A fixed valve and rod-operated oil pumping equipment with throttling function

Abstract

This application discloses a fixed valve with a throttling function, comprising an outer shell and an inner cylinder. The fixed valve is combined with the pump barrel of a rod-pumped oil pumping equipment. The inner cylinder has an open end and a closed end, with the open end closer to the pump barrel than the closed end. The inner cylinder communicates with the pump barrel of the rod-pumped oil pumping equipment through the open end, and the open end is separated from the inner cavity of the outer shell. The open end is only indirectly connected to the inner cavity of the outer shell through the interior of the inner cylinder. The inner cylinder wall has flow holes and throttling holes, allowing the inner cylinder to communicate with the inner cavity of the outer shell through the flow holes and throttling holes. The flow holes are closer to the open end than the throttling holes. The fixed valve with a throttling function and the rod-pumped oil pumping equipment of this application possess the lifting function of a conventional mechanical rod-pumped oil pumping equipment, and also have a downhole adjustable flow and pressure control function. This realizes the conversion between two production modes—rod-pumped oil pumping and downhole pressure control during the fluid-carrying "self-flowing" stage—when not in operation, solving the technical problem that conventional mechanical rod-pumped oil pumping equipment cannot perform multi-stage pressure control.

Description

Technical Field

[0001] This application relates to the field of oil production technology, specifically to a "valve device for a wellbore or well," which is "located within the well." Furthermore, this application relates to a rod-operated pumping unit, belonging to "a method or apparatus for extracting oil, gas, water, soluble or fusible substances, or mineral mud from a well," which has a throttling function; therefore, it further belongs to "a method or apparatus for controlling the flow rate of produced fluids into or within the well." Additionally, this application also relates to "blowout preventers" in the field of oil production. Specifically, this application relates to a fixed valve with a throttling function and a rod-operated pumping unit. Background Technology

[0002] Gas-driven oil recovery involves injecting gases (such as carbon dioxide, nitrogen, or natural gas) into the reservoir. The gases improve the flow properties of the crude oil, reduce its viscosity, and increase its pressure, making it easier for the crude oil to be displaced from the rock pores and driven to the production well, thus enabling extraction.

[0003] Gas-driven oil wells generally exhibit a high gas-liquid ratio after they become effective. This can lead to reduced pump efficiency and "gas lock" in the pump during the lifting process of rod pumping equipment. In some wells, the excessively high gas-liquid ratio can even cause "self-flowing" of gas-liquid, resulting in high wellhead pressure and high-pressure fluid entering the surface system, which can pose safety hazards.

[0004] For wells with excessively high gas-liquid ratios leading to "self-flowing," existing rod-pumped oil lifting processes can only control the pressure of the produced fluid before it enters the surface pipeline by installing a wellhead throttle valve to ensure the safe operation of the surface system. However, the scope of throttling pressure control on the surface is limited, and freezing and blockage can occur in extreme weather conditions or in gaseous media containing high CO2 or other hydrate-forming gases, thus failing to meet the requirements for safe pressure control. Summary of the Invention

[0005] This application proposes a fixed valve with throttling function to at least partially solve the problems in the prior art.

[0006] This application proposes a fixed valve with throttling function to solve the problem of excessively high gas-liquid ratio in oil well production, which fails to meet the requirements for safe pressure control.

[0007] This application proposes a fixed valve with throttling function, which has adjustable flow control pressure control function downhole.

[0008] This application proposes a fixed valve with throttling function to reduce the occurrence of freezing and blockage under special conditions.

[0009] This application also proposes a rod-operated oil pumping device.

[0010] To achieve the above objectives, this application provides a fixed valve with a throttling function, comprising a housing and an inner cylinder located within the housing.

[0011] The fixed valve is configured to be compatible with the pump barrel of a rod-operated oil pumping unit.

[0012] The inner cylinder has an open end and a closed end arranged opposite to each other. The open end is closer to the pump barrel of the rod-operated oil pumping device than the closed end. The inner cylinder and the outer shell are configured such that the inner cylinder communicates with the pump barrel of the rod-operated oil pumping device through the open end, and the open end is separated from the inner cavity of the outer shell. The open end communicates with the inner cavity of the outer shell only indirectly through the interior of the inner cylinder.

[0013] The inner cylinder has flow-through holes and throttling holes on its wall. The inner cylinder can communicate with the inner cavity of the outer shell through the flow-through holes and the throttling holes. The flow-through holes are closer to the open end than the throttling holes. The flow area of ​​the flow-through holes is larger than that of the throttling holes.

[0014] The inner cylinder includes a limiting structure for restricting the downward height of the plunger as it penetrates the inner cylinder. The limiting structure is configured such that the maximum downward height of the plunger lies between the throttling orifice and the flow orifice.

[0015] The flow passage consists of multiple flow passages arranged spirally around the axis of the inner cylinder. The diameter of the multiple flow passages gradually increases from the closed end to the open end, and the diameter of the flow passage closest to the closed end is larger than the diameter of the throttling orifice.

[0016] According to a preferred embodiment of the present invention, the limiting structure is a limiting protrusion, which protrudes from the inner wall of the inner cylinder and is located between the throttling orifice and the flow passage orifice.

[0017] According to a preferred embodiment of the present invention, the limiting structure is a spring disposed inside the inner cylinder, with one end of the spring abutting against the closed end of the inner cylinder.

[0018] According to a preferred embodiment of the present invention, the limiting structure includes a plurality of support bars spaced apart along the inner circumferential wall of the inner cylinder, the support bars being staggered from the throttling orifice, the first end of the support bar being connected to the closed end of the inner cylinder, and the second end of the support bar being located between the throttling orifice and the flow orifice.

[0019] According to a preferred embodiment of the present invention, the inner cylinder and the outer shell are an integral structural component, or are relatively fixed separate structural components.

[0020] According to a preferred embodiment of the present invention, the outer shell is fixedly connected to the inner cylinder; or, the outer shell is detachably connected to the inner cylinder.

[0021] According to a preferred embodiment of the present invention, the open end of the inner cylinder is connected to the first end of the outer casing near the pump barrel of the rod-operated oil pumping device by a connecting means;

[0022] The open end of the inner cylinder is lower than the first end of the outer shell, and a stepped structure is formed between the open end of the inner cylinder and the inner wall of the first end of the outer shell. The open end of the inner cylinder can abut against the lower end of the pump cylinder.

[0023] According to a preferred embodiment of the present invention, the first end of the housing is provided with an internal thread or an external thread for threaded connection with the pump barrel.

[0024] According to another aspect of the present invention, a rod-operated oil pumping device is provided, comprising a pump barrel and a fixed valve with a throttling function, wherein the fixed valve with the throttling function is connected to the pump barrel, and the fixed valve with the throttling function is any one of the fixed valves with the throttling function described in the foregoing embodiments.

[0025] According to a preferred embodiment of the present invention, the pump cylinder includes an upper pump cylinder and a lower pump cylinder, the lower pump cylinder being connected to the fixed valve with throttling function.

[0026] A gas-liquid displacement cylinder is provided between the upper pump cylinder and the lower pump cylinder. The inner diameters of the upper pump cylinder and the lower pump cylinder are equal, and the inner diameter of the gas-liquid displacement cylinder is larger than that of the lower pump cylinder. The gas-liquid displacement cylinder is used for gas-liquid separation of gas-liquid mixtures.

[0027] According to a preferred embodiment of the present invention, the gas-liquid displacement cylinder, the upper pump cylinder, and the lower pump cylinder are integrally formed, welded together, or threaded together. The fixed valve with throttling function provided in this application embodiment includes an outer shell and an inner cylinder, with the inner cylinder installed inside the outer shell. The fixed valve with throttling function has a two-layer structure of an inner cylinder and an outer shell. It has an inner cavity formed by the inner cylinder and an annular cavity formed between the inner cylinder and the outer shell. The inner cylinder wall has flow holes and throttling holes. The inner cavity of the inner cylinder communicates with the annular cavity through the throttling holes and the flow holes. The flow holes are closer to the open end of the inner cylinder than the throttling holes, and the flow area of ​​the flow holes is larger than that of the throttling holes. When the gas-liquid ratio of an oil well reaches a certain level and it has the ability to produce fluids by flowing, the plunger is lowered above the throttling orifice to seal the flow passage. The inlet hole of the valve seat of the fixed valve cooperates with the throttling orifice to form a unique flow passage for downhole throttling. This allows the pressure of the fluid produced at the wellhead to be controlled before it enters the surface pipeline, achieving primary downhole pressure control production. At the same time, it works in conjunction with the surface system, such as the wellhead throttling valve, to perform secondary throttling and pressure control. This avoids freezing and blockage that can easily occur with only primary throttling at the wellhead under extreme weather conditions or when the produced gas contains high CO2. This ensures the safe operation of the surface system and solves the problem that conventional rod pump lifting technology cannot perform downhole pressure control. It meets the needs of gas-driven high gas-liquid ratio oil wells at different stages for gas lift prevention and pressure control production.

[0028] This application discloses a rod-type oil pumping device, including a pump barrel and a fixed valve with a throttling function. The pump barrel is connected to the fixed valve with the throttling function, which is the fixed valve with the throttling function described in any of the above-mentioned embodiments. Since the fixed valve with the throttling function has the above-mentioned technical effects, the rod-type oil pumping device with the fixed valve with the throttling function also has the same technical effects, which will not be elaborated further here. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort, and this application can be applied to other similar scenarios based on the provided drawings. Unless obvious from the linguistic context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0030] Figure 1 This is a schematic diagram of the structure of a fixed valve with throttling function disclosed in the embodiments of this application;

[0031] Figure 2 This is a schematic diagram of the structure of the rod-type oil pumping device (pump) disclosed in the embodiments of this application;

[0032] Figure 3 This is a schematic diagram of the structure of the inner cylinder with flow passage and throttling orifice disclosed in the first embodiment of this application;

[0033] Figure 4 This is a schematic diagram of the structure of the inner cylinder with flow passages and throttling holes disclosed in the second embodiment of this application;

[0034] Figure 5 This is a schematic diagram of the structure of the inner cylinder with flow passages and throttling holes disclosed in the third embodiment of this application;

[0035] Figure 6 This is a schematic diagram of the structure of the inner cylinder with flow passages and throttling holes disclosed in the fourth embodiment of this application;

[0036] Figure 7 This is a schematic diagram of the structure of the inner cylinder with flow passages and throttling holes disclosed in the fifth embodiment of this application.

[0037] The attached diagram is described below:

[0038] 10-Fixed valve; 101-Outer shell; 102-Inner cylinder; 1021-Open end; 1022-Closed end; 1023-Flow hole; 1024-Throttle hole; 1025-Limiting structure;

[0039] 20-Plunger;

[0040] 30 - Pump cylinder; 301 - Upper pump cylinder; 302 - Lower pump cylinder; 303 - Gas-liquid displacement cylinder. Detailed Implementation

[0041] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. The described embodiments are only a part of the embodiments of the present application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without inventive effort are within the scope of protection of the present application.

[0042] It should be noted that, for ease of description, only the parts relevant to the application are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined, provided that the combined technical features are not contradictory. All feasible combinations of features are the technical content explicitly described herein. Any one of the multiple sub-features contained in the same statement can be applied independently, without necessarily being applied together with other sub-features.

[0043] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0044] In the description of the embodiments of this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more.

[0045] Gas-driven oil recovery, as a method that can significantly improve oil recovery, is gradually being promoted and applied in low-permeability oilfields. As gas media is continuously injected into the reservoir, the gas production and gas-liquid ratio of the produced wells gradually increase after they become effective. The lifting efficiency of conventional rod pumps is significantly affected by gas. At the same time, due to the strong heterogeneity of low-permeability oilfield reservoirs, unidirectional gas channeling is prone to occur, resulting in an excessively high gas-liquid ratio in the wells and the phenomenon of gas-liquid "self-flowing," which poses a high pressure hazard at the wellhead and surface system.

[0046] In related technologies, for oil wells that produce "self-flowing" due to excessively high gas-liquid ratios, a throttling valve is installed at the wellhead to control the pressure of the produced fluid before it enters the surface pipeline, in order to ensure the safe operation of the surface system. However, throttling only at the surface has a limited pressure control range, and freezing and blockage may occur in extreme weather conditions or in gaseous media containing high CO2 or other gases that are prone to forming hydrates, thus failing to meet the requirements for safe pressure control.

[0047] In a first aspect, the fixed valve 10 with throttling function disclosed in the embodiments of this application includes a housing 101 and an inner cylinder 102. This application describes the application of the fixed valve 10 with throttling function to a rod-type oil pump (equipment) as an example, but it is not limited to application to rod-type oil pumps.

[0048] The first end of the outer casing 101 (the end closest to the wellhead) is connected to the pump barrel 30 of the rod-mounted oil pump. The second end of the outer casing 101 (the end furthest from the wellhead) is provided with a valve seat, which has a liquid inlet hole and a valve ball, which can seal the liquid inlet hole.

[0049] The inner cylinder 102 is located inside the outer shell 101. The inner cylinder 102 and the outer shell 101 can be an integral structural component or relatively fixed separate structural components. The two ends of the inner cylinder 102 along its axial direction are an open end 1021 and a closed end 1022, respectively. The open end 1021 of the inner cylinder 102 corresponds to the first end of the outer shell 101 and is closer to the wellhead. The closed end 1022 of the inner cylinder 102 corresponds to the second end of the outer shell 101 and is further away from the wellhead. The open end 1021 of the inner cylinder 102 is connected to the first end of the outer shell 101. When the inner cylinder 102 and the outer shell 101 are an integral structural component, the open end 1021 of the inner cylinder 102 and the first end of the outer shell 101 can be inherently connected. When the inner cylinder 102 and the outer shell 101 are relatively fixed separate structural components, the open end 1021 of the inner cylinder 102 and the first end of the outer shell 101 can be connected by a connection means.

[0050] It should be noted that, in Figure 1In one embodiment, the inner cylinder 102 and the outer shell 101 are joined at the open end 1021 and the first end of the outer shell 101; however, in an alternative embodiment, they may be joined at other locations.

[0051] Whether the inner cylinder 102 and the outer shell 101 are integral or separate structural components, and whether they are joined at the open end 1021 and the first end or at other locations, advantageously, the joining of the inner cylinder 102 and the outer shell 101 allows the inner cylinder 102 to communicate with the pump barrel 30 of the rod-type oil pump through the open end 1021, while the inner cylinder 102 does not communicate with the inner cavity of the outer shell 101 at the open end 1021. This joining of the open end 1021 and the first end of the outer shell 101 is considered a sealed joining.

[0052] The inner cylinder 102 is connected to the pump barrel 30 of the rod-type oil pump through the open end 1021. The closed end 1022 of the inner cylinder 102 is not connected to the inner cavity of the outer casing 101. It should be noted that the pump barrel 30 is connected to the inner cylinder 102, but not to the outer casing 101. The plunger 20 of the rod-type oil pump reciprocates within the inner cylinder 102 and the pump barrel 30. The closed end 1022 is higher than the working height of the valve ball to ensure that the inner cylinder 102 does not affect the normal opening of the valve ball. Here, "closed end" is a relative concept; it is relative to the open end. This end is relatively closed, not completely open, and it also includes the case where the closed end has a limited throttling orifice (described later). Of course, advantageously, the closed end 1022 is completely closed and does not have any orifice communicating with the inner cavity of the outer casing 101.

[0053] The fixed valve 10 with throttling function disclosed in the embodiments of this application has a two-layer structure of inner cylinder 102 and outer shell 101. The fixed valve 10 with throttling function has an inner cavity formed by the inner cylinder 102 and an annular cavity formed between the inner cylinder 102 and the outer shell 101. The annular cavity is located outside the inner cavity. The cylinder wall of the inner cylinder 102 is provided with a flow hole 1023 and a throttling hole 1024. The inner cylinder 102 communicates with the annular cavity through the flow hole 1023 and the throttling hole 1024. Figure 1 As shown, the flow passage 1023 is closer to the open end 1021 of the inner cylinder 102 than the throttling orifice 1024. The flow area of ​​the flow passage 1023 is larger than that of the throttling orifice 1024. The flow passage 1023 has a greater capacity to supply gas-liquid mixture than the throttling orifice 1024, so as to ensure the flow rate of gas-liquid mixture entering the inner cylinder 102 during the mechanical pumping stage.

[0054] The flow area and number of throttling orifices 1024 need to be designed according to the pressure control requirements. Specifically, when the pressure required for pressure control is large and the pressure of the gas-liquid mixture is large, the flow area of ​​the throttling orifice 1024 should be reduced; when the pressure required for pressure control is small and the pressure of the gas-liquid mixture is small, the flow area of ​​the throttling orifice 1024 can be appropriately increased.

[0055] During the pumping production stage, the anti-impact distance is adjusted so that the downward height of the plunger 20 is higher than that of the flow hole 1023. The oil-gas mixture entering the outer shell 101 enters the inner cylinder 102 through the flow hole 1023 and the throttle hole 1024, and then enters the pump cylinder 30 through the inner cylinder 102.

[0056] During the self-flowing production stage, pumping is stopped, and the plunger 20 is lowered to below the flow passage 1023 and above the throttling orifice 1024. The plunger 20 blocks the flow passage 1023, leaving only the throttling orifice 1024 connected to the outer casing 101. The oil-gas mixture entering the outer casing 101 enters the inner cylinder 102 through the throttling orifice 1024, and then enters the pump cylinder 30 through the inner cylinder 102.

[0057] In some embodiments of this application, the inner cylinder 102 has the same inner diameter as the pump cylinder 30.

[0058] When the fixed valve 10 with throttling function disclosed in the embodiments of this application is applied to a rod-type oil pump, the fixed valve 10 with throttling function is located at the bottom of the rod-type oil pump, that is, the bottom of the rod-type oil pump using the fixed valve 10 with throttling function disclosed in the embodiments of this application has a throttling structure. During the lifting stage of the rod-type oil pump, the anti-surge distance at the bottom is adjusted to be higher than the position of the throttling orifice of the fixed valve. At this time, the rod-type oil pump has the functions of a conventional rod-type oil pump. When the gas-liquid ratio of the oil well reaches a certain level and has the self-flowing production capacity, that is, the gas-liquid "self-flowing" stage, the flow passage 1023 is blocked by lowering the plunger 20. The liquid inlet of the valve seat of the fixed valve and the throttling orifice cooperate to form a unique flow passage, so as to perform downhole throttling, so that the pressure of the fluid produced at the wellhead is controlled before entering the surface pipeline, realizing downhole primary control. It controls production by simultaneously using surface systems such as wellhead throttling valves for secondary throttling and pressure control. This avoids freezing and blockage that can easily occur with only primary throttling at the wellhead under extreme weather conditions or when the produced gas contains high CO2. This ensures the safe operation of the surface system and solves the problem that conventional rod pump lifting technology cannot perform downhole pressure control. It meets the gas-proof lift and pressure control production needs of gas-driven high gas-liquid ratio oil wells at different stages. When the production gas-liquid ratio is insufficient to meet the conditions for self-flowing production, the anti-rush distance is adjusted before pumping production begins, realizing the lifting function of conventional anti-gas pumping pumps.

[0059] The fixed valve 10 with throttling function disclosed in this application achieves downhole throttling by setting throttling orifices 1024 in the inner cylinder 102. It not only has the advantages of simple structure and easy processing and manufacturing, but also high reliability, low risk of damage, and after blockage, it can be reverse-cleaned by annular water injection well washing to restore the flow capacity of throttling orifices 1024, and can be reused.

[0060] In extreme weather conditions, or when the produced gas contains high levels of CO2 or other gases that easily form hydrates, freezing and blockage may occur when it enters the surface pipeline, making it impossible to meet safety pressure control requirements. This application proposes to implement flow throttling downhole, which can effectively prevent freezing and blockage caused by temperature drop after flow throttling by utilizing the downhole temperature. This effectively prevents freezing and blockage and improves the reliability of safety pressure control.

[0061] The embodiments of this application disclose a fixed valve 10 with a throttling function. The inner cylinder 102 includes a limiting structure 1025. The limiting structure 1025 is located between the throttling orifice 1024 and the flow passage 1023, and is used to limit the downward height of the plunger 20 to prevent the plunger 20 from blocking the throttling orifice 1024.

[0062] During the self-spraying production stage, the pumping stops, and the plunger 20 is lowered to the limiting structure 1025. The limiting structure 1025 prevents the plunger 20 from descending further, ensuring that the plunger 20 is always above the throttle orifice 1024, and ensuring that the inner cylinder 102 can always communicate with the outer shell 101 through the throttle orifice 1024.

[0063] In some embodiments, the limiting structure 1025 is a limiting protrusion that protrudes from the inner wall of the inner cylinder 102. The limiting protrusion may be an annular protrusion, coaxial with the inner cylinder 102; the limiting protrusion may also be a boss spaced along the cylinder wall of the inner cylinder 102.

[0064] The limiting structure 1025 can also be a spring installed in the inner cylinder 102. One end of the spring abuts against the closed end 1022 of the inner cylinder 102, and the other end of the spring is higher than the throttling orifice 1024 and abuts against the plunger 20. After the plunger 20 abuts against the spring, the plunger 20 compresses the spring, and the spring applies a spring force to the plunger 20 to support it, so that the downward height of the plunger 20 is always higher than the throttling orifice 1024.

[0065] The limiting structure 1025 can also be a support bar spaced along the inner circumferential wall of the inner cylinder 102. The support bar is staggered with the throttling hole 1024. The first end of the support bar is connected to the closed end 1022 of the inner cylinder 102. The second end of the support bar is located between the throttling hole 1024 and the flow hole 1023. The second end of the support bar abuts against the plunger 20.

[0066] The limiting structure 1025 is not limited to the above embodiment. Other structures that can limit the downward height of the plunger 20 without obstructing the throttle orifice 1024 are also within the scope of protection of this case.

[0067] In some embodiments, the inner cylinder 102 and the outer shell 101 are arranged coaxially.

[0068] The inner cylinder 102 and the outer shell 101 can be connected in a fixed way or in a detachable way.

[0069] The inner cylinder 102 and the outer shell 101 are connected by a fixed connection, resulting in a more stable structure for the fixed valve 10 with a throttling function. Optionally, the inner cylinder 102 and the outer shell 101 are integrally formed, welded, keyed, or connected by other fixed connection methods.

[0070] The inner cylinder 102 and the outer shell 101 are connected in a detachable manner. When the inner cylinder 102 and / or the outer shell need to be replaced or repaired, the inner cylinder 102 and the outer shell 101 can be separated, and the operator can replace or repair the inner cylinder 102 and / or the outer shell 101 as needed. Optionally, the inner cylinder 102 and the outer shell 101 are connected by threads, or by snap-fit ​​connection, or by other detachable means.

[0071] like Figure 1 As shown, the open end 1021 of the inner cylinder 102 is lower than the first end of the outer shell 101. The open end 1021 of the inner cylinder 102 and the inner wall of the first end of the outer shell 101 form a stepped structure. The inner wall of the first end of the outer shell 101 has internal threads. After the pump cylinder 30 is connected to the fixed valve 10 with throttling function, the pump cylinder 30 abuts against the open end 1021 of the inner cylinder 102, and the inner cylinder 102 limits the installation of the pump cylinder 30.

[0072] In some embodiments, the first end of the housing 101 is connected to the pump barrel 30 by a thread. Specifically, the first end of the housing 101 has an internal thread, and the pump barrel 30 has an external thread that mates with the internal thread.

[0073] In some embodiments, the throttling orifice 1024 and / or the flow passage 1023 are arranged circumferentially along the inner cylinder 102. Specifically, the throttling orifice 1024 is arranged circumferentially along the inner cylinder 102; or, the flow passage 1023 is arranged circumferentially along the inner cylinder 102; or, the throttling orifice 1024 and the flow passage 1023 are arranged circumferentially along the inner cylinder 102. The distribution of the throttling orifice 1024 and the flow passage 1023 on the inner cylinder 102 can be the same or different.

[0074] Optionally, the throttling orifice 1024 is at the same height along the circumference of the inner cylinder 102 (e.g., Figure 3 (as shown) or misaligned distribution (such as) Figure 4 (As shown); the flow passage 1023 is at the same height along the circumference of the inner cylinder 102 (as shown). Figure 3 (as shown) or misaligned distribution (such as) Figure 4 (As shown) Distribution. It should be noted here that, regardless of the distribution of the flow orifice 1023 and the throttling orifice 1024, the flow orifice 1023 is always closer to the open end 1021 of the inner cylinder 102 than the throttling orifice 1024.

[0075] In embodiments where the throttling orifice 1024 and / or the flow passage 1023 are arranged along the circumference of the inner cylinder 102, the throttling orifice 1024 and / or the flow passage 1023 may be uniformly distributed or non-uniformly distributed along the circumference of the inner cylinder 102.

[0076] In some embodiments, the flow passage 1023 is spirally arranged around the axis of the inner cylinder 102, such as... Figure 5 As shown.

[0077] The inner cylinder 102 has at least one ring of flow holes 1023 along its axial direction. Specifically, the inner cylinder 102 has one, two, three or more rings of flow holes 1023 along its axial direction.

[0078] During the mechanical pumping production stage, the anti-impact distance is adjusted so that the downward height of the plunger 20 is higher than that of the flow passage 1023. The oil-gas mixture entering the outer shell 101 enters the inner cylinder 102 through at least one ring of flow passage 1023 and throttle hole 1024, and then enters the pump cylinder 30 through the inner cylinder 102.

[0079] During the self-flowing production stage, when pumping stops, the plunger 20 can be lowered to the limiting structure, retaining only the flow capacity of the throttling orifice. The downhole pressure is controlled to the maximum extent through the throttling orifice. Alternatively, it can be left unlowered to the limiting structure, retaining some of the flow capacity of the flow orifice. By coordinating the throttling orifice with the flow capacity retained, the downhole pressure control range can be adjusted.

[0080] In embodiments where the inner cylinder 102 has at least two rings of flow holes 1023 along its axial direction, the flow area of ​​the flow holes 1023 can gradually increase from the closed end to the open end of the inner cylinder 102, such as... Figure 6 As shown, it should be noted that the flow area of ​​the throttling orifice is less than or equal to the flow area of ​​the flow orifice 1023 near the closed end of the inner cylinder 102; or, the flow areas of the flow orifice 1023 from the closed end to the open end of the inner cylinder 102 are equal, such as... Figure 7 As shown.

[0081] Secondly, embodiments of this application disclose a rod-type oil pump suitable for gas-driven oil wells, particularly for gas-driven oil wells with a high gas-liquid ratio, such as... Figure 2 As shown, it includes a pump cylinder 30 and a fixed valve 10 with throttling function. The pump cylinder 30 is connected to the fixed valve 10 with throttling function. The fixed valve 10 with throttling function is the fixed valve 10 with throttling function described in any of the above schemes.

[0082] When a gas-liquid "self-flowing" phenomenon occurs in an oil well during gas drive, the flow passage 1023 can be blocked by stopping pumping and lowering the plunger 20 of the rod pump. This allows the downhole gas-liquid mixture to flow through the throttling orifice 1024, through the pump, and into the tubing, and be lifted to the surface, achieving downhole pressure control during the "self-flowing" production stage. At the same time, secondary throttling can be performed in conjunction with the surface system to further improve the pressure control range. This effectively solves the problem that the rod pump lifting process cannot perform downhole pressure control during the gas-liquid ratio caused by gas channeling and the "self-flowing" stage.

[0083] The pump cylinder 30 includes an upper pump cylinder 301 and a lower pump cylinder 302. The upper pump cylinder 301 and the lower pump cylinder 302 are coaxially arranged. The upper end of the upper pump cylinder 301 extends towards the ground, and the lower end of the lower pump cylinder 302 (or the end of the lower pump cylinder 302 away from the upper pump cylinder 301) is connected to a fixed valve 10 with a throttling function.

[0084] In some embodiments, a gas-liquid displacement chamber 303 is provided between the upper pump barrel 301 and the lower pump barrel 302. The inner diameters of the upper pump barrel 301 and the lower pump barrel 302 are equal, and the diameter of the gas-liquid displacement chamber 303 is larger than the diameter of the lower pump barrel 302. The gas-liquid displacement chamber is used to provide space for gas-liquid separation of the gas-liquid mixture, improve the filling degree of the rod-type oil pump, and avoid the "gas lock" phenomenon.

[0085] A gas-liquid replacement chamber is formed inside the gas-liquid replacement cylinder 303. During the operation of the rod-type oil pump, especially in the middle and later stages of high gas-liquid ratio oil well production, gas tends to accumulate in the pump chamber. The gas-liquid replacement chamber utilizes the density difference between gas and liquid to displace the gas in the pump chamber through replacement, preventing gas from occupying too much space and causing the floating valve and the fixed valve 10 with throttling function to fail to open properly. This prevents gas lock in the oil pump and ensures the normal operation of the oil pump.

[0086] During the mechanical pumping production stage of the rod-type oil pump, the anti-surge distance is adjusted so that the downward height of the plunger 20 is higher than the height of the flow orifice 1023 of the fixed valve 10 with throttling function. During the pumping process of the rod-type oil pump, both the throttling orifice 1024 and the flow orifice 1023 of the fixed valve 10 with throttling function can allow the gas-liquid mixture to pass through. The gas-liquid displacement cylinder 303 designed between the upper pump cylinder 301 and the lower pump cylinder 302 provides a gas-liquid separation space for the high gas-liquid ratio fluid entering the pump, improves the pump's filling degree, and plays a role in preventing gas lift.

[0087] When the gas-liquid ratio of the oil well reaches a certain level and it has the ability to produce oil through self-flowing, that is, during the self-flowing production stage, the plunger 20 is lowered to the limiting structure 1025, the plunger 20 closes the flow passage 1023, the valve ball of the fixed valve 10 with throttling function leaves the valve seat, and the outer shell 101 is connected to the inner cylinder 102 through the throttling hole 1024 to form a unique flow passage, thereby realizing downhole throttling and pressure control production of the gas channeling self-flowing well.

[0088] When the gas-liquid ratio is insufficient to meet the conditions for self-flowing production, the anti-impact distance is adjusted to enter the mechanical pumping production stage, realizing the lifting function of the conventional anti-gas pumping oil pump.

[0089] When the throttle orifice 1024 becomes blocked, it can be reverse-cleaned by annular water injection to restore the flow capacity of the throttle orifice 1024.

[0090] In some embodiments, the gas-liquid displacement cylinder 303 is integrally formed, welded, or threadedly connected to the upper pump cylinder 301 and / or the lower pump cylinder 302.

[0091] The rod-operated pumping equipment / rod-operated pump disclosed in this application has the functions of improving pump efficiency and preventing "gas lock" during the lifting stage of the rod-operated pump, as well as the downhole throttling and pressure control function during the stage when the gas-liquid ratio is high enough and the gas carries the liquid to "flow".

[0092] Conventional downhole choke devices are primarily used in natural gas wells. They achieve downhole pressure control by installing the device in the downhole tubing. Because they utilize a bare tubing production method, choke devices of different sizes can be deployed. Furthermore, since the main components of the downhole fluid are water and gas, clogging of the downhole choke device is less likely. In recent years, with the increasing adoption of gas-driven development methods, some oil wells, after gas breakthrough, experience high gas production and high wellhead pressure, necessitating pressure control production methods to ensure the safe and stable entry of high-pressure fluid into the surface system. Unlike natural gas wells, gas-driven oil wells primarily employ a mechanically pumped rod pump lift process. The process tubing structure limits the possibility of deploying downhole choke devices. Specifically, conventional downhole chokes require the removal of the downhole tubing, sucker rod, and pump (a combination of tubing, sucker rod, and pump) for re-completion, the installation of clean tubing, and the deployment of the downhole choke device. The choke device then functions as a choke. Because gas-driven oil well production is significantly affected by bottomhole pressure and the gas-liquid ratio, if "self-flowing" is not achieved, the downhole choke device and clean tubing must be removed, and the tubing, sucker rod, and pump must be reinstalled to resume mechanical pumping. This not only impacts production efficiency but also necessitates frequent operations, increasing production costs. Furthermore, the complex downhole conditions in oil wells, particularly high-viscosity fluids, can easily lead to choke device blockage, resulting in poor process stability. When the choke device fails, retrieval operations are required, further impacting production efficiency and increasing costs.

[0093] Considering the above factors, conventional gas-driven oil wells can only achieve pressure control through wellhead throttling, but the control range is limited. The fixed valve and rod-mounted pump with throttling function disclosed in this application are suitable for downhole operations in gas-driven oil production wells. In addition to the lifting function of conventional mechanically pumped rod-mounted pumps, they also possess downhole throttling pressure control capabilities. During the gas-driven fluid "self-flowing" stage of the oil well, different degrees of downhole throttling pressure control can be achieved by adjusting the anti-surge distance. This solves the technical problem that conventional mechanically pumped rod-mounted pumps can only use wellhead pressure control, enabling the switching between two production modes—rod-mounted pump lifting and downhole pressure control during the fluid-driven "self-flowing" stage—when not in operation, greatly improving production efficiency and reducing operating costs.

[0094] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed, and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. The scope of this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described application concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A fixed valve (10) with throttling function, characterized in that, It includes an outer shell (101) and an inner cylinder (102) located inside the outer shell (101). The fixed valve (10) is configured to engage with the pump barrel (30) of a rod-operated pumping unit. The inner cylinder (102) has an open end (1021) and a closed end (1022) arranged opposite to each other. The open end (1021) is closer to the pump barrel (30) of the rod-operated oil pumping device than the closed end (1022). The inner cylinder (102) and the outer shell (101) are configured such that the inner cylinder (102) communicates with the pump barrel (30) of the rod-operated oil pumping device through the open end (1021), and the open end (1021) is separated from the inner cavity of the outer shell (101). The open end (1021) communicates indirectly with the inner cavity of the outer shell (101) only through the interior of the inner cylinder (102). The inner cylinder (102) has an overflow hole (1023) and a throttling hole (1024) on its wall. The inner cylinder (102) can communicate with the inner cavity of the outer shell (101) through the overflow hole (1023) and the throttling hole (1024). The overflow hole (1023) is closer to the open end (1021) than the throttling hole (1024). The flow area of ​​the overflow hole (1023) is larger than the flow area of ​​the throttling hole (1024). The inner cylinder (102) includes a limiting structure (1025) for limiting the downward height of the plunger (20) when it extends into the inner cylinder (102). The limiting structure (1025) is configured such that the maximum downward height of the plunger (20) is located between the throttling orifice (1024) and the flow passage (1023). The flow passage (1023) comprises multiple flow passages (1023), which are spirally arranged around the axis of the inner cylinder (102). The diameter of the multiple flow passages (1023) gradually increases from the closed end (1022) to the open end (1021), and the diameter of the flow passage (1023) closest to the closed end (1022) is larger than the diameter of the throttling orifice (1024). The limiting structure (1025) is a limiting protrusion that protrudes from the inner wall of the inner cylinder (102) and is located between the throttling orifice (1024) and the flow passage (1023). The inner cylinder (102) and the outer shell (101) are either an integral structural component or relatively fixed separate structural components.

2. The fixed valve (10) with throttling function according to claim 1, characterized in that: The limiting structure (1025) is a spring installed inside the inner cylinder (102), with one end of the spring abutting against the closed end (1022) of the inner cylinder (102).

3. The fixed valve (10) with throttling function according to claim 1, characterized in that: The limiting structure (1025) includes a plurality of support bars spaced apart along the inner circumferential wall of the inner cylinder (102). The support bars are staggered with the throttling hole (1024). The first end of the support bar is connected to the closed end (1022) of the inner cylinder (102), and the second end of the support bar is located between the throttling hole (1024) and the flow hole (1023).

4. The fixed valve (10) with throttling function according to any one of claims 1-3, characterized in that: The open end (1021) of the inner cylinder (102) is connected to the first end of the outer shell (101) near the pump barrel (30) of the rod-operated oil pumping equipment by a connection means; The open end (1021) of the inner cylinder (102) is lower than the first end of the outer shell (101). The open end (1021) of the inner cylinder (102) and the inner wall of the first end of the outer shell (101) form a stepped structure, and the open end (1021) of the inner cylinder (102) can abut against the lower end of the pump cylinder (30).

5. The fixed valve (10) with throttling function according to claim 4, characterized in that: The first end of the outer casing (101) is provided with an internal thread or an external thread for threaded connection with the pump barrel (30).

6. A rod-operated oil pumping device, characterized in that, It includes a pump cylinder (30) and a fixed valve (10) with throttling function, wherein the fixed valve (10) with throttling function is connected to the pump cylinder (30), and the fixed valve (10) with throttling function is the fixed valve (10) with throttling function according to any one of claims 1-5.

7. The rod-operated oil pumping device according to claim 6, characterized in that, The pump cylinder (30) includes an upper pump cylinder (301) and a lower pump cylinder (302), the lower pump cylinder (302) being connected to the fixed valve (10) with throttling function. A gas-liquid displacement cylinder (303) is provided between the upper pump cylinder (301) and the lower pump cylinder (302). The inner diameters of the upper pump cylinder (301) and the lower pump cylinder (302) are equal, and the inner diameter of the gas-liquid displacement cylinder (303) is larger than the inner diameter of the lower pump cylinder (302). The gas-liquid displacement cylinder (303) is used for gas-liquid separation of gas-liquid mixtures.

8. The rod-operated oil pumping device according to claim 7, characterized in that, The gas-liquid displacement cylinder (303), the upper pump cylinder (301), and the lower pump cylinder (302) are integrally formed, welded together, or threaded together.

Images