Application technical equipment for enhancing oil extraction, water shutoff, oil increase and recovery efficiency improvement through electroosmotic flow

Abstract

The invention discloses application technical equipment for enhancing oil extraction, water shutoff, oil increase and recovery efficiency improvement through electroosmotic flow, belongs to the technical field of oil exploitation, and solves the problems that an existing device only depends on basic electroosmotic flow to act on an oil reservoir, dead oil areas and remaining oil areas are difficult to activate, and the yield increasing effect is limited. Comprising a combined transformer, a switch cabinet, a high-frequency oil extraction power supply device, a transmission cable and a sleeve group, according to the device, the high-frequency oil extraction power source device is arranged and can accurately dredge a dead oil area, a remaining oil area and a capillary bound water area which are not used in water injection development through the synergistic effect of multiple mechanisms of fracture forming, water plugging and electrochemical plugging removal of high-frequency pulse electromagnetic waves, the swept volume is increased, meanwhile, a water film on the surface of rock is driven to be thinned, and the oil extraction efficiency is improved. A seepage space is vacated for oil flow, the water reducing and oil increasing effects are more remarkable, and the purpose of high recovery efficiency is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil exploitation, and particularly relates to an electroosmotic flow enhanced oil recovery and water plugging technology equipment for improving oil recovery. Background Art

[0002] As one of the most important energy resources globally, the efficient development of petroleum and the improvement of its recovery rate have always been the core propositions of the petroleum industry. With the continuous deepening of global oil and gas resource development, most major oilfields have entered the middle and late stages of development, and problems such as significant attenuation of formation energy, decline in permeability, and increase in water content of the produced crude oil (such as water channeling and water flooding channels formed after water injection development, and aggravated reservoir heterogeneity) have become increasingly prominent, resulting in a decline in crude oil recovery rate. How to tap the potential of remaining oil and improve the recovery rate through technological innovation has become the key to the sustainable development of the petroleum industry.

[0003] Currently, the technologies for improving crude oil recovery rate are mainly divided into two categories: chemical flooding technology and physical field control technology. The chemical flooding technology has significant limitations: on the one hand, the injection cost of chemical agents is high, and they are prone to degradation, adsorption loss under high temperature and high pressure formation environments, and the actual effective utilization rate is low; on the other hand, some chemical agents may cause irreversible damage to the formation or environmental problems such as groundwater pollution, restricting their popularization and application in environmentally sensitive areas.

[0004] Chinese Patent CN112211605A discloses a pulsed electroosmotic flow oil production operation device, which includes an operation box. A power supply, a pulse generator, two electrode wires, and two electrode plates are arranged in the operation box. Four universal wheels are arranged at the bottom of the operation box. A support plate is fixedly installed in the operation box. The power supply and the pulse generator are both arranged on the top of the support plate. A storage box is arranged on the top of the operation box. Both electrode plates are arranged in the storage box. A push plate is vertically slidably installed in the operation box. Four support legs are fixedly installed at the bottom of the push plate; however, the existing device only relies on the basic electroosmotic flow acting on the oil reservoir, and it is difficult to activate the dead oil area and the remaining oil area, and the oil production increase effect is limited. In view of the above problems, we propose an electroosmotic flow enhanced oil recovery and water plugging technology equipment for improving oil recovery. Summary of the Invention

[0005] The purpose of the present invention is to provide an electroosmotic flow enhanced oil recovery and water plugging technology equipment for improving oil recovery in view of the deficiencies of the prior art, and solve the problem that the existing device only relies on the basic electroosmotic flow acting on the oil reservoir.

[0006] Existing devices only rely on the basic electroosmotic flow acting on the reservoir, making it difficult to activate dead oil zones and remaining oil zones, and the effect of increasing production is limited. To address the above problems, we have proposed an electroosmotic flow enhanced oil recovery, water plugging and oil increasing, and enhanced oil recovery application technology equipment. Briefly, the equipment consists of a combined transformer, a switch cabinet, a high-frequency oil production power supply device, a transmission cable, and a casing group. During operation, the combined transformer is connected to the on-site 10KV high-voltage line and converts the 10KV high-voltage line into the voltage required for high-frequency pulsed current. The switch cabinet is synchronously turned on, and the combined transformer supplies power to the high-frequency oil production power supply device. The current and voltage are selected (determined according to the well spacing, physical properties, and electrical properties of the formation). The high-frequency oil production power supply device generates high-frequency pulsed current for oil production. The high-frequency pulsed current is transmitted through the transmission cable to the connected positive electrodes, and the connected positive electrodes form a high-frequency pulsed wave. Continuous operation for about 24 to 72 hours can achieve the effects of reducing water production, increasing liquid production, and increasing production. According to the different viscosities of heavy oil, the operation time can be appropriately increased. After 24 hours of operation, the water content of the produced liquid is measured and analyzed, and the increase and change of the liquid volume and the change of temperature are used to determine whether to extend the operation time, adjust the operation parameters, or end the current operation. In the embodiment of the present invention, a high-frequency oil production power supply device is provided. As the core component of the high-frequency electroosmotic flow oil production technology, by outputting high-frequency pulsed electromagnetic waves with a specific frequency (≥10kHz), through the multi-mechanism synergistic action of "fracture creation - water plugging - electrochemical plugging removal" of the high-frequency pulsed electromagnetic waves, it can accurately dredge the unexploited dead oil zones, remaining oil zones, and capillary-bound water zones in water injection development, expand the swept volume, and at the same time drive the thinning of the water film on the rock surface to create seepage space for oil flow, significantly improving the oil-phase flow capacity, directly reducing the oil-water interfacial tension, and at the same time using electroosmotic flow to directionally drive the bound water and narrow the water-phase seepage channel, resulting in a more significant effect of reducing water production and increasing oil production.

[0007] The present invention is implemented as follows. The electroosmotic flow enhanced oil recovery, water plugging and oil increasing, and enhanced oil recovery application technology equipment includes:

[0008] A combined transformer, electrically connected to the 10KV high-voltage line, for converting the high-voltage electricity of the 10KV high-voltage line into the voltage required for high-frequency pulsed current;

[0009] A switch cabinet, electrically connected to the combined transformer, for controlling the on / off of the circuit and overcurrent protection;

[0010] A high-frequency oil production power supply device, electrically connected to the switch cabinet, for generating and outputting high-frequency pulsed current for oil production;

[0011] A transmission cable, electrically connected to the high-frequency oil production power supply device, for transmitting high-frequency pulsed current;

[0012] A casing group, arranged in the reservoir, for supporting the positive and negative electrodes and assisting the positive and negative electrodes to generate high-frequency pulsed waves.

[0013] Preferably, the combined transformer includes:

[0014] The high-voltage transformer is electrically connected to the 10 kV high-voltage line and is used to convert the high voltage of the 10 kV high-voltage line into 380 V alternating current;

[0015] The low-voltage transformer is electrically connected to the high-voltage transformer and is also electrically connected to the switch cabinet. The low-voltage transformer is used to supply power to the high-frequency oil production power supply device.

[0016] Preferably, the bushing group includes:

[0017] The positive bushing is installed in the oil reservoir. A connecting positive electrode is sleeved on the positive bushing, and the connecting positive electrode is electrically connected to the high-frequency oil production power supply device through a transmission cable;

[0018] The negative bushing is installed in the oil reservoir. A connecting negative electrode is sleeved on the negative bushing, and the connecting negative electrode is electrically connected to the high-frequency oil production power supply device through a transmission cable.

[0019] Preferably, the high-frequency oil production power supply device includes:

[0020] The high-frequency electric processing main control is fixedly installed in the high-frequency oil production power supply device;

[0021] The power conversion module is electrically connected to the high-frequency electric processing main control and is used to convert low-voltage alternating current into high-frequency pulsed current. The frequency adjustment range of the power conversion module is 10 kHz - 1 MHz;

[0022] The isolation transformer is arranged in the high-frequency oil production power supply device, and the isolation transformer is electrically connected to the high-frequency electric processing main control;

[0023] At least one group of isolation protectors is arranged in the high-frequency oil production power supply device. The isolation protectors are electrically connected to the high-frequency electric processing main control and are also electrically connected to the transmission cable.

[0024] Preferably, the high-frequency electric processing main control includes:

[0025] The data acquisition unit is used to acquire and analyze the high-frequency pulsed current generation parameters and generate high-frequency electric processing instructions based on the high-frequency pulsed current generation parameters;

[0026] The electric access unit, in response to the high-frequency electric processing instructions, controls the combined transformer and the switch cabinet to turn on, enables the power conversion module to access alternating current, and converts the alternating current into high-frequency pulsed special electromagnetic waves through rectification and frequency conversion;

[0027] A multiple operation unit, in response to high-frequency electric treatment instructions, applies different high-frequency pulsed waves to an oil reservoir based on different high-frequency electric treatment instructions. When applying different high-frequency pulsed waves to the oil reservoir based on different high-frequency electric treatment instructions, the high-frequency pulsed waves generate electric explosions, electric shocks, and high-temperature and high-pressure gases when passing through the formation, improving the diversion capacity of the oil reservoir.

[0028] Preferably, the working voltage of the high-frequency oil production power supply device is 150V, the maximum current is 1500A, the loading rate of the high-frequency pulsed current ≥ 10 6 V / s, and the high-frequency pulsed current is 0 - 120V isolated high-frequency direct current to ensure that the peak pressure is reached within 0.1 - 20ms.

[0029] Preferably, the negative electrode sleeve is arranged in a water well, and the positive electrode sleeve is arranged in an oil well.

[0030] Preferably, the transmission cable is a 120mm 2 copper cable with a length of 1500m.

[0031] Compared with the prior art, the embodiments of the present application mainly have the following beneficial effects:

[0032] In the embodiments of the present invention, a high-frequency oil production power supply device is provided. As the core component of the high-frequency electroosmotic flow oil production technology, the high-frequency oil production power supply device outputs high-frequency pulsed electromagnetic waves with a specific frequency (≥ 10kHz). Through the multi-mechanism synergistic action of "fracture creation - water plugging - electrochemical plug removal" of the high-frequency pulsed electromagnetic waves, it can accurately dredge the unexploited dead oil areas, remaining oil areas, and capillary-bound water areas in water injection development, expand the swept volume, and at the same time drive the water film on the rock surface to thin, creating seepage space for oil flow, significantly enhancing the oil-phase flow capacity, directly reducing the oil-water interfacial tension, and at the same time using electroosmotic flow to directionally drive the bound water and narrow the water-phase seepage channels, with a more significant effect of reducing water and increasing oil.

[0033] The high-frequency oil production power supply device can act on formations of general sandstone and carbonate. At the same time, it is suitable for formations with high, medium, and low permeabilities or ultra-low permeabilities after fracturing production. Practice has proved that some low-permeability or ultra-low-permeability oil wells with ineffective or poor acid fracturing effects will produce very obvious and satisfactory effects after adopting this technology. And this technology can be applied to increase liquid production, injection, and production in low-permeability oilfields with a liquid production water cut of 95%, thereby improving the oil recovery rate, and is not restricted or affected by the formation temperature and water salinity.

[0034] The oil production and water plugging and oil increment enhancing oil recovery application technology equipment provided by the embodiments of the present invention has the following advantages: simple operation, convenient to operate, and easy to construct. It can solve the problems in production at any time as needed, such as high water cut in produced fluid, formation plugging (structural plugging or wax plugging) between two wells, too high injection pressure or inability to inject water, etc.; strong adaptability. During operation, only two wells are required to be in the same production layer. During operation, only geological personnel need to put forward the problems and requirements to be solved, and a construction plan and purpose can be compiled for operation; wide application range, many types of problems can be handled, short operation time, and production can be carried out without stopping; environmentally friendly and pollution-free, and it will not cause damage to the formation; it will not cause any side effects and subsequent problems to the oilfield; the operation direction can be arbitrarily arranged to drive the parts with more remaining oil in the formation. Brief Description of the Drawings

[0035] Figure 1 is a schematic structural diagram of the oil production and water plugging and oil increment enhancing oil recovery application technology equipment provided by the present invention.

[0036] Figure 2 is a schematic structural diagram of the high-frequency oil production power supply device provided by the present invention.

[0037] In the figure: 100 - combined transformer, 110 - high-voltage transformer, 120 - low-voltage transformer, 200 - switch cabinet, 300 - high-frequency oil production power supply device, 310 - high-frequency electric treatment main control, 311 - data acquisition unit, 312 - power access unit, 313 - multiple operation unit, 320 - power conversion module, 330 - isolation transformer, 340 - isolation protector, 400 - transmission cable, 500 - casing group, 510 - positive casing, 520 - negative casing. Detailed Embodiments

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of this application or the above drawings are used to distinguish different objects and are not used to describe a specific order.

[0039] Existing devices only rely on the basic electroosmotic flow acting on the oil reservoir, resulting in the inability to achieve selective regulation of "water plugging without oil plugging", and it is difficult to activate dead oil areas and remaining oil areas, with limited production increase effect. To address the above problems, we have proposed an electroosmotic flow enhanced oil production, water plugging and oil production, and enhanced oil recovery application technology equipment. Briefly, the equipment consists of a combined transformer 100, a switch cabinet 200, a high-frequency oil production power supply device 300, a transmission cable 400, and a casing group 500. During operation, the combined transformer 100 is connected to the on-site 10KV high-voltage line and converts the 10KV high-voltage line into the voltage required for high-frequency pulsed current. The switch cabinet 200 is synchronously turned on, and the combined transformer 100 supplies power to the high-frequency oil production power supply device 300. The current voltage is selected (determined according to the well spacing, physical properties, and electrical properties of the formation). The high-frequency oil production power supply device 300 generates high-frequency pulsed current for oil production. The high-frequency pulsed current is transmitted through the transmission cable 400 to the connection positive electrode, connection positive electrode, connection positive electrode to form a high-frequency pulsed wave. After continuous operation for about 24 to 72 hours, the effects of reducing water production, increasing liquid production, and increasing production can be achieved, and the operation time can be appropriately increased according to the different viscosities of the crude oil. After 24 hours of operation, the water content of the produced liquid is measured and analyzed, and the increase and change of the liquid volume and the change of temperature are used to determine whether to extend the operation time, adjust the operation parameters, or end the current operation. In the embodiment of the present invention, a high-frequency oil production power supply device 300 is provided. As the core component of the high-frequency electroosmotic flow oil production technology, by outputting high-frequency pulsed electromagnetic waves with a specific frequency (≥10kHz), through the multi-mechanism synergistic action of "fracture creation - water plugging - electrochemical plugging removal" of the high-frequency pulsed electromagnetic waves, it can accurately dredge the unexploited dead oil areas, remaining oil areas, and capillary bound water areas in water injection development, expand the swept volume, at the same time drive the water film on the rock surface to thin, create seepage space for oil flow, significantly enhance the oil-phase flow capacity, and directly reduce the oil-water interfacial tension. At the same time, use electroosmotic flow to directionally drive bound water and narrow the water-phase seepage channel, and the effect of reducing water production and increasing oil production is more significant.

[0040] The embodiment of the present invention provides an electroosmotic flow enhanced oil production, water plugging and oil production, and enhanced oil recovery application technology equipment, as Figure 1 shown, the electroosmotic flow enhanced oil production, water plugging and oil production, and enhanced oil recovery application technology equipment includes:

[0041] A combined transformer 100, electrically connected to the 10KV high-voltage line, for converting the high-voltage electricity of the 10KV high-voltage line into the voltage required for high-frequency pulsed current;

[0042] A switch cabinet 200, electrically connected to the combined transformer 100, for controlling the on-off of the circuit and overcurrent protection;

[0043] It should be noted that the switch cabinet 200 is also connected to a water cooling device.

[0044] The high-frequency oil production power supply device 300 is electrically connected to the switch cabinet 200 and is used to generate and output high-frequency pulsed current for oil production;

[0045] The transmission cable 400 is electrically connected to the high-frequency oil production power supply device 300 and is used to transmit high-frequency pulsed current. Among them, the transmission cable 400 is a 120 mm 2 copper cable with a length of 1500 m;

[0046] The casing group 500 is arranged in the oil reservoir and is used to support the positive and negative electrodes and assist the positive and negative electrodes to generate high-frequency pulsed waves.

[0047] In this embodiment, the casing group 500 includes:

[0048] The positive electrode casing 510 is installed in the oil reservoir. A connecting positive electrode is sleeved on the positive electrode casing 510, and the connecting positive electrode is electrically connected to the high-frequency oil production power supply device 300 through the transmission cable 400;

[0049] The negative electrode casing 520 is installed in the oil reservoir. A connecting negative electrode is sleeved on the negative electrode casing 520, and the connecting negative electrode is electrically connected to the high-frequency oil production power supply device 300 through the transmission cable 400.

[0050] Among them, the negative electrode casing 520 is arranged in the water well, and the positive electrode casing 510 is arranged in the oil well. The depth of the oil well is not more than 3500 meters. For oil wells over 3500 meters, parameters need to be tested before a decision can be made. Generally, the surface well spacing should not exceed 500 meters.

[0051] In the embodiment of the present invention, there is a high-frequency oil production power supply device 300. As the core component of the high-frequency electroosmotic flow oil production technology, the high-frequency oil production power supply device 300 outputs high-frequency pulsed electromagnetic waves with a specific frequency (≥10 kHz). Through the multi-mechanism synergistic effect of "fracture formation - water plugging - electrochemical plug removal" of the high-frequency pulsed electromagnetic waves, it can accurately dredge the untouched dead oil areas, remaining oil areas and capillary bound water areas in water injection development, expand the swept volume, and at the same time drive the thinning of the water film on the rock surface, create seepage space for the oil flow, significantly improve the oil-phase flow capacity, and directly reduce the oil-water interfacial tension. At the same time, it uses electroosmotic flow to directionally drive the bound water and narrow the water-phase seepage channel, and the effect of reducing water and increasing oil is more significant.

[0052] In a further preferred embodiment of the present invention, the combined transformer 100 includes:

[0053] The high-voltage transformer 110 is electrically connected to the 10 kV high-voltage line and is used to convert the high voltage of the 10 kV high-voltage line into 380 V alternating current;

[0054] A low-voltage transformer 120, which is electrically connected to the high-voltage transformer 110 and also electrically connected to the switch cabinet 200, is used to supply power to the high-frequency oil production power supply device 300.

[0055] In a further preferred embodiment of the present invention, as Figure 2 shown, the high-frequency oil production power supply device 300 includes:

[0056] A high-frequency electric processing main control 310, which is fixedly installed inside the high-frequency oil production power supply device 300;

[0057] A power conversion module 320, which is electrically connected to the high-frequency electric processing main control 310 and is used to convert low-voltage alternating current into high-frequency pulsed current. The frequency adjustment range of the power conversion module 320 is 10 kHz - 1 MHz;

[0058] An isolation transformer 330, which is arranged inside the high-frequency oil production power supply device 300 and is electrically connected to the high-frequency electric processing main control 310;

[0059] At least one group of isolation protectors 340, which are arranged inside the high-frequency oil production power supply device 300. The isolation protectors 340 are electrically connected to the high-frequency electric processing main control 310 and are also electrically connected to the transmission cable 400.

[0060] In this embodiment, the oil production mechanism of the high-frequency oil production power supply device 300 is that through the action of high-frequency special electromagnetic waves, the spatial and interfacial structures of the oil layer are changed, that is, the blockage between two wells in the oil layer is cleared, the permeability is increased, and tiny fractures are generated, reducing the interfacial tension and adhesion between oil and water and between rock, especially the electrostatic attraction of oil in the formation. At the same time, where there is a lot of capillary water, the heat generated by electricity vaporizes the water, blocking the seepage of water, thereby reducing the water content in the produced liquid. In fact, under the action of high-frequency special waves, the physical properties of the oil layer are transformed, the crude oil production and the oilfield recovery rate are increased. In this embodiment, the high-frequency oil production power supply device 300 can act on general sandstone and carbonate formations. It is also suitable for formations with high, medium and low permeabilities or ultra-low permeabilities after fracturing production. Practice has proved that some low-permeability or ultra-low-permeability oil wells that do not produce effective results or have poor results after acid fracturing will produce very obvious and satisfactory results after adopting this technology. And in the case where the water content in the produced liquid of low-permeability oilfields is 95%, this technology can be used for increasing liquid production, injection and production, thereby improving the application of the recovery rate. It is not restricted or affected by the formation temperature and water salinity.

[0061] It should be noted that the combined transformer 100, switch cabinet 200, and high-frequency oil production power supply device 300 can all be installed on the on-site operation vehicle, so that the operation vehicle can flexibly transport the combined transformer 100, switch cabinet 200, and high-frequency oil production power supply device 300 to the vicinity of the 10KV high-voltage line.

[0062] In a further preferred embodiment of the present invention, as Figure 2 shown, the high-frequency electric treatment main control 310 includes:

[0063] A data acquisition unit 311, configured to acquire and analyze high-frequency pulse current generation parameters, and generate a high-frequency electric treatment instruction based on the high-frequency pulse current generation parameters;

[0064] An electric access unit 312, in response to the high-frequency electric treatment instruction, controls the combined transformer 100 and the switch cabinet 200 to be turned on, enables the power conversion module 320 to access alternating current, and converts the alternating current into high-frequency pulse special electromagnetic waves through rectification and frequency conversion;

[0065] A multiple operation unit 313, in response to the high-frequency electric treatment instruction, applies different high-frequency pulse waves to the oil layer based on different high-frequency electric treatment instructions. Among them, when applying different high-frequency pulse waves to the oil layer based on different high-frequency electric treatment instructions, the high-frequency pulse waves generate electric explosion, electric shock, and generate high-temperature and high-pressure gas when passing through the formation, improving the diversion ability of the oil layer.

[0066] In this embodiment, the multiple operation unit 313 applies different high-frequency pulse waves to the oil layer based on different high-frequency electric treatment instructions, and has the following functions:

[0067] 1) Fracture formation function. When the high-frequency pulse passes through the formation, it generates electric explosion, electric shock, and generates a large amount of high-temperature and high-pressure gas, reaching the peak pressure within 0.1 - 20 ms. This relatively high loading rate leads to the formation of a radial multi-fracture system in the formation, increasing the chance of communicating natural fractures and greatly improving the diversion ability of the oil layer.

[0068] 2) Water plugging and water control to improve the oil-phase permeability and reduce the water-phase permeability. The high-frequency pulse generates electric explosion and high temperature in the water-rich and multi-water areas when passing through the formation, vaporizing the water and pushing the water to both sides. When the temperature drops, a vacuum is formed, thus blocking the water channel and the seepage of water. Under the action of direct current, the water-phase permeability can be reduced and the oil-phase permeability can be improved. The water-phase permeability drops from 20 millidarcies to 12 millidarcies, while the oil-phase permeability increases from 39 millidarcies to 50 millidarcies. Since water in the oil layer is positively charged, during operation, the water well is connected to the negative electrode. Affected by the electric field, water will migrate towards the water well, hindering the flow of water towards the oil well.

[0069] 3) Electro-driven effect: In formation capillaries, the flow rate of electroosmotic flow is proportional to the square of the capillary radius, and the flow rate of hydrodynamic flow is proportional to the fourth power of the capillary radius. Therefore, electroosmotic flow can drive fluids that hydrodynamic flow cannot drive, thereby increasing the oil well production and improving the oil recovery rate of the oilfield.

[0070] 4) Electrochemical effect: When the applied DC electric field is greater than the electric field strength of the formation fluid, the oil reservoir is equivalent to a sealed electrolytic cell, and a large amount of gas will be electrolyzed from the formation fluid. The energy of the gas expansion increases the oil reservoir pressure, thereby increasing the oil production. At the same time, the expansion and diffusion of the gas can relieve the blockage of the pore channels and improve the permeability of the fluid in the oil reservoir.

[0071] 5) Electroosmotic flow effect: According to the formation diffusion double layer theory, in a water-wet formation, a double layer is formed at the interface between the formation water and the rock. Under the action of an applied DC electric field, the mobile layer of the double layer carries water molecules and moves together, generating an electroosmotic flow effect that is beneficial to water flooding oil. Water is positively charged and moves towards the negative electrode, while oil is negatively charged and moves towards the positive electrode. The number of cations moving towards the cathode in the mobile layer of the diffusion double layer is greater than that of anions, carrying macromolecules to generate an additional electroosmotic flow towards the cathode, thereby reducing the flow ability of the water phase. At the same time, the thickness of the water film on the rock surface becomes thinner, making room for the oil flow. Since the oil phase surface is negatively charged, the flow ability towards the positive electrode increases. The electroosmotic flow in the capillary is proportional to the square of the capillary radius.

[0072] 6) Heating and viscosity reduction effect: The energy input into the formation, according to the law of conservation of energy, is finally converted into heat energy, which is very beneficial to the wax blockage in the formation and the viscosity reduction of heavy oil. At the same time, due to the dual action of high-frequency pulses and heat, long carbon chains are easily broken to form lower molecular weight carbon chains, playing a role in viscosity reduction. The chain-breaking effect can play a certain chain-breaking role for long-chain heavy oil in heavy oil oilfields, making the heavy oil more fluid.

[0073] In the embodiment of the present invention, the working voltage of the high-frequency oil production power supply device 300 is 150V, the maximum current is 1500A, the loading rate of the high-frequency pulse current ≥ 10 6 V / s, and the high-frequency pulse current is 0 - 120V isolated high-frequency direct current, ensuring that the peak pressure is reached within 0.1 - 20ms.

[0074] In the embodiment of the present invention, an operating method for the electroosmotic flow enhanced oil production, water plugging, oil increasing, and oil recovery improvement application technology equipment is also provided. The method includes:

[0075] S10, setting up safety isolation fences and safety signs in the operation area before the operation;

[0076] S20. Place the equipment in the operation space convenient for activities on the well site, and connect all electrical equipment, that is, erect a transformer according to the well site operation regulations, connect the safety device and the switch cabinet 200, and the power supply passes through the switch cabinet 200 and then is connected to the high-frequency oil production power supply device 300 through a cable. At the same time, connect the water-cooling equipment to ensure that the water-cooling equipment can correctly dissipate heat for the oil production equipment;

[0077] S30. Connect the flexible copper core cable line connected to the electrical output of the electroosmotic flow enhanced oil production, water plugging and oil increment, and enhanced oil recovery application technology equipment to the wellhead, and require that the wellhead wiring position is in good electrical contact with the casing group 500;

[0078] S40. After the operation measures start, it is necessary to remove the flow path of one of the oil wells first to prevent the energized reflux from conducting and affecting the current transmission to the formation oil reservoir area;

[0079] S50. Operation of the high-frequency oil production technology electrical treatment equipment: During operation, take power from below the zero shell of the power grid to the transformer. The combined transformer 100 outputs 380V alternating current and supplies power to the high-frequency oil production power supply device 300 through the switch cabinet 200. The high-frequency oil production power supply device 300 processes the 380V power supply into the current, voltage, frequency, etc. required for operation, and transports it to the wellhead and then to the oil-bearing formation through the isolation transformer 330 and the transmission cable 400. Determine the specific power-on time according to the changes in current, voltage and the wellhead;

[0080] S60. According to the actual situation of the well group, select water wells and oil wells, and connect direct current treatment oil production equipment between oil wells for power-on operation to overall increase the production of the injection-production well group.

[0081] Among them, record the operating current, voltage, and oil casing pressure of the wellhead at any time during operation. Oil well samples should be taken before operation because the oil samples change every day in the first two days of operation. The construction party starts to take oil and water samples for testing 24 hours after operation, and then takes samples every 12 hours for 15 consecutive days to observe the changes in the oil and water samples. Sampling buckets and 1000-liter measuring cups should be prepared at the operation site to detect the change in water content.

[0082] In the embodiment of the present invention, the high-frequency oil production power supply device 300 converts the 380V alternating current sent by the combined transformer 100 into special high-frequency direct current. The manufacturing of this device adopts conventional rectification, filtering, inversion and voltage regulation to obtain direct current of 0-120V (150 adjustable). The positive and negative poles of this direct current are connected to the casing group 500 (used as an electricity connection pile). Since the connection of the positive pole and the connection of the negative pole of the high-frequency direct current output by the device form a closed loop, the step voltage of the wellhead electricity connection pile to the ground during the operation process is 8-28V, which is a safe voltage and will not cause harm to people and objects. Even if a person or livestock touches the electricity connection pile, this step voltage is very low and there will be no harm. Moreover, when the high-frequency oil production power supply device 300 outputs high-frequency electricity, it conducts energy to the oil well in the form of special electromagnetic waves, thereby playing a role in enhancing oil production and increasing production. This electromagnetic wave has no impact on people and other equipment; the high-frequency oil production power supply device 300 meets the GB9706 standard for power consumption. The output uses an isolation transformer 330, which can well isolate the input and output safely and has functions of short-circuit and over-current protection. At the same time, there is a protection switch on the switch cabinet 200, and multiple measures ensure the personal safety of the operation area. The combined transformer 100 is installed by professional electricians according to the oilfield operation specifications. The transformer is placed on a special bench, keeping a proper safe distance from the ground. There is an isolation guardrail around the transformer to prevent outsiders from approaching.

[0083] After tests and applications in multiple oilfield mines, the following series of good and obvious results have been obtained for the oil and water after high-frequency pulse treatment: the success rate of the operation reaches more than 90%. The water content of the produced liquid has been significantly reduced, with an average reduction of water content by 10%-25%, and in some wells, the water content reduction can reach more than 50%. The average production increase is more than doubled, and in some cases, it can reach 3-4 times. For injection wells (except for those with montmorillonite formations or strongly water-sensitive formations), the plugging removal can achieve on-demand water injection. The operation validity period is generally 3-6 months, and in some cases, it can reach more than one year. The single-well operation time is about 24-36 hours, and the effect can be seen after 24 hours of operation.

[0084] It can be seen from this that the electroosmotic flow enhanced oil production, water plugging and oil increasing, and enhanced oil recovery application technology equipment provided by the embodiment of the present invention has the following advantages: the operation is simple, the operation is convenient, and it is easy to construct. It can solve the problems in production at any time as needed, such as the high water content of the produced liquid, formation plugging (structural plugging or wax plugging), too high injection pressure or inability to inject water, etc.; it has strong adaptability. During the operation, only two wells are required in the same production layer. During the operation, only the geological personnel need to put forward the problems and requirements to be solved, and a construction plan and purpose can be compiled for operation; it has a wide application range, can handle various types of problems, has a short operation time, and can operate without stopping production; it is environmentally friendly and pollution-free, and will not cause harm to the formation; it will not cause any side effects and aftereffects to the oilfield; the operation direction can be arbitrarily arranged to drive the parts with more remaining oil in the formation.

[0085] In summary, the present invention provides an electroosmotic flow enhanced oil recovery and water plugging and oil increasing application technology device. In the embodiment of the present invention, a high-frequency oil production power supply device 300 is provided. The high-frequency oil production power supply device 300 is the core component of the high-frequency electroosmotic flow oil production technology. By outputting high-frequency pulsed electromagnetic waves with a specific frequency (≥10 kHz), through the multi-mechanism synergistic action of "fracture creation - water plugging - electrochemical plugging removal" of the high-frequency pulsed electromagnetic waves, it can accurately dredge the unexploited dead oil areas, remaining oil areas and capillary bound water areas in water injection development, expand the swept volume, and at the same time drive the water film on the rock surface to thin, creating seepage space for oil flow, significantly enhancing the oil-phase flow capacity, directly reducing the oil-water interfacial tension, and at the same time using electroosmotic flow to directionally drive the bound water and narrow the water-phase seepage channels, and the effect of reducing water and increasing oil is more significant.

[0086] It should be noted that for the foregoing embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps may be in other sequences or carried out simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0087] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on these embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still, without conflict, make combinations, additions, deletions or other adjustments to the features in the embodiments of the present invention according to the situation without creative efforts, so as to obtain different technical solutions that essentially do not deviate from the concept of the present invention, and these technical solutions also belong to the scope of protection of the present invention.

Claims

1. Electroosmotic flow enhanced oil recovery and water plugging and oil production increasing application technology equipment, characterized in that, Including: A combined transformer, electrically connected to a 10 kV high-voltage line, for converting the high voltage of the 10 kV high-voltage line into the voltage required for high-frequency pulsed electromagnetic waves; A switchgear, electrically connected to the combined transformer, for controlling the on / off of the circuit and various protections necessary; A high-frequency oil production power supply device, electrically connected to the switchgear, for generating and outputting high-frequency pulsed current for oil production; A transmission cable, electrically connected to the high-frequency oil production power supply device, for transmitting high-frequency pulsed current; A casing group, arranged in the oil reservoir, for supporting the positive and negative electrodes and assisting the positive and negative electrodes to generate high-frequency pulsed waves.

2. The electroosmotic flow enhanced oil recovery, water plugging and oil increment, and enhanced oil recovery application technology equipment according to claim 1, characterized in that: The combined transformer includes: A high-voltage transformer, electrically connected to the 10 kV high-voltage line, for converting the high voltage of the 10 kV high-voltage line into 380 V alternating current; A low-voltage transformer, electrically connected to the high-voltage transformer and also electrically connected to the switchgear, for supplying power to the high-frequency oil production power supply device.

3. The electroosmotic flow enhanced oil recovery, water plugging and oil increment, and enhanced oil recovery application technology equipment according to claim 1, characterized in that: The casing group includes: A positive electrode casing, installed in the oil reservoir, with a connecting positive electrode sleeved on the positive electrode casing, and the connecting positive electrode is electrically connected to the high-frequency oil production power supply device through a transmission cable; A negative electrode casing, installed in the oil reservoir, with a connecting negative electrode sleeved on the negative electrode casing, and the connecting negative electrode is electrically connected to the high-frequency oil production power supply device through a transmission cable.

4. The electroosmotic flow enhanced oil recovery and water plugging and oil increment and enhanced oil recovery application technology equipment according to claim 3, characterized in that: The high-frequency oil production power supply device includes: A high-frequency electrical processing main control, fixedly installed in the high-frequency oil production power supply device; A power conversion module, electrically connected to the high-frequency electrical processing main control, for converting low-voltage alternating current into high-frequency pulsed current, and the frequency adjustment range of the power conversion module is 10 kHz - 1 MHz; An isolation transformer, arranged in the high-frequency oil production power supply device, and the isolation transformer is electrically connected to the high-frequency electrical processing main control; At least one group of isolation protectors, arranged in the high-frequency oil production power supply device, the isolation protectors are electrically connected to the high-frequency electrical processing main control and also electrically connected to the transmission cable.

5. The electroosmotic flow enhanced oil recovery, water plugging and oil increment, and enhanced oil recovery application technology equipment according to claim 4, characterized in that: The high-frequency electrical processing main control includes: A data acquisition unit, for acquiring and analyzing the parameters for generating high-frequency pulsed current, and generating high-frequency electrical processing instructions based on the parameters for generating high-frequency pulsed current; An electrical access unit, in response to the high-frequency electrical processing instructions, controls the combined transformer and the switchgear to turn on, enables the power conversion module to access alternating current, and converts the alternating current into high-frequency pulsed special electromagnetic waves through rectification and frequency conversion; A multiple operation unit, in response to the high-frequency electrical processing instructions, applies different high-frequency pulsed waves to the oil layer based on different high-frequency electrical processing instructions. When applying different high-frequency pulsed waves to the oil layer based on different high-frequency electrical processing instructions, the high-frequency pulsed waves generate electric explosion, electric shock, and high-temperature and high-pressure gas when passing through the formation, improving the conductivity of the oil layer.

6. The electroosmotic flow enhanced oil recovery, water plugging and oil increment, and enhanced oil recovery application technology equipment according to claim 5, characterized in that: The working voltage of the high-frequency oil production power supply device is 150 V and the current is 1500 A.

7. The electroosmotic flow enhanced oil recovery, water plugging and oil increment, and enhanced oil recovery application technology equipment according to claim 3, characterized in that: The negative electrode casing is arranged in a water well, and the positive electrode casing is arranged in an oil well.

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