwise isolated from one another within the earth. It is also frequently desired to treat such hydrocarbon bearing formations with pressurized treatment fluids prior to producing from those formations. In order to ensure that a proper treatment is performed on a desired formation, that formation is typically isolated during treatment from other formations traversed by the wellbore. To achieve sequential treatment of multiple formations, the casing adjacent to the toe of a horizontal, vertical, or deviated wellbore is first perforated while the other portions of the casing are left unperforated. The perforated zone is then treated by pumping fluid under pressure into that zone through perforations. Following treatment a plug is placed adjacent to the perforated zone. The process is repeated until all the zones are perforated. The plugs are particularly useful in accomplishing operations such as isolating perforations in one portion of a well from perforations in another portion or for isolating the bottom of a well from a wellhead. The purpose of the plug is to isolate some portion of the well from another portion of the well.
Conventional prior art frac balls are typically made of a non-metallic material, such as reinforced epoxies and phenolics, that may be removed by milling in the event the balls become stuck. Such conventional prior art frac balls are made of materials that are designed to remain intact when exposed to hydraulic fracturing temperatures and pressures and are not significantly dissolved or degraded by the hydrocarbons or other media present within the well. When one of these prior art balls does not return to the surface and prevents lower balls from purging, coiled tubing must be lowered into the wellbore to mill the stuck ball and remove it from the seat. In addition, smaller-sized prior art balls that are not stuck in their seats still might not return to the surface because the pressure differential across the ball due to the uprising current in the large diameter casing might not be significant enough to overcome gravity. Consequently, while such smaller-sized balls may not completely block a zone, they are still likely to impede production by partially blocking the wellbore.
Subsequently, production of hydrocarbons from these zones requires that the sequentially set plugs be removed from the well. In order to reestablish flow past the existing plugs an operator must remove and/or destroy the plugs by milling, drilling, or dissolving the plugs.
As generally seen in the system diagram of
Furthermore, after well completions, sleeves used to set frac plugs may have a smaller inner diameter constricting fluid flow when well production is initiated. Therefore, there is a need for a relatively large inner diameter sleeves after well completion that allow for unrestricted well production fluid flow.
Additionally, frac plugs can be inadvertently set at undesired locations in the wellbore casing creating unwanted constrictions. The constrictions may latch wellbore tools that are run for future operations and cause unwanted removal process. Therefore, there is a need to prevent premature set conditions caused by conventional frac plugs.
Exemplary prior art covering degrading frac plugs includes the following:
U.S. Pat. No. 8,714,268, Method of making and using multi-component disappearing tripping ball; A method for making a tripping ball comprising configuring two or more parts to collectively make up a portion of a tripping ball; and assembling the two or more parts by adhering the two or more parts together with an adherent dissolvable material to form the tripping ball, the adherent dissolvable material operatively arranged to dissolve for enabling the two or more parts to separate from each other;
U.S. Pat. No. 8,231,947, Oilfield elements having controlled solubility and methods of use; Oilfield elements are described, one embodiment comprising a combination of a normally insoluble metal with an element selected from a second metal, a semi-metallic material, and non-metallic materials; and one or more solubility-modified high strength and/or high-toughness polymeric materials selected from polyamides, polyethers, and liquid crystal polymers;
U.S. Pat. No. 8,567,494, Well operating elements comprising a soluble component and methods of use; comprising a first component that is substantially non-dissolvable when exposed to a selected wellbore environment and a second component that is soluble in the selected wellbore environment and whose rate and/or location of dissolution is at least partially controlled by structure of the first component; A second embodiment includes the component that is soluble in the selected wellbore environment, and one or more exposure holes or passages in the soluble component to control its solubility;
US 20120181032, Disintegrating ball for sealing frac plug seat; A composition for a ball that disintegrates, dissolves, delaminates or otherwise experiences a significant degradation of its physical properties over time in the presence of hydrocarbons and formation heat;
U.S. Pat. No. 8,657,018, Circulating sub; teaches erodible hollow balls in the fluid flow and more particularly is adapted to be eroded to a certain extent and then collapse or implode due to the pressure of the external fluid being far higher than the internal pressure of the ball;
The aforementioned prior art teach frac balls that degrade, unlink, dissolve, and erode in the presence of wellbore fluids. However, they do not teach any methodology by which frac balls change shape by melting, phase change, strength, or elasticity to address a wide variety of system applications, including but not limited to wellbore plug isolation.
As generally seen in the method of
The step (0206) requires that removal/milling equipment be run into the well on a conveyance string which may typically be wire line, coiled tubing or jointed pipe. The process of perforating and plug setting steps represent a separate “trip” into and out of the wellbore with the required equipment. Each trip is time consuming and expensive. In addition, the process of drilling and milling the plugs creates debris that needs to be removed in another operation. Therefore, there is a need for isolating multiple hydraulic fracturing zones without the need for a milling operation. Furthermore, there is a need for positioning restrictive plug elements that could be removed in a feasible, economic, and timely manner before producing gas.
The prior art as detailed above suffers from the following deficiencies:
While some of the prior art may teach some solutions to several of these problems, the core issue of isolating hydraulic fracturing zones without the need for a milling operation has not been addressed by prior art.
While the use of degradable/dissolvable frac balls has been proven for many years, they have certain limitations. The prior art as detailed above suffers from the following deficiencies:
While some of the prior art may teach some solutions to several of these problems, the core issue of removing reduced size plugs after changing phase to pass through the restriction sleeve members (ball seats) without the need for milling operation has not been addressed by prior art.
Accordingly, the objectives of the present invention are (among others) to circumvent the deficiencies in the prior art and affect the following objectives:
While these objectives should not be understood to limit the teachings of the present invention, in general these objectives are achieved in part or in whole by the disclosed invention that is discussed in the following sections. One skilled in the art will no doubt be able to select aspects of the present invention as disclosed to affect any combination of the objectives described above.
The present invention in various embodiments addresses one or more of the above objectives in the following manner. The present invention provides a system to isolate fracture zones in a horizontal, vertical, or deviated wellbore without the need for a milling operation. The system includes a wellbore casing laterally drilled into a hydrocarbon formation, a setting tool that sets a large inner diameter (ID) restriction sleeve member (RSM), and a restriction plug element (RPE). A setting tool deployed on a wireline or coil tubing into the wellbore casing sets and seals the RSM at a desired wellbore location. The setting tool forms a conforming seating surface (CSS) in the RSM. The CSS is shaped to engage/receive RPE deployed into the wellbore casing. The engaged/seated RPE isolates toe ward and heel ward fluid communication of the RSM to create a fracture zone. The RPEs are removed or pumped out or left behind without the need for a milling operation. A large ID RSM diminishes flow constriction during oil production.
A restriction plug element (RPE) for use in a wellbore casing comprising a first composition and a heating insert wherein the first composition is non-dissolvable at temperatures expected in said wellbore casing. The heating insert is configured with heating source that is configured to generate heat. When said heating source generates heat upon activation, the first composition changes physical property such that the restriction plug element changes shape to enable substantially unrestricted fluid flow fluid flow in the wellbore casing during production
The present invention system may be utilized in the context of an overall gas extraction method, wherein the wellbore plug isolation system described previously is controlled by a method having the following steps:
Integration of this and other preferred exemplary embodiment methods in conjunction with a variety of preferred exemplary embodiment systems described herein in anticipation by the overall scope of the present invention.
The present invention in various embodiments addresses one or more of the above objectives in the following manner. The present invention provides a system to isolate fracture zones in a horizontal, vertical, or deviated wellbore without the need for a milling operation. The system includes a wellbore casing laterally drilled into a hydrocarbon formation, a wellbore setting tool (WST) that sets a large inner diameter (ID) restriction sleeve member (RSM), and a restriction plug element (RPE). The RPE includes a first composition and a second composition that changes phase or strength under wellbore conditions. After a stage is perforated, RPEs are deployed to isolate toe ward pressure communication. The second composition changes phase to create flow channels in the RPE during production. In an alternate system/method, the second composition changes phase or strength thereby deforming the RPE to reduce size and pass through the RSM's. The RPEs are removed or left behind prior to initiating well production without the need for a milling procedure.
The present invention system may be utilized in the context of an overall gas extraction method, wherein the wellbore plug isolation system with a restriction plug element described previously is controlled by a method having the following steps:
Integration of this and other preferred exemplary embodiment methods in conjunction with a variety of preferred exemplary embodiment systems described herein in anticipation by the overall scope of the present invention.
For a fuller understanding of the advantages provided by the invention, reference should be made to the following detailed description together with the accompanying drawings wherein:
a illustrates an exemplary system side view of a spherical restriction plug element/restriction sleeve member overview depicting a presently preferred embodiment of the present invention.
a illustrates a side perspective view of a dart restriction plug element depicting a preferred exemplary system embodiment.
b illustrates another perspective view of a dart restriction plug element depicting a preferred exemplary system embodiment.
a illustrates a cross section view of a restriction plug element with a first composition surrounding a second composition with a passage way and the restriction plug element positioned in a restriction sleeve member during production according to a preferred exemplary system embodiment.
b illustrates a cross section view of a restriction plug element with a first composition surrounding a second composition with a passage way and the restriction plug element positioned in a restriction sleeve member during fracturing according to a preferred exemplary system embodiment.
a illustrates an ovoid restriction plug element with a first composition mechanically held together by a toroid mechanical second composition according to a preferred exemplary system embodiment.
While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detailed preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiment illustrated.
The numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiment, wherein these innovative teachings are advantageously applied to the particular problems of a wellbore plug isolation system and method. However, it should be understood that this embodiment is only one example of the many advantageous uses of the innovative teachings herein. In general, statements made in the specification of the present application do not necessarily limit any of the various claimed inventions. Moreover, some statements may apply to some inventive features but not to others.
The present invention may be seen in more detail as generally illustrated in
In a preferred exemplary embodiment, the WST may set RSM (0303) to the ICS in compression mode to form an inner profile on the RSM (0303). The inner profile could form a tight or leaky seal preventing substantial axial movement of the RSM (0303). In another preferred exemplary embodiment, the WST may set RSM (0303) to the ICS in expansion mode providing more contact surface for sealing RSM (0303) against ICS. Further details of setting RSM (0303) through compression and expansion modes are further described below in
In another preferred exemplary embodiment, the WST may set RSM (0303) using a gripping/sealing element disposed of therein with RSM (0303) to grip the outside surface of RSM (0303) to ICS. Further details of setting RSM (0303) through compression and expansion modes are described below in
In another preferred exemplary embodiment, the WST may set RSM (0303) at any desired location within wellbore casing (0304). The desired location may be selected based on information such as the preferred hydrocarbon formation area, fraction stage, and wellbore conditions. The desired location may be chosen to create uneven hydraulic fracturing stages. For example, a shorter hydraulic fracturing stage may comprise a single perforating position so that the RSM locations are selected close to each other to accommodate the perforating position. Similarly, a longer hydraulic fracturing stage may comprise multiple perforating positions so that the RSM locations are selected as far to each other to accommodate the multiple perforating positions. Shorter and longer hydraulic fracturing positions may be determined based on the specific information of hydrocarbon formation (0302). A mudlog analyzes the mud during drilling operations for hydrocarbon information at locations in the wellbore. Prevailing mudlog conditions may be monitored to dynamically change the desired location of RSM (0303).
The WST may create a conforming seating surface (CSS) (0306) within RSM (0303). The WST may form a beveled edge on the production end (heel end) of the RSM (0303) by constricting the inner diameter region of RSM (0303) to create the CSS (0306). The inner surface of the CSS (0306) could be formed such that it seats and retains a restriction plug element (RPE) (0305). The diameter of the RPE (0305) is chosen such that it is less than the outer diameter and greater than the inner diameter of RSM (0303). The CSS (0306) and RPE (0305) may be complementary shaped such that RPE (0305) seats against CSS (0306). For example, RPE (0306) may be spherically shaped and the CSS (0306) may be beveled shaped to enable RPE (0305) to seat in CSS (0306) when a differential pressure is applied. The RPE (0305) may pressure lock against CSS (0306) when differential pressure is applied i.e., when the pressure upstream (production or heel end) of the RSM (0303) location is greater than the pressure downstream (injection or toe end) of the RSM (0303). The differential pressure established across the RSM (0303) locks RPE (0305) in place isolating downstream (injection or toe end) fluid communication. According to one preferred exemplary embodiment, RPE (0305) seated in CSS (0306) isolates a zone to enable hydraulic fracturing operations to be performed in the zone without affecting downstream (injection or toe end) hydraulic fracturing stages. The RPE (0305) may also be configured in other shapes such as a plug, dart or a cylinder. It should be noted that one skilled in the art would appreciate that any other shapes conforming to the seating surface may be used for RPEs to achieve similar isolation affect as described above.
According to another preferred exemplary embodiment, RPE (0305) may seat directly in RSM (0303) without the need for a CSS (0306). In this context, RPE (0305) may lock against the vertical edges of the RSM (0303) which may necessitate a larger diameter RPE (0305).
According to yet another preferred exemplary embodiment, RPE (0305) may degrade over time in the well fluids eliminating the need to be removed before production. The RPE (0305) degradation may also be accelerated by acidic components of hydraulic fracturing fluids or wellbore fluids, thereby reducing the diameter of RPE (0305) enabling it to flow out (pumped out) of the wellbore casing or flow back (pumped back) to the surface before production phase commences.
In another preferred exemplary embodiment, RPE (0305) may be made of a metallic material, non-metallic material, a carbide material, or any other commercially available material.
The present invention may be seen in more detail as generally illustrated in
According to one aspect of a preferred exemplary embodiment, RSMs may be set by WST at desired locations to enable RPEs to create multiple hydraulic fracturing zones in the wellbore casing. The hydraulic fracturing zones may be equally spaced or unevenly spaced depending on wellbore conditions or hydrocarbon formation locations.
According to another preferred exemplary embodiment, RPEs are locked in place due to pressure differential established across RSMs. For example, RPE (0502) is locked in the seat of RSM (0512) due to a positive pressure differential established across RSM (0512) i.e., pressure upstream (hydraulic fracturing stages 0520, 0521 and stages towards heel of the wellbore casing) is greater than pressure downstream (hydraulic fracturing stages 0522, 0523 and stages towards toe of the wellbore casing).
According a further preferred exemplary embodiment, RPEs (0501, 0502, 0503) may degrade over time, flowed back by pumping, or flowed into the wellbore, after completion of all stages in the wellbore, eliminating the need for additional milling operations.
According a further preferred exemplary embodiment the RPE's may change shape or strength such that they may pass through a RSM in either the production (heel end) or injection direction (toe end). For example RPE (0512) may degrade and change shape such it may pass through RSM (0511) in the production direction or RSM (0513) in the injection direction. The RPEs may also be degraded such that they are in between the RSMs of current stage and a previous stage restricting fluid communication towards the injection end (toe end) but enabling fluid flow in the production direction (heel end). For example, RPE (0502) may degrade such it is seated against the injection end (toe end) of RSM (0511) that may have flow channels. Flow channels in the RSM are further described below in
According to yet another preferred exemplary embodiment, inner diameters of RSMs (0511, 0512, 0513) may be the same and large enough to allow unrestricted fluid flow during well production operations. The RSMs (0511, 0512, 0513) may further degrade in well fluids to provide an even larger diameter comparable to the inner diameter of the well casing (0504) allowing enhanced fluid flow during well production. The degradation could be accelerated by acids in the hydraulic fracturing fluids.
It should be noted that some of the material and designs of the RPE described below may not be limited and should not be construed as a limitation. This basic RPE design and materials may be augmented with a variety of ancillary embodiments, including but not limited to:
As generally seen in the flow chart of
One preferred embodiment may be seen in more detail as generally illustrated in
The diameter of the RPE (0702) is chosen such that it is less than the outer diameter and greater than the inner diameter of RSM (0703). The CSS (0704) and RPE (0702) may be complementary shaped such that RPE (0702) seats against CSS (0704). For example, RPE (0702) may be cylindrically shaped and CSS (0704) may be beveled shaped to enable RPE (0702) to seat in CSS (0704) when a differential pressure is applied. The RPE (0702) may pressure lock against CSS (0704) when differential pressure is applied.
It should be noted that, if a CSS is not present in the RSM (0703) or not formed by the WST, the cylindrical RPE (0702) may directly seat against the edges of the RSM (0703).
Yet another preferred embodiment may be seen in more detail as generally illustrated in
One preferred embodiment may be seen in more detail as generally illustrated in
Yet another preferred embodiment may be seen in more detail as generally illustrated in
Similarly,
As generally seen in the aforementioned flow chart of
As described above in steps (0601), (0602), and (0603)
A further preferred embodiment may be seen in more detail as generally illustrated in
According to yet another preferred embodiment, the RSMs may be designed with fingers on either end to facilitate milling operation, if needed. Toe end fingers (3302) and heel end fingers (3304) may be designed on the toe end and heel end the RSM (3306) respectively. In the context of a milling operation, the toe end fingers may be pushed towards the heel end fingers of the next RSM (toe ward) such that the fingers are intertwined and interlocked. Subsequently, all the RSMs may be interlocked with each other finally eventually mill out in one operation as compared to the current method of milling each RSM separately.
As generally illustrated in
According to a preferred exemplary embodiment, a double set option is provided with a WST to seal one end of the RSM directly to the inner surface of the wellbore casing while the other end is sealed with a gripping element to prevent substantial axial and longitudinal movement.
As generally illustrated in
According to a preferred exemplary embodiment, the restricted sleeve member could still be configured with or without a CSS. The inner sleeve surface (ISS) of the RSM may be made of a polished bore receptacle (PBR). Instead of an independently pumped down RPE, however, a sealing device could be deployed on a wireline or as part of a tubular string. The sealing device could then seal with sealing elements within the restricted diameter of the internal sleeve surface (ISS), but not in the ICS surface. PBR surface within the ISS provides a distinct advantage of selectively sealing RSM at desired wellbore locations to perform treatment or re-treatment operations between the sealed locations, well production test, or test for casing integrity.
The RPEs of the present invention are designed for strength, rigidity and hardness sufficient to withstand the high pressure differentials required during well stimulation, which typically range from about 1,000 pounds per square inch (psi) to about 10,000 psi. According to certain embodiments, the RPE of the present invention is formed of a material or combination of materials having sufficient strength, rigidity and hardness at a temperature of from about 150° F. to about 350° F., from about 150° F. to about 220° F. or from about 150° F. to about 200° F. to seat in the RSM and then withstand deformation under the high pressure ranging from about 1,000 psi to about 10,000 psi associated with hydraulic fracturing processes. The materials selected for first composition deform enough to allow a second composition to exit through a passage when the second composition changes phase or loses strength upon exposure to wellbore temperature or fracturing fluids.
One class of useful materials for the first composition is elastomers. “Elastomer” as used herein is a generic term for substances emulating natural rubber in that they stretch under tension, have a high tensile strength, retract rapidly, and substantially recover their original dimensions. The term includes natural and man-made elastomers, and the elastomer may be a thermoplastic elastomer or a non-thermoplastic elastomer. The term includes blends (physical mixtures) of elastomers, as well as copolymers, terpolymers, and multi-polymers. Useful elastomers may also include one or more additives, fillers, plasticizers, and the like. Other materials may non-degradable group that includes G-10 (glass reinforced Epoxy Laminate), FR4, PEEK (Injection Molded), Nylon GF, Torlon, Steel, Aluminum, Stainless Steel, Nylon MF, Nylon GF, Magnesium Alloy (without HCL), Ceramic, Cast Iron, Thermoset Plastics, and Elastomers (rubber, nitrile, niton, silicone, etc.). The first composition may also include materials from a long term degradable group that includes PGA (polyglycolic acid) and Magnesium Alloy (with HCL).
According to a preferred exemplary embodiment, the second composition may change phase, when exposed to the wellbore temperature conditions, in a controlled fashion. The second composition may comprise a solid, a liquid, or a gas. The second composition may melt to change phase from solid to liquid, may change phase from solid to gas, or may vaporize to change phase from liquid to gas. The second composition may also be selected from materials that change a physical property such as strength or elasticity upon exposure to wellbore fluids or fracturing fluids. Table 2.0 as generally illustrated below, shows a yield temperature for individual alloy that change strength above the yield temperature. The alloys in Table 2.0 are a combination of weight percentages as shown in individual columns. The first composition may control the rate of phase change in the second composition. The second composition in the RPE may be tailored to the temperature profile of the wellbore conditions. The second composition may comprise a eutectic alloy, a metal, a non-metal, and combinations thereof. Eutectic alloys have two or more materials and have a eutectic composition. When a well-mixed, eutectic alloy melts (changes phase), it does so at a single, sharp temperature. The eutectic alloys may be selected from the list shown in Table 1.0. As generally shown in Table 1.0, the eutectic alloys may have a melting point (The temperature at which a solid changes state from solid to liquid at atmospheric pressure) range from 150° F. to 350° F. Eutectic or Non-Eutectic metals with designed melting points may be combinations of Bismuth, Lead, Tin, Cadmium, Thallium, Gallium, Antimony, also fusible alloys as shown below in Table 1.0 and Table 2.0.
Thermoplastics with low melting points such as Acrylic, Nylon, Polybenzimidazole, Polyethylene, Polypropylene, Polystyrene, Polyvinyl Chloride, Teflon may also function as a second composition material that change phase or change physical property such as strength or elasticity. These thermoplastics, when reinforced with glass or carbon fiber may initially create stronger materials that change physical property such as strength or elasticity upon exposure to temperatures in the wellbore or fracturing fluids.
Materials which transform from solid to gas (sublimation), or are solid only at high pressures and low temperatures may also be selected as shown below in Table 3.0. For example, balls of Dry Ice (Solid Carbon Dioxide) would need to be kept at temperature below the specified melting point prior to use as a second composition material.
A cross section of the present invention may be seen in more detail as generally illustrated in
According to another preferred exemplary embodiment, the second composition (4202) may change phase, strength, or elasticity when exposed to the wellbore temperature conditions, in a controlled fashion. The first composition (4201) may control the rate of phase, strength, or elasticity change in the second composition (4202). In one preferred exemplary embodiment, the first composition may be an insulator such as ceramic, elastomer or plastic that surrounds the second composition and slows the rate at which the second composition changes phase. In another preferred exemplary embodiment, the first composition may be a conductor such as steel, stainless steel, aluminum, and copper that accelerates the rate of phase, strength, or elasticity change. The selection of second composition may depend on the temperature profile of the well.
In some wells that may be under higher temperature conditions than others, a higher melting point eutectic alloy may be used as a second composition in the RPE. According to another preferred exemplary embodiment, the second composition (4202) in the RPE may be tailored to adapt to the temperature profile of the wellbore conditions. Furthermore, the RPEs comprising second composition (4202) with different melting point temperature materials may be used in higher or lower temperature fracturing stages of the wellbore accordingly. For example, an RPE comprising a second composition with a melting point greater than 150° F. may be used in fracturing stage that has a wellbore temperature of 150° F. Similarly, an RPE comprising a second composition with a melting point of greater than 250° F. may be used in fracturing stage that has a wellbore temperature of 250° F.
According to another preferred exemplary embodiment, the RPE is shaped as a sphere, a cylinder or a dart. The first composition (4201) is shaped in the form of a sphere surrounding a hollow spherical shaped second composition (4202). Likewise, the first composition (4201) may be shaped in the form of a cylinder surrounding a hollow cylindrical shaped second composition (4202). Similarly, the RPE may be shaped in the form of a dart. The dart may have a property (Phase, strength, elasticity) changeable first composition fins (7401) attached to a hollow/solid dart shaped second composition (7402). The hollow/solid dart shaped second composition (7402) may change phase, strength or elasticity, thereby deforming/collapsing the dart RPE.
According to yet another preferred exemplary embodiment, the RPE is shaped as a sphere, a cylinder or a dart. The first composition (4301) is shaped in the form of a sphere surrounding a solid core spherical shaped second composition (4302). Likewise, the first composition (4301) may be shaped in the form of a cylinder surrounding a solid core cylindrical shaped second composition (4302).
A cross section of the present invention may be seen in more detail as generally illustrated in
Alternately, the second composition may exit the RPE by stress or pressure as illustrated in
A cross section of the present invention may be seen in more detail as generally illustrated in
According to another preferred exemplary embodiment, the RPE is shaped as a sphere or a cylinder. The second composition (4702) is shaped in the form of a sphere surrounding a solid core spherical shaped first composition (4701). Likewise, the second composition (4702) may be shaped in the form of a cylinder surrounding a solid cylindrical shaped first composition (4701).
According to yet another preferred exemplary embodiment, the RPE is shaped as a sphere or a cylinder. The second composition (4801) is shaped in the form of a sphere surrounding a hollow spherical shaped first composition (4801). Likewise, the second composition (4802) may be shaped in the form of a cylinder surrounding a hollow cylindrical shaped first composition (4801).
Similarly, the RPE may be shaped in the form of a dart as shown in
As shown in
As generally illustrated in the cross section of
It should be noted that even though the RPE illustrated in
As generally illustrated in the cross section of
According to a presently preferred exemplary embodiment, upon exposure to temperatures in a wellbore higher than the phase/strength/elasticity change temperature, the second composition in the flow channel changes phase (melt/vaporize) or weakens in strength, thereby exiting the RPE and creating vacant flow channels in the RPE. The first composition (5001) may maintain its shape and structure while the second composition (5002) exits. After a fracturing treatment and exodus of the second composition (5002), the RPE may disengage from a restriction sleeve member and position itself between RSMs. The RPE may also stay engaged in the RSM. During production, the vacated flow channels may facilitate production fluids to flow in the production direction. Additionally, the flow channels in the RSM may be used in conjunction with the flow channels in the RPE to provide substantially unobstructed production flow. It should be noted that fluids may take any path that is least resistant in the flow channels during production and are not limited to a specific flow channel, axis, or alignment. For example, horizontal flow channel (5003) may be an ingress path and vertical flow channel (5004) may be an egress path for fluids to flow through. Similarly, horizontal flow channel (5003) may be used as both an ingress and egress for fluid flow. A perspective view of the RPE is illustrated in more detail in
As generally seen in the flow chart of
As generally illustrated in the cross section of
According to a preferred exemplary embodiment, the toroid mechanical insert may change phase (melt/vaporize) or loose strength or elasticity after a fracture treatment upon contact with wellbore formations or fluids pumped from the surface. The un-bonded mechanical linkage progressively weakens at well temperatures, allowing the ball to change shape in one or more coordinate directions, or to separate into multiple parts, whether or not the ball was in multiple parts before mechanically linked. The second composition may melt/vaporize and crumble the RPE into individual small segments like orange segments. The protrusions shown in
A perspective view of the restriction plug element with toroid mechanical insert is illustrated further in
As generally illustrated in the cross section of
A perspective view of the restriction plug element with a sliding piston is illustrated further in
As generally illustrated in
According to a presently preferred exemplary embodiment, upon exposure to temperatures in a wellbore higher than the phase/strength/elasticity change temperature, the second composition in the flow channel changes phase (melt/vaporize) or weakens in strength/elasticity, thereby exiting the RPE and creating vacant flow channels in the RPE. The first composition (6401) may maintain its shape and structure while the second composition (6402) exits. After a fracturing treatment and exodus of the second composition (6402), the RPE may disengage from a restriction sleeve member and position itself between RSMs. The RPE may also stay engaged in the RSM. During production, the vacated flow channels may facilitate production fluids to flow in the production direction. Additionally, the flow channels in the RSM may be used in conjunction with the flow channels in the RPE to provide substantially unobstructed production flow. It should be noted that fluids may take any path that is least resistant in the flow channels during production and are not limited to a specific flow channel, axis, or alignment.
Similarly, an exemplary embodiment ovoid RPE is illustrated in
According to an exemplary embodiment, the first composition and second composition may be reversed. For example, the internal flow channels may be filled with first composition surrounded by a second composition. In this case, the overall size of the RPE diminishes as the second compositions changes property (phase/strength/elasticity) enabling substantially larger fluid flow during production.
According to another exemplary embodiment, the flow channels may be exterior to the RPE. As generally illustrated in
According to a presently preferred exemplary embodiment, upon exposure to temperatures in a wellbore higher than the phase/strength/elasticity change temperature, the second composition in the flow channel changes phase (melt/vaporize) or weakens in strength, thereby exiting the RPE and creating vacant flow channels in the RPE. The first composition (6301) may maintain its shape and structure while the second composition (6302) exits.
Similarly, an exemplary embodiment ovoid RPE is illustrated in
According to an exemplary embodiment, the first composition and second composition may be reversed. For example, the internal flow channels may be filled with first composition surrounded by a second composition. In this case, the overall size of the RPE diminishes as the second compositions changes property (phase/strength/elasticity) enabling substantially larger fluid flow during production.
According to another exemplary embodiment, the flow channels may be banded in the RPE. As generally illustrated in
According to a presently preferred exemplary embodiment, upon exposure to temperatures in a wellbore higher than the phase/strength/elasticity change temperature, the second composition in the flow channel changes phase (melt/vaporize) or weakens in strength, thereby exiting the RPE and creating vacant flow channels in the RPE. The first composition (6501) may maintain its shape and structure while the second composition (6502) exits.
Similarly, an exemplary embodiment ovoid RPE is illustrated in
According to an exemplary embodiment, the first composition and second composition may be reversed. For example, the internal flow channels may be filled with first composition surrounded by a second composition. In this case, the overall size of the RPE diminishes as the second compositions changes property (phase/strength/elasticity) enabling substantially larger fluid flow during production.
A typical temperature profile in a wellbore is shown in the plot (7400). The plot shows a time (x-axis) (7401) plotted against a temperature (y-axis) (7402) in the wellbore. The temperature of the RSM may be at constant temperature (for example 150° F.) before fracturing treatment (7403) in a zone. The temperature may rise to 190° F. during fracturing operation (7404) and further increase to 250° F. after fracturing treatment (7405) and stay at the temperature during production (7406). The temperature profile may be used to select RPEs with a specific melting point, strength, or phase changing temperature.
An exemplary restrictive plug element with an integrated resistive heater may be generally illustrated in more detail in
One class of useful materials for the first composition is elastomers. “Elastomer” as used herein is a generic term for substances emulating natural rubber in that they stretch under tension, have a high tensile strength, retract rapidly, and substantially recover their original dimensions. The term includes natural and man-made elastomers, and the elastomer may be a thermoplastic elastomer or a non-thermoplastic elastomer. The term includes blends (physical mixtures) of elastomers, as well as copolymers, terpolymers, and multi-polymers. Useful elastomers may also include one or more additives, fillers, plasticizers, and the like. Other materials may non-degradable group that includes G-10 (glass reinforced Epoxy Laminate), FR4, PEEK (Injection Molded), Nylon GF, Torlon, Steel, Aluminum, Stainless Steel, Nylon MF, Nylon GF, Magnesium Alloy (without HCL), Ceramic, Cast Iron, Thermoset Plastics, and Elastomers (rubber, nitrile, niton, silicone, etc.). The first composition may also include materials from a long term degradable group that includes PGA (polyglycolic acid) and Magnesium Alloy (with HCL).
The resistive heating insert (7502) in the restriction plug element may comprise a voltage source (7504), a resistive heating element (7505), a pressure switch (7503) and a sealed cap (7514). The resistance heating element (7505) may be wire or ribbon, straight or coiled. The resistive heating element (7505) material may be selected from a common classes of materials that include: Kanthal (FeCrAl) wires, Nichrome 80/20 and Cupronickel (CuNi) alloys for low temperature heating and combinations thereof. The resistive heating element (7505) may also be supported by ceramic insulators. Electric heating is any process in which electrical energy is converted to heat. The resistive heating element inside works on the principle of Joule heating wherein an electric current passing through a resistor will convert that electrical energy into heat energy. The material of the resistance heating element (7505) may be selected such that the rate of degradation of the first composition material (7501) is controlled. For example, material of the resistance element (7505) may be cupronickel alloy that has a low trigger for heating. The length of the resistance element material (7505) may also be selected to control the rate of degradation of the first composition material (7501).
The resistive heating insert is designed to withstand the temperatures during fracturing process, but trigger the heating process during the subsequent exposure to wellbore fluids. The trigger conditions for the resistance heating element (7505) may be temperatures expected in the wellbore or a pressure condition as detected by a pressure switch (7503). The pressure switch (7503) may activate a voltage source (7504) that in turn enables the flow of current inside the resistive heating element (7505). A pressure activating device such as a reverse acting rupture disk may be part of the pressure switch. The pressure switch may be activated when the pressure in the wellbore exceeds a rated pressure of the pressure activating device. After a ball is seated in a restriction sleeve member, the fracturing pressure may be ramped up to exceed the rated pressure of the pressure activating device. The rated pressure may be in between a treatment pressure and a breakdown pressure. When the pressure switch (7503) is activated it may enable a connection of a through wire to an arming terminal in the voltage source (7504) completing the circuit for the voltage source. In one preferred exemplary embodiment, the voltage source is a battery. A sealed cap (7514) may seal the exposed end of the resistive heating insert (7502) to physically protect the resistive heating insert (7502) from undesired wellbore conditions.
The first composition further may comprise a plurality of parts. Alternatively, the first composition is a solitary integral part. The heating insert may further provide structural integrity to the restriction plug element. When the resistive heating insert generates heat, the first composition may collapse and the restriction plug element may break into smaller parts. The restriction plug element may have a shape that is selected from a group comprising: sphere, cylinder, or ovoid. When the resistive heating insert generates heat, the restriction plug element may deform to enable the restriction plug element to pass through a restriction sleeve member in the wellbore casing. Alternatively, when the resistive heating insert generates heat, the restriction plug element may reduce size to enable it to pass through a restriction sleeve member in the wellbore casing. The first composition may be selected from a group comprising plastics, non-degradable or long term degradable.
According to a preferred exemplary embodiment, the restriction plug element with the integrated resistive heating insert may further be surrounded by an insulating coating. The insulating coating (7608) may surround the first composition to further control the rate of degradation of the first composition (7501). In one preferred exemplary embodiment, the insulator may be a ceramic, elastomer or plastic that surrounds the first composition and slows the rate at which the first composition changes phase, strength or elasticity.
According to another preferred exemplary embodiment, the restriction plug element with the integrated resistive heating insert may be used in conjunction with a restriction sleeve member, such that when in production the restriction plug element degrades or deforms and passes through the restriction sleeve member or a plurality of restriction sleeve members.
An exemplary restrictive plug element with an integrated chemical heater may be generally illustrated in more detail in
The pressure mixing chamber (7705) may be activated by a pressure event in the wellbore such as a perforation or fracturing. The pressure event may enable the first chemical composition (7703) and the second chemical composition (7704) to mix and react in the pressure mixing chamber (7705). A pressure activating device such as a reverse acting rupture disk may be part of the pressure switch. The pressure switch may be activated when the pressure in the wellbore exceeds a rated pressure of the pressure activating device. After a ball is seated in a restriction sleeve member, the fracturing pressure may be ramped up to exceed the rated pressure of the pressure activating device. The rated pressure may be in between a treatment pressure and a breakdown pressure. The chemical reaction may be an exothermic reaction that gives off heat. The energy needed to initiate the chemical reaction is less than the energy that is subsequently released by the chemical reaction.
The rate of the chemical reaction may be accelerated or retarded based on factors such as nature of the reactants, particle size of the reactants, concentration of the reactants, pressure of gaseous reactants, temperature and catalysts. According to a preferred exemplary embodiment, a catalyst may be added to the pressure mixing chamber to alter the rate of the reaction. The first composition chemical may be selected from a group comprising: mixture of aluminum, copper sulfate, potassium chlorate, and calcium sulfate, magnesium, magnesium-iron alloy, particulate oxide of an alkali or alkaline earth metal and a solid, particulate acid or strongly acid salt, or mixtures thereof. Similarly, the second composition chemical may be selected from a group comprising: NaCl, acetic acid, and water. The catalyst may be selected from a group comprising salts.
Exothermic compositions have been provided which are comprised of a particulate oxide of an alkali or alkaline earth metal and a solid, particulate acid or strongly acid salt, or mixtures thereof. The proportion of the alkaline and acidic reactants is selected so that at least an amount of the alkaline oxide reactant is present in the composition which, when converted to the corresponding hydroxide, will neutralize the acidic reactant. Advantageously, an excess of the oxide is employed in order to obtain higher temperature.
The exothermic reactants for the first composition may also be selected from a group comprising: quicklime, sodium hydroxide, cobalt, chromium, iron, iron hydroxide, magnesium, manganese, molybdenum, tin oxide (II), titanium, sodium, calcium hydroxide, sulfuric acid, nitric acid, metallic sodium, etc. Among them, a powder of magnesium chloride is preferable. The reactants are those generating an oxide reacting with oxygen at room temperature in the form of a revived metal having an exothermic characteristic. It is preferable to mix two or more metal powders. The reaction of magnesium chloride with water, avoids the use of either a strong acid or base.
A sealed cap (7714) may seal the exposed end of the chemical heating insert (7702) to physically protect the chemical heating insert (7702) from undesired wellbore conditions.
According to a preferred exemplary embodiment, the restriction plug element with the integrated chemical heating insert may further be surrounded by an insulating coating layer. As illustrated in
According to another preferred exemplary embodiment, the restriction plug element with the integrated chemical heating insert may be used in conjunction with a restriction sleeve member, such that when in production the restriction plug element degrades or deforms and passes through the restriction sleeve member or a plurality of restriction sleeve members.
The first composition further may comprise a plurality of parts. Alternatively, the first composition is a solitary integral part. The heating insert may further provide structural integrity to the restriction plug element. When the chemical heating insert generates heat, the first composition may collapse and the restriction plug element may break into smaller parts. The restriction plug element may be have a shape that is selected from a group comprising: sphere, cylinder, or ovoid. When the chemical heating insert generates heat, the restriction plug element may deforms to enable the restriction plug element to pass through a restriction sleeve member in the wellbore casing. Alternatively, when the chemical heating insert generates heat, the restriction plug element reduces size to enable it to pass through a restriction sleeve member in the wellbore casing. The first composition may be selected from a group comprising plastics, non-degradable or long term degradable.
An exemplary restrictive plug element with an integrated chemical heater may be generally illustrated in more detail in
The cartridge insert (7902) is designed to withstand the temperatures during fracturing process, but trigger a heating process during the subsequent exposure to wellbore fluids. The trigger condition for the circuit board (7512) may be a pressure condition as detected by a pressure switch (7904). The pressure switch (7904) may activate a timer in the circuit board (7906) that enables a circuit to activate an energetic device (7903). The timer could be programmed prior to deploying the RPE into the wellbore casing. The energetic device (7903) may be an ignitor. A pressure activating device such as a reverse acting rupture disk may be part of the pressure switch (7904). The pressure switch (7904) may be activated when the pressure in the wellbore exceeds a rated pressure of the pressure activating device. After a ball is seated in a restriction sleeve member, the fracturing pressure may be ramped up to exceed the rated pressure of the pressure activating device. The rated pressure may be in between a treatment pressure and a breakdown pressure.
According to a preferred exemplary embodiment, an energetic device may initiate combustion of a combustible material that generates heat such that the first composition changes a physical property to deform or collapse the restriction plug element. The combustible material may be selected from a group comprising thermite, solid rocket propellant.
A sealed cap (7914) may seal the exposed end of the cartridge insert (7902) to physically protect the chemical heating insert (7902) from undesired wellbore conditions.
According to a preferred exemplary embodiment, the restriction plug element with the integrated cartridge insert may further be surrounded by an insulating coating layer. The insulating coating layer (8015) may surround the first composition to further control the rate of degradation of the first composition (7901). In one preferred exemplary embodiment, the insulator may be a ceramic, elastomer or plastic that surrounds the first composition and slows the rate at which the first composition changes phase, strength or elasticity.
According to another preferred exemplary embodiment, the restriction plug element with the integrated cartridge heating insert may be used in conjunction with a restriction sleeve member, such that when in production the restriction plug element degrades or deforms and passes through the restriction sleeve member or a plurality of restriction sleeve members.
The first composition further may comprise a plurality of parts. Alternatively, the first composition is a solitary integral part. The cartridge insert may further provide structural integrity to the restriction plug element. When the heating insert generates heat, the first composition may collapse and the restriction plug element may break into smaller parts. The restriction plug element may have a shape that is selected from a group comprising: sphere, cylinder, or ovoid. When the cartridge insert generates heat, the restriction plug element may deform to enable the restriction plug element to pass through a restriction sleeve member in the wellbore casing. Alternatively, when the cartridge insert generates heat, the restriction plug element reduces size to enable it to pass through a restriction sleeve member in the wellbore casing. The first composition may be selected from a group comprising plastics, non-degradable or long term degradable.
The present invention system anticipates a wide variety of variations in the basic theme of extracting gas utilizing wellbore casings, but can be generalized as a wellbore isolation plug system comprising:
This general system summary may be augmented by the various elements described herein to produce a wide variety of invention embodiments consistent with this overall design description.
The present invention method anticipates a wide variety of variations in the basic theme of implementation, but can be generalized as a wellbore plug isolation method wherein the method is performed on a wellbore plug isolation system comprising:
This general method summary may be augmented by the various elements described herein to produce a wide variety of invention embodiments consistent with this overall design description.
The present invention anticipates a wide variety of variations in the basic theme of oil and gas extraction. The examples presented previously do not represent the entire scope of possible usages. They are meant to cite a few of the almost limitless possibilities.
This basic system and method may be augmented with a variety of ancillary embodiments, including but not limited to:
One skilled in the art will recognize that other embodiments are possible based on combinations of elements taught within the above invention description.
The present invention system anticipates a wide variety of variations in the basic theme of extracting gas utilizing wellbore casings, but can be generalized a restriction plug element (RPE) for use in a wellbore casing comprising a first composition and a heating insert wherein the heating insert is configured with heating source; the heating source is configured to generate heat; and when the heating source generates the heat, the first composition changes physical property such that the restriction plug element changes shape to enable substantially unrestricted fluid flow fluid flow in the wellbore casing during production.
This general system summary may be augmented by the various elements described herein to produce a wide variety of invention embodiments consistent with this overall design description.
The present invention system anticipates a wide variety of variations in the basic theme of extracting gas utilizing wellbore casings, but can be generalized as a restriction plug element in a wellbore isolation plug system comprising:
This general system summary may be augmented by the various elements described herein to produce a wide variety of invention embodiments consistent with this overall design description.
The present invention method anticipates a wide variety of variations in the basic theme of implementation, but can be generalized as a wellbore plug isolation method wherein the method is performed on a wellbore plug isolation system with a restriction plug element comprises a first composition and a heating insert wherein the first composition is non-dissolvable at temperatures expected in the wellbore casing; the heating insert is configured with heating source; the heating source is configured to generate heat; and when the heating source generates the heat, the first composition changes physical property such that the restriction plug element changes shape to enable substantially unrestricted fluid flow fluid flow in the wellbore casing during production;
This general method summary may be augmented by the various elements described herein to produce a wide variety of invention embodiments consistent with this overall design description.
The present invention anticipates a wide variety of variations in the basic theme of oil and gas extraction. The examples presented previously do not represent the entire scope of possible usages. They are meant to cite a few of the almost limitless possibilities. This basic system and method may be augmented with a variety of ancillary embodiments, including but not limited to:
A wellbore plug isolation system and method for positioning plugs to isolate fracture zones in a horizontal, vertical, or deviated wellbore has been disclosed. The system/method includes a wellbore casing laterally drilled into a hydrocarbon formation, a wellbore setting tool (WST) that sets a large inner diameter (ID) restriction sleeve member (RSM), and a restriction plug element (RPE). The RPE includes a first composition and a second composition that changes phase or strength under wellbore conditions. After a stage is perforated, RPEs are deployed to isolate toe ward pressure communication. The second composition changes phase to create flow channels in the RPE during production. In an alternate system/method, the second composition changes phase or strength thereby deforming the RPE to reduce size and pass through the RSM's. The RPEs are removed or left behind prior to initiating well production without the need for a milling procedure.
Although a preferred embodiment of the present invention has been illustrated in the accompanying drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications, and substitutions without departing from the spirit of the invention as set forth and defined by the following claims.
This application is a continuation in part application of, and claims priority to, U.S. continuation in part patent application Ser. No. 14/721,784, entitled WELLBORE PLUG ISOLATION SYSTEM AND METHOD, filed May 26, 2015, and claims benefit of U.S. provisional patent Application No. 62/081,399, entitled WELLBORE PLUG ISOLATION SYSTEM AND METHOD, filed Nov. 18, 2014, and is a continuation in part application of, and claims priority to, U.S. nonprovisional patent application Ser. No. 14/459,042, entitled WELLBORE PLUG ISOLATION SYSTEM AND METHOD, filed Aug. 13, 2014, which are all hereby incorporated by reference in their entirety as examples.
| Number | Date | Country | |
|---|---|---|---|
| 62081399 | Nov 2014 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14459042 | Aug 2014 | US |
| Child | 14732391 | US |
