A system for intensifying production and injection by water shock wave focusing and a working method thereof

Abstract

This invention relates to a system for enhancing production and injection through focused water shockwave generation and its operating method. The system includes a water storage tank, an energy storage buffer, a pressure control valve, a power pump source, and an injection well. The water storage tank is connected to the power pump source, which is connected to the injection well via two pipelines. An energy storage buffer is installed on one pipeline between the power pump source and the injection well, while the pressure control valve and a water distribution station are installed on the other pipeline. Valve a is installed on the pipeline from the power pump source to the energy storage buffer, valve b is installed on the pipeline from the power pump source to the pressure control valve, valve c is installed on the pipeline from the energy storage buffer to the injection well, and valve d is installed on the pipeline from the water distribution station to the injection well. This invention utilizes the principle of dynamic pressure energy conversion, employing a combination of an energy storage buffer and a pressure control valve to generate focused water shockwaves. This creates a permeability enhancement zone near the well and disrupts the oil-water interface balance further from the well, achieving enhanced production and injection through hydraulic pulsation.

Description

Technical Field

[0001] This invention relates to a shaped water shock wave enhanced production and injection generation system and its working method, belonging to the field of petroleum extraction technology. Background Technology

[0002] Currently, most oilfields in my country have entered the high water-cut stage. Due to heterogeneity, high-speed mainstream channels have formed within the reservoirs, and a large amount of residual oil is concentrated in small pores and cannot be extracted. Moreover, as development enters the middle and late stages, the distribution of residual oil becomes increasingly complex, making it more and more difficult to tap its potential. Therefore, finding residual oil has become the core content of development adjustment and enhanced oil recovery in the high water-cut stage of old oilfields. Faced with high water-cut reservoirs, conventional water injection technology can no longer meet development needs, while fracturing and chemical permeation enhancement of the reservoir face limitations in geological conditions, technology, and cost. Therefore, hydraulic pulse enhanced production and injection technology has gradually developed as a new water injection technology. This technology causes less damage and pollution to the reservoir. Through hydraulic pulse waves, it continuously impacts the reservoir rock skeleton, causing elastic deformation of the rock and periodic changes in pore capillary pressure, thereby reducing fluid flow resistance and allowing residual oil to break through capillary force constraints and be displaced, thus improving the oilfield recovery rate.

[0003] While research on the mechanism of hydraulic pulsed water injection technology has made some progress, the implementation methods for applying theoretical research results in the field still need to be explored. For example, Chinese patent document CN111852432B discloses a ground-controlled hydraulic pulse device and its application. Although this device also uses hydraulic pulsed technology, during the energy storage process, the water injection channel is closed, and no fluid flows through. That is, there is no stable water injection process during the energy storage period, resulting in the formation lacking a certain energy foundation during energy release and water injection, thus limiting the pulse effect. Therefore, this invention is proposed. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a focused water shock wave enhanced production and injection generation system. Utilizing the principle of dynamic pressure energy conversion, it employs a combination of an energy storage buffer and a amplitude pressure control valve to generate focused water shock waves, forming a permeability enhancement zone near the well and disrupting the oil-water interface balance at the far well, thereby achieving hydraulic pulsation enhanced production and injection.

[0005] The present invention also provides a working method for the above-mentioned focused water shock wave enhanced production and injection generation system.

[0006] The technical solution of the present invention is as follows:

[0007] A system for enhancing water production and injection capacity using focused water shock waves includes a water storage tank, an energy storage buffer, an amplitude and pressure control valve, a power pump source, an injection well, and a control system.

[0008] The water storage tank is connected to a power pump source, which is connected to the water injection well via two pipelines. Several energy storage buffers are installed on one pipeline between the power pump source and the water injection well, and a pressure control valve and a water distribution station are installed on the other pipeline. Valve a is installed on the pipeline from the power pump source to the energy storage buffer, valve b is installed on the pipeline from the power pump source to the pressure control valve, valve c is installed on the pipeline from the energy storage buffer to the water injection well, and valve d is installed on the pipeline from the water distribution station to the water injection well. The energy storage buffer, pressure control valve, power pump source, valves a, b, c, and d are all connected to a control system.

[0009] According to a preferred embodiment of the present invention, the energy storage buffer includes a tank, an air bladder, an air injection pump, and a pressure detection panel. An air bladder is provided at the top of the tank, and the air bladder is connected to the air injection pump through an air injection inlet at the top of the tank. The bottom of the tank is connected to a pipeline between the power pump source and the water injection well through a drainage inlet and outlet. The pressure detection panel is connected to pressure sensors in the air bladder and the tank respectively to detect the pressure values ​​in the air bladder and the tank. Both the air injection pump and the pressure detection panel are connected to a control system.

[0010] According to a further preferred embodiment of the present invention, a valve e is provided on the gas injection inlet pipe, and a valve f is provided on the drainage inlet and outlet pipes.

[0011] According to a preferred embodiment of the present invention, the amplitude pressure control valve is a YB43X ultra-high pressure fixed proportional pressure reducing valve.

[0012] According to a preferred embodiment of the present invention, a flow meter is installed on the outlet pipe of the power pump source, and a flow meter and a pressure gauge are installed on the connecting pipe of the injection well to detect the flow rate and pressure of the liquid in the pipe.

[0013] The working method of the above-mentioned focused water shock wave enhanced production and injection generation system is as follows:

[0014] (1) Based on the reservoir water injection requirements and on-site construction conditions, set the number of energy storage buffers and the pressure inside the airbag, set the outlet pressure of the amplitude pressure control valve, and set the power pump source drainage flow rate.

[0015] (2) Open valves a, b and d, close valve c, start the power pump to drain water, and the water flows into two branch pipes. Part of the water flows into the tank of the energy storage buffer, and the other part flows through the pressure control valve and the water distribution station and enters the water injection well.

[0016] (3) The power pump source continuously discharges water at a constant flow rate. Under the pressure reduction effect of the pressure control valve, some of the water that cannot pass through the pressure control valve enters the energy storage buffer, contacts and squeezes the air bag, and the kinetic energy of the water is converted into the pressure energy of the air bag. At this time, the pressure at the inlet end of the pressure control valve gradually increases and the pressure at the outlet end stabilizes. The water injection well maintains a stable pressure constant pressure water injection.

[0017] (4) The power pump continuously drains water until the pressure inside the airbag reaches the preset value. Then, valve c is opened, and the gas pressure energy inside the airbag of the energy storage buffer is converted back into the kinetic energy of the water. The water in the compression tank is quickly injected into the water injection well. The kinetic energy of the water in the water injection well is converted into the pressure energy of the pore water, and the pressure at the wellhead of the water injection well rises rapidly.

[0018] (5) Observe the pressure at the wellhead of the injection well until the pressure drops and stabilizes, then close valve c and the energy storage buffer will re-store water and energy.

[0019] (6) Repeat steps (3)-(5), and after multiple rounds of energy accumulation and release, repeatedly convert the water injection kinetic energy into pore pressure pulsation, forming a permeability enhancement zone near the well and breaking the oil-water interface balance at the far well, thereby improving the water drive recovery rate.

[0020] According to a preferred embodiment of the present invention, in step (1), based on a reservoir thickness of 20m, four energy storage buffers are set, the pressure inside the gasbag is 5MPa, valve e is opened, and high-pressure nitrogen is injected into the gasbag using an injection pump until the pressure inside the gasbag reaches 5MPa. The injection pump and valve e are then closed, the outlet pressure of the amplitude control valve is set to 5MPa, and the drainage flow rate of the power pump source is set to 200m³ / h. 3 / d;

[0021] In step (4), the preset pressure inside the airbag is 15 MPa;

[0022] In step (5), after observing the pressure drop at the injection wellhead stabilize at 5 MPa, valve c is closed.

[0023] The energy-concentrating pulsation of this invention can generate a "tsunami-like" fluid-structure coupling displacement wave in the reservoir, repeatedly converting the kinetic energy of water injection into pore pressure pulsation, and stimulating the coupled elastic expansion and contraction of pore space and saturated fluid. This can achieve a permeability enhancement zone within a range of 5-10 meters near the well (increasing permeability by more than 20%, until microfractures are generated), and stimulate inertial stacking in the far well range, breaking the oil-water interface balance, increasing the utilization rate of chemical agents by more than 2 times. Indoor experiments have shown that this can increase the water drive recovery rate by more than 8%-21%.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. This invention utilizes the principle of dynamic pressure energy conversion and employs a combination of energy storage buffer and amplitude pressure control valve to generate energy-concentrating water shock waves, forming a permeability enhancement zone near the well and breaking the oil-water interface balance at the far well, thereby achieving enhanced production and injection through hydraulic pulsation. Simultaneously, during the energy storage process, water is still injected at a stable pressure, which can simulate pulsation injection based on different initial formation pressures (or energies). This construction method results in better pulse effect and stronger adaptability to oilfield conditions.

[0026] 2. The present invention can adjust the water injection construction parameters (injection pressure, frequency and discharge volume) in a timely manner through the control system to achieve flexible water injection control and optimal water injection effect.

[0027] 3. This invention uses a pressure control valve to control the downstream pressure, ensuring stable injection in the injection well and minimizing the impact of upstream pressure changes. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the energy storage buffer of the present invention;

[0030] Figure 3 This is a schematic diagram of the process flow of the present invention.

[0031] Wherein: 1-Water storage tank, 2-Energy storage buffer, 3-Pressure control valve, 4-Power pump source, 5-Flow meter, 6-Pressure gauge, 7-Water injection well, 8-Water distribution station, 9-Pipeline, 10-Control system, 11-Tank body, 12-Air injection pump, 13-Air injection inlet, 14-Drainage inlet / outlet, 15-Airbag, 16-Pressure detection panel, 17-Valve a, 18-Valve b, 19-Valve c, 20-Valve d, 21-Valve e, 22-Valve f. Detailed Implementation

[0032] The present invention will be further described below with reference to the embodiments and accompanying drawings, but is not limited thereto.

[0033] Example 1:

[0034] like Figure 1-3 As shown, this embodiment provides a focused water shock wave enhanced production and injection generation system, including a water storage tank 1, an energy storage buffer 2, an amplitude and pressure control valve 3, a power pump source 4, an injection well 7, and a control system 10, wherein...

[0035] The water storage tank 1 is connected to a power pump source 4. The power pump source 4 is connected to the water injection well 7 via two pipes 9. Several energy storage buffers 2 are installed on one pipe between the power pump source 4 and the water injection well 7. A pressure control valve 3 and a water distribution station 8 are installed on the other pipe. A valve a17 is installed on the pipe from the power pump source 4 to the energy storage buffer 2. A valve b18 is installed on the pipe from the power pump source 4 to the pressure control valve 3. A valve c19 is installed on the pipe from the energy storage buffer 2 to the water injection well 7. A valve d20 is installed on the pipe from the water distribution station 8 to the water injection well 7. The energy storage buffer 2, pressure control valve 3, power pump source 4, valve a17, valve b18, valve c19 and valve d20 are all connected to a control system 10.

[0036] The energy storage buffer 2 includes a tank 11, an air bladder 15, an air injection pump 12, and a pressure detection panel 16. An air bladder 15 is installed at the top of the tank 11. The air bladder 15 is connected to the air injection pump 12 through the air injection inlet 13 at the top of the tank 11. The bottom of the tank 11 is connected to the pipeline between the power pump source 4 and the water injection well 7 through the drainage inlet 14. The pressure detection panel 16 is connected to the pressure sensors in the air bladder 15 and the tank 11 respectively to detect the pressure values ​​in the air bladder and the tank. Both the air injection pump 12 and the pressure detection panel 16 are connected to the control system 10.

[0037] A valve e21 is installed on the gas injection inlet pipe, and a valve f22 is installed on the drainage inlet / outlet pipe 14. Both valves e21 and f22 are connected to a control system.

[0038] The pressure control valve 3 is a YB43X ultra-high pressure fixed proportional pressure reducing valve.

[0039] A flow meter 5 is installed on the outlet pipe of the power pump source 4, and a flow meter and pressure gauge 6 are installed on the connecting pipe of the injection well 7 to detect the flow rate and pressure of the liquid in the pipe.

[0040] The working method of the above-mentioned focused water shock wave enhanced production and injection generation system is as follows:

[0041] (1) Based on the reservoir water injection requirements and on-site construction conditions, set the number of energy storage buffers and the pressure inside the airbag, set the outlet pressure of the amplitude pressure control valve, and set the power pump source drainage flow rate.

[0042] (2) Open valves a, b and d, close valve c, start the power pump to drain water, and the water flows into two branch pipes. Part of the water flows into the tank of the energy storage buffer, and the other part flows through the pressure control valve and the water distribution station and enters the water injection well.

[0043] (3) The power pump source continuously discharges water at a constant flow rate. Under the pressure reduction effect of the pressure control valve, some of the water that cannot pass through the pressure control valve enters the energy storage buffer, contacts and squeezes the air bag, and the kinetic energy of the water is converted into the pressure energy of the air bag. At this time, the pressure at the inlet end of the pressure control valve gradually increases and the pressure at the outlet end stabilizes. The water injection well maintains a stable pressure constant pressure water injection.

[0044] (4) The power pump continuously drains water until the pressure inside the airbag reaches the preset value. Then, valve c is opened, and the gas pressure energy inside the airbag of the energy storage buffer is converted back into the kinetic energy of the water. The water in the compression tank is quickly injected into the water injection well. The kinetic energy of the water in the water injection well is converted into the pressure energy of the pore water, and the pressure at the wellhead of the water injection well rises rapidly.

[0045] (5) Observe the pressure at the wellhead of the injection well until the pressure drops and stabilizes, then close valve c and the energy storage buffer will re-store water and energy.

[0046] (6) Repeat steps (3)-(5), and after multiple rounds of energy accumulation and release, repeatedly convert the water injection kinetic energy into pore pressure pulsation, forming a permeability enhancement zone near the well and breaking the oil-water interface balance at the far well, thereby improving the water drive recovery rate.

[0047] Example 2:

[0048] A method for operating a shaped-wave enhanced production and injection generation system as described in Example 1, when applied to an oil reservoir with a reservoir thickness of 20m, differs in that...

[0049] In step (1), four energy storage buffers are set, the pressure inside the airbag is 5 MPa, valve e is opened, and high-pressure nitrogen is injected into the airbag using an air injection pump until the pressure inside the airbag reaches 5 MPa. The air injection pump and valve e are then closed, the outlet pressure of the amplitude control valve is set to 5 MPa, and the drainage flow rate of the power pump source is set to 200 m³ / h. 3 / d;

[0050] In step (4), the preset pressure inside the airbag is 15 MPa;

[0051] In step (5), after observing the pressure drop at the injection wellhead stabilize at 5 MPa, valve c is closed.

[0052] Example 3:

[0053] A method for operating a shaped-wave enhanced production and injection generation system as described in Example 1 was applied to an oil reservoir with a reservoir thickness of 20m. In a reservoir in the Shengli Oilfield, the formation depth is 1000m, the sand layer thickness is 18m, the original formation pressure is 11MPa, the original formation temperature is 43.5℃, and the surface crude oil density in this area is 0.97g / cm³. 3 Under the formation conditions, the crude oil viscosity is 2100 mPa·s. The crude oil viscosity is high, the oil-water viscosity ratio is large, the fingering phenomenon is serious, and the residual oil saturation is relatively high. Based on the reservoir geological conditions, the difference between this and Example 1 is that:

[0054] In step (1), four energy storage buffers are set, the pressure inside the airbag is 20 MPa, valve e is opened, and high-pressure nitrogen is injected into the airbag using the air injection pump until the pressure inside the airbag reaches 20 MPa. The air injection pump and valve e are then closed, the outlet pressure of the amplitude control valve is set to 15 MPa, and the drainage flow rate of the power pump source is set to 200 m³ / h. 3 / d, the pressure reduction ratio of the amplitude pressure control valve is 2:1;

[0055] In step (4), the preset pressure inside the airbag is 25 MPa;

[0056] In step (5), after observing the pressure drop at the injection wellhead stabilize at 15MPa, valve c is closed.

[0057] By performing several rounds of high-pressure pulsed injection, pore pulse waves are generated, causing periodic changes in the capillary pressure in the pores. This reduces the flow resistance of the remaining oil, allowing it to break free from capillary force constraints and be displaced, thus improving the sweep efficiency and washing efficiency.

[0058] The specific embodiments described in this specification may differ in the shape and name of their parts and components. All equivalent or simple variations made to the structure, features, and principles described in this patent concept are included within the scope of protection of this patent. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, as long as they do not depart from the structure of this invention or exceed the scope defined in these claims, all of which should fall within the scope of protection of this invention.

Claims

1. A working method for a focused water shock wave enhanced production and injection generation system, characterized in that, The system includes a water storage tank, an energy storage buffer, a pressure control valve, a power pump source, an injection well, and a control system. The water storage tank is connected to a power pump source, which is connected to the water injection well via two pipelines. Several energy storage buffers are installed on one pipeline between the power pump source and the water injection well, and a pressure control valve and a water distribution station are installed on the other pipeline. Valve a is installed on the pipeline from the power pump source to the energy storage buffer, valve b is installed on the pipeline from the power pump source to the pressure control valve, valve c is installed on the pipeline from the energy storage buffer to the water injection well, and valve d is installed on the pipeline from the water distribution station to the water injection well. The energy storage buffer, pressure control valve, power pump source, valve a, valve b, valve c, and valve d are all connected to a control system. The energy storage buffer includes a tank, an air bladder, an air injection pump, and a pressure detection panel. An air bladder is installed at the top of the tank. The air bladder is connected to the air injection pump through the air injection inlet at the top of the tank. The bottom of the tank is connected to the pipeline between the power pump source and the water injection well through the drainage inlet and outlet. The pressure detection panel is connected to the pressure sensors in the air bladder and the tank respectively. Both the air injection pump and the pressure detection panel are connected to the control system. Valve e is installed on the gas injection inlet pipe, and valve f is installed on the drainage inlet and outlet pipes; The working method of the above-mentioned focused water shock wave enhanced production and injection generation system is as follows: (1) Based on the reservoir water injection requirements and on-site construction conditions, set the number of energy storage buffers and the pressure inside the airbag, set the outlet pressure of the amplitude pressure control valve, and set the power pump source drainage flow rate; (2) Open valves a, b and d, close valve c, start the power pump to drain water, and the water flows into two branch pipes. Part of the water flows into the tank of the energy storage buffer, and the other part flows through the pressure control valve and the water distribution station and into the water injection well. (3) The power pump source continuously discharges water at a constant flow rate. Under the pressure reduction effect of the pressure control valve, some of the water that cannot pass through the pressure control valve enters the energy storage buffer, contacts and squeezes the air bag, and the kinetic energy of the water is converted into the pressure energy of the air bag. At this time, the pressure at the inlet end of the pressure control valve gradually increases and the pressure at the outlet end stabilizes. The water injection well maintains a stable pressure constant pressure water injection. (4) The power pump continues to drain water until the pressure inside the airbag reaches the preset value. Then, valve c is opened, and the gas pressure energy inside the airbag of the energy storage buffer is converted back into the kinetic energy of the water. The water in the compression tank is quickly injected into the water injection well, and the kinetic energy of the water is converted into the pressure energy of the pore water in the water injection well. The pressure at the wellhead of the water injection well rises rapidly. (5) Observe the pressure at the wellhead of the injection well until the pressure drops and stabilizes, then close valve c and the energy storage buffer will re-store water and energy. (6) Repeat steps (3)-(5), and after multiple rounds of energy accumulation and release, repeatedly convert the water injection kinetic energy into pore pressure pulsation, forming a permeability enhancement zone near the well and breaking the oil-water interface balance at the far well.

2. The working method of the focused water shock wave enhanced production and injection generation system as described in claim 1, characterized in that, The pressure control valve is a YB43X ultra-high pressure fixed proportional pressure reducing valve.

3. The working method of the focused water shock wave enhanced production and injection generation system as described in claim 2, characterized in that, A flow meter is installed on the outlet pipe of the power pump source, and a flow meter and pressure gauge are installed on the connecting pipe of the injection well.

4. The working method of the focused water shock wave enhanced production and injection generation system as described in claim 3, characterized in that, In step (1), based on a reservoir thickness of 20 m, four energy storage buffers are set, the pressure inside the gasbag is 5 MPa, valve e is opened, and high-pressure nitrogen is injected into the gasbag using an injection pump until the pressure inside the gasbag reaches 5 MPa. The injection pump and valve e are then closed, the outlet pressure of the amplitude control valve is set to 5 MPa, and the drainage flow rate of the power pump source is set to 200 m³ / s. 3 / d; In step (4), the preset pressure inside the airbag is 15 MPa; In step (5), after observing the pressure drop at the injection wellhead stabilize at 5 MPa, valve c is closed.

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