Hybrid photonic-pulsed fracturing tool and related methods
11255172 · 2022-02-22
Assignee
Inventors
- Sameeh Issa Batarseh (Dhahran, SA)
- Wisam Jamal Assiri (Dhahran, SA)
- Abdullah M. Al-Harith (Dhahran, SA)
Cpc classification
E21B27/02
FIXED CONSTRUCTIONS
E21B43/2405
FIXED CONSTRUCTIONS
E21B37/00
FIXED CONSTRUCTIONS
International classification
E21B27/02
FIXED CONSTRUCTIONS
Abstract
This application relates to systems and methods for stimulating hydrocarbon bearing formations using a hybrid downhole tool that uses a high power laser and chemicals.
Claims
1. A hybrid tool for stimulating a hydrocarbon-bearing formation, the tool comprising: an elongate tool body comprising a plurality of evenly spaced and insulated chemical compartments along a length of the tool, the chemical compartments comprising: storage means for storing at least one chemical for reaction and delivery to a wellbore of the formation; and delivery means for delivering a product of the chemical reaction to the wellbore, where the product of the chemical reaction comprises a mix of two or more chemicals; and a laser head coupled to a distal end of the tool body and configured to operate within the wellbore, the laser head comprising: one or more optical transmission media, the one or more optical transmission media being part of an optical path originating at a laser generating unit configured to generate a raw laser beam, the one or more optical transmission media configured for passing the raw laser beam; and an optical assembly coupled to the optical transmission media and configured to shape a laser beam for output.
2. The tool of claim 1, where the storage means of the chemical compartments comprise: two receptacles configured for storing two or more chemicals for mixing; a piston configured for advancing within the two receptacles to eject the chemicals from the two receptacles to the mixing compartment; and a one-way valve disposed on a distal end of each of the two receptacles configured for passing the chemicals to the mixing compartment.
3. The tool of claim 1, where the delivery means comprises one or more relief valves disposed in a wall of each of the chemical compartments, where the one or more relief valves are pre-set at certain pressures such that the one or more relief valves act like rupture disks to allow the pressurized gas to be released into the formation.
4. The tool of claim 1, where the chemical compartments further comprise a rotational assembly to orient the chemical compartments and delivery means towards a desired target, and where the chemical compartments comprise a centralizer to center and lock the tool at the desired target location to ensure accurate operation and orientation.
5. The tool of claim 3, where the chemical compartments further comprise heating means for triggering a reaction of the one or more chemicals stored therein, where the one or more relief valves are pre-set to relieve at about 200 psi, and where the chemical reaction generates a pressure of about 4000 psi.
6. The tool of claim 1, where the laser head further comprises a housing that contains at least a portion of the optical assembly, the housing being configured for movement within the wellbore to direct the laser beam relative to the wellbore.
7. The tool of claim 1, where the laser head further comprises a plurality of orientation nozzles disposed about an outer circumference of the laser head, the plurality of nozzles configured to provide thrust to the laser head to control motion and orientation of the tool within the wellbore.
8. The tool of claim 7, where the plurality of orientation nozzles are movably coupled to the laser head to allow the orientation nozzles to rotate or pivot relative to the laser head to provide forward motion, reverse motion, rotational motion, or combinations thereof to at least the laser head.
9. The tool of claim 1, where the laser head further comprises a purging assembly disposed at least partially within or adjacent to the laser head and configured for delivering a purging fluid to an area proximate the output laser beam, the purging assembly comprising purge nozzles.
10. The tool of claim 9, where at least a portion of the purge nozzles are vacuum nozzles connected to a vacuum source and configured to remove debris and gaseous fluids from the area proximate the output laser beam.
11. The tool of claim 1, further comprising at least one centralizer coupled to the tool and configured to hold the tool in place relative to an outer casing in the wellbore.
12. The tool of claim 1, where the tool comprises an articulated arm disposed between the laser head and the laser generating unit.
13. The tool of claim 12, where the articulated arm comprises a snake robot having locomotion means for maneuvering the tool within the wellbore.
14. The tool of claim 13, where the locomotion means comprises at least one of an electrical motor or a hydraulic actuator.
15. The tool of claim 1 further comprising a control system configured to control at least one of a movement or an operation of the tool.
16. The tool of claim 1 further comprising at least one rotational assembly configured for rotating at least one of the laser head or the chemical compartment relative to a central axis of the tool body.
17. The tool of claim 1 further comprising: a plurality of chemical compartments; and a plurality of rotational systems, where the chemical compartments are separated by the rotational systems so that each chemical compartment can rotate independently.
18. The tool of claim 1 further comprising: one or more acoustic cameras located around a circumference of the laser head; where the one or more acoustic cameras visualize the laser head and the surrounding area, where the one or more acoustic cameras characterize the formation based on a visualization of the laser head and surrounding area, where data captured from the acoustics comprise velocities of the sound waves that travel through, and are reflected within, the formation, and where the velocities of the sound waves are used to calculate the mechanical properties of the formation, predict the formation stability, evaluate tool performance, and support tool orientation and troubleshooting.
19. The tool of claim 18, where the one or more acoustic cameras provide information while drilling and guide the tool by measuring the densities of the formation; and where the one or more acoustic cameras are used to generate tomographic images.
20. The tool of claim 18, where the tool is programmed to navigate and drill in specified rock densities, where acoustic sensing data and the sound waves are used as a monitoring tool to steer a snake robot.
21. A system for stimulating a hydrocarbon-bearing formation, the system comprising: one or more hybrid tools for deployment within a wellbore of the formation, the one or more hybrid tools comprising: an elongate tool body comprising a plurality of evenly spaced and insulated chemical compartments along a length of the one or more hybrid tools, the chemical compartments comprising: two receptacles for storing at least one chemical for use in a chemical reaction; and one or more relief valves disposed in a wall of the chemical compartment for controlling the delivery of a product of the chemical reaction to the wellbore, where the product of the chemical reaction comprises a mix of two or more chemicals; and a laser head coupled to a distal end of the elongate tool body and configured to operate within the wellbore.
22. The system of claim 21, where the laser head comprises: one or more optical transmission media, the one or more optical transmission media being part of an optical path originating at a laser generating unit configured to generate a raw laser beam, the one or more optical transmission media configured for passing the raw laser beam; and an optical assembly coupled to the one or more optical transmission media and configured to shape the raw laser beam for output.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the disclosed systems and methods and are not intended as limiting. For purposes of clarity, not every component may be labeled in every drawing. In the following description, various embodiments are described with reference to the following drawings, in which:
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DETAILED DESCRIPTION
(15) This application is directed to a tool and related systems and methods to establish communications between a wellbore and a hydrocarbon bearing formation to improve production and increase a recovery factor in both conventional and unconventional reservoirs. The disclosed technology provides non-damaging alternative means for several downhole stimulations and applications, including drilling, notching, and fracture initiation. Generally, the laser tool is combined with chemical compartments disposed in a body of the tool that can discharge chemicals that are energized when mixed or triggered to deliver pressure and temperature energy to the formation. This energy can be used in different patterns and architectures to establish communication between a tight formation and the wellbore for production of hydrocarbons.
(16)
ΔH=H.sub.products−H.sub.reactants(where H=Heat).
(17) Many exothermic reactions produce gases among the products of the reaction. These kinds of reactions can do work on their surroundings, because of the pressure from the release of the gas, as shown in equation 2:
w=−PΔV(where w=work,P=pressure, and V=volume)
(18) In addition, the pressure of released gas and volume can be calculated using the ideal gas law: PV=nRT, as known to those of skill in the art.
(19) Accordingly, based on the foregoing information, a chemical reaction can be used to generate energy that can be used to create fractures in a formation, and the pressure and temperature of reaction can be estimated.
(20) The following are examples of chemical reactions that produce a gas by mixing the chemicals together. The reaction of sodium nitrite (NaNO.sub.2) and sulfamic acid (HSO.sub.3NH.sub.2) will produce nitrogen gas (along with sodium bisulfate and water) as shown in the following reaction:
NaNO.sub.2+HSO.sub.3NH.sub.2N.sub.2+NaHSO.sub.4+H.sub.2O.
(21) A reaction between sodium bicarbonate (NaHCO.sub.3) and acetic acid (HC.sub.2H.sub.3O.sub.2) will produce carbon dioxide gas (along with sodium acetate and water) as shown in the following reaction:
NaHCO.sub.3+HC.sub.2H.sub.3O.sub.2.fwdarw.NaC.sub.2H.sub.3O.sub.2+H.sub.2O+CO.sub.2.
(22) Some chemicals require heat to start the reaction, for example, the decomposition of ammonium nitrite (NH.sub.4NO.sub.2). This reaction will take place very slowly at room temperature; however the reaction will occur extremely fast if triggered at a temperature of about 60-70° C., producing a very high amount of nitrogen gas as shown in the following reaction:
NH.sub.4NO.sub.2=>N.sub.2+H.sub.2O.
(23) Another example is the decomposition of sodium azide (NaN.sub.3), which requires a temperature of about 300° C. to start the reaction as shown in the following reaction:
2NaN.sub.3=2Na+3N.sub.2.
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(25) With reference to
(26) Generally, the laser head 104 (904 in
(27) The optical assembly 105, 905 includes the various optical components, such as lenses, prisms, and a collimator as necessary to shape and size a desired output beam 109, 909. In some embodiments, the cover lens also protects the optical assembly 105, for example, by preventing dust and vapor from entering the laser head 104. The various optical components previously described can be any material, for example, glass, plastic, quartz, crystal or other material capable of withstanding the environmental conditions to which they are subjected. The shapes and curvatures of any lenses can be determined by one of skill in the art based on the application of downhole laser systems.
(28) In some embodiments, in addition to the fiber optics for beam delivery 110, the cable 546 also includes another low power fiber optic cable 112 for heating. The power of this cable 112 can be less than 5 kW. The cable 112 has two functions: temperature and pressure measurements and logging; and to generate heat for a chemical reaction. The specific placement of the cable 112 on the tool 100 can vary to suit a particular application. In some embodiments, the cable 112 is disposed on an outer surface of the chemical compartments 106 to provide heat directly to the compartments 106.
(29) The tool 100 depicted in
(30) Additionally, not just the fiber optic cables, but the main cable 546, or at least a portion thereof, can be disposed or embedded within the robotic arm 101. The tool 100 or a portion thereof, such as the laser head 104, can also include one or more low power fiber optics sensors for temperature and pressure logging, and one or more acoustic cameras (903 in
(31) Generally, the acoustic sensing 903 can provide information while drilling and guide the tool (similar to geo-steering) by measuring the densities of the formation. By knowing the density, the formation and structure will also be known. The integrated acoustics provide high definition reservoir characterization and mapping. For example, while the tool 100 is penetrating the formation, the tool will send live data to the surface to an operator, the operator can teach the tool 100 to stick to specific density ranges and not penetrate other ranges, for example, sandstone densities range between 2.2 to 2.6 grams per cubic centimeter (g/cc), so the tool will follow and penetrate only in sandstone and at the same time provide mapping of the sandstone structure. The acoustics also provide vision via the acoustic camera(s). These features enable the tool 100 to target hydrocarbon zones only. Also, the information provided via the acoustics can be used to calculate the mechanical properties of the formation and generate tomographic images. Machine learning can also be utilized to “teach” the tool how to self-navigate the formation via the information provided by the acoustics and fiber optic sensors 913.
(32) The tool 100 can be programmed to navigate and drill in specified rock densities, with the acoustic sensing and the sound waves used as a monitoring tool to steer the snake robot. More specifically, the tool 100 will send and receive sound waves, and from the velocity differences, the tool can be directed to the target formation or identify particular subsurface structures, because the data is sent directly to the surface to control the snake robot, or the snake robot can be preprogrammed to analyze the velocity and steer based on these sound waves. Further details of the disclosed snake robotics and acoustic sensing are depicted in
(33) Furthermore, the tool 100 can also include a plurality of orientation nozzles 111, 911 and a purging system 107, 907. The tool 100, 900 also includes centralizers or packers 114, 914 to centralize the tool 100, 900 and isolate a zone if needed to perform a specific task in that zone upon reaching a target. The centralizers 114, 914 can be disposed at various points along the tool 100, 900 as need to suit a particular application. The centralizers 114, 914 support the weight of the tool body and can be spaced along the tool 100, 900 as needed to accommodate the tool 100, 900 extending deeper into the formation. The centralizers 114, 914 can be metal, polymer, or any other suitable material. One of ordinary skill in the art will be familiar with suitable materials. In some embodiments, the centralizer 114, 914 can include a spring or a damper, or both. In some embodiments, the centralizer includes a solid piece of a deformable material, for example, a polymer or a swellable packer. In some embodiments, the centralizer is or includes a hydraulic or pneumatic device, such as a bladder.
(34) One of the features of the tool 100 is its precise control over the motion and location of the laser head 104 within the wellbore. The tool 100 can also be positioned and oriented via the snake robot. Also provided are means for sensing the orientation and location of the tool 100 within the wellbore, such means including the various sensors and imaging as known to those of skill in the art.
(35) In the embodiment shown, the orientation means 111, 911 include a plurality of nozzles disposed about the outer circumference of the laser head 104, 904. The nozzles may be coupled to the laser head 104, 904 housing via known mechanical means as either fixed (for example, via fasters or bonding) or movable (for example, via a ball joint or servo motors). Typically, the nozzles will be movably coupled to the laser head 104, 904 and controlled via a control system to provide forward, reverse, or rotational motion to the laser head 104, 904, and by extension the tool 100, 900.
(36) Generally, the tool 100/head 104 is oriented by controlling a flow of a fluid (either liquid or gas) through the nozzles. For example, by directing the flow of the fluid in a rearward direction (opposite the direction of the output laser beam 109), the tool 100 will be pushed forward in the wellbore by utilizing thrust action, where the opening of the nozzles are facing the opposite directions of the tool head 104 and the fluid flows backward providing the thrust force moving the tool 100 forward. Controlling the flow rate will control the speed of the tool 100 within the wellbore. The fluid for providing the thrust can be supplied from the surface and delivered by a fluid line included within the cable 546.
(37) In some embodiments, there are four (4) nozzles evenly spaced around the laser head 104 and each nozzle can be separately controlled. For example, if only one nozzle on, then the tool 100 will turn in a direction opposite of the nozzle. The turn degree depends on the controlled flow rate from that nozzle. If all of the nozzles are evenly turned on, then the tool will move linearly forward or in reverse depending on the position of the nozzles. See, for example,
(38) As previously mentioned, the nozzles can be movably mounted to the laser head 104, for example, via servo motors with swivel joints that can control whether the nozzles ends face rearward (forward motion), forward (reverse motion), or at an angle to a central axis 148 (948 in
(39) Referring back to
(40) The chemical compartments 106, 206 are described in greater detail in
(41) Each compartment 206 can also include a centralizer(s) 214 to center and lock the tool at a desired target location to ensure accurate operation and orientation. A piston 228 is included to push the chemicals in the storage region 216. As shown in
(42) The end of the compartment 206 includes an additional rotational head 231 to assist with the rotation of the compartment, so that they both rotate in the same direction. This end rotational head 231 can be equipped with a reinforced plug 226 to prevent the energy from leaking or otherwise exiting the tool 200 in an unwanted direction or damage the tool. This compartment 206 is designed to have chemicals mix to trigger the reaction, in other embodiments, the chemicals are triggered by heat, where a fiber optic heating cable 212 is used to generate heat to trigger the reaction; however, other heat sources can be used, such as microwave or filament. The other fiber optic cable 210 shown is the main fiber optics to deliver the raw beam to the laser head.
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(44) Typically, the chemicals are loaded into the tool at the surface, with the tool then lowered and stabilized in the wellbore at the desired target zone or zones. In some embodiments, the tool may include the necessary plumbing to introduce the chemicals into the tool after it has been positioned; for example, where multiple, repetitive reactions are desired.
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(48) Besides the ability of the compartment 206 to orient and rotate, the external ports 221 of the relief valves 208 can be oriented up to 360 degrees for more specific targeting, for example, usually in a heterogeneous reservoir and applications where more energy and more than one valve are needed. Specifically, the external ports 221 can be oriented at the same target to provide maximum energy, for example in the case of a very strong formation, where the energy required may be very great and one valve might not be sufficient to release enough energy. As shown in
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(54) A flow 749 toward a well can be expressed in Darcy's law:
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(where, q is flow rate, c is conversion factor, k is permeability, h is the height of production zone, μ is viscosity, B.sub.o is the formation volume factor, P.sub.r is reservoir pressure, P.sub.wf is the wellbore flowing pressure, r.sub.e is the reservoir extend. and r.sub.eff is the effective wellbore radius).
(56) The effective wellbore radius is the radius of the well that can be recalculated from testing the flow of the well. It will be equal to the actual radius if the well is not damaged or enhanced around the wellbore. If there is damage, it will be smaller than the actual radius and larger if there is enhancement. In the case here of hydraulic fracture, the effective wellbore radius can be calculated as:
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(where, r.sub.weff is the effective wellbore radius and x.sub.F is the fracture half length).
(58) Keeping in mind that conventional hydraulic fractures create damage around the created fracture, as long as the effective radius is significantly higher than the actual radius, the process is still considered a success. Using the tool, systems, and methods disclosed herein, creating a radial fracture of half of x.sub.F should mathematically give similar results to that of a hydraulic fracture, but without the need of a large amount of water, proppants, and horsepower. From a practical point of view, creating the micro fractures and enhancements due to this non-damaging technology, smaller radii may result in similar effective radii.
(59) In some embodiments of the methods disclosed herein, the drilling can be carried out by either using a high power laser tool or conventional drilling and completions tools. The laser tool is equipped with high power fiber optics and beam delivery means to drill, as previously described. If conventional drilling is used and the tool is used for fracturing, then the tool can be used without the high power laser capability. In both cases, the tool can store and carry chemicals in specially designed insulated compartments. When the tool is used to drill, the tool can penetrate the formation at any orientation regardless of the strength of the formation and have the capability to deliver high power laser energy to create holes or tunnels.
(60) In general, the construction materials of the downhole hybrid tool and related systems can be of any types of materials that are resistant to the high temperatures, pressures, and vibrations that may be experienced within an existing wellbore, and that can protect the system from fluids, dust, and debris. One of ordinary skill in the art will be familiar with suitable materials.
(61) The laser generating unit can excite energy to a level greater than a sublimation point of the hydrocarbon bearing formation, which is output as the raw laser beam. The excitation energy of the laser beam required to sublimate the hydrocarbon bearing formation can be determined by one of skill in the art. In some embodiments, the laser generating unit can be tuned to excite energy to different levels as required for different hydrocarbon bearing formations. The hydrocarbon bearing formation can include limestone, shale, sandstone, or other rock types common in hydrocarbon bearing formations. The discharged laser beam can penetrate a wellbore casing, cement, and hydrocarbon bearing formation to form, for example, holes or tunnels.
(62) The laser generating unit can be any type of laser unit capable of generating high power laser beams, which can be conducted through a fiber optic cable, such as, for example, lasers of ytterbium, erbium, neodymium, dysprosium, praseodymium, and thulium ions. In some embodiments, the laser generating unit includes, for example, a 5.34-kW Ytterbium-doped multi-clad fiber laser. In some embodiments, the laser generating unit can be any type of laser capable of delivering a laser beam at a minimum loss. The wavelength of the laser generating unit can be determined by one of skill in the art as necessary to penetrate hydrocarbon bearing formations.
(63) The hybrid tool can also include a motion system that lowers the tool to a desired elevation within the wellbore. In various embodiments, the motion system can be in electrical or optical communication with the laser generating unit; such that the motion system can relay its elevation within the wellbore to the laser generating unit and can receive an elevation target from the laser generating unit. The motion system can move the tool up or down to a desired elevation and can include, for example, a hydraulic system, an electrical system, or a motor operated system to drive the tool into a desired location. In some embodiments, controls for the motion system are included as part of the laser generating unit. In some embodiments, the laser generating unit can be programmed to control placement of the tool based only on a specified elevation target and a position target. In some embodiments, the tool can receive an elevation target from the laser generating unit and move to the elevation target.
(64) At least parts of the tools, systems, methods and their various modifications may be controlled, at least in part, by a computer program product, such as a computer program tangibly embodied in one or more information carriers, such as in one or more tangible machine-readable storage media, for execution by, or to control the operation of, data processing apparatus, for example, a programmable processor, a computer, or multiple computers, as would be familiar to one of ordinary skill in the art.
(65) It is contemplated that systems, devices, methods, and processes of the present application encompass variations and adaptations developed using information from the embodiments described in the following description. Adaptation or modification of the methods and processes described in this specification may be performed by those of ordinary skill in the relevant art.
(66) Throughout the description, where compositions, compounds, or products are described as having, including, or comprising specific components, or where processes and methods are described as having, including, or comprising specific steps, it is contemplated that, additionally, there are articles, devices, and systems of the present application that consist essentially of, or consist of, the recited components, and that there are processes and methods according to the present application that consist essentially of, or consist of, the recited processing steps.
(67) It should be understood that the order of steps or order for performing certain action is immaterial so long as the described method remains operable. Moreover, two or more steps or actions may be conducted simultaneously.