An experimental system for multifunctional reservoir dynamic stimulation

Abstract

This invention discloses a multifunctional experimental system for reservoir dynamic stimulation, comprising a pulse generator, a booster, a triaxial clamp, a simulated casing fracturing device, a pressure fluctuation pipeline, a core clamp, a manual pump, a pressure replenishment pump, a conversion interface, a check valve, a first valve, a second valve, a third valve, a fourth valve, a fifth valve, a sixth valve, a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor, a fifth pressure sensor, a sixth pressure sensor, and a high-speed pressure sensor. This experimental system can perform reservoir stimulation analysis under different operating conditions indoors, mainly used for: evaluating the effects of dynamic / static load fracturing, evaluating dynamic / static load displacement, evaluating pulsed water injection, evaluating oscillating acidizing experiments, and evaluating pressure wave disturbances from multi-cluster fracturing. The experimental system of this invention can accurately study the production enhancement efficiency of different formation rocks under various reservoir stimulation measures, has high economic value, and broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of reservoir stimulation technology, and specifically relates to a multifunctional experimental system for reservoir dynamic stimulation. Background Technology

[0002] In the extraction of underground energy resources such as oil, natural gas, coalbed methane, and geothermal energy, the reservoirs are often deeply buried with dense matrices. Even with varying degrees of natural fractures such as pores, cracks, and cavities, their connectivity is poor, making it impossible to establish effective seepage channels for oil, gas, or geothermal energy, resulting in low underground energy recovery rates. Therefore, hydraulic fracturing to break up the reservoir matrix or connect natural fractures is crucial for the efficient development of underground oil, gas, or geothermal energy. Hydraulic fracturing uses low-viscosity, drag-reducing water as the fracturing fluid, generating a complex fracture network in the reservoir through water pressure, effectively increasing fracture propagation. In addition to the conventional hydrostatic load of hydraulic fracturing, there are also dynamic loads such as impact loads and alternating loads. Dynamic loads are generally more likely to damage the reservoir rock. Multifunctional reservoir dynamic stimulation experimental systems are important tools for evaluating the effects of static and dynamic load fracturing.

[0003] Therefore, there is an urgent need to provide a multifunctional experimental system for reservoir dynamic transformation to make up for the current deficiencies in the hardware for evaluating and testing the effects of dynamic and static load fracturing. Summary of the Invention

[0004] This invention provides a multifunctional experimental system for reservoir dynamic stimulation, which solves the problem that due to the deep burial of reservoirs and the dense matrix, even if natural fractures such as pores, cracks, and cavities of varying degrees are developed, their connectivity is poor, making it impossible to establish effective seepage channels for oil, gas, or geothermal energy, resulting in low underground energy recovery rates.

[0005] To solve the above problems, the technical solution provided by the present invention is as follows:

[0006] This invention provides a multifunctional reservoir dynamic stimulation experimental system, which includes a pulse generator (1), a first booster (2-1), a second booster (2-2), a first triaxial clamp (3), a simulated casing fracturing device (4), a pressure fluctuation pipeline (5), a core clamp (6), a manual pump (7), a pressure replenishment pump (8), a conversion interface (9), a one-way valve (10), a first valve (11-1), a second valve (11-2), a third valve (11-3), a fourth valve (11-4), a fifth valve (11-5), a sixth valve (11-6), a first pressure sensor (12-1), a second pressure sensor (12-2), a third pressure sensor (12-3), a fourth pressure sensor (12-4), a fifth pressure sensor (12-5), a sixth pressure sensor (12-6), and a high-speed pressure sensor (13).

[0007] The pulse generator (1) is connected to the first booster (2-1) through the first pipe (21), the first booster (2-1) is connected to the first triaxial clamp (3) through the second pipe (22), and a high-speed pressure sensor (13) is connected to a branch pipe of the second pipe (22).

[0008] The first interface of the conversion interface (9) is connected to the second pipe (22) through the third pipe (23), and the third pipe (23) is equipped with a second valve (11-2); the second interface of the conversion interface (9) is connected to the fourth pipe (24), and the fourth pipe (24) is equipped with a second booster (2-2), a pressure replenishing pump (8), a first valve (11-1), a one-way valve (10) and a first pressure sensor (12-1); the third interface of the conversion interface (9) is connected to the fifth pipe (25), and the fifth pipe (25) is connected to the simulated casing fracturing device (4); the fourth interface of the conversion interface (9) is connected to the pressure fluctuation pipe (5), and the pressure fluctuation pipe (5) is equipped with 3 core holders;

[0009] The first triaxial clamp (3) is an acid-resistant clamp. A second pressure sensor (12-2), a third pressure sensor (12-3), and a fourth pressure sensor (12-4) are connected to the first triaxial clamp (3). A sixth pipe (26) is connected to the upper right side of the first triaxial clamp (3). The sixth pipe (26) is connected to a third valve (11-3) and a fifth pressure sensor (12-5). A seventh pipe (27) is connected to the lower right side of the first triaxial clamp (3). The end of the seventh pipe (27) is connected to the sixth pressure sensor (12-6); the lower left side of the first three-axis clamp (3) is connected to the eighth pipe (28) and the ninth pipe (29). The eighth pipe (28) is connected to the fifth valve (11-5), and the ninth pipe (29) is connected to the fourth valve (11-4) and the manual pump (7). The branch pipe of the ninth pipe (29) is connected to the seventh pipe (27), and the branch pipe of the ninth pipe (29) is equipped with the sixth valve (11-6).

[0010] According to an optional embodiment of the present invention, the experimental system further includes a pulse generator (14), a pulse oscillation device (15), a second three-axis clamp (16), an analysis system (17), and a third booster (18). The pulse generator (14) is located at the bottom of the pulse oscillation device (15), the second three-axis clamp (16) is located on the left side of the pulse oscillation device (15), the second three-axis clamp (16) is connected to the pulse generator (14) through a tenth pipe (30), and the pulse generator (14) is connected to the pulse oscillation device (15) through an eleventh pipe (31). The analysis system (17) is located on the right side of the pulse oscillation device (15), and the third booster (18) is located on the right side of the analysis system (17).

[0011] According to an optional embodiment of the present invention, the first valve (11-1), the second valve (11-2), the third valve (11-3), the fourth valve (11-4), the fifth valve (11-5), and the sixth valve (11-6) are all fluid switching valves.

[0012] Beneficial Effects: This invention provides a multifunctional experimental system for reservoir dynamic stimulation. The system includes a pulse generator, a first booster, a second booster, a first triaxial clamp, a simulated casing fracturing device, a pressure fluctuation pipeline, a core clamp, a manual pump, a pressure replenishment pump, a conversion interface, a check valve, a first valve, a second valve, a third valve, a fourth valve, a fifth valve, a sixth valve, a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor, a fifth pressure sensor, a sixth pressure sensor, and a high-speed pressure sensor. This experimental system can perform reservoir stimulation analysis under different working conditions indoors, mainly used for: evaluating the effects of dynamic / static load fracturing, evaluating dynamic / static load displacement, evaluating pulsed water injection, evaluating oscillating acidizing experiments, and evaluating pressure wave disturbances from multi-cluster fracturing. The method of this invention is reliable in principle, rationally designed, and easy to operate. It can accurately study the production enhancement efficiency of different formation rocks under various reservoir stimulation measures, has high economic value, and broad application prospects. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments or prior art, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a partial functional structure diagram of an experimental system for multifunctional reservoir dynamic modification provided in an embodiment of this application.

[0015] Figure 2 This is a schematic diagram of another part of the functional structure of an experimental system for multifunctional reservoir dynamic modification provided in an embodiment of this application. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0017] like Figure 1 As shown in the diagram, this embodiment of the invention provides a partial functional structure schematic of an experimental system for multifunctional reservoir dynamic stimulation. This multifunctional reservoir dynamic stimulation experimental system includes a pulse generator 1, a first booster 2-1, a second booster 2-2, a first triaxial clamp 3, a simulated casing fracturing device 4, a pressure fluctuation pipeline 5, a core clamp 6, a manual pump 7, a pressure replenishment pump 8, a conversion interface 9, a one-way valve 10, a first valve 11-1, a second valve 11-2, a third valve 11-3, a fourth valve 11-4, a fifth valve 11-5, a sixth valve 11-6, a first pressure sensor 12-1, a second pressure sensor 12-2, a third pressure sensor 12-3, a fourth pressure sensor 12-4, a fifth pressure sensor 12-5, a sixth pressure sensor 12-6, and a high-speed pressure sensor 13.

[0018] The pulse generator 1 is connected to the first booster 2-1 through the first pipe 21, the first booster 2-1 is connected to the first triaxial clamp 3 through the second pipe 22, and a high-speed pressure sensor 13 is connected to a branch pipe of the second pipe 22.

[0019] The first interface of the conversion interface 9 is connected to the second pipe 22 via the third pipe 23, and the third pipe 23 is equipped with a second valve 11-2; the second interface of the conversion interface 9 is connected to the fourth pipe 24, and the fourth pipe 24 is equipped with a second booster 2-2, a pressure replenishing pump 8, a first valve 11-1, a one-way valve 10 and a first pressure sensor 12-1; the third interface of the conversion interface 9 is connected to the fifth pipe 25, and the fifth pipe 25 is connected to the simulated casing fracturing device 4; the fourth interface of the conversion interface 9 is connected to the pressure fluctuation pipe 5, and the pressure fluctuation pipe 5 is equipped with 3 core holders 6.

[0020] The first three-axis clamp 3 is an acid-resistant clamp. The first three-axis clamp 3 is connected to the second pressure sensor 12-2, the third pressure sensor 12-3, and the fourth pressure sensor 12-4. The sixth pipe 26 is connected to the upper right side of the first three-axis clamp 3. The sixth pipe 26 is connected to the third valve 11-3 and the fifth pressure sensor 12-5. The seventh pipe 27 is connected to the lower right side of the first three-axis clamp 3. The sixth pressure sensor 12-6 is connected to the end of the seventh pipe 27. The eighth pipe 28 and the ninth pipe 29 are connected to the lower left side of the first three-axis clamp 3. The fifth valve 11-5 is connected to the eighth pipe 28. The fourth valve 11-4 and the manual pump 7 are connected to the ninth pipe 29. The branch pipe of the ninth pipe 29 is connected to the seventh pipe 27. The branch pipe of the ninth pipe 29 is equipped with the sixth valve 11-6.

[0021] like Figure 2 As shown, the experimental system for multifunctional reservoir dynamic modification also includes a pulse generator 14, a pulse fluctuation device 15, a second and third-axis clamp 16, an analysis system 17, and a third booster 18. The pulse generator 14 is located at the bottom of the pulse fluctuation device 15, and the second and third-axis clamp 16 is located to the left of the pulse fluctuation device 15. The second and third-axis clamp 16 is connected to the pulse generator 14 through the tenth pipe 30, and the pulse generator 14 is connected to the pulse fluctuation device 15 through the eleventh pipe 31. The analysis system 17 is located to the right of the pulse fluctuation device 15, and the third booster 18 is located to the right of the analysis system 17.

[0022] The functional structure of the multifunctional reservoir dynamic stimulation experimental system is as follows:

[0023] A 70MPa miniature multiplier mounted on the pulse generator 1 provides alternating pressure waves for the experimental system. The first booster 2-1, the second booster 2-2, and the third booster 18 have a pressure of 140MPa and a volume of 1L. When used with the pressure replenishment pump 8 (constant speed and constant pressure pump), hydraulic fracturing experiments (static pressure) with a maximum pressure of 140MPa can be carried out; pulse fracturing experiments can also be carried out when used with the pulse plunger pump and multiplier (140MPa).

[0024] The first three-axis clamp 3 and the second three-axis clamp 16 are the main components of the equipment, used to clamp the rock core, apply confining pressure and axial pressure to the rock core; conduct displacement experiments on the rock core; conduct oscillatory acidizing experiments on the rock core; conduct pulse fracturing experiments on the rock core; and monitor the pressure at different locations on the rock core.

[0025] The simulated casing fracturing device 4 is used to replace the formation rock with cast cement blocks. The material of the cement blocks is adjusted according to different formation characteristics, and pressure is input into the cast core to carry out static pressure fracturing experiments. Alternatively, a pulse plunger pump and multiplier (140MPa) can be used to input pulse pressure into the cast core through a conversion interface.

[0026] The pressure fluctuation pipeline 5 is used to scale down and simplify the structure of the fracturing site pipeline. By studying the energy loss caused by the friction between the pulse wave generated by the pulse generator and the inner wall of the pipeline when it flows in the pipeline, the pressure change of the pulse wave when it enters the formation can be obtained.

[0027] The core holder 6 is used to apply the same axial and radial pressure to the end face and surrounding cylindrical surface of the rock sample; it is used to determine the pore volume compressibility coefficient and porosity permeability under overburden pressure of the rock sample, as well as to conduct displacement tests on full-diameter cores. Due to the large pressure applied to the rubber sleeve and the end of the core, it has excellent anti-leakage performance and the working pressure can reach 105MPa.

[0028] Manual pump 7 provides triaxial pressure to the triaxial clamp. Different confining and axial pressures can be applied to the core by switching between the fifth valve 11-5 and the sixth valve 11-6. Pressure replenishment pump 8 is a plunger pump with constant pressure / constant flow function. It provides an initial pressure to the system and can also track alternating pressure, automatically replenishing pressure when peak pressure is lost.

[0029] The conversion interface 9 is used for switching between different experiments. The one-way valve 10 is used to control the unidirectional flow of fluid. The first valve 11-1, the second valve 11-2, the third valve 11-3, the fourth valve 11-4, the fifth valve 11-5, and the sixth valve 11-6 are all fluid switching valves.

[0030] The first pressure sensor 12-1, the second pressure sensor 12-2, the third pressure sensor 12-3, the fourth pressure sensor 12-4, the fifth pressure sensor 12-5, and the sixth pressure sensor 12-6 are all pressure sensors that monitor the pressure at various points in the pipeline and in the core sample. The high-speed pressure sensor 13 is a high-speed pressure sensor with a higher sampling frequency compared to ordinary sensors.

[0031] After the core is installed, close all valves and apply axial and confining pressure to the core using manual pump 7, fifth valve 11-5, and sixth valve 11-6. Set the initial pressure on the pressure replenishment pump 8, open the third valve 11-3, and then start the pulse plunger pump (pressure replenishment pump 8) to perform pulse fracturing experiments on the core in the triaxial holder. At this time, the computer will collect the pressure at each point and also plot the pressure-time curve based on the pressure collected by the high-speed pressure sensor 13.

[0032] Disconnect the pipeline connection between the pulse plunger pump and the triaxial clamp, and input pressure into the cast core through the pressure replenishment pump 8, the second valve 11-2, the multiplier (140MPa), the check valve 10, and the reserved interface to conduct static pressure fracturing experiments. Alternatively, the pulse plunger pump and the multiplier (140MPa) can be used to input pulse pressure into the cast core through the reserved interface.

[0033] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A multifunctional experimental system for reservoir dynamic stimulation, characterized in that, It includes a pulse generator (1), a first booster (2-1), a second booster (2-2), a first triaxial clamp (3), a simulated casing fracturing device (4), a pressure fluctuation pipeline (5), a core clamp (6), a manual pump (7), a pressure replenishment pump (8), a conversion interface (9), a one-way valve (10), a first valve (11-1), a second valve (11-2), a third valve (11-3), a fourth valve (11-4), a fifth valve (11-5), a sixth valve (11-6), a first pressure sensor (12-1), a second pressure sensor (12-2), a third pressure sensor (12-3), a fourth pressure sensor (12-4), a fifth pressure sensor (12-5), a sixth pressure sensor (12-6), and a high-speed pressure sensor (13). The pulse generator (1) is connected to the first booster (2-1) through the first pipe (21), the first booster (2-1) is connected to the first triaxial clamp (3) through the second pipe (22), and a high-speed pressure sensor (13) is connected to a branch pipe of the second pipe (22). The first interface of the conversion interface (9) is connected to the second pipe (22) through the third pipe (23), and the third pipe (23) is equipped with a second valve (11-2); the second interface of the conversion interface (9) is connected to the fourth pipe (24), and the fourth pipe (24) is equipped with a second booster (2-2), a pressure replenishing pump (8), a first valve (11-1), a one-way valve (10) and a first pressure sensor (12-1); the third interface of the conversion interface (9) is connected to the fifth pipe (25), and the fifth pipe (25) is connected to the simulated casing fracturing device (4); the fourth interface of the conversion interface (9) is connected to the pressure fluctuation pipe (5), and the pressure fluctuation pipe (5) is equipped with 3 core holders; The first three-axis clamp (3) is an acid-resistant clamp. A second pressure sensor (12-2), a third pressure sensor (12-3), and a fourth pressure sensor (12-4) are connected to the first three-axis clamp (3). A sixth pipe (26) is connected to the upper right side of the first three-axis clamp (3). The sixth pipe (26) is connected to a third valve (11-3) and a fifth pressure sensor (12-5). A seventh pipe (27) is connected to the lower right side of the first three-axis clamp (3). The end of the seventh pipe (27) is connected to the sixth pressure sensor (12-6); the lower left side of the first three-axis clamp (3) is connected to the eighth pipe (28) and the ninth pipe (29). The eighth pipe (28) is connected to the fifth valve (11-5), and the ninth pipe (29) is connected to the fourth valve (11-4) and the manual pump (7). The branch pipe of the ninth pipe (29) is connected to the seventh pipe (27), and the branch pipe of the ninth pipe (29) is equipped with the sixth valve (11-6).

2. The experimental system for multifunctional reservoir dynamic stimulation according to claim 1, characterized in that, The first valve (11-1), the second valve (11-2), the third valve (11-3), the fourth valve (11-4), the fifth valve (11-5), and the sixth valve (11-6) are all fluid switching valves.

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