Embedded microwave radiation reservoir transformation simulation method and device and computer program product
By using an embedded microwave radiation triaxial clamp to hold the core and perform microwave heating, the problem of secondary pollution in unconventional oil and gas reservoir stimulation has been solved, achieving efficient reservoir stimulation and permeability improvement, and promoting the application of microwave heating technology in unconventional reservoirs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2024-10-22
- Publication Date
- 2026-04-24
AI Technical Summary
Existing technologies pose secondary pollution problems in unconventional oil and gas reservoir stimulation, and there is a lack of indoor research, which affects the further application of microwave heating technology in permeability enhancement and extraction.
An embedded microwave radiation triaxial clamp was used to hold the core, and confining pressure and pore pressure were set to simulate depletion mining. The core outlet end was heated by a microwave generator, and the relationship between microwave parameters and core permeability was determined by combining experimental data.
This study provides an environmentally friendly and efficient reservoir stimulation method, deepens the understanding of the mechanism of microwave heating in unconventional reservoir stimulation, provides a theoretical basis for microwave heating technology, and improves reservoir permeability and development effect.
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Figure CN121915993A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of reservoir stimulation technology, and in particular to an embedded microwave radiation reservoir stimulation simulation method, apparatus, and computer program product. Background Technology
[0002] my country possesses abundant unconventional oil and gas resources, but their extraction is significantly more challenging than that of conventional oil and gas reservoirs. For reservoirs such as heavy oil, shale gas, coalbed methane, tight gas, and hydrates, reservoir modification is typically required to achieve optimal development results. Heavy oil reservoirs generally utilize steam injection for thermal recovery; shale gas, coalbed methane, and tight oil and gas reservoirs often employ hydraulic fracturing, multi-stage fracturing, clear water fracturing, and repeated fracturing techniques; and the extraction methods for natural gas hydrates primarily include hot water or steam injection, microwave heating, electric heating, and solar heating.
[0003] For the above-mentioned unconventional oil and gas, there are many reservoir stimulation technologies, but most of them will bring secondary pollution to the reservoir. Sun Zhigang, Wang Yudou, Yang Tianfang. A review of the application research of microwave heating technology in shale gas extraction [J / OL]. World Petroleum Industry, 1-9 [2024-04-02] mentioned: Microwave heating has the advantages of environmental protection, high efficiency and selective heating, and is gradually being applied to the extraction of unconventional oil and gas. Ren Shuqi, Liu Tao, Song Pingping et al. Research on a microwave heating reservoir technology based on oil drilling tools [J]. Journal of Microwave, 2023, 39(03):97-102 mentioned: Microwave energy can directly heat the oil-bearing reservoir to reduce the viscosity of crude oil and improve the recovery rate of heavy oil; Zhang Han. The effect of microwave response on the physical and chemical properties of gas-bearing shale and the adsorption / desorption performance of CH4 [D]. Kunming University of Science and Technology, 2022. mentioned: Microwave energy can promote the rapid heating of shale matrix, promote the desorption of physically adsorbed CH4, and reduce the shale matrix. The number of adsorption pores in the material increases the number of seepage pores, thereby improving the permeability of shale reservoirs; Yang Changxin, Yang Zhaozhong, Li Xiaogang, et al. Current Status and Prospect of Reservoir Stimulation Technology for Coalbed Methane Surface Well Development in China [J]. Natural Gas Industry, 2022, 42(06):154-162 mentioned that microwave heating can promote the movement of gas molecules in coal and rock and the evaporation of water in pores, promote the formation and development of microfractures, thereby increasing the seepage channels and improving the permeability of coal and rock; for tight gas reservoirs, microwave heating can also relieve the water-locking damage in the near-wellbore zone, thereby improving the tight gas recovery rate.
[0004] Currently, there is a lack of indoor research on microwave radiation for reservoir modification, which affects further research on microwave heating technology for enhancing permeability and improving production. Summary of the Invention
[0005] This disclosure aims to at least partially solve one of the technical problems in the aforementioned technologies, and to this end proposes an embedded microwave radiation reservoir stimulation simulation method, comprising:
[0006] Core samples were held using an embedded microwave radiation triaxial clamp.
[0007] Increase the confining pressure of the embedded microwave radiation triaxial clamp to a preset value, and after the confining pressure stabilizes, inject nitrogen gas from both ends of the core to bring its pore pressure to the preset value.
[0008] Open the core outlet end, set the gas extraction rate, and conduct a depletion extraction simulation;
[0009] When the pressure at the outlet drops to the waste pressure, turn on the microwave generator at the outlet, set the experimental parameters including microwave power and heating time, and use the embedded microwave radiation triaxial clamp to heat the outlet of the core.
[0010] The relationship between microwave parameters and core permeability was determined based on experimental data.
[0011] Furthermore, before using the embedded microwave radiation triaxial clamp to hold the core, the process also includes: drying the core, vacuuming and saturating it with formation water, and using the gas drive method to establish the initial water saturation of the reservoir.
[0012] Furthermore, before drying, vacuuming, and saturating the core with formation water, the process also includes: measuring the diameter, length, and porosity of the core, and measuring the core permeability using a steady-state method.
[0013] Furthermore, the steady-state method is used to measure core permeability, and the corresponding calculation formulas include:
[0014]
[0015] Where K represents absolute permeability; Q represents the flow rate through the core under a pressure difference Δp; A represents the cross-sectional area of the core perpendicular to the flow direction; L represents the core length; μ represents the fluid viscosity through the core; and Δp represents the pressure difference before and after the fluid passes through the core.
[0016] Furthermore, determining the relationship between microwave parameters and core permeability based on experimental data includes: fitting the curves of core permeability versus core temperature after microwave radiation under different microwave radiation powers and different heating times to determine the relationship between microwave parameters and core permeability.
[0017] This disclosure also proposes an embedded microwave radiation reservoir stimulation simulation device applicable to the above method, comprising:
[0018] The ISCO pump, first regulating valve, air source, first switch, first pressure sensor, embedded microwave radiation triaxial clamp, second pressure sensor, second switch, second regulating valve, metering device, and data acquisition terminal are connected in sequence; among them,
[0019] The confining pressure air inlet of the embedded microwave radiation triaxial clamp is connected to the confining pressure pump;
[0020] The embedded microwave radiation triaxial clamp heating module is connected to a temperature sensor;
[0021] The embedded microwave radiation triaxial clamp connects the microwave input end to the microwave generator.
[0022] This disclosure also proposes an embedded microwave radiating triaxial clamping device applicable to the above method, comprising: a cylindrical body, an upper end cap, a lower end cap, an upper pressure cap, a lower pressure cap, a horn antenna, a gasket, and a thermocouple; wherein...
[0023] The interior of the cylinder is provided with a first accommodating space;
[0024] The upper and lower pressure caps are located outside the cylinder;
[0025] The upper plug and the lower plug are respectively provided with axially penetrating air inlets;
[0026] The upper plug is fixed to the first end within the first accommodating space by the upper pressure cap, and the lower plug is fixed to the second end within the first accommodating space by the lower pressure cap; the lower end of the upper plug and the upper end of the lower plug are connected by a rubber sleeve, and the rubber sleeve, the upper plug and the lower plug together form a second accommodating space;
[0027] The lower plug is equipped with a microwave radiation emitting device;
[0028] The cylinder wall is equipped with a thermocouple and a confining pressure air inlet.
[0029] Furthermore, the second accommodating space is used to place a rock core with an axial groove on its bottom surface; a ceramic gasket made of microwave transparent material is also provided between the rock core and the lower plug.
[0030] This disclosure also proposes an electronic device, including a memory and a processor, wherein the memory stores a computer program or instructions, which, when executed by the processor, are at least used to implement the methods described above.
[0031] This disclosure also proposes a computer-readable storage medium storing a computer program or instructions, which, when executed by a processor, are at least used to implement the above-described method.
[0032] This disclosure also proposes a computer program product stored in a computer-readable storage medium, which, when executed by a processor, is used to implement at least the above-described method.
[0033] Compared with the prior art, the beneficial effects of this disclosure are: This disclosure designs an embedded microwave radiation reservoir stimulation simulation device and evaluation method, and provides an improved clamp that can simulate the stimulation effect of microwave heating on the reservoir during reservoir mining, further deepening the mechanism and experimental research of microwave heating in unconventional reservoir stimulation, and providing a certain theoretical basis and technical support for microwave heating technology.
[0034] Other features and advantages of this disclosure will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the disclosure. The objects and other advantages of this disclosure may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. The technical solutions of this disclosure will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0035] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the embodiments of the present disclosure to explain the disclosure and do not constitute a limitation thereof. In the drawings:
[0036] Figure 1 This is a schematic diagram of the embedded microwave radiation reservoir modification simulation method given in the embodiment;
[0037] Figure 2 The schematic diagram of the embedded microwave radiation reservoir modification simulation device is shown in the embodiment.
[0038] Figure 3 The following is a schematic diagram of an embedded microwave radiation triaxial clamp provided as an example.
[0039] Figure 4 The following is a graph showing the relationship between microwave power and core temperature, provided as an example.
[0040] Figure 5 The example provides a graph showing the relationship between microwave heating time and core temperature.
[0041] Figure 6 The figure showing the relationship between core temperature and core permeability is provided in the example.
[0042] Figure 7 The diagram shows an electronic device as illustrated in the embodiment.
[0043] Figure 8 This is a schematic diagram of a computer-readable storage medium provided for an embodiment. Detailed Implementation
[0044] The present disclosure will be described below with reference to the accompanying drawings. The preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present disclosure.
[0045] Based on the advantages of microwave reservoir modification, such as environmental protection, high efficiency, and selective heating, this disclosure provides an embedded microwave radiation reservoir modification simulation device and evaluation method. Using this method and device, the modification effect of microwaves on unconventional reservoirs during the development process can be studied, which is of positive significance for improving the development effect of unconventional reservoirs.
[0046] Figure 1 The embedded microwave radiation reservoir stimulation simulation method disclosed herein includes:
[0047] Core samples were held using an embedded microwave radiation triaxial clamp.
[0048] Increase the confining pressure of the embedded microwave radiation triaxial clamp to a preset value, and after the confining pressure stabilizes, inject nitrogen gas from both ends of the core to bring its pore pressure to the preset value.
[0049] Open the core outlet end, set the gas extraction rate, and conduct a depletion extraction simulation;
[0050] When the pressure at the outlet drops to the waste pressure, turn on the microwave generator at the outlet, set the experimental parameters including microwave power and heating time, and use the embedded microwave radiation triaxial clamp to heat the outlet of the core.
[0051] The relationship between microwave parameters and core permeability was determined based on experimental data.
[0052] According to some embodiments of this disclosure, before clamping the core using an embedded microwave radiation triaxial clamp, the process further includes: measuring the core's diameter, length, and porosity; measuring the core permeability using a steady-state method; drying the core, vacuuming, and saturating it with formation water; and establishing the initial water saturation of the reservoir using a gas drive method.
[0053] According to some embodiments of this disclosure, the steady-state method is used to measure core permeability, and the corresponding calculation formula includes:
[0054]
[0055] Where K represents absolute permeability; Q represents the flow rate through the core under a pressure difference Δp; A represents the cross-sectional area of the core perpendicular to the flow direction; L represents the core length; μ represents the fluid viscosity through the core; and Δp represents the pressure difference before and after the fluid passes through the core.
[0056] According to some embodiments of this disclosure, the relationship between microwave parameters and core permeability is determined based on experimental data, including: fitting the curves of core permeability and core temperature after microwave radiation under different microwave radiation powers and different heating times to determine the relationship between microwave parameters and core permeability.
[0057] According to some embodiments of this disclosure, the experimental apparatus includes a microwave generator, an embedded microwave radiation triaxial clamp, a measuring device, a data acquisition terminal, a temperature sensor, a first pressure sensor, a second pressure sensor, an ISCO pump, a confining pressure pump, a back pressure pump, a first regulating valve, a second regulating valve, a first switch, and a second switch. The ISCO pump, the first regulating valve, the air source, the first switch, the first pressure sensor, the embedded microwave radiation triaxial clamp, the second pressure sensor, the second switch, the second regulating valve, the measuring device, and the data acquisition terminal are connected sequentially. The confining pressure air inlet of the embedded microwave radiation triaxial clamp is connected to the confining pressure pump; the heating module of the embedded microwave radiation triaxial clamp is connected to the temperature sensor; and the microwave input terminal of the embedded microwave radiation triaxial clamp is connected to the microwave generator.
[0058] The embedded microwave radiation triaxial clamp consists of a horn antenna and a Φ10cm core clamp. In this embodiment, the embedded microwave radiation triaxial clamp includes: a cylindrical body, an upper plug, a lower plug, an upper pressure cap, a lower pressure cap, a horn antenna, a gasket, and a thermocouple. The cylindrical body has a first accommodating space inside; the upper and lower pressure caps are located outside the cylindrical body; the upper and lower plugs each have an axially penetrating air inlet; the upper plug is fixed to a first end within the first accommodating space via the upper pressure cap, and the lower plug is fixed to a second end within the first accommodating space via the lower pressure cap; the lower end of the upper plug and the upper end of the lower plug are connected by a rubber sleeve, and the rubber sleeve, the upper plug, and the lower plug form a second accommodating space; a microwave radiation emitting device is located inside the lower plug; a thermocouple and a confining pressure air inlet are located on the cylindrical wall of the cylindrical body.
[0059] In some embodiments of this disclosure, the embedded microwave radiation triaxial clamp is an improvement on the outlet end of a Φ10cm core clamp. The lower plug is modified into a cylindrical shape with openings at both ends and a certain thickness. A horn-shaped microwave radiation antenna with a diameter of 71.25mm*44.45mm is placed inside the plug. To allow microwave energy to enter the core, a gasket made of microwave transparent material (99 ceramic) is placed at the contact surface between the plug and the core, and a small hole is drilled at the outlet end of the core to allow microwave radiation to enter the core and be fully heated. The embedded microwave radiation triaxial clamp withstands a pressure of 30MPa and a temperature of 200℃.
[0060] The aforementioned embedded microwave radiation reservoir stimulation simulation device, such as Figure 2 As shown, the embedded microwave radiation triaxial clamp is as follows: Figure 3 As shown, the above device is used for indoor research on the effects of microwave radiation on reservoir modification. The specific method includes the following steps:
[0061] 1. Measure the core diameter, length, and porosity. Measure the core permeability using the steady-state method (record the initial gas permeability of the core as K0). The principle is as follows:
[0062]
[0063] Where K represents absolute permeability, D; and Q represents the flow rate through the core under a pressure difference Δp, in cm³. 3 / s; A represents the cross-sectional area of the core sample perpendicular to the flow direction, in cm². 2 L represents the core length in cm; μ represents the fluid viscosity passing through the core in mPa·s; Δp represents the pressure difference before and after the fluid passes through the core.
[0064] 2. Dry the core, vacuum it, saturate the formation water, and establish the initial water saturation of the reservoir using the gas drive method;
[0065] 3. Connect the embedded microwave radiation triaxial clamp to the other equipment and pipelines, then apply confining pressure to 30MPa. After the confining pressure stabilizes, inject nitrogen from both ends of the core to increase the pore pressure to 20MPa. After the pressure stabilizes, stop the injection, close the inlet and outlet ends, and remove the gas source.
[0066] 4. Open the core outlet, set the gas extraction rate, perform depletion extraction, and record the data;
[0067] 5. When the outlet pressure drops to the waste pressure, turn on the microwave generator at the outlet, set the microwave power, heating time and other parameters, use the embedded microwave radiation triaxial clamp to heat the core outlet, and record data such as pressure, flow rate and temperature.
[0068] 6. Repeat steps 1-5, changing the microwave power, heating time, etc., to continue the experiment. At the end of the experiment, plot the curves of permeability versus core temperature after microwave radiation for different powers and heating times, and perform fitting to clarify the relationship between microwave parameters and core permeability.
[0069] T=0.0611P-3.6003#(2)
[0070] T = 1.8715t - 1.838#(3)
[0071] K1 = 3 × 10 -5 T+0.0145#(4)
[0072] Figure 4 The curve showing the relationship between microwave power and core temperature corresponding to equation (2) is shown below. Figure 5 The curve showing the relationship between microwave heating time and core temperature corresponding to equation (3) is shown below. Figure 6 The curve showing the relationship between core temperature and core permeability corresponding to equation (4) is shown.
[0073] Based on the above formulas, the relationship between the permeability of the core after microwave heating and the microwave power and heating time can be further calculated:
[0074] K1 = 9.2 × 10 -7 P + 2.81 × 10 -5 t+0.014#(5)
[0075] Among them, all known coefficients in equations (2) to (5) are obtained through experiments. The coefficients corresponding to different experimental conditions and lithologies vary. The relevant coefficients can be obtained based on specific experiments. In equations (2) to (5) above, T represents the core temperature, °C; P represents the microwave power, W; and t represents the heating time, s.
[0076] The permeability of the core after microwave heating is denoted as K1. The effect of reservoir stimulation can be evaluated based on the permeability change rate (I) before and after microwave heating. Furthermore, the effect of different microwave parameters on reservoir stimulation can be studied through the permeability change rate, as expressed below:
[0077]
[0078] It should be noted that when I < 1, it means that microwave heating has not effectively modified the reservoir; when I > 1, the reservoir has been modified.
[0079] like Figure 7 As shown, this disclosure provides an electronic device 1000, which includes a memory 1002 and a processor 1001. The memory 1002 stores computer programs or instructions, which, when executed by the processor 1001, are used to implement at least the methods described above. Figure 8 As shown, this disclosure provides a computer-readable storage medium 1100, which stores a computer program or instructions that, when executed by a processor, are at least used to implement the above-described method.
[0080] In addition, this disclosure provides a computer program product stored in a computer-readable storage medium, which, when executed by a processor, is used to implement at least the above-described methods.
[0081] It is obvious that those skilled in the art can make various modifications and variations to this disclosure without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include such modifications and variations.
Claims
1. An embedded microwave radiation reservoir stimulation simulation method, characterized in that, include: Core samples were held using an embedded microwave radiation triaxial clamp. Increase the confining pressure of the embedded microwave radiation triaxial clamp to a preset value, and after the confining pressure stabilizes, inject nitrogen gas from both ends of the core to bring its pore pressure to the preset value. Open the core outlet end, set the gas extraction rate, and conduct a depletion extraction simulation; When the pressure at the outlet drops to the waste pressure, turn on the microwave generator at the outlet, set the experimental parameters including microwave power and heating time, and use the embedded microwave radiation triaxial clamp to heat the outlet of the core. The relationship between microwave parameters and core permeability was determined based on experimental data.
2. The method as described in claim 1, characterized in that, Before using an embedded microwave radiation triaxial clamp to hold the core, the process includes: drying the core, vacuuming and saturating it with formation water, and using a gas drive method to establish the initial water saturation of the reservoir.
3. The method as described in claim 2, characterized in that, Before drying, vacuuming, and saturating the core with formation water, the process also includes: measuring the diameter, length, and porosity of the core, and measuring the core permeability using a steady-state method.
4. The method as described in claim 3, characterized in that, The formulas for calculating core permeability using the steady-state method include: Where K represents absolute permeability; Q represents the flow rate through the core under a pressure difference Δp; A represents the cross-sectional area of the core perpendicular to the flow direction; L represents the core length; μ represents the fluid viscosity through the core; and Δp represents the pressure difference before and after the fluid passes through the core.
5. The method as described in claim 1, characterized in that, The step of determining the relationship between microwave parameters and core permeability based on experimental data includes: fitting the curves of core permeability versus core temperature after microwave radiation under different microwave radiation powers and different heating times to determine the relationship between microwave parameters and core permeability.
6. An embedded microwave radiation reservoir stimulation simulation device applicable to the method described in any one of claims 1-5, characterized in that, include: The ISCO pump, first regulating valve, air source, first switch, first pressure sensor, embedded microwave radiation triaxial clamp, second pressure sensor, second switch, second regulating valve, metering device, and data acquisition terminal are connected in sequence; among them, The confining pressure air inlet of the embedded microwave radiation triaxial clamp is connected to the confining pressure pump; The embedded microwave radiation triaxial clamp heating module is connected to a temperature sensor; The embedded microwave radiation triaxial clamp connects the microwave input end to the microwave generator.
7. An embedded microwave radiation triaxial clamp suitable for the method of any one of claims 1-5, characterized in that, include: The components include: cylinder body, upper plug, lower plug, upper pressure cap, lower pressure cap, horn antenna, gasket, and thermocouple; among which, The interior of the cylinder is provided with a first accommodating space; The upper and lower pressure caps are located outside the cylinder; The upper plug and the lower plug are respectively provided with axially penetrating air inlets; The upper plug is fixed to the first end within the first accommodating space by the upper pressure cap, and the lower plug is fixed to the second end within the first accommodating space by the lower pressure cap; the lower end of the upper plug and the upper end of the lower plug are connected by a rubber sleeve, and the rubber sleeve, the upper plug and the lower plug together form a second accommodating space; The lower plug is equipped with a microwave radiation emitting device; The cylinder wall is equipped with a thermocouple and a confining pressure air inlet.
8. The embedded microwave radiation triaxial clamp as described in claim 7, characterized in that, The second accommodating space is used to place a rock core with an axial groove on its bottom surface; a ceramic gasket made of microwave transparent material is also provided between the rock core and the lower plug.
9. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program or instructions, which, when executed by the processor, are used to implement at least the method described in any one of claims 1-5.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions, which, when executed by a processor, are used to implement at least the method described in any one of claims 1-5.
11. A computer program product, said computer program product being stored in a computer-readable storage medium, characterized in that, When the computer program product is executed by a processor, it is used to implement at least the method described in any one of claims 1-5.