CN111550361B

CN111550361B - Novel positive displacement is electricity generation in pit device and contains its novel oil field water injection system

Info

Publication number: CN111550361B
Application number: CN202010598546.7A
Authority: CN
Inventors: 黄鹏
Original assignee: Hebei Zhongqing Yongsheng Petroleum Technology Co ltd
Current assignee: Hebei Zhongqing Yongsheng Petroleum Technology Co ltd
Priority date: 2020-06-28
Filing date: 2020-06-28
Publication date: 2022-03-18
Anticipated expiration: 2040-06-28
Also published as: CN111550361A

Abstract

The invention relates to a novel oilfield water injection system comprising a positive displacement underground power generation device, which comprises a main cavity body and the positive displacement underground power generation device, wherein a water injection channel and a generator cavity body are arranged in the main cavity body, the positive displacement underground power generation device is positioned in the generator cavity body, the upper end of the generator cavity body is communicated to the water injection channel of the main cavity body through an independent channel, and the positive displacement underground power generation device is assembled in the generator cavity body in a mode that a hollow inner cavity and the water injection channel are coaxially arranged, so that the drift diameter of a channel section on the water injection channel, which corresponds to the positive displacement underground power generation device, is almost unchanged in the axial direction, and a liquid column flowing through the channel section cannot be influenced by the diameter reduction caused by assembling the positive displacement underground power generation device.

Description

Novel positive displacement is electricity generation in pit device and contains its novel oil field water injection system

Technical Field

The invention relates to the technical field of oil field water injection systems, in particular to a novel positive displacement underground power generation device and a novel oil field water injection system comprising the same.

Background

Water injection is a main development technology of domestic oil fields, and because domestic oil fields generally have the characteristics of multilayer and heterogeneity, and the single-layer plunging can be caused by common separate injection, layered water injection is widely adopted. With the continuous application and development of the automatic layered water injection technology, the layered flow control and downhole parameter monitoring are realized by the domestic layered water injection technology.

The current automated zonal injection techniques can be broadly divided into two categories: firstly, a preset cable is adopted to supply power to an underground intelligent water distributor, and ground and underground measurement and control signals are transmitted; and secondly, the ground and underground measurement and control signals are transmitted in a wireless mode, and the underground intelligent water distributor is powered by a battery. Compared with a preset cable mode, the wireless mode has the technical advantages of simple construction, low cost and the like. However, the underground battery is adopted to supply power to the water distributor in a wireless mode, the size of underground space is small, the battery volume and the battery capacity are severely limited, and high energy consumption can be continuously generated in underground parameter acquisition, flow regulation and control and data transmission, so that the underground working time of the underground intelligent water distributor is short, the measurement and control frequency is low, and the development and application of a wireless layered water injection technology are severely restricted. Therefore, the underground power generation device suitable for the wireless separated layer water injection technology is researched and developed, and the problem that long-term stable electric energy supply is needed to be solved for the wireless separated layer water injection technology is solved urgently.

To this, at present in oil field layering water injection system technical field, especially the leading edge technique that relates to power generation and water injection system in the pit can be divided into two main stream water injection systems: one is a water injection system of a fusion structure, such as a downhole power generation device proposed in patent document No. CN108119293B, in which a generator is designed to have a size corresponding to the inner diameter of a water injection passage, and the generator is directly mounted on the inner wall of the water injection passage, and the device generates power by means of a liquid injected into the water injection passage impacting a turbine assembly. Although the power generation efficiency is relatively high, since the generator occupies the entire water injection channel, the channel of the water injection channel at the generator is forced to be reduced in diameter (the reduced diameter refers to the path of the water injection channel through which the liquid can flow, and is forced to be reduced by the influence of the generator assembled in the pipe), resulting in high-speed impact between a large amount of the injected liquid and the generator.

The other is a split-type structure water injection system, for example, a water injection well ball-throwing type downhole power generation device proposed by patent document No. CN109681368A, which divides an original cavity into two parallel generator cavities and water injection channels, and although the phenomenon of high-speed impact between a large amount of injected liquid and a generator is avoided in the arrangement, the drift diameters of the generator cavities and the water injection channels are greatly reduced due to the parallel arrangement, and at least the following problems exist: on one hand, the liquid impact force, the liquid flow, the turbine blades and the like in the generator cavity are greatly reduced, and the generating efficiency is directly influenced; on the other hand, the channel of the water injection channel at the generator is forced to be reduced (the reduced diameter refers to the drift diameter of the water injection channel for liquid to flow through and is forced to be reduced due to the influence of the generators assembled side by side), so that the water injection resistance in the pipeline is directly increased and even blocked, and the normal production requirement of the oil field cannot be met; in addition, because power generation facility's eccentric settings, power generation facility operation and arouse the unordered vibration of eccentric formula in the water injection process, aggravated power generation facility operation to whole device structural stability's harmful effects.

In addition, in both of the two main flow water injection systems, a power generation device composed of a turbine and a generator is mainly adopted, and downhole power generation is realized by using the flow of downhole liquid as a power source. However, because the power generation devices in the two main stream water injection systems occupy the central channel of the water injection pipe column, the requirement that the drift diameter in the central channel of the pipe column is larger than or equal to 46mm in the separate-layer water injection technology cannot be met in practical application, and a test tool cannot be put into the pipe column to perform subsequent production test of the water injection well. Simultaneously, because the water injection system that is used for carrying oil, water is mostly metal material and makes, just is corroded or forms the salt deposit in the profit pipeline by the chemical composition in the injected water (oil-displacing agent) easily originally, including the undergauge setting that above-mentioned two major stream water injection systems all adopted, will make profit pipeline internal diameter sharp reduce aggravation and increased the interior stifled probability of dying of pipeline, seriously influence the normal production in oil field.

Furthermore, on the one hand, due to the differences in understanding to the person skilled in the art; on the other hand, since the inventor has studied a lot of documents and patents when making the present invention, but the space is not limited to the details and contents listed in the above, however, the present invention is by no means free of the features of the prior art, but the present invention has been provided with all the features of the prior art, and the applicant reserves the right to increase the related prior art in the background.

Disclosure of Invention

In order to solve the problem that it is difficult to provide a long-term stable electric energy supply for a wireless separated layer water injection technology in the prior art, a current mainstream fusion structure water injection system (such as a downhole power generation device proposed by a patent document with the publication number of CN 108119293B) or a split structure water injection system (such as a water injection well ball-throwing type downhole power generation device proposed by a patent document with the publication number of CN 109681368A) both propose a power generation device which adopts a turbine and a generator and utilizes the flow of downhole liquid as a power source to realize downhole power generation:

however, in the case of the fusion structure water injection system, although the power generation efficiency is theoretically relatively high, since the generator occupies the whole water injection channel, the channel of the water injection channel at the generator is forced to be reduced in diameter (the reduced diameter refers to the diameter of the water injection channel through which the liquid can flow and is forced to be reduced due to the influence of the generator assembled in the pipe), so that a large amount of injected liquid is forced to impact with the whole power generation device shell at a high speed, the degradation of the oil displacement agent is further intensified, and the turbine blade is located at the lower part of the whole power generation device shell, namely, the injected water with reduced flow speed after being forced to impact at a high speed is used for driving the turbine blade to rotate, so that the actually achievable power generation efficiency is greatly reduced, and the generated energy is not enough to meet the underground power generation requirement;

for a water injection system with a split structure, firstly, the liquid impact force, the liquid flow, the size of a turbine blade and the like in a cavity of a generator are greatly reduced, the generating efficiency is directly influenced, and the generating capacity is very small; secondly, the channel of the water injection channel at the generator is forced to be reduced (the reduced diameter refers to the drift diameter of the water injection channel for liquid to flow through and is forced to be reduced due to the influence of the generators assembled side by side), so that the water injection resistance in the pipeline is directly increased or even blocked, the degradation of the oil displacement agent is further aggravated, and the normal production requirement of the oil field cannot be met; in addition, due to the eccentric arrangement of the power generation device, the power generation device operates in the water injection process to cause eccentric disordered vibration, so that the adverse effect of the operation of the power generation device on the structural stability of the whole device is aggravated;

as for the problems existing in the two main stream water injection systems, the underground power generation devices provided by the two main stream water injection systems occupy the central channel of the water injection pipe column, the requirement that the inner diameter of the central channel of the pipe column is larger than or equal to 46mm by the separate-layer water injection technology cannot be met in practical application, and a test tool cannot be put into the pipe column to perform subsequent production test of the water injection well.

In order to at least solve at least one of the problems of the existing water injection system capable of generating power underground, the invention provides a novel oil field water injection system with more optimized structure and more excellent working efficiency: novel oil field water injection system, including the main cavity body and positive displacement power generation facility in the pit, the internal portion of main cavity is provided with water injection passageway and generator cavity, positive displacement power generation facility in the pit is located generator cavity, generator cavity's upper end communicates to the water injection passageway of the main cavity body through independent passageway, positive displacement power generation facility in the pit is with its cavity inner chamber with the mode assembly of the coaxial setting of water injection passageway is in generator cavity, make on the water injection passageway with the latus rectum of the passageway district section that positive displacement power generation facility corresponds is almost unchangeable and is flowed through in the axial the liquid column of passageway district section can not receive because the undergauge that assembly positive displacement power generation facility arouses in the pit.

The utility model provides a novel oil field water injection system mainly used oil field layering water injection well is electricity generation in pit, can provide sufficient electric energy supply for intelligent injection mandrel in the pit, and the generating efficiency is high, can high-efficiently solve because of the limited restriction to injection mandrel down-hole operating time and measure and regulate the frequency of battery electric energy. In addition, the structure of the underground power generation device is optimally designed, so that the volumetric underground power generation device can be coaxially arranged with the water injection channel, under the arrangement, the drift diameter of the channel section on the water injection channel, which corresponds to the volumetric underground power generation device, is almost unchanged in the axial direction, the requirement of a separate layer water injection technology on the drift diameter in the central water injection channel can be met, the problem that the existing turbine type underground power generation device occupies the central water injection channel of the tubular column is effectively solved, and when the novel oil field water injection system provided by the application is used, a test tool can be put into the tubular column for subsequent test; meanwhile, under the arrangement, the injected water flowing through the channel section corresponding to the volumetric underground power generation device on the water injection channel is not affected by the diameter shrinkage caused by assembling the volumetric underground power generation device and does not impact on the housing of the volumetric underground power generation device or the motor, so that the mechanical shearing action of the injected water (oil displacement agent) in the injection process is greatly reduced, the performance of the injected water (oil displacement agent) is stable, and the normal production requirement of an oil field can be met; in addition, under this setting, volumetric power generation facility in the pit with the coaxial setting of water injection passageway, volumetric power generation facility in the pit's focus is more well relatively, and the unordered vibration distribution that power generation facility operation and arouse is relatively even in the water injection in-process, and is less to overall structure stability influence.

For ease of understanding, the above-described problem of exacerbating degradation of the oil-displacing agent is further described herein: the prior art is that the underground power generation device mostly adopts a turbine and a generator, the guide vane and the turbine are main parts of the device, fluid is beaten on a turbine blade (and/or directly impacted on the whole power generation device shell) through the guide vane, and the turbine drives a load to rotate through a shaft under the impact of the fluid, so that the power generation function is realized. However, for oil displacement agents such as polyacrylamide, the oil displacement agents are easily degraded by mechanical shearing, so that the oil displacement agents violently impact on turbine blades in the actual injection process, the molecular weight is greatly reduced, the viscosity loss of polymer solution injected into a stratum is large, and the oil displacement effect is directly influenced. In a fusion structure water injection system (such as a downhole power generation device proposed by a patent publication No. CN 108119293B) or a split structure water injection system (such as a water injection well ball-throwing type downhole power generation device proposed by a patent publication No. CN 109681368A) which is mainstream in the field, because the passages of the water injection passages at the power generator are forced to be reduced in diameter, the water injection resistance in the pipeline is increased and even blocked, and the degradation of the oil displacement agent is further accelerated. Further explanation is provided herein as to why degradation of oil displacing agents can be substantially reduced: the novel oil field water injection system that this application provided has abandoned traditional turbine formula power generation facility and undergauge formula assembled mode completely, and has adopted novel positive displacement power generation facility and non-undergauge formula assembled mode after the structure optimization. The power generation driving is realized by means of the volume change value of the volume cavity, and the oil displacement agent does not violently impact on a power generation device in the actual injection process, so that the degradation of the oil displacement agent such as polyacrylamide is greatly reduced; and by combining a non-reducing assembly mode, the liquid column flowing through the channel section cannot be influenced by reducing diameter caused by assembling the volumetric downhole power generation device, and the stability of oil displacement agents such as polyacrylamide is further ensured.

For ease of understanding, the following further description is provided with respect to existing turbine and positive displacement power plants: the existing underground power generation devices mostly adopt turbines and generators, and the turbines are driven sufficiently by the fact that the shaft blades of the turbines are faster than the small rotating speed, so that the power generation devices can only be arranged in a water injection channel or arranged side by side with the water injection channel, but the drift diameter of the original water injection channel cannot be lowered into a test tool due to the fact that the turbines are arranged in the water injection channel or arranged side by side with the water injection channel; if directly improve its structure for the coaxial cup joint structure who sets up that this application provided, require to improve the axle leaf ratio of turbine promptly, and can't provide enough drive with greatly reduced turbine generator's generating efficiency, can't have enough latus rectum and generating efficiency concurrently. In addition, at present, a small number of underground power generation devices adopt a conventional positive displacement generator, the positive displacement power generation efficiency of the conventional positive displacement generator depends on the volume change value of a volume cavity and the change times of the volume cavity in unit time, and although structurally, the novel positive displacement power generation device which is improved to be communicated with the middle part as provided by the application is easy to realize, the key problem lies in that the novel positive displacement power generation device which is communicated with the middle part is applied to underground power generation and at least has the following problems: firstly, the volume requirement of the underground power generation device is small, namely the volume change value of a volume cavity of the volume type generator is limited, the energy loss is large, and enough driving cannot be obtained; secondly, because the change times of the volume cavity depend on the whole-course sliding of the blade, two end faces and side end faces of the blade are seriously abraded, so that the volume type generator is short in service life and high in maintenance cost. Therefore, the application of the conventional positive displacement generator in the technical field of underground power generation is severely limited, and no relevant literature adopting the positive displacement generator exists in the field at present.

The new positive displacement power plant proposed in the present application, suitable for downhole power generation, is further described herein: in order to solve at least one of the problems of the existing turbine type and positive displacement type power generation devices, the structure of the existing conventional positive displacement type power generator is optimized and improved, and a novel oil field water injection system capable of overcoming at least one technical problem is provided. The mode that has adopted the independent water inlet channel of cascaded hierarchical water inlet structure and the blade motor rotor of outer wall indent formula to combine together among this novel oil field water injection system provides its bigger injected water flow for overcome motor self on inhaling the not enough basis of ability, still improved volume chamber volume change value. The device can meet the small-volume requirement of the underground discovery device, can provide enough drive, and has enough drift diameter and generating efficiency. Meanwhile, the novel oilfield water injection system is provided with the upper cam structure and the lower cam structure to replace the existing elastic pushing part (see figure 8) to realize the relative positioning of the blades, the blades can be always in close contact with the inner wall of the stator under the structure, and the problems that the existing elastic pushing part applies pressure to the blades, the contact area between the blades and the rotor is large, and the two end faces and the side end faces of the blades are seriously abraded can be effectively avoided, so that the service life of the generator is effectively prolonged, and the maintenance cost is reduced.

According to a preferred embodiment, the inside of the independent channel is of a stepped water inlet structure.

The hierarchical water inlet structure of ladder mentioned in this application indicates when the injected water from top to bottom, and the passageway that the injected water flowed through is dwindled gradually, changes the injected water flow direction for the injected water can get into the motor with the most suitable angle, improves motor work efficiency more effectively. In the novel oil field water injection system that this application provided, it passes through gradually to intake between section to the water delivery section, resistance when having reduced the injected water entering independent passageway effectively, not only can strengthen the flow of the inside injected water of independent passageway, and can effectively avoid among the prior art because of adopting vertical straight-through water delivery section, injected water easily dashes and hits water delivery section inner wall and each subassembly, and the aquatic products that lead to high-speed flow produce swirl and flow direction difference, cause the loss of a large amount of rivers energy of injected water, and the problem that the utilization efficiency is low. Simultaneously, cascaded hierarchical structure of intaking can adapt the limited volumetric downhole power generation facility of the inlet channel area that has the cavity inner chamber that this application provided when can support bigger inflow.

According to a preferred embodiment, the motor assembly comprises a water inlet end cover which is arranged at the upper end of the generator cavity and is provided with a matched double-through-hole structure so that injected water enters the generator cavity along an independent channel in an eccentric axial liquid inlet mode.

In the novel oil field water injection system that this application provided, intake and adopted the cooperation formula bi-pass pore structure on the end cover, bi-pass pore structure does not mean only has seted up two through-holes, but means the through-hole of seting up two kinds. Traditional single waist type through-hole structure has been abandoned to two through-hole structures of matched type in this application, has set up the inclined hole and the waist type through-hole of mutually supporting effect each other, and the inclined hole is close to the blade root more than waist type through-hole on its direction of lining up. Under traditional single waist type through-hole structure, the injected water gets into the volume intracavity through blade root, just can be full of blade root after the volume intracavity is full of the injected water for the injected water plays the impetus to blade root, under this setting, can't guarantee on the one hand that the injected water is to blade root's stable impetus, and on the other hand has leaded to the blade motor function inefficiency. And in the novel oil field water injection system who adopts above-mentioned cooperation formula bi-pass hole structure that this application provided, injected water is along the inclined hole direct entry blade root and make the top of blade be kept throughout with the stator inner wall in the state of in close contact with, effectively guaranteed the stable operation of vane motor. And the channel depth of the inclined hole is shorter than that of the waist-shaped through hole, and the volume of a gap at the root of the blade 6 is smaller than that of a volume cavity, so that the blade 6 can be quickly pushed by high-pressure injected water to abut against the inner wall of the blade motor stator 5 during water injection. The blade tips are tightly abutted against the inner wall of the stator to form a plurality of volume cavities which are independent relatively, so that the operation efficiency of the blade motor is further improved.

As another preferred embodiment, besides a matched double-through-hole structure, the application also provides a novel oilfield water injection system adopting a single waist-shaped through-hole structure, which is different from the traditional waist-shaped through-hole, wherein the waist-shaped through-hole is in an inclined state in the axial depth direction. The waist-shaped through hole can further guide the injected water to flow in a direction close to the hollow inner cavity of the positive displacement downhole power generation device. Because the volumetric underground power generation device in novel oil field water injection system is under the cup joint structure of coaxial setting with the water injection passageway, for obtaining higher power generation effect, and intake passage area is limited, to this, the novel oil field water injection system that provides in this application, through the structure setting of interconnect between tilting waist type through-hole and the cascaded hierarchical water inflow structure, the injected water under the tilting water inflow form is difficult for vertical collision rotor or passageway inner wall etc. department, can guide injected water to volumetric underground power generation device's intake passageway with injected water under the prerequisite of rivers energy loss minimizing, can be with the energy conversion of the flow of injected water electric energy into electric energy, directly supply power for intelligent water distributor in the pit, also can charge for rechargeable battery simultaneously. Meanwhile, the structure setting that cascaded hierarchical water inlet structure, tilting waist type through-hole and positive displacement motor positive displacement power generation facility used in coordination each other is adopted in this application, positive displacement power generation facility's rotational speed is decided by the injected water flow size of input motor in the pit, self ability of inhaling is relatively poor, and cascaded hierarchical water inlet structure can provide its bigger injected water flow with tilting waist type through-hole, overcome its self ability of inhaling not enough problem, and the oil mass that each volume chamber extruded in every pivoted every twinkling of an eye in the vane motor is the same basically, output flow and output pressure are all comparatively even, operate steadily.

According to a preferred embodiment, the positive displacement downhole power generation device comprises a motor assembly and a generator assembly coupled to each other, each having a hollow interior adapted to the water injection passage path. According to a preferred embodiment, the generator assembly is arranged below the motor assembly and can realize driving power generation by utilizing the conversion of kinetic energy and potential energy of injected water in the motor assembly.

In the prior art, most of downhole power generation devices adopt a turbine and a generator, for example, a water injection well ball-throwing type downhole power generation device proposed by patent document with publication number CN109681368A is provided with a turbine motor assembly and a generator assembly which are of an integral structure, and the turbine motor assembly and the generator assembly need to be removed together for replacement when being replaced, and the structure is relatively fixed, so that structural parameters cannot be adjusted according to requirements of different power generation powers. To this, in the novel oil field water injection system that this application provided, mutual independence between blade motor subassembly and the generator subassembly all arranges along the axial, does not receive the limited restriction of latus rectum in the pit shaft, can adjust the structural parameter of blade motor subassembly and generator subassembly according to actual demand to satisfy different generated power requirements. Under this setting, the generator module is located the below of blade motor subassembly and play liquid hole and does not contact with the injected water, and the injected water is derived from generator module's sealed shell outside, provides the dry operational environment of relative insulation in the generator module when can giving generator module cooling, has promoted generator module operating stability and life.

According to a preferred embodiment, the injection-moulded generator stator of the generator assembly is nested inside the permanent magnet rotor of the generator relatively closer to the water injection channel.

The prior art downhole power generation device mostly adopts a turbine and a generator, for example, a water injection well ball-throwing type downhole power generation device proposed by the patent document with the publication number of CN109681368A, because a guide vane and the turbine are main parts of the device, fluid is beaten on a turbine blade through the guide vane, and the turbine drives a load to rotate through a shaft under the impact of the fluid, so that the power generation function is realized. However, if the turbine generator is directly assembled in the novel oil field water injection system provided by the application, the generator cavity is sleeved outside the water injection pipeline, the effective radius of the generator cavity is smaller, the rotating shaft of the turbine generator occupies a larger space, the guide vane is shorter in length, and the energy conversion efficiency is very low. In contrast, in the novel oilfield water injection system provided by the application, the structural arrangement that the vane motor with a more optimized structure is matched with the generator assembly is adopted, firstly, the vane motor rotor is directly connected with the permanent magnet rotor of the generator, an intermediate motion conversion structure is not needed, and the problem that sealing is easy to lose efficacy due to the adoption of a conventional rotary dynamic seal design is avoided; meanwhile, the injection molding generator stator seals the silicon steel sheet and the coil winding inside through an injection molding process, so that the coil winding is sealed, and an independent generator sealing cavity is not needed.

In addition, different from the conventional technical means that the rotor is inserted into the stator core, which is usually adopted in the prior art, the generator assembly is provided with an iron core-free structure that the injection molding power generation stator is inserted into the permanent magnet rotor of the generator, namely the inner stator of the outer rotor, on one hand, the structure that the stator is closer to the water injection channel relative to the rotor is provided under the arrangement, and in the power generation process, because the winding on the stator has resistance, the heat can be continuously generated when current flows, at the moment, the stator is close to the outer wall of the water injection channel, namely, the water is continuously injected into the water injection channel, so that the effective convection heat exchange and heat conduction effects of the stator can be realized, and the performance of the power generation set is greatly improved. On the other hand, under the condition of a certain volume, the iron core-free structure of the outer rotor and the inner stator can obtain higher output torque and output power; in addition, the structure without the iron core with the hollow inner cavity can thoroughly eliminate the electric energy loss caused by the formation of eddy current by the iron core, greatly reduce the weight and the rotational inertia, reduce the mechanical energy loss when the rotor rotates, and greatly improve the running characteristic and the energy conversion efficiency of the generator. In summary, the novel positive displacement downhole power generation device and the novel oil field water injection system comprising the same have the advantages of being simple and compact in structure, simple and convenient to install, reliable in sealing and the like, and reliable in working of the device in a downhole high-temperature high-pressure liquid environment for a long time is guaranteed.

According to a preferred embodiment, the vane motor rotor in the motor assembly can guide the sliding direction of at least one vane through a plurality of bosses arranged on the side wall of the vane motor rotor, and a continuously variable volume cavity is formed between every two vanes.

In the prior art, such as a vane type hydraulic motor proposed by a patent document with publication number CN204283725U, a vane motor proposed by a patent document with publication number CN105650234B, a vane motor mechanism proposed by a patent document with publication number CN204212814U, a vane pneumatic motor proposed by a patent document with publication number CN102748078A, etc., a conventional inner rotor structure with radial narrow grooves uniformly distributed on a disc as shown in fig. 8 is adopted, and if the conventional inner rotor structure is directly applied to a generator cavity with a limited volume, the change rate of a volume cavity formed under the conventional inner rotor structure is small, which results in a great reduction of the working efficiency of the vane motor. To this, adopted the structure among the novel oil field water injection system of this application more to optimize blade motor rotor structure, the outer terminal surface that is provided with a plurality of bosss and boss on the circumference lateral wall of blade motor rotor is interior concave structure. Therefore, in the elliptical inner wall of the stator, the volume cavity change rate of the rotor between the partial region of the short diameter of the stator and the partial region of the long diameter of the stator is greatly increased, the working efficiency of the vane motor is greatly improved, and the vane motor can be well adapted to a generator cavity with limited volume for underground power generation.

The invention also provides a novel volumetric underground power generation device which comprises a motor assembly and a generator assembly which are coupled with each other, wherein the volumetric underground power generation device is assembled on a main cavity body with a water injection channel, and the volumetric underground power generation device is characterized in that the motor assembly and the generator assembly are respectively provided with a hollow inner cavity matched with the drift diameter of the water injection channel, and the sleeving sequence of a stator and a rotor of the motor assembly and the generator assembly is different from that of the stator and the rotor of the generator assembly.

In the current art, as proposed in patent document CN204704306U, a built-in vane motor type energy recovery damper is used to realize power generation by motion coupling of a generator and a motor through an intermediate motion conversion structure, however, in practical application, because the intermediate motion conversion structure is usually assembled by a conventional rotary dynamic seal structure, the problem of seal failure is easily caused under long-term operation. In contrast, the novel volumetric underground power generation device provided by the invention adopts a structure that the vane motor rotor is directly connected with the generator permanent magnet rotor, does not need an intermediate motion conversion structure, and avoids the problem that the sealing is easy to lose efficacy due to the adoption of the conventional rotary dynamic sealing design; meanwhile, the iron-core-free structure of the outer rotor inner stator, which is inserted into the generator permanent magnet rotor by the injection molding power generation stator, is adopted in the application, the sequence of the injection molding power generation stator is different from the sleeving sequence of the inner rotor of the outer stator in the motor assembly, under the arrangement, the available volume is limited aiming at underground power generation, the iron-core-free structure of the outer rotor inner stator can obtain higher output torque and output power, and the requirement of a layered water injection technology on the inner diameter of a central water injection channel can be met.

According to a preferred embodiment, the motor assembly comprises a vane motor rotor and at least one cam adapted to one of the upper and lower end faces of the vane motor rotor, which cooperates with a fitted double through-hole structure such that the tip of at least one vane on the vane motor rotor always abuts against the inner wall of the vane motor stator during water injection. According to a preferred embodiment, at least one blade on the vane motor rotor is inclined with respect to a radial direction of the vane motor rotor.

The arrangement mode to the blade among the prior art is including radially settling and slope arrangement, adopts blade slope arrangement form usually more, and its aim at is for preventing the oil drain district blade motion auto-lock, the blade retraction of being convenient for, however among the practical application process, this kind of slope arrangement form not only can make blade groove processing technology complicated, and can cause the flexible insensitive of blade because of the pressure differential of oil drain district blade top and bottom moreover, seriously influence the wearing and tearing of stator, blade and blade groove, will further influence the life of blade. In the water injection well ball-throwing type underground power generation device proposed by the patent document with the publication number of CN109681368A in the prior patent document, the prior vane motor power generation structure is directly adopted in the device, and the realization of the excellent power generation effect in the technical scheme is actually established on the premise that the realization difficulty of the vane motor power generation structure in an ideal working state is extremely high, and the practical use problem is not considered. To this, this application has blade motor electricity generation structure now on, has proposed the structure more optimized, and can effectively solve because of the blade slope arrangement form leads to be difficult to the novel positive displacement power generation facility in pit of the problem of avoiding. As shown in fig. 6 and 7, the most common blade-inclined arrangement is adopted in the present application, but at the same time, a water inlet end cover and a water outlet end cover adapted to the blade motor rotor are provided, so that the tip of at least one blade on the blade motor rotor can always abut against the inner wall of the blade motor stator. Under the arrangement, the advantage of smooth sliding of the inclined blade arrangement mode is fully exerted, and the inclined blade occupies smaller space, so that a hollow inner cavity which is large enough for a motor assembly is further ensured, and the requirement of a layered water injection technology on the drift diameter in a central channel of a pipe column can be met; in addition, the blade does not can realize with the help of elastic expansion and contraction that the blade top hangs down all the time on the inner wall of vane motor stator in the water injection process in this application, has eliminated because of the flexible sensitivity of the blade that the form leads to is poor, the big problem of degree of wear of blade slope arrangement form, is favorable to guaranteeing the long-term work of motor element in the pit, and structural stability is strong, reduces the maintenance cost.

Drawings

FIG. 1 is a schematic cross-sectional view of a simplified overall structure of a novel oilfield flooding system provided by the present invention;

FIG. 2 is a simplified schematic illustration of section A-A provided by the present invention;

FIG. 3 is an upper end face of the water inlet end cap provided by the present invention;

FIG. 4 is a lower end face of the outlet end cap provided by the present invention;

FIG. 5 is a simplified overall structure of the intake cam provided by the present invention;

FIG. 6 is a simplified overall structural schematic of a vane motor rotor provided by the present invention;

FIG. 7 is a simplified top view schematic illustration of a vane motor rotor provided in accordance with the present invention;

FIG. 8 is a simplified overall structural schematic of a prior art vane motor rotor provided by the present invention; and

fig. 9 is a simplified overall structure schematic diagram of the water inlet end cover provided by the invention.

List of reference numerals

1: an upper joint 2: outer cylinder

3: water inlet end cover 4: water inlet cam

5: vane motor stator 6: blade

7: vane motor rotor 8: vane motor center tube

9: the pin 10: permanent magnet rotor of generator

11: injection molding of the generator stator 12: magnetic steel

13: the baffle ring 14: electric energy output to annular electric energy control circuit

15: circuit chamber center tube 16: lower joint

17: water outlet end cover 18: water outlet cam

19: positioning key 20: output lead terminal of annular electric energy control circuit

21: injection molding of the generator stator power lead terminal 22: boss

23: water injection channel 24 generator cavity

25: the independent passages 26: waist-shaped through hole

27: positioning ring body 28: ring base

29: first fitting end surface 30: second assembly end face

31: inclined hole

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 shows a simplified schematic diagram of the overall structure of the novel oilfield water injection system provided by the invention.

The novel oilfield water injection system mainly comprises a main cavity and a positive displacement underground power generation device. The main cavity comprises a water injection channel 23 and a generator cavity 24 sleeved outside the water injection channel 23. The water injection channel 23 is a cylindrical structure which is through from top to bottom, and the generator cavity 24 is a hollow annular structure. The positive displacement downhole power generation device is mounted in a generator cavity 24. The upper end of the generator chamber 24 is provided with an independent channel 25 for guiding injected water into the interior of the positive displacement downhole power generation device.

The positive displacement downhole power generation device may be divided into a two-part structure of a vane motor assembly and a generator assembly. The rotor of the vane motor assembly is connected to the permanent magnet rotor of the generator assembly. Therefore, in the water injection process, injected water serves as a power source to drive the rotor of the blade motor assembly to rotate, and then the permanent magnet rotor of the generator is driven to rotate, so that underground power generation is achieved.

The following description will be made for the main components and the operation principle of the vane motor assembly:

the vane motor assembly mainly comprises a vane motor rotor 7, vanes 6 and a vane motor stator 5. A plurality of vane grooves are formed in a circumferential side wall of the vane motor rotor 7. A plurality of vanes 6 are fitted in the vane grooves with one end thereof beyond the vane grooves. The vane motor rotor 7 is rotatably fitted in the inner cavity of the vane motor stator 5. So that the tip of the blade 6, which is located near the inner wall of the vane motor stator 5, protrudes beyond the blade groove, with a gap for guiding the injected water being formed between the root of the blade 6 and the blade groove.

Furthermore, during the water injection process, when the high-pressure injection water is guided into the gap between the root of the blade 6 and the blade groove, the high-pressure injection water forces the blade 6 to slide further outwards, so that between every two blades 6, the inner wall of the blade motor stator 5 and the outer wall of the blade motor rotor 7 jointly form volume cavities which are closed relatively to each other and have different adjacent volumes.

Then, when high-pressure injection water is introduced into the inner cavity of the vane motor stator 5, the volumes of the two adjacent volume cavities are different from each other, so that pressure difference exists, the torque acted on the vanes 6 on the two sides by hydraulic pressure is unbalanced, and the rotation of the vane motor rotor 7 is pushed. When the vane motor rotor 7 rotates, the volume in each volume chamber is changed continuously, and a force for continuously pushing the vane motor rotor 7 to rotate is formed. Therefore, the purpose that the injected water is used as a power source to drive the rotor of the vane motor assembly to rotate in the water injection process is achieved.

The structure and the operation principle of the vane motor stator 5 are further explained as follows:

the vane motor stator 5 is a cylindrical structure provided with a vertical mounting hole. The longitudinal extension direction of the vertical mounting holes coincides with the longitudinal extension direction of the water injection channel 23. The vane motor stator 5 may be sleeved outside the water injection passage 23 through the vertical mounting hole.

The vane motor stator 5 has a hollow interior within its cylindrical structure. The inner cavity of which is used for assembling the vane motor rotor 7 and the vanes 6 and for receiving high-pressure liquid injected from the outside.

In the section a-a shown in fig. 2, a simplified sectional structural view of the vane motor stator 5 is shown, and the inner wall of the hollow inner cavity of the vane motor stator 5 is a cam-shaped line or an oval. Taking the elliptical inner wall as an example, the distance from a point on the inner wall to the center of the ellipse varies with the circumferential movement of the point along the elliptical inner wall, which is equivalent to the distance between the vane slot and the inner wall of the vane motor stator 5. When the distance is changed, the vane motor rotor 7 carries the vane 6 to rotate, so that the length of the vane 6 exceeding the vane slot is increased or decreased, namely, the volume of each volume chamber is changed continuously. This realizes that "when the vane motor rotor 7 rotates, the volume in each volume chamber is constantly changing, and a force for continuously pushing the vane motor rotor 7 to rotate" is formed.

The structure of the vane motor rotor 7 is further explained as follows:

the vane motor rotor 7 is a cylindrical structure provided with a vertical mounting hole. The vane motor rotor 7 is sleeved outside the water injection channel 23 through the vertical mounting hole. The vane motor rotor 7 is freely rotatable independently of the water injection channel 23 and the vane motor stator 5.

The vane motor rotor 7 is located in the hollow interior of the vane motor stator 5. An annular space remains between the outer wall of the vane motor rotor 7 and the inner wall of the vane motor stator 5. The annular space is divided into volume chambers by vanes 6.

The structure of the blade 6 is further explained as follows:

the blade 6 and the blade motor rotor 7 are in clearance fit. The vane 6 is capable of sliding flexibly in the radial direction of the vane motor rotor 7 without the vane 6 being affected by other limit components.

In this application, through the mode that adopts spacing subassembly and cooperation formula bi-pass pore structure to act together, and make in the water injection process, the top of blade 6 can hug closely all the time on the inner wall of vane motor stator 5. Under the arrangement, the volume chambers are relatively independent and can provide 'pressure difference existing between two adjacent volume chambers', and the normal operation of the motor is ensured. In view of the above, the present application also lists the overall structural schematic diagram of the most widely used vane motor rotor, as shown in fig. 8, the limiting component in the vane motor rotor is an elastic pushing portion with the highest application frequency, and the elastic pushing portion is compressively disposed between the vane slot and the root of the vane 6, so that the vane can be in close contact with the inner wall of the stator under the action of the elastic force. However, such solutions have very high technical requirements and poor performance stability: if the elasticity is too large, the two end faces and the side end face of the blade are seriously abraded, if the elasticity is too small, the adjacent volume cavities are not tightly sealed, and the motor cannot normally work, and if the motor is continuously used for a long time, the elasticity is gradually weakened, and the performance of the motor is unstable. Therefore, the elastic limiting mode of the original elastic pushing part is abandoned, and the novel limiting assembly which can replace the original elastic pushing part and can well overcome adverse factors caused by the elastic limiting mode is provided.

The above-mentioned spacing subassembly that proposes in this application mainly includes into water cam and play water cam. The water inlet cam and the water outlet cam are distributed on the upper side and the lower side of the vane motor rotor 7. The water inlet cam and the water outlet cam are used for carrying out preliminary limit on the blades 6 from the upper side and the lower side of the blade motor rotor 7 respectively. The vanes 6 can be pushed to a position substantially close to the inner wall of the vane motor stator 5 by the preliminary limit. And then the inclined holes 31 in the matching type double-through-hole structure are reused, and the injected water is directly guided into the root parts of the blades 6 by the inclined holes 31. The vane 6 is forced to move accurately toward a direction closer to the inner wall of the vane motor stator 5. The continuous high pressure injection of water forces the blades 6 to maintain close contact between their tips and the inner wall of the stator at all times. Meanwhile, the problem that the two end faces and the side end face of the blade are seriously abraded due to the fact that the existing elastic pushing part applies pressure to the blade and the contact area between the blade and the rotor is large can be effectively solved, the service life of the generator is effectively prolonged, and the maintenance cost is reduced.

The structure of the above-mentioned position limiting assembly is further explained as follows:

the limiting component mainly comprises a water inlet cam 4 and a water outlet cam 18. The inlet cam 4 and the outlet cam 18 each comprise a positioning ring 27 and a ring base 28.

The intake cam 4 and the outlet cam 18 are each fixed to at least one end cap by means of a respective positioning ring 27. The positioning ring body 27 of the water inlet cam 4 is sleeved on the inner wall of the through hole of the water inlet end cover 3. The positioning ring body 27 of the water outlet cam 18 is sleeved on the inner wall of the through hole of the water outlet end cover 17.

During assembly, the water inlet end cover 3 and the water outlet end cover 17 are respectively fixed on the upper end face and the lower end face of the vane motor stator 5. So that the ring base 28 of the inlet cam 4 and the ring base 28 of the outlet cam 18 extend into the hollow interior of the vane motor stator 5. And both are located at positions close to the upper and lower end faces of the vane motor rotor 7, respectively. Preferably, neither is in contact with the vane motor rotor 7 to avoid affecting the rotation of the vane motor rotor 7.

The ring base 28 of the inlet cam 4 and the ring base 28 of the outlet cam 18 occupy partial positions of a plurality of vane grooves in the vane motor rotor 7. Forcing the root of the blade 6 not to abut against the inner wall of the blade groove. And the vane motor rotor 7 is looped inside the vane motor stator 5, i.e., the vanes 6 are forced to slide toward the direction close to the inner wall of the vane motor stator 5.

As shown in fig. 5, the outer wall of the ring base 28 is cam-shaped or oval. In the present application, the ratio of the cam profile outer wall of the ring mount 28 to the cam profile inner wall of the vane motor stator 5 is the same but the outer wall size of the ring mount 28 is smaller than the inner wall size of the vane motor stator 5. The ring base 28 is coaxial with the center of the vane motor stator 5. Between the outer wall of the ring base 28 and the inner wall of the vane motor stator 5, i.e. between two cam profiles/ellipses of equal proportion to each other, the vertical distances between the two wall surfaces are circumferentially equal to each other and are both L. L is slightly smaller than the width of the blade 6. That is, a certain gap is left between the vane 6 and the inner wall of the vane motor stator 5 before water injection. The "width of the vane 6" mentioned here refers to a dimension of the vane 6 in a radial direction as viewed in a plan view perpendicular to an axial direction of the vane motor rotor 7 after the vane 6 is vertically inserted into the vane groove.

The structure of the water inlet end cover 3 is further explained as follows:

as shown in fig. 9, the inlet end cap 3 has a first fitting end surface 29 and a second fitting end surface 30 which are opposite to each other. The first assembly end face 29 is located above the second assembly end face 30 during assembly, and the second assembly end face 30 is used for assembling the water inlet cam 4.

The water inlet end cover 3 is provided with a matched type double-through hole structure. The fitted double through-hole structure includes the inclined hole 31 and the kidney-shaped through-hole. The two ends of the inclined hole 31 and the waist-shaped through hole penetrate through the two assembling end faces front and back. An acute angle is formed between the extending direction of the channel of the inclined hole 31 and the central axis of the water inlet end cover 3, and the liquid outlet end of the inclined hole 31 is closer to the central axis relative to the liquid inlet end thereof. The channel extending direction of the waist-shaped through hole is parallel to the central axis of the water inlet end cover 3.

The angled holes 31 are aligned with gaps between the vane motor rotor 7 and the roots of the plurality of vanes 6. The kidney shaped through hole is aligned with the at least one volume chamber. The injected water may enter the blade root directly along the angled holes 31. So that the tips of the blades can be always maintained in close contact with the inner wall of the stator during the water injection process.

The passage depth of the inclined hole 31 is short relative to the passage depth of the kidney-shaped through hole and the relative volume of the void at the root of the blade 6 is small relative to the volume of the volume chamber. When the injected water is introduced from above the water inlet end cover 3, the injected water flows into the inclined hole 31 and the kidney-shaped through hole at the same time, and the blades 6 can be quickly pushed by the high-pressure injected water to abut against the inner wall of the blade motor stator 5 during water injection from the inclined hole 31. The tips of the vanes 6 are closely abutted against the inner wall of the stator to form a plurality of volume cavities which are independent relatively to each other, thereby further improving the operating efficiency of the vane motor.

When water is injected, the tips of the plurality of blades 6 are all in close contact with the inner wall of the vane motor stator 5 by the hydraulic pressure of the high-pressure injected water. The roots of the blades 6 are tightly abutted against the ring base 28 of the water inlet cam 4 and the ring base 28 of the water outlet cam 18. With this realization "through adopting spacing subassembly and the mode of the cooperation formula bi-pass pore structure looks combined action, and make in the water injection process, the top of blade 6 can hug closely on the inner wall of blade motor stator 5 all the time".

The water inlet cam 4 and the water outlet cam 18 are provided with mounting holes which are through from front to back. The water inlet cam 4 and the water outlet cam 18 are respectively sleeved outside the water injection channel 23 through mounting holes, and the mounting holes are also used for guiding the liquid to circulate.

During the water filling process, inlet water enters each volume cavity through the mounting hole on the water inlet cam 4. The bottom end surface of the volume cavity is limited by the upper end surface of the water outlet end cover 17, and part of the volume cavity is positioned on the kidney-shaped through hole of the water outlet end cover 17. The high-pressure injected water in at least one volume cavity flows out through the waist-shaped through hole. The pressure difference existing between the adjacent two volume chambers is further increased. The injection water is injected into the stratum through the outflow holes on the outer cylinder 2. In the existing underground power generation, the injected water is guided to flow back to the water injection channel 23, and the injected water is guided to the water injection channel 23 in the radial direction, so that the injected water is directly guided to the stratum in the application, and does not need to be guided back to the water injection channel 23, and the mechanical shearing action of the injected water in the water injection channel 23 in the injection process is further reduced.

To this end, the overall structure and assembly method of the vane motor assembly will be further explained as follows:

the overall structure of the vane motor assembly may include, for example, one or more of the inlet end cap 3, inlet cam 4, vane motor rotor 7, vanes 6, vane motor stator 5, outlet cam 18, outlet end cap 17, positioning key 19, and vane motor center tube 8.

When assembling the vane motor assembly: the water outlet cam 18 is in interference fit with the water outlet end cover 17. The water outlet cam 18 is fixed at the upper end of the water outlet end cover 17 in a press-fitting mode. As shown in fig. 2, the vane 6 is placed in a slot of a vane motor rotor 7. The vane motor stator 5 is fitted outside the vane motor rotor 7. The water inlet cam 4 is in interference fit with the water inlet end cover 3. The water inlet cam 4 is fixed at the lower end of the water inlet end cover 3 in a press-fitting mode. The water inlet end cover 3 is then mounted on top of the vane motor stator 5 and vane motor rotor 7. And the positioning key 19 is arranged in key grooves of the water inlet end cover 3, the vane motor stator 7 and the water outlet end cover 17 and is used for determining the circumferential relative positions among the water inlet end cover 3, the vane motor stator 7 and the water outlet end cover 17. So far, the vane motor assembly is installed.

The novel oilfield water injection system further comprises an upper joint 1, an outer cylinder 2 and a pin 9. The vane motor component and the outer cylinder 2 are in interference fit. The vane motor assembly is press-fitted inside the outer cylinder 2. The pins 9 on the outer barrel 2 are used to locate the axial position of the vane motor assembly. The upper joint 1 is connected with the outer cylinder 2 through threads. And the lower end surface of the upper joint 1 is pressed on the upper end surface of the water inlet end cover 3 of the vane motor assembly. The two end faces form an end face seal. The vane motor assembly is completely fixed in axial position under the combined action of the upper joint 1 and the pin 9.

Preferably, the upper joint 1 is designed with a liquid inflow hole for introducing the injected water into the interior of the vane motor assembly.

Preferably, as shown in fig. 3, a kidney-shaped through hole for water inlet is processed on the water inlet end cover 3. The water inlet end cover 3 is provided with an inclined hole 31 for leading inlet water to the root of the blade. A key groove for circumferential positioning is processed on the water inlet end cover 3. The outer wall of the water inlet end cover 3 is in interference fit with the inner wall of the outer barrel 2.

Preferably, the vane motor rotor 7 is of hollow construction. The vane motor rotor 7 is sleeved outside the vane motor central tube 8. The vane motor rotor 7 is eccentrically mounted in the inner cavity of the vane motor stator 5. The vane motor rotor 7 is freely rotatable. The vane motor rotor 7 is provided with a plurality of vane grooves. The blade 6 and the blade motor rotor 7 are in clearance fit.

Preferably, a key groove for circumferential positioning is machined on the outer wall of the vane motor stator 5. The outer wall of the vane motor stator 5 is in interference fit with the inner wall of the outer cylinder 2.

Preferably, as shown in fig. 4, a waist-shaped through hole for water outlet is processed on the water outlet end cover 17. A key groove for circumferential positioning is processed on the water outlet end cover 17. The outer wall of the water outlet end cover 17 is in interference fit with the inner wall of the outer cylinder 2.

The overall structure and the assembly method of the generator assembly in the novel oilfield water injection system are further explained as follows:

the generator assembly may include one or more of an injection molded generator stator 11, injection molded generator stator power lead terminals 21, generator permanent magnet rotor 10, and magnetic steel 12. During assembly, the generator permanent magnet rotor 10 is screwed onto the vane motor rotor 7. The inner wall of the generator permanent magnet rotor 10 is pasted with magnetic steel 12. The vane motor center tube 8 is fitted from the lower end of the outer cylinder 2 to the center position of the vane motor assembly. The injection-molded generator stator 11 is loaded from the lower end of the outer cylinder 2 until the upper part of the injection-molded generator stator 11 is in full contact with the lower part of the vane motor center tube 8.

Preferably, the generator stator 11 is manufactured by first sealing the silicon steel sheets and the coil windings inside by an injection molding process and then machining. The lower end face of the injection-molded generator stator 11 is extended with injection-molded generator stator power lead terminals 21.

The novel oilfield water injection system further comprises one or more of an annular electric energy control circuit 14, an annular electric energy control circuit output lead terminal 20, a circuit cavity central tube 15, a baffle ring 13 and a lower joint 16. In assembly, the circuit chamber center tube 15 is inserted from the lower end of the outer cylinder 2 until the upper portion of the circuit chamber center tube 15 is in full contact with the lower portion of the injection molded generator stator 11. The injection-molded generator stator power lead terminals 21 are connected to the annular power control circuit 14. The annular electric energy control circuit 14 is sleeved outside the circuit cavity central tube 15 and fixed on the outer wall of the circuit cavity central tube 15. The retainer ring 13 is inserted from the lower end of the outer cylinder 2. The lower joint 16 and the outer cylinder 2 are connected by screw threads. As the lower connector 16 is screwed in, the retainer ring 13 is brought into full contact with the injection-molded generator stator 11, so that the position of the injection-molded generator stator 11 is completely fixed.

Preferably, the lower connector 16 is designed with a plurality of liquid outflow holes and a pin hole. Pins threaded on the pin holes are used for axial positioning of the vane motor assembly. The lower connector 16 is provided with a through hole for the output lead terminal 20 of the annular power control circuit to pass through.

Preferably, the annular power control circuit 14 has functions of current rectification and filtering. The upper end of the annular electric energy control circuit 14 is connected with a power lead terminal 21 of the injection-molded generator stator. The lower end of the annular electric energy control circuit 14 is provided with an annular electric energy control circuit output lead terminal 20 for outputting electric energy, supplying electric energy for the underground intelligent water distributor and charging a rechargeable battery.

The annular power control circuit output lead terminal 20 on the annular power control circuit 14 is passed out from the through hole on the lower tab 16. The upper joint 1, the water inlet end cover 3, the vane motor central pipe 8, the injection molding generator stator 11 and the outer barrel 2 form an independent cavity together. Both the vane motor assembly and the injection-molded generator stator 11 are arranged inside this separate cavity. The injection-molded generator stator 11, the outer cylinder 2, the circuit cavity central tube 15 and the lower joint 16 form a sealed cavity together. An annular power control circuit 14 is located within this sealed chamber.

When the novel positive displacement downhole power generation device and the novel oilfield water injection system comprising the same are used on site, the lower joint 16 is connected with an oil pipe through an oil pipe buckle. The upper end of the upper joint 1 can be connected with an underground intelligent water distributor through threads. A water nozzle assembly mechanism of the water distributor is connected with an injected water inflow hole at the upper end of the upper joint 1. When water is normally injected, the water nozzle of the water distributor is opened. The injected water enters the injected water inflow pore channel on the upper joint 1 through the water nozzle and then enters the blade motor through the waist-shaped through hole of the water inlet end cover 4. Under the combined action of the water inlet cam 4 and the water outlet cam 18, the top of the blade 6 is always in close contact with the inner wall of the blade motor stator 5. Meanwhile, injected water enters the bottom of the blade 6 through the inclined hole 31 of the water inlet end cover 4, and volume cavities with different volumes are formed among the blade 6, the rotor 7 and the stator 5.

Under the action of injected water, the two sides of the blade 6 in the volume cavity are unbalanced in stress, and the rotor 7 is driven to rotate. When the rotor 7 rotates to the position of the kidney-shaped through hole of the water outlet end cover 17, the injected water flows out through the kidney-shaped through hole of the water outlet end cover 17. The injection water is injected into the stratum through the outflow holes on the outer cylinder 2.

When the rotor 7 rotates, the generator permanent magnet rotor 10 and the magnetic steel 12 are driven to rotate at the same time, and a rotating magnetic field is formed. The coil windings inside the injection-molded generator stator 11 cut the magnetic lines of force. So that electrical energy of a certain power is generated on the coil windings inside the injection-molded generator stator 11. The electric power is output to the ring-shaped electric power control circuit 14 through the injection-molded generator stator power lead terminals 21. The output lead terminal 20 of the annular electric energy control circuit penetrates out of the through hole in the lower connector 16, and the electric energy is rectified and filtered by the annular electric energy control circuit 14, so that the electric energy is output to other underground intelligent water distributors or underground testing instruments.

It should be noted that the above-mentioned embodiments are exemplary, and that those skilled in the art, having benefit of the present disclosure, may devise various arrangements that are within the scope of the present disclosure and that fall within the scope of the invention. It should be understood by those skilled in the art that the present specification and figures are illustrative only and are not limiting upon the claims. The scope of the invention is defined by the claims and their equivalents.

Claims

1. The novel oil field water injection system comprises a volume type underground power generation device, and comprises a main cavity body and the volume type underground power generation device, wherein a water injection channel (23) and a generator cavity body (24) are arranged in the main cavity body, the volume type underground power generation device is positioned in the generator cavity body (24), the upper end of the generator cavity body (24) is communicated to the water injection channel (23) of the main cavity body through an independent channel (25),

it is characterized in that the preparation method is characterized in that,

the volume type downhole power generation device is assembled in the generator cavity (24) in a mode that a hollow inner cavity of the volume type downhole power generation device is coaxial with the water injection channel (23), so that the drift diameter of a channel section corresponding to the volume type downhole power generation device on the water injection channel (23) is almost unchanged in the axial direction, and a liquid column flowing through the channel section is not influenced by the diameter reduction caused by assembling the volume type downhole power generation device;

the inside of the independent channel (25) is of a stepped grading water inlet structure.

2. A novel oilfield waterflooding system as defined in claim 1, wherein the positive displacement downhole power generation means comprises a motor assembly and a generator assembly coupled to each other, each of the motor assembly and the generator assembly having a hollow interior adapted to the bore of the waterflooding channel (23).

3. A novel oilfield flooding system according to claim 2, wherein the motor assembly comprises a water inlet end cap (3) which is arranged at the upper end of the generator cavity (24) and which is provided with a fitted double through hole structure so that the injected water enters the generator cavity (24) along an independent channel (25) in an eccentric axial liquid inlet manner.

4. The novel oilfield water injection system of claim 3, wherein the generator assembly is disposed below the motor assembly and is driven to generate electricity by conversion of kinetic and potential energy of the injected water in the motor assembly.

5. The novel oilfield flooding system of claim 4 wherein the injection molded generator stator (11) of the generator assembly is nested inside the generator permanent magnet rotor (10) and relatively closer to the flooding channel (23).

6. A novel oilfield flooding system according to claim 5, characterized in that the vane motor rotor (7) in the motor assembly is capable of guiding the sliding direction of at least one vane (6) by means of bosses (22) provided on its side wall and forming a continuously variable volume chamber between every two vanes (6).