An oilfield diaphragm water injection system

Abstract

This invention discloses an oilfield diaphragm water injection system, comprising: a water injection diaphragm pump, including a water injection pump housing, an oil injection pump housing, and a diaphragm assembly; the water injection pump housing includes a water channel communicating with a first cavity surface, the oil injection pump housing includes an oil channel communicating with a second cavity surface, and the diaphragm assembly includes a pump membrane sandwiched between the first and second cavity surfaces; a pressurization unit includes a shut-off cylinder communicating with the oil channel, the liquid column pushed by the shut-off cylinder being adapted to the size and stroke of the pump membrane. This invention achieves high-pressure, stable, and efficient water injection operations through the coordinated operation of the water injection diaphragm pump and the pressurization unit. Compared with hydraulically driven dual-medium pressurization cylinders, it eliminates the need for complex reducers and linkage mechanisms. Furthermore, the pump membrane of this invention completely avoids mixing with the pressurizing and driving media, making it more suitable for more demanding operating conditions. Simultaneously, the pump membrane of this invention has no moving parts, and the membrane contraction does not wear the sealing ring, adapting to media with many impurities, improving oil recovery while reducing maintenance frequency and costs.

Description

Technical Field

[0001] This invention relates to the field of oilfield pressurized water injection technology, and in particular to an oilfield diaphragm water injection system. Background Technology

[0002] In oilfield development, water injection is a crucial step in maintaining formation pressure and improving oil recovery. Water is typically injected into the underground oil layer using injection pumps. Currently, the most commonly used water injection equipment in oilfields includes centrifugal pumps and plunger pumps. Centrifugal pumps have low efficiency under high head and variable operating conditions and poor adaptability to different media. Plunger pumps are three-plunger pumps, consisting of a crankshaft, connecting rod, reducer, and piston. The crankshaft and connecting rod mechanism drives the reducer, which in turn drives the piston in a reciprocating motion to achieve water output. This method is complex, costly, and the piston's moving parts cause seal wear and shorten its lifespan. As oilfield development enters the middle and late stages, the permeability of the oil layer continues to decline, increasing the requirements for the pressure rating, operational stability, and adaptability of the booster water injection system. In particular, the high pressure, impurity-containing reinjection water, and drastic diurnal temperature variations make optimizing the design of the booster water injection system a key area for technological breakthroughs in the industry.

[0003] In existing technologies, traditional booster water injection devices have complex structures, numerous transmission links, and a large number of moving parts. This not only results in high manufacturing costs, but also makes them prone to problems such as jamming, wear, and seal failure due to impurities in the medium under long-term continuous and high-load operation conditions in oil fields. This leads to frequent maintenance and repairs, which seriously affects the continuity and reliability of the water injection system.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] To address the challenges posed by existing technologies such as centrifugal pumps, plunger pumps, and oil-water isolation cylinders in oilfield water injection, where the continuous decline in oil reservoir permeability necessitates increasingly stringent requirements for pressure ratings, operational stability, and adaptability of booster water injection systems. Furthermore, traditional booster water injection devices are structurally complex, with numerous transmission links and a large number of moving parts. Under long-term, continuous, and high-load operation in oilfields, these devices are prone to problems such as jamming, wear, and seal failure due to impurities in the medium, leading to frequent maintenance and severely impacting the continuity and reliability of the water injection system. This invention provides an oilfield diaphragm water injection system.

[0006] This invention is achieved through the following technical solution: An oilfield diaphragm water injection system, wherein the oilfield diaphragm water injection system comprises: A water-injection diaphragm pump includes a water-injection pump housing, an oil-injection pump housing, and a diaphragm assembly. The water-injection pump housing includes a first cavity surface and a water channel communicating with the first cavity surface. The oil-injection pump housing includes a second cavity surface and an oil channel communicating with the second cavity surface. The diaphragm assembly includes a pump membrane tightly sandwiched between the first cavity surface and the second cavity surface. The booster unit includes a diaphragm cylinder connected to the oil passage. The diaphragm cylinder is used to push hydraulic medium. The volume of the liquid column pushed by the diaphragm cylinder is adapted to the size and stroke of the pump diaphragm so that the oscillation limit position of the pump diaphragm does not contact the first cavity surface and the second cavity surface.

[0007] The oilfield diaphragm water injection system, wherein the first cavity surface is respectively provided on both sides of the water injection pump housing, two oil injection pump housings are provided, the two oil injection pump housings are mirror-coupled and sandwiched on both sides of the water injection pump housing, and the two diaphragm assemblies are respectively sandwiched between the two oil injection pump housings and the water injection pump housing. The water injection pump housing and the oil injection pump housing on one side are sandwiched together to form a pump set. The isolation cylinder is connected to the guide port of the multiple sets of pump sets through an external pipe.

[0008] The oilfield diaphragm water injection system includes a diaphragm assembly comprising multiple pump membranes, which are fitted together and a leakage sensor is provided between adjacent pump membranes.

[0009] The oilfield diaphragm water injection system further includes: A reversing control unit, including a reversing valve connected to the isolation cylinder; The return oil filtration unit includes an oil suction filter connected to the reversing valve; The pressure stabilization unit includes an accumulator located between the oil suction filter and the reversing valve.

[0010] The oilfield diaphragm water injection system includes a diaphragm cylinder comprising a variable displacement piston pump, which is used to control the moving speed of the pump diaphragm.

[0011] The oilfield diaphragm water injection system, wherein the first cavity surface is located on one side of the water injection pump casing, and the water channel is provided through both ends of the water injection pump casing along its length; the second cavity surface is located on one side of the water injection pump casing, and the oil channel is provided through both ends of the oil injection pump casing along its length. At least one of the first cavity surface and the second cavity surface is recessed along a predetermined arc, and the first cavity surface and the second cavity surface are opposite to each other to form a booster cavity, and the middle part of the pump diaphragm is oscillating in the booster cavity.

[0012] The oilfield diaphragm water injection system, wherein the water injection pump casing is provided with a plurality of first through holes along the width direction, and the plurality of first through holes connect the water channel and the first cavity surface; The oil pump housing is provided with a plurality of second through holes along the width direction, and the plurality of second through holes connect the oil channel and the second cavity surface.

[0013] The oilfield diaphragm water injection system, wherein the cross-sectional shape of the water injection pump casing and the oil injection pump casing is one of a circle, a regular polygon, or a centrally symmetrical truncated circle; The water pump housing is provided with a plurality of water channels, which are interconnected, and a plurality of first through holes are evenly arranged corresponding to the plurality of water channels. The oil pump housing is provided with a plurality of oil channels, which are interconnected, and a plurality of second through holes are evenly arranged corresponding to the plurality of oil channels.

[0014] The oilfield diaphragm water injection system includes water channels with inlets and outlets. The inlets of multiple water channels are connected through external pipes, and the outlets of multiple water channels are connected through external pipes.

[0015] The oilfield diaphragm water injection system includes an oil channel with a guide port located at one end of the oil channel and the other end of the oil channel being closed; or, the guide port extends along the center of the oil channel to the side of the oil injection pump housing opposite to the second cavity surface, and both ends of the oil channel are closed.

[0016] The beneficial effects of this invention are as follows: This invention achieves high-pressure, stable, and efficient water injection operations through the coordinated operation of a water injection diaphragm pump and a booster unit. Compared with a hydraulically driven dual-medium booster cylinder, it does not require a complex reducer or linkage mechanism. Furthermore, the pump diaphragm of this invention can completely avoid being mixed with the booster medium and the driving medium, thus making it more suitable for more demanding working conditions. At the same time, the pump diaphragm of this invention has no moving parts, and the pump diaphragm contraction will not wear the sealing ring, making it adaptable to media with many impurities. This improves the oil recovery rate while reducing the frequency and cost of maintenance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the first embodiment of the oilfield water injection device of the present invention; Figure 2 This is a schematic diagram of the second embodiment of the oilfield water injection device of the present invention; Figure 3 This is a three-dimensional structural schematic diagram of the water injection diaphragm pump of the present invention; Figure 4 This is a cross-sectional structural diagram of the water injection diaphragm pump of the present invention; Figure 5This is an exploded cross-sectional view of the water injection diaphragm pump of the present invention.

[0018] exist Figures 1 to 5 In the middle: 100, water pump housing; 110, first cavity surface; 111, first through hole; 120, water channel; 200, oil pump housing; 210, second cavity surface; 211, second through hole; 220, oil channel; 230, guide port; 300, diaphragm assembly; 310, pump diaphragm; 400, isolation cylinder; 500, reversing valve; 600, suction filter; 700, accumulator. Detailed Implementation

[0019] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0020] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0022] In oilfield development, water injection is a crucial step in maintaining formation pressure and improving oil recovery. Water is typically injected into the underground oil layer using injection pumps. Currently, the most commonly used water injection equipment in oilfields includes centrifugal pumps and plunger pumps. Centrifugal pumps have low efficiency under high head and variable operating conditions and poor adaptability to different media. Plunger pumps are three-plunger water pumps, consisting of a crankshaft, connecting rod, reducer, and piston. The crankshaft and connecting rod mechanism drives the reducer, which in turn drives the piston in a reciprocating motion to achieve water output. This process is complex, costly, and the piston's moving parts cause wear on the seals, resulting in a short lifespan. As oilfield development enters the middle and late stages, reservoir permeability continues to decline, leading to increasingly higher requirements for the pressure rating, operational stability, and adaptability of booster water injection systems. In particular, the characteristics of high-pressure, impurity-containing reinjection water, and drastic diurnal temperature variations make traditional booster water injection devices complex in structure, with numerous transmission links and a large number of moving parts. This not only results in high manufacturing costs but also makes them prone to problems such as jamming, wear, and seal failure due to the large amount of impurities in the medium under long-term continuous and high-load operation conditions in oilfields. This leads to frequent maintenance and repairs, seriously affecting the continuity and reliability of the water injection system.

[0023] To address the aforementioned problems in the prior art, this invention provides an oilfield diaphragm water injection system, such as... Figure 1 As shown, the oilfield diaphragm water injection system includes: a water injection diaphragm pump, comprising a water injection pump housing 100, an oil injection pump housing 200, and a diaphragm assembly 300. The water injection pump housing 100 includes a first cavity surface 110 and a water channel communicating with the first cavity surface 110. The oil injection pump housing 200 includes a second cavity surface 210 and an oil channel 220 communicating with the second cavity surface 210. The diaphragm assembly 300 includes a pump membrane 310 tightly clamped between the first cavity surface 110 and the second cavity surface 210. A pressurization unit includes a shut-off cylinder 400 communicating with the oil channel 220. The shut-off cylinder 400 is used to push hydraulic medium. The volume of the liquid column pushed by the shut-off cylinder 400 is adapted to the size and stroke of the pump membrane 310 so that the swing limit position of the pump membrane 310 does not contact the first cavity surface 110 and the second cavity surface 210.

[0024] This invention achieves high-pressure, stable, and efficient water injection through the coordinated operation of a water injection diaphragm pump and a booster unit. Compared to a hydraulically driven dual-medium booster cylinder, it eliminates the need for complex reducers and linkage mechanisms. Furthermore, the pump diaphragm of this invention completely avoids mixing with the booster and driving media, making it more suitable for more demanding operating conditions. Simultaneously, the pump diaphragm of this invention has no moving parts, and diaphragm contraction does not wear the sealing ring, allowing it to adapt to media with many impurities. This improves oil recovery while reducing maintenance frequency and costs. In the above embodiments, as... Figure 1 , Figure 2 and Figure 3As shown, the main body of the water injection diaphragm pump of the present invention consists of a water injection pump housing 100, an oil injection pump housing 200, and a diaphragm assembly 300. The water injection pump housing 100 has an overall columnar structure. The main difference from the prior art is that it has a first cavity surface 110 integrally formed on its outer side, and a water channel 120 extending through both ends along the length direction is opened inside. Several first through holes 111 are opened along the width direction. The first through holes 111 connect the first cavity surface 110 and the water channel 120, realizing the connection between the water channel 120 and the pressurization chamber, and providing a channel for the flow of water injection medium.

[0025] The oil pump housing 200 has a columnar structure adapted to the water pump housing 100. A second cavity surface 210 is provided on the outer side corresponding to the first cavity surface 110. An oil channel 220 extending through both ends along its length is provided inside. Several second through holes 211 are provided along their width, connecting the second cavity surface 210 and the oil channel 220, for the flow and transmission of hydraulic medium, providing power for the oscillation of the diaphragm assembly 300. To optimize fluid flow, reduce fluid resistance, and avoid diaphragm wear caused by localized pressure concentration, at least one of the first through holes 111 and the second through holes 211 is recessed along a predetermined arc. This predetermined arc matches the oscillation trajectory of the pump diaphragm 310, allowing the hydraulic medium and water medium to enter and exit the pressurization chamber more smoothly, ensuring stable oscillation of the pump diaphragm 310 and extending its service life.

[0026] The core of the diaphragm assembly 300 is the pump diaphragm 310, which is sealed and clamped between the water injection pump housing 100 and the oil injection pump housing 200. Static sealing is achieved through bolt tightening, ensuring the sealing of the pressurization chamber and preventing leakage of hydraulic or water media. The first chamber surface 110 and the second chamber surface 210 are fitted together to form a sealed pressurization chamber. The middle part of the pump diaphragm 310 is located within the pressurization chamber and can swing freely. Pressure changes in the hydraulic medium drive the pump diaphragm 310 to swing, realizing the intake and discharge of the water media, thus completing the pressurized water injection action.

[0027] The pressurization unit includes a shut-off cylinder 400, which is connected to the oil passage 220. The shut-off cylinder 400 receives external high-pressure hydraulic medium, drives an internal plunger to reciprocate, and thus promotes the flow of hydraulic medium within the oil passage 220. The hydraulic medium enters the pressurization chamber through the second through-hole 211, pushing the pump diaphragm 310 to oscillate within the pressurization chamber, thereby achieving the intake and pressurized discharge of the injection medium, completing the oilfield water injection operation. The shut-off cylinder 400 replaces traditional complex mechanical transmission components, simplifies the drive structure, improves the stability and reliability of equipment operation, and reduces maintenance costs.

[0028] In one possible embodiment of the present invention, such as Figure 1 As shown, the oil pump housing 200 can be configured as a single unit, which cooperates with the water pump housing 100 to form a pump assembly; in another possible embodiment of the present invention, such as Figure 2 As shown, two oil injection pump housings 200 can be provided. In this embodiment, a first cavity surface 110 is provided on both sides of the water injection pump housing 100. The two oil injection pump housings 200 are mirror-symmetrically sandwiched on both sides of the water injection pump housing 100. Two diaphragm assemblies 300 are respectively sandwiched between the two oil injection pump housings 200 and the water injection pump housing 100, forming a double-sided diaphragm drive structure. This structural design does not require an additional drive source. Parallel drive is sufficient to achieve the alternating oscillation of the double-sided diaphragms. When one side of the diaphragm oscillates to draw in water, the other side oscillates to drain water, ensuring the continuity of water injection and significantly improving water injection efficiency. It is suitable for the large-scale water injection needs of oil fields, and both stability and efficiency are significantly improved.

[0029] In the above embodiments, such as Figure 1 and Figure 2 As shown, the water injection pump casing 100 and the oil injection pump casing 200 located on one side, or two oil injection pump casings 200 sandwiched on both sides, can be combined to form an independent pump set. A single pump set can meet a certain flow rate of water injection demand. The structure is compact and easy to install and maintain. When the water injection demand of the oilfield is large, the isolation cylinder 400 is connected to the guide port 230 (detailed below) of multiple pump sets through an external pipeline, so that a single hydraulic drive source can drive multiple pump sets to work synchronously. There is no need for multiple independent water injection devices to be connected in parallel, which greatly reduces the equipment footprint, simplifies the system pipeline layout, reduces equipment investment and maintenance costs, and improves the flexibility of water injection flow rate adjustment. The number of pump sets can be flexibly adjusted according to the water injection demand of the oilfield.

[0030] In another possible embodiment of the invention, such as Figure 3 and Figure 5 As shown, the diaphragm assembly 300 can be configured as a multi-layer structure with multiple pump membranes 310 bonded together. A sealing detection gap is reserved between two adjacent pump membranes 310, and a leakage sensor is installed in the sealing detection gap. The leakage sensor is a pressure sensor, which has the characteristics of high sensitivity and good stability, and can monitor the pressure change or medium leakage between adjacent pump membranes 310 in real time. When any layer of pump membrane 310 is damaged, the injection medium or hydraulic medium will enter the sealing detection gap, causing the pressure in the gap to change. The leakage sensor will capture the signal in time and transmit it to the external alarm device, reminding the staff to replace the pump membrane 310 in time, avoiding problems such as hydraulic system contamination and formation blockage caused by medium cross-contamination, improving the safety and reliability of equipment operation, and meeting the production needs of continuous water injection in oil fields.

[0031] In one possible embodiment of the present invention, such as Figure 1 and Figure 2As shown, the oilfield diaphragm water injection system also includes a reversing control unit, a return oil filtration unit, and a pressure stabilizing unit. The reversing control unit includes a reversing valve 500 connected to the isolation cylinder 400. The reversing valve 500 is an electromagnetic reversing valve, characterized by fast response and precise control. It controls the flow direction of the hydraulic medium, thereby driving the plunger in the isolation cylinder 400 to reciprocate, achieving alternating oscillation of the pump diaphragm 310 and ensuring continuous water injection. The return oil filtration unit includes a suction filter 600 connected to the reversing valve 500. The suction filter 600 uses a high-pressure... The precision filter element effectively filters impurities in the hydraulic medium, preventing them from entering the isolation cylinder 400, oil passage 220, and diaphragm assembly 300, thus avoiding component wear or blockage and ensuring the stable operation of the hydraulic system. The pressure stabilization unit includes an accumulator 700 located between the suction filter 600 and the reversing valve 500. The accumulator 700 absorbs the hydraulic shock generated when the isolation cylinder 400 reverses, reducing equipment vibration and noise. It also recovers excess flow during reversal, preventing overflow energy waste and improving energy utilization, which meets the development needs of energy conservation and consumption reduction in oil fields.

[0032] In one embodiment of the present invention, the aforementioned isolation cylinder 400 further includes a variable displacement piston pump. As the power source of the hydraulic drive system, the variable displacement piston pump features a wide flow adjustment range and stable pressure. It is used to output high-pressure hydraulic medium to the oil passage 220. In actual use, the displacement of the variable displacement piston pump can be adjusted according to actual needs, thereby controlling the output flow rate and pressure of the hydraulic medium, and subsequently controlling the moving speed and oscillation frequency of the pump diaphragm 310. This achieves precise adjustment of the water injection flow rate, flexibly adapting to the dynamic adjustment needs of water injection volume and pressure after the permeability of the oil layer decreases in the middle and late stages of the oilfield, improving the water injection effect and increasing the crude oil recovery rate. It should be noted that the variable displacement piston pump is the core power component of the isolation cylinder 400, integrated with the isolation cylinder 400 to jointly constitute the hydraulic drive mechanism, ensuring the stability and efficiency of power transmission.

[0033] In the above embodiments, such as Figure 4 and Figure 5As shown, the first cavity surface 110 is located on one side of the water injection pump housing 100, and the water channel 120 is provided through both ends of the water injection pump housing 100 in the length direction. Correspondingly, the second cavity surface 210 is located on one side of the water injection pump housing 100, and a channel is provided through both ends of the oil injection pump housing 200 in the length direction. At least one of the first cavity surface 110 and the second cavity surface 210 is recessed along a predetermined arc, so that the relatively engaged first cavity surface 110 and the second cavity surface 210 form a pressurizing cavity. After the pump diaphragm 310 is sandwiched between the water injection pump housing 100 and the oil injection pump housing 200, the middle part of the pump diaphragm 310 corresponds to the cavity of the pressurizing cavity and can swing freely with the pressure change of the hydraulic medium. The water injection medium is sucked in and discharged through the swing. Specifically, when the hydraulic medium pushes the pump diaphragm 310 to swing towards the water channel 120, the space inside the booster chamber increases, and the water injection medium in the water channel 120 is drawn into the booster chamber through the first through hole 111 under the action of the pressure difference. When the hydraulic medium pushes the pump diaphragm 310 to swing towards the oil channel 220, the space inside the booster chamber decreases, the water injection medium is compressed and discharged into the water channel 120 through the first through hole 111, completing one water injection cycle. This method of media delivery through the swinging of the pump diaphragm 310 has better sealing performance and lower wear rate compared to the reciprocating motion of traditional plunger pumps, effectively reducing leakage problems and extending the service life of the equipment.

[0034] Furthermore, such as Figure 3 , Figure 4 and Figure 5 As shown, a plurality of first through holes 111 are provided on the water injection pump housing 100 along the width direction, and the plurality of first through holes 111 connect the water channel 120 and the first cavity surface 110; a plurality of second through holes 211 are provided on the oil injection pump housing 200 along the width direction, and the plurality of second through holes 211 connect the oil channel 220 and the second cavity surface 210. The first through holes 111 and the second through holes 211 are both positioned along the arc surface of the corresponding first cavity surface 110 and the second cavity surface 210, forming corresponding through holes adapted to the swing trajectory of the pump diaphragm 310, so as to significantly reduce the local resistance loss of fluid in the process of entering and exiting the pressurization chamber, making the flow of hydraulic medium and water injection medium more stable and orderly, thereby reducing the impact and wear on the surface of the pump diaphragm 310, ensuring the structural stability of the pump diaphragm 310 under high-frequency swing conditions, and extending its fatigue life.

[0035] In one possible implementation, such as Figure 3 As shown, the cross-sectional shape of the water injection pump housing 100 and the oil injection pump housing 200 can be flexibly set according to the installation space and water injection flow requirements at the oilfield site. They can be selected as circles, regular polygons or centrally symmetrical cut circles. Their structural design takes into account both compactness and practicality, making it easy to install and deploy at the oilfield site, while reducing the space occupied by the equipment.

[0036] Multiple water channels 120 are provided inside the water injection pump housing 100. These multiple water channels 120 are interconnected to form an integral water injection channel 120. Several first through holes 111 are evenly arranged corresponding to the multiple water channels 120 to ensure that each water channel 120 can be connected to the pressurization chamber through the first through hole 111, so as to achieve uniform distribution of the water injection medium and avoid pressure fluctuations caused by excessive or insufficient flow in a single water channel 120. Similarly, multiple oil channels 220 are provided inside the oil injection pump housing 200. These multiple oil channels 220 are also interconnected to form an integral hydraulic medium channel. Several second through holes 211 are evenly arranged corresponding to the multiple oil channels 220 to ensure that the hydraulic medium can act evenly on the middle of the pump diaphragm 310, drive the pump diaphragm 310 to swing smoothly, avoid wear or damage to the pump diaphragm 310 due to uneven force, and extend the service life of the pump diaphragm 310.

[0037] Specifically, the aforementioned water channel 120 includes an inlet and an outlet. The inlet is used to connect to the oilfield injection medium, and the outlet is used to transport the pressurized injection medium to the underground oil layer. To achieve coordinated operation of multiple water channels 120, improve water injection efficiency, and ensure stable water injection pressure, the inlets of multiple water channels 120 are interconnected through external pipelines to centrally connect to the water source and achieve centralized supply of the injection medium. The outlets of multiple water channels 120 are also interconnected through external pipelines to centrally output the pressurized injection medium, ensuring uniform water injection pressure and avoiding the impact of flow fluctuations in a single water channel 120 on the overall water injection effect. At the same time, it is convenient to uniformly control the water injection flow.

[0038] Furthermore, such as Figure 1 and Figure 2 As shown, the oil passage 220 includes a guide port 230, which is used to communicate with an external hydraulic drive component (isolation cylinder 400) to transmit high-pressure hydraulic medium. The configuration of the guide port 230 can be flexibly adjusted according to the layout of the oil passage 220. In one embodiment, the guide port 230 is located at one end of the oil passage 220, and the other end of the oil passage 220 is closed, so that the hydraulic medium enters the oil passage 220 from the guide port 230, enters the booster chamber through the second through hole 211, drives the pump diaphragm 310 to swing, and then flows from the same... One flow guide port 230 is used for return flow, which is simple in structure, facilitates pipeline layout, and reduces installation difficulty. In another embodiment, the flow guide port 230 extends through the center of multiple oil channels 220 to the outside of the oil pump housing 200. Both ends of the oil channels 220 are closed. This structure can realize the centralized flow guidance of multiple oil channels 220. The hydraulic medium enters multiple oil channels 220 through the central flow guide port 230 and is evenly distributed to each second through hole 211, which further improves the uniformity of hydraulic medium flow, reduces pressure loss, and improves driving efficiency.

[0039] It should be noted that the water injection medium mentioned above is not limited to water, and the hydraulic medium mentioned above is not limited to oil. When the technical solution of the present invention is applied to other technical fields, those skilled in the art can replace the specific types of water injection medium and hydraulic medium, as well as the specific materials of the functional components mentioned above, according to actual needs. The present invention does not limit these aspects.

[0040] Based on the above embodiments, the actual application process of the oilfield diaphragm water injection system of the present invention is as follows: During equipment assembly, firstly, the pump membrane 310 of the diaphragm assembly 300 is sealed and clamped between the water injection pump housing 100 and the oil injection pump housing 200, and tightened with bolts to form a sealed pressure boosting chamber with the first cavity surface 110 and the second cavity surface 210 facing each other. Then, according to the water injection requirements, a single oil injection pump housing 200 or a double oil injection pump housing 200 structure is selected, and the oil injection pump housing 200 is fixedly connected to the water injection pump housing 100 to ensure smooth communication between the first through hole 111, the second through hole 211 and the pressure boosting chamber. Finally, the isolation cylinder 400 is connected to the guide port 230 of the oil injection pump housing 200 through a pipe, and the reversing control unit, the return oil filter unit and the pressure stabilizing unit are assembled to complete the assembly of the entire oilfield water injection device.

[0041] Install the assembled oilfield water injection device at the oilfield water injection site, connect the water inlet of the water injection pump casing 100 to the water source (including impurity reinjection water) through a pipeline, and connect the drain outlet to the underground oil layer water injection pipeline through a pipeline to complete the pipeline connection.

[0042] After assembly and debugging, the equipment is started. The variable piston pump outputs high-pressure hydraulic medium, which is filtered by the suction filter 600. The flow direction of the hydraulic medium is controlled by the reversing valve 500. The hydraulic medium enters the isolation cylinder 400, which drives the piston in the isolation cylinder 400 to reciprocate. This, in turn, pushes the hydraulic medium in the oil passage 220 to flow. The hydraulic medium enters the booster chamber through the second through hole 211 and acts on the middle of the pump diaphragm 310, driving the pump diaphragm 310 to swing in the booster chamber. When the pump diaphragm 310 swings towards the oil pump housing 200, the volume of the booster chamber near the water pump housing 100 increases, and the pressure decreases. The water injection medium enters the booster chamber through the first through hole 111, completing the water intake action. When the pump diaphragm 310 swings towards the water pump housing 100, the volume of the booster chamber near the water pump housing 100 decreases, and the pressure increases. The water injection medium is pressurized and discharged through the first through hole 111, completing the drainage action. Through the reciprocating swing of the pump diaphragm 310, continuous pressurized water injection is achieved. If a double-sided oil pump housing 200 structure is adopted, the pump diaphragms 310 on both sides alternately complete the water intake and drainage actions, further improving the continuity and efficiency of water injection.

[0043] During equipment operation, the accumulator 700 absorbs the hydraulic shock during the reversal of the isolation cylinder 400, reducing equipment vibration and noise, while recovering excess flow and improving energy utilization. The suction filter 600 continuously filters impurities in the hydraulic medium, ensuring stable operation of the hydraulic system. If the diaphragm assembly 300 adopts a multi-layer pump diaphragm 310 structure, the leakage sensor monitors the damage of the diaphragm assembly 300 in real time, and issues an alarm signal in time once damage occurs. The proximity switch (optional) monitors the swing stroke of the pump diaphragm 310 to avoid excessive swing causing component damage, further ensuring long-term stable operation of the equipment.

[0044] When maintenance or replacement of the diaphragm assembly 300 is required, simply remove the bolts between the water injection pump housing 100 and the oil injection pump housing 200, remove the damaged pump diaphragm 310, replace it with a new one, and then tighten it again. The operation is convenient and does not require disassembling the entire equipment or complex pipelines, which greatly shortens maintenance time and avoids affecting the oilfield water injection process. When it is necessary to adjust the water injection flow rate, the output flow rate of the hydraulic medium is controlled by adjusting the displacement of the variable piston pump, thereby adjusting the oscillation frequency of the pump diaphragm 310 to achieve precise adjustment of the water injection flow rate and adapt to different water injection conditions.

[0045] In summary, the present invention provides an oilfield diaphragm water injection system, comprising: a water injection diaphragm pump, including a water injection pump housing, an oil injection pump housing, and a diaphragm assembly; the water injection pump housing includes a first cavity surface and a water channel communicating with the first cavity surface; the oil injection pump housing includes a second cavity surface and an oil channel communicating with the second cavity surface; the diaphragm assembly includes a pump membrane tightly clamped between the first cavity surface and the second cavity surface; and a pressurization unit, including a shut-off cylinder communicating with the oil channel, the shut-off cylinder being used to push hydraulic medium, the volume of the liquid column pushed by the shut-off cylinder being adapted to the size and stroke of the pump membrane, so that the swing limit position of the pump membrane does not contact the first cavity surface and the second cavity surface. This invention achieves high-pressure, stable, and efficient water injection through the coordinated operation of a water injection diaphragm pump and a booster unit. Compared to a hydraulically driven dual-medium booster cylinder, it eliminates the need for complex reducers and linkage mechanisms. Furthermore, the pump diaphragm of this invention completely avoids mixing with the booster and driving media, making it more suitable for more demanding operating conditions. Simultaneously, the pump diaphragm of this invention has no moving parts, and diaphragm contraction does not wear the sealing ring, allowing it to adapt to media with many impurities. This improves oil recovery while reducing maintenance frequency and costs. It should be understood that the application of this invention is not limited to the examples described above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An oilfield diaphragm water injection system, characterized in that, The oilfield diaphragm water injection system includes: A water-injection diaphragm pump includes a water-injection pump housing, an oil-injection pump housing, and a diaphragm assembly. The water-injection pump housing includes a first cavity surface and a water channel communicating with the first cavity surface. The oil-injection pump housing includes a second cavity surface and an oil channel communicating with the second cavity surface. The diaphragm assembly includes a pump membrane tightly sandwiched between the first cavity surface and the second cavity surface. The booster unit includes a diaphragm cylinder connected to the oil passage. The diaphragm cylinder is used to push hydraulic medium. The volume of the liquid column pushed by the diaphragm cylinder is adapted to the size and stroke of the pump diaphragm so that the oscillation limit position of the pump diaphragm does not contact the first cavity surface and the second cavity surface.

2. The oilfield diaphragm water injection system according to claim 1, characterized in that, The first cavity surface is provided on both sides of the water injection pump housing. There are two oil injection pump housings. The two oil injection pump housings are mirror images sandwiched between the two sides of the water injection pump housing. The two diaphragm assemblies are sandwiched between the two oil injection pump housings and the water injection pump housing. The water injection pump housing and the oil injection pump housing on one side are sandwiched together to form a pump set. The isolation cylinder is connected to the guide port of the multiple sets of pump sets through an external pipe.

3. The oilfield diaphragm water injection system according to claim 1, characterized in that, The diaphragm assembly includes a plurality of pump membranes, which are attached to each other, and a leakage sensor is provided between adjacent pump membranes.

4. The oilfield diaphragm water injection system according to claim 1, characterized in that, The oilfield diaphragm water injection system also includes: A reversing control unit, including a reversing valve connected to the isolation cylinder; The return oil filtration unit includes an oil suction filter connected to the reversing valve; The pressure stabilization unit includes an accumulator disposed between the oil suction filter and the reversing valve.

5. The oilfield diaphragm water injection system according to claim 1, characterized in that, The isolation cylinder includes a variable displacement piston pump, which is used to control the movement speed of the pump diaphragm.

6. The oilfield diaphragm water injection system according to claim 1, characterized in that, The first cavity surface is located on one side of the water injection pump housing, and the water channel is provided through both ends of the water injection pump housing in the length direction; the second cavity surface is located on one side of the water injection pump housing, and the oil channel is provided through both ends of the oil injection pump housing in the length direction. At least one of the first cavity surface and the second cavity surface is recessed along a predetermined arc, and the first cavity surface and the second cavity surface are opposite to each other to form a booster cavity, and the middle part of the pump diaphragm is oscillating in the booster cavity.

7. The oilfield diaphragm water injection system according to claim 6, characterized in that, The water pump casing is provided with a plurality of first through holes along the width direction, and the plurality of first through holes connect the water channel and the first cavity surface; The oil pump housing is provided with a plurality of second through holes along the width direction, and the plurality of second through holes connect the oil channel and the second cavity surface.

8. The oilfield diaphragm water injection system according to claim 7, characterized in that, The cross-sectional shape of the water injection pump casing and the oil injection pump casing is one of the following: circular, regular polygonal, or centrally symmetrical circumscribed circle. The water pump housing is provided with a plurality of water channels, which are interconnected, and a plurality of first through holes are evenly arranged corresponding to the plurality of water channels. The oil pump housing is provided with a plurality of oil channels, which are interconnected, and a plurality of second through holes are evenly arranged corresponding to the plurality of oil channels.

9. The oilfield diaphragm water injection system according to claim 6, characterized in that, The water channel includes an inlet and an outlet. The inlets of the multiple water channels are connected through external pipes, and the outlets of the multiple water channels are connected through external pipes.

10. The oilfield diaphragm water injection system according to claim 6, characterized in that, The oil passage includes a guide port located at one end of the oil passage, and the other end of the oil passage is closed; or, the guide port extends along the center of the oil passage to the side of the oil pump housing opposite to the second cavity surface, and both ends of the oil passage are closed.

Images