Device and method for oil injection and production in underground salt cavern oil depot

Abstract

The present invention relates to the field of salt cavern oil storage, and in particular to a device and method for injecting and producing oil in an underground salt cavern oil depot, comprising a pipeline mechanism and a control mechanism; the pipeline mechanism comprises a first pipeline and a second pipeline; one end of the first pipeline is fluidly connected to a gas phase region of the oil storage salt cavern, and one end of the second pipeline is fluidly connected to a liquid phase region of the oil storage salt cavern; the control mechanism is installed on the pipeline mechanism, and the control mechanism is used to regulate the pressure state of the gas during oil production; the problem in the prior art that the saturated brine process is difficult to source and requires a large amount of saturated brine during oil production, the oil production mode is single, and there is a hidden danger that the equipment cannot perform oil replacement, the project progress is guaranteed, and the production efficiency and safety are improved.

Description

Technical Field

[0001] The invention relates to the technical field of underground salt cavern oil depots, and in particular to a device and method for injecting and producing oil in underground salt cavern oil depots. Background Art

[0002] Underground salt caverns are mines left behind after salt mining. They take advantage of their huge size and good sealing. Salt under high temperature and high pressure has the characteristic of automatically healing cracks. By injecting crude oil and exchanging it with brine or saturated brine, they can not only achieve the technical effect of safely storing oil, natural gas and related products, but also save investment compared to ground storage. They are widely used in developed countries such as the United States and Germany.

[0003] At present, underground salt cavern oil depots usually use saturated salt water or saturated brine to replace crude oil in caverns. However, due to the saturated brine process, it is difficult to source saturated brine during oil production, and a large amount of saturated brine is required. Existing technology shows that it takes about 300,000 cubic meters of brine to replace crude oil or refined oil in a salt cavern. When the storage of saturated brine resources is insufficient, there is a hidden danger that the equipment cannot perform oil replacement due to the single equipment replacement mode, which affects the project progress and reduces production efficiency. Summary of the invention

[0004] The purpose of the present invention is to provide a device and method for injecting and producing oil in an underground salt cavern oil depot, so as to alleviate the technical problems in the prior art that, when producing oil using a saturated brine process, it is difficult to source saturated brine, and due to the single equipment replacement mode, when there is saturated brine, the equipment cannot replace oil, which affects the progress of the project and reduces production efficiency.

[0005] In a first aspect, the present invention provides a device for injecting and producing oil in an underground salt cavern oil depot, comprising a pipeline mechanism and a control mechanism;

[0006] The pipeline mechanism includes a first pipeline and a second pipeline; one end of the first pipeline is in fluid communication with the gas phase region of the oil storage salt cavern, and one end of the second pipeline is in fluid communication with the liquid phase region of the oil storage salt cavern;

[0007] The control mechanism is installed on the pipeline mechanism, and the control mechanism is used to adjust the on-off state of the first pipeline and the second pipeline.

[0008] In combination with the first aspect, the present invention provides a first possible implementation manner of the first aspect, wherein an end of the first pipeline facing the oil storage salt cavern is higher than an end of the second pipeline facing the oil storage salt cavern.

[0009] In combination with the first aspect, the present invention provides a second possible implementation manner of the first aspect, wherein the control mechanism includes a gas injection and production assembly, and the fluid of the gas injection and production assembly is connected to the end of the first pipeline away from the oil storage salt cavern; the first pipeline is provided with a first branch pipe, and the first branch pipe is connected to the first pipeline in parallel with the gas injection and production assembly, and the end of the first branch pipe away from the oil storage salt cavern is connected to the end of the gas injection and production assembly away from the oil storage salt cavern.

[0010] In combination with the first possible implementation of the first aspect, the present invention provides a third possible implementation of the first aspect, wherein the gas injection and production assembly includes a first valve body, a second valve body and a pressure control valve, the pressure control valve is fluidly connected between the first valve body and the second valve body, and the second valve body is installed at the end of the gas injection and production assembly facing the oil storage salt cavern.

[0011] In combination with the first possible implementation manner of the first aspect, the present invention provides a fourth possible implementation manner of the first aspect, wherein the gas injection and production assembly further includes a third valve body, and the first branch pipe is connected to the third valve body.

[0012] In combination with the first possible implementation manner of the first aspect, the present invention provides a fifth possible implementation manner of the first aspect, wherein the control mechanism further includes a fourth valve body, and the fourth valve body is arranged at the end of the second pipeline away from the oil storage salt cavern.

[0013] In combination with the first possible implementation of the first aspect, the present invention provides a sixth possible implementation of the first aspect, wherein the second pipeline is connected to a second branch, the control mechanism also includes a fifth valve body, and the fifth valve body is arranged at the end of the second branch away from the second pipeline; the second branch is provided with an anti-corrosion material.

[0014] In a second aspect, the present invention further provides a method for injecting and producing oil in an underground salt cavern oil depot, comprising the above-mentioned device for injecting and producing oil in an underground salt cavern oil depot, including an oil production step and an oil injection step;

[0015] The oil recovery step comprises:

[0016] S11: connecting the end of the pipeline mechanism away from the oil storage salt cavern to the displacement object, and adjusting the control mechanism according to the pressure of the displacement object relative to the stored oil in the oil storage salt cavern so that the displacement object enters the oil storage salt cavern along the pipeline mechanism;

[0017] When the pressure of the displacement object is lower than the oil storage pressure, the displacement object enters the oil storage salt cavern along the first pipeline;

[0018] When the pressure of the displacement object is greater than the oil storage pressure, the displacement object enters the oil storage salt cavern along the second pipeline;

[0019] S12: When the pressure of the displacement object is lower than the pressure of the stored oil, the stored oil is discharged along the second pipeline;

[0020] When the pressure of the displacement object is greater than the pressure of the stored oil, the stored oil is discharged along the first pipeline;

[0021] S13: when the pressure of the displacement object is lower than the oil storage pressure, and when the liquid level of the oil storage drops to the end of the second pipeline facing the oil storage salt cavern, the injection of the displacement object is stopped through the control mechanism, and oil production is stopped;

[0022] When the pressure of the displacement material is greater than the oil storage pressure, and when the liquid level of the oil storage rises to the top of the oil storage salt cavern, the injection of the displacement material is stopped through the control mechanism, and the oil production is stopped;

[0023] The oil injection step comprises:

[0024] S21: connecting the end of the pipeline mechanism away from the oil storage salt cavern to the crude oil pump, and adjusting the control mechanism and the crude oil pump according to the pressure of the displacement object in the oil storage salt cavern relative to the stored oil in the oil storage salt cavern to allow the crude oil to enter the oil storage salt cavern along the pipeline mechanism;

[0025] When the pressure of the crude oil is greater than the pressure of the displacement object, the crude oil enters the oil storage salt cavern along the second pipeline;

[0026] When the pressure of the crude oil is less than the pressure of the displacement material, the displacement material enters the oil storage salt cavern along the first pipeline;

[0027] S22: When the pressure of the crude oil is greater than the pressure of the displacement material, the displacement material is discharged along the first pipeline;

[0028] When the pressure of the crude oil is less than the pressure of the displacer, the displacer is discharged along the second pipeline;

[0029] S23: When the pressure of the crude oil is greater than the pressure of the displacement material and the liquid level of the stored oil rises to the top of the oil storage salt cavern, the injection of the crude oil is stopped by a control mechanism, and the oil injection is stopped;

[0030] When the pressure of the crude oil is lower than that of the displacement material, and when the liquid level of the stored oil drops to the end of the second pipeline facing the oil storage salt cavern, the injection of the crude oil is stopped by the control mechanism, and the oil injection is stopped.

[0031] In combination with the second aspect, the present invention provides a first possible implementation of the second aspect, wherein when the pressure of the displacement object is less than the stored oil, when oil production starts, the fourth valve body, the first valve body, the pressure control valve and the second valve body are opened, and the fifth valve body and the third valve body are closed, and when oil production ends, the first valve body and the fourth valve body are closed;

[0032] When the pressure of the replacement object is greater than the stored oil, when oil production starts, the fourth valve body, the first valve body, the control pressure valve and the second valve body are closed, and the third valve body and the fifth valve body are opened; when oil production ends, the third valve body and the fifth valve body are closed.

[0033] In combination with the second aspect, the present invention provides a second possible implementation manner of the second aspect, wherein when the pressure of the crude oil is greater than the pressure of the displacement material, when oil injection starts, the fourth valve body and the third valve body are opened, and the first valve body, the pressure control valve, the second valve body and the fifth valve body are closed; when oil injection ends, the third valve body and the fourth valve body are closed;

[0034] When the pressure of the crude oil is less than the pressure of the displacement material, when oil injection starts, the fifth valve body and the third valve body are opened, and the first valve body, the pressure control valve, the second valve body and the fourth valve body are closed; when oil injection ends, the fifth valve body and the third valve body are closed.

[0035] The embodiment of the present invention brings the following beneficial effects: the control mechanism is installed on the pipeline mechanism, the pipeline mechanism includes a first pipeline and a second pipeline; one end of the first pipeline is connected to the gas phase fluid of the oil storage salt cavern, and one end of the second pipeline is connected to the liquid phase fluid of the oil storage salt cavern. According to the difference in pressure between different replacement objects and crude oil, the crude oil replacement mode of the pipeline mechanism relative to the oil storage salt cavern can be switched by adjusting the control mechanism, thereby alleviating the problem in the prior art that a large amount of saturated brine is required during oil production in the saturated brine process. When the amount of saturated brine is insufficient, there is a hidden danger that the equipment cannot perform oil replacement due to the single equipment replacement mode, thereby ensuring the progress of the project and improving production efficiency.

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A schematic diagram of the structure of an apparatus for injecting and producing oil in an underground salt cavern oil depot provided by an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of the structure of a gas injection and production assembly in an oil injection and production device for an underground salt cavern oil depot provided by an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of the positions of a connecting pipe and a sixth valve body in an underground salt cavern oil depot oil injection and production device provided in an embodiment of the present invention.

[0041] Icons: 100 - pipeline mechanism; 110 - first pipeline; 120 - second pipeline; 130 - first branch pipe; 140 - second branch pipe; 150 - connecting pipe; 200 - control mechanism; 210 - gas injection and production assembly; 211 - first valve body; 212 - second valve body; 213 - pressure control valve; 220 - third valve body; 230 - fourth valve body; 240 - fifth valve body; 250 - sixth valve body; 300 - oil storage salt cavern; 410 - first interface; 420 - second interface. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Physical quantities in formulas, if not separately marked, should be understood as basic quantities of the base units of the International System of Units, or derived quantities derived from the basic quantities through mathematical operations such as multiplication, division, differentiation or integration.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In the description of the present invention, it should be noted that the control mechanism can be "manual", "electric", "pneumatic", "gas-liquid linkage", "electric-liquid linkage", etc. For ordinary technicians in this field, the specific meanings of the above action modes in the present invention can be understood according to specific circumstances.

[0046] Embodiment 1

[0047] like Figure 1 and Figure 2 As shown, the device for injecting and producing oil in an underground salt cavern oil depot provided by the present invention comprises a pipeline mechanism 100 and a control mechanism 200; the control mechanism 200 is installed on the pipeline mechanism 100; the pipeline mechanism 100 comprises a first pipeline 110 and a second pipeline 120; one end of the first pipeline 110 and one end of the second pipeline 120 are both fluidically connected to the oil storage salt cavern 300; the end of the first pipeline 110 facing the oil storage salt cavern 300 is higher than the end of the second pipeline 120 facing the oil storage salt cavern 300.

[0048] The control mechanism 200 is installed on the pipeline mechanism 100, and the pipeline mechanism 100 includes a first pipeline 110 and a second pipeline 120; one end of the first pipeline 110 is connected to the gas phase fluid of the oil storage salt cavern 300, and one end of the second pipeline 120 is connected to the liquid phase fluid of the oil storage salt cavern 300; according to the difference between the pressure of different replacement objects and crude oil, the crude oil replacement mode of the pipeline mechanism 100 relative to the oil storage salt cavern 300 can be switched by adjusting the control mechanism 200, thereby alleviating the problem in the prior art that the saturated brine process is difficult to source during oil production, a large amount of saturated brine is required, the replacement mode is single, and there is a hidden danger that the equipment cannot perform oil replacement, thereby ensuring the progress of the project and improving production efficiency.

[0049] It should be noted that in order to avoid hidden dangers such as natural gas leakage and brine leakage, a first interface 410 and a second interface 420 are respectively provided in the oil storage salt cavern 300. The second interface 420 is located on the upper part of the first interface 410. An operation area is formed between the first interface 410 and the second interface 420. One end of the first pipeline 110 facing the oil storage salt cavern 300 and one end of the second pipeline 120 facing the oil storage salt cavern 300 are located in the operation area.

[0050] Furthermore, the control mechanism 200 includes a gas injection and production component 210, and the fluid of the gas injection and production component 210 is connected to the end of the first pipeline 110 away from the oil storage salt cavern 300; the first pipeline 110 is provided with a first branch pipe 130, and the first branch pipe 130 and the gas injection and production component 210 are connected to the first pipeline 110 in parallel, and the end of the first branch pipe 130 away from the oil storage salt cavern 300 is connected to the end of the gas injection and production component 210 away from the oil storage salt cavern 300.

[0051] When the displacer is a substance such as natural gas whose pressure is lower than that of crude oil, the displacer can enter the oil storage salt cavern 300 from the first pipeline 110 along the gas injection and production assembly 210. Since the end of the first pipeline 110 facing the oil storage salt cavern 300 is higher than the end of the second pipeline 120 facing the oil storage salt cavern 300, the crude oil is discharged along the second pipeline 120 under the pressure of the displacer, thereby realizing the oil production process.

[0052] Furthermore, the gas injection and production assembly 210 includes a first valve body 211, a second valve body 212 and a pressure control valve 213, the first valve body 211 and the second valve body 212 are fluidically connected via the pressure control valve 213, and the second valve body 212 is installed at the end of the gas injection and production assembly 210 facing the oil storage salt cavern 300.

[0053] The pressure control valve 213 can provide pressure for the displacement material entering the injection and production gas assembly 210. At the same time, the two ends of the pressure control valve 213 can be connected to the fluid through the first valve body 211 and the second valve body 212. The first valve body 211 is used to control the on-off of the displacement material entering the first pipeline 110. After the displacement material is regulated by the pressure control valve 213, the displacement material that meets the displacement pressure conditions enters the oil storage salt cavern 300 through the second valve body 212, avoiding insufficient displacement material pressure and affecting the project progress.

[0054] Furthermore, the gas injection and production component 210 further includes a third valve body 220 , and the first branch pipe 130 is connected to the third valve body 220 .

[0055] Furthermore, the end of the first pipeline 110 facing the oil-storage salt cavern 300 is higher than the end of the second pipeline 120 facing the oil-storage salt cavern 300 .

[0056] When the displacement pressure in the oil storage salt cavern 300 is lower than that of the crude oil, during the oil injection process, the crude oil can enter the oil storage salt cavern 300 along the second pipeline 120. Since the end of the first pipeline 110 facing the oil storage salt cavern 300 is higher than the end of the second pipeline 120 facing the oil storage salt cavern 300, the crude oil can push the displacement into the end of the first pipeline 110 facing the oil storage salt cavern 300. By opening the third valve body 220, the displacement is discharged from the second branch pipe 140.

[0057] It should be noted that, since the pressure control valve 213 is a one-way air intake component, the provision of the second branch pipe 140 can ensure the discharge of the replacement material and the quality of the oil injection process.

[0058] Furthermore, the control mechanism 200 further includes a fourth valve body 230 , which is disposed at the end of the second pipeline 120 away from the oil storage salt cavern 300 .

[0059] When the pressure of the displaced object is greater than the pressure of the crude oil, during the oil production process, the displaced object can be allowed to enter the oil storage salt cavern 300 from the second pipeline 120 by controlling the on / off of the fourth valve body 230. Since the end of the first pipeline 110 facing the oil storage salt cavern 300 is higher than the end of the second pipeline 120 facing the oil storage salt cavern 300, the displaced object can push the crude oil to the end of the first pipeline 110 facing the oil storage salt cavern 300, and the crude oil is output through the first pipeline 110 along the first branch pipe 130.

[0060] When the pressure of the displacement object is greater than the pressure of the crude oil, during the oil injection process, the crude oil is injected into the oil storage salt cavern 300 along the first pipeline 110 through the first branch pipe 130, and the displacement object in the oil storage salt cavern 300 is output through the second pipeline 120.

[0061] Furthermore, the second pipeline 120 is connected to the second branch pipe 140, and the control mechanism 200 also includes a fifth valve body 240, which is arranged at the end of the second branch pipe 140 away from the second pipeline 120; the second branch pipe 140 is provided with anti-corrosion material.

[0062] When the replacement is a corrosive substance such as saturated brine and the pressure of which is greater than the pressure of the crude oil, since the second branch pipe 140 is provided with an anti-corrosion material, during the oil injection process, the crude oil is injected into the oil storage salt cavern 300 along the first pipeline 110 through the first branch pipe 130, and the replacement in the oil storage salt cavern 300 is output through the second branch pipe 140 along the second pipeline 120; at the same time, during the oil production process, the replacement can be controlled by controlling the on-off of the fifth valve body 240 to allow the replacement to enter the oil storage salt cavern 300 from the second branch pipe 140 along the second pipeline 120. Since the end of the first pipeline 110 facing the oil storage salt cavern 300 is higher than the end of the second pipeline 120 facing the oil storage salt cavern 300, the replacement can push the crude oil to the end of the first pipeline 110 facing the oil storage salt cavern 300, and the crude oil is output through the first pipeline 110 along the first branch pipe 130, thereby increasing the anti-corrosion properties of the pipeline, extending the service life, and reducing the production cost.

[0063] It should be noted that the first valve body 211, the second valve body 212, the third valve body 220, the fourth valve body 230 and the fifth valve body 240 are all pneumatic battery valves, and the control mechanism 200 is installed on the ground to facilitate operation and inspection by operators.

[0064] The present invention also provides a method for injecting and producing oil in an underground salt cavern oil depot, comprising the above-mentioned device for injecting and producing oil in an underground salt cavern oil depot, including an oil production step and an oil injection step;

[0065] The oil recovery steps include:

[0066] S1: Connect the end of the pipeline mechanism 100 away from the oil storage salt cavern 300 to the displacement object, and adjust the control mechanism 200 according to the pressure of the displacement object relative to the oil stored in the oil storage salt cavern 300 so that the displacement object enters the oil storage salt cavern 300 along the pipeline mechanism 100;

[0067] When the pressure of the displaced material is lower than the oil storage pressure, the displaced material enters the oil storage salt cavern 300 along the first pipeline 110;

[0068] When the pressure of the displaced material is greater than the stored oil pressure, the displaced material enters the oil storage salt cavern 300 along the second pipeline 120;

[0069] S2: When the pressure of the displaced object is lower than the stored oil pressure, the stored oil is discharged along the second pipeline 120;

[0070] When the pressure of the displaced object is greater than the stored oil pressure, the stored oil is discharged along the first pipeline 110;

[0071] S3: When the pressure of the displacement material is lower than the oil storage pressure, and when the liquid level of the oil storage drops to the end of the second pipeline 120 facing the oil storage salt cavern 300, the injection of the displacement material is stopped through the control mechanism 200, and oil production is stopped;

[0072] When the pressure of the displacement material is greater than the oil storage pressure, and when the liquid level of the oil storage rises to the top of the oil storage salt cavern 300, the injection of the displacement material is stopped through the control mechanism 200, and oil production is stopped;

[0073] The oil filling steps include:

[0074] S1: Connect the end of the pipeline mechanism 100 away from the oil storage salt cavern 300 to the crude oil pump, and adjust the control mechanism 200 and the crude oil pump according to the pressure of the displacement in the oil storage salt cavern 300 relative to the stored oil in the oil storage salt cavern 300 so that the crude oil enters the oil storage salt cavern 300 along the pipeline mechanism 100;

[0075] When the pressure of the crude oil is greater than the pressure of the displacement material, the crude oil enters the oil storage salt cavern 300 along the second pipeline 120;

[0076] When the pressure of the crude oil is less than the pressure of the displacement material, the displacement material enters the oil storage salt cavern 300 along the first pipeline 110;

[0077] S2: When the pressure of the crude oil is greater than the pressure of the displacement material, the displacement material is discharged along the first pipeline 110;

[0078] When the pressure of the crude oil is less than the pressure of the displacer, the displacer is discharged along the second pipeline 120;

[0079] S3: When the pressure of the crude oil is greater than the pressure of the displacement material and the liquid level of the stored oil rises to the top of the oil storage salt cavern 300, the injection of the crude oil is stopped through the control mechanism 200, and the oil injection is stopped;

[0080] When the pressure of the crude oil is lower than that of the displacement material, when the liquid level of the stored oil drops to the end of the second pipeline 120 facing the oil storage salt cavern 300, the injection of the crude oil is stopped by the control mechanism 200, and the oil injection is stopped.

[0081] Furthermore, when the pressure of the displaced object is less than the stored oil, when oil production starts, the fourth valve body 230, the first valve body 211, the pressure control valve 213 and the second valve body 212 are opened, and the fifth valve body 240 and the third valve body 220 are closed; when oil production ends, the first valve body 211 and the fourth valve body 230 are closed; when the pressure of the displaced object is greater than the stored oil, when oil production starts, the fourth valve body 230, the first valve body 211, the control pressure valve and the second valve body 212 are closed, and the third valve body 220 and the fifth valve body 240 are opened; when oil production ends, the third valve body 220 and the fifth valve body 240 are closed.

[0082] When the pressure of the replacement is lower than the stored oil, when oil production begins, the fourth valve body 230, the first valve body 211, the pressure control valve 213 and the second valve body 212 are opened, and the fifth valve body 240 and the third valve body 220 are closed. The replacement enters the oil storage salt cavern 300 along the passage formed by the injection and production gas assembly 210, and the stored oil in the oil storage salt cavern 300 is output along the second pipeline 120 where the fourth valve body 230 is located. When oil production ends, the first valve body 211 and the fourth valve body 230 are closed.

[0083] When the pressure of the replacement is greater than the stored oil, when oil production begins, the fourth valve body 230, the first valve body 211, the control pressure valve and the second valve body 212 are closed, and the third valve body 220 and the fifth valve body 240 are opened; the replacement enters the oil storage salt cavern 300 along the second branch pipe 140 where the fifth valve body 240 is located, and the stored oil in the oil storage salt cavern 300 is output along the first branch pipe 130 where the third valve body 220 is located. When oil production ends, the third valve body 220 and the fifth valve body 240 can be closed.

[0084] Further, when the pressure of the crude oil is greater than the pressure of the displacement object, when oil injection starts, the fourth valve body 230 and the third valve body 220 are opened, and the first valve body 211, the pressure control valve 213, the second valve body 212 and the fifth valve body 240 are closed; when oil injection is finished, the third valve body 220 and the fourth valve body 230 are closed; when the pressure of the crude oil is less than the pressure of the displacement object, when oil injection starts, the fifth valve body 240 and the third valve body 220 are opened, and the first valve body 211, the pressure control valve 213, the second valve body 212 and the fourth valve body 230 are closed; when oil injection is finished, the fifth valve body 240 and the third valve body 220 are closed.

[0085] When the pressure of the crude oil is greater than the pressure of the displacement material, when oil injection begins, the fourth valve body 230 and the third valve body 220 are opened, the first valve body 211, the pressure control valve 213, the second valve body 212 and the fifth valve body 240 are closed, and the crude oil enters the oil storage salt cavern 300 along the second pipeline 120 where the fourth valve body 230 is located, and the displacement material in the oil storage salt cavern 300 is output along the first branch pipe 130 where the third valve body 220 is located;

[0086] When the oil injection is stopped, the third valve body 220 and the fourth valve body 230 are closed.

[0087] When the pressure of the crude oil is lower than the pressure of the displacement material, when oil injection starts, the fifth valve body 240 and the third valve body 220 are opened, and the first valve body 211, the pressure control valve 213, the second valve body 212 and the fourth valve body 230 are closed; the crude oil enters the oil storage salt cavern 300 along the first branch pipe 130 where the third valve body 220 is located, and the displacement material in the oil storage salt cavern 300 is discharged along the second branch pipe 140 where the fifth valve body 240 is located; when oil injection stops, the third valve body 220 and the fifth valve body 240 are closed.

[0088] It should be noted that when the pressure of the crude oil is less than the pressure of the replacement and the replacement is a non-corrosive material, the replacement can also be directly connected to the liquid phase zone through the second pipeline 120, and the second branch pipe 140 is closed at the same time. The specific method is: when starting oil production, close the fifth valve body 240, the first valve body 211, the control pressure valve and the second valve body 212, and open the third valve body 220 and the fourth valve body 230; when ending oil production, close the third valve body 220 and the fourth valve body 230; when starting oil injection, open the fourth valve body 230 and the third valve body 220, close the first valve body 211, the pressure control valve 213, the second valve body 212 and the fifth valve body 240; when ending oil injection, close the fourth valve body 230 and the third valve body 220.

[0089] Embodiment 2

[0090] like Figure 3As shown, the device for injecting and producing oil in an underground salt cavern oil depot provided by the present invention may further include a connecting pipe 150 and a sixth valve body 250. The first branch pipe 130 and the second pipeline 120 are fluidically connected by the connecting pipe 150, and the sixth valve body 250 is provided at one end of the connecting pipe 150 facing the second pipeline 120. When producing oil, the steps are as follows:

[0091] S31: When the pressure of the replacement in the oil storage salt cavern 300 is greater than the oil storage pressure, the gas injection and production assembly 210 and the fourth valve body 230 are closed, and the third valve body 220, the fifth valve body 240 and the sixth valve body 250 are opened, and the replacement enters the oil storage salt cavern 300 along the second branch pipe 140;

[0092] S32: The crude oil is discharged simultaneously along the first branch pipe 130 and the connecting pipe 150;

[0093] S33: When the oil-water interface of the stored oil drops to the first interface 410 or when the displacement pressure of the first pipeline 110 is equal to the crude oil pressure of the second pipeline 120, the third valve body 220, the fifth valve body 240 and the sixth valve body 250 are closed.

[0094] When filling oil, the steps are:

[0095] S41: When the pressure of the displaced material in the oil storage salt cavern 300 is greater than the oil storage pressure, the sixth valve body 250, the third valve body 220 and the fifth valve body 240 are opened, and the crude oil enters the oil storage salt cavern 300 along the connecting pipe 150 and the first branch pipe 130 respectively;

[0096] S42: The replacement substance is discharged along the second pipe 120;

[0097] S43: When the oil-water interface of the stored oil rises to the second interface 420 or the crude oil pressure in the first pipeline 110 is equal to the pressure of the displacement in the second pipeline 120, the third valve body 220, the fifth valve body 240 and the sixth valve body 250 are closed to stop the oil injection.

[0098] The arrangement of the sixth valve body 250 and the connecting pipe 150 can reduce the time for oil injection or oil production and improve work efficiency.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for injecting and producing oil in an underground salt cavern oil depot, characterized in that: It comprises a pipeline mechanism (100) and a control mechanism (200); The pipeline structure (100) comprises a first pipeline (110) and a second pipeline (120); one end of the first pipeline (110) is in fluid communication with a gas phase region of an oil-storage salt cavern (300), and one end of the second pipeline (120) is in fluid communication with a liquid phase region of the oil-storage salt cavern (300); The control mechanism (200) is installed on the pipeline mechanism (100), and the control mechanism (200) is used to adjust the on / off state of the first pipeline (110) and the second pipeline (120); The control mechanism (200) comprises a gas injection and production component (210), wherein the gas injection and production component (210) is fluidically connected to an end of the first pipeline (110) away from the oil storage salt cavern (300); the first pipeline (110) is provided with a first branch pipe (130), the first branch pipe (130) and the gas injection and production component (210) are connected to the first pipeline (110) in parallel, and the end of the first branch pipe (130) away from the oil storage salt cavern (300) is connected to the end of the gas injection and production component (210) away from the oil storage salt cavern (300); The second pipeline (120) is connected to a second branch pipe (140), and a connecting pipe (150) is provided to fluidically connect the first branch pipe (130) and the second pipeline (120).

2. The device for injecting and producing oil in an underground salt cavern oil depot according to claim 1, characterized in that: The end of the first pipeline (110) facing the oil-storage salt cavern (300) is higher than the end of the second pipeline (120) facing the oil-storage salt cavern (300).

3. The device for injecting and producing oil in an underground salt cavern oil depot according to claim 1, characterized in that: The gas injection and production assembly (210) comprises a first valve body (211), a second valve body (212) and a pressure control valve (213); the pressure control valve (213) is fluidically connected between the first valve body (211) and the second valve body (212), and the second valve body (212) is installed at the end of the gas injection and production assembly (210) facing the oil storage salt cavern (300).

4. The device for injecting and producing oil in an underground salt cavern oil depot according to claim 3, characterized in that: The gas injection and production assembly (210) further comprises a third valve body (220), and the first branch pipe (130) is connected to the third valve body (220).

5. The device for injecting and producing oil in an underground salt cavern oil depot according to claim 1, characterized in that: The control mechanism (200) further comprises a fourth valve body (230), and the fourth valve body (230) is arranged at the end of the second pipeline (120) away from the oil storage salt cavern (300).

6. The device for injecting and producing oil in an underground salt cavern oil depot according to claim 5, characterized in that: The control mechanism (200) further comprises a fifth valve body (240), wherein the fifth valve body (240) is arranged at an end of the second branch pipe (140) away from the second pipe (120); The second branch pipe (140) is provided with anti-corrosion material.

7. A method for injecting and producing oil in an underground salt cavern oil depot, comprising the device for injecting and producing oil in an underground salt cavern oil depot according to any one of claims 1 to 6, characterized in that: It includes oil production step and oil injection step, The oil recovery step comprises: S11: connecting the end of the pipeline mechanism (100) away from the oil-storing salt cavern (300) to the displacement object, adjusting the control mechanism (200) to adjust the pressure of the displacement object according to the pressure of the displacement object relative to the oil stored in the oil-storing salt cavern (300), and allowing the displacement object to enter the oil-storing salt cavern (300) along the pipeline mechanism (100); When the pressure of the displacement object is lower than the pressure of the stored oil, the displacement object enters the oil storage salt cavern (300) along the first pipeline (110); When the pressure of the displacement object is greater than the pressure of the stored oil, the displacement object enters the oil storage salt cavern (300) along the second pipeline (120); S12: When the pressure of the displaced object is lower than the pressure of the stored oil, the stored oil is discharged along the second pipeline (120); When the pressure of the displaced object is greater than the pressure of the stored oil, the stored oil is discharged along the first pipeline (110); S13: when the pressure of the displacement object is lower than the pressure of the stored oil, and when the liquid level of the stored oil drops to the end of the second pipeline (120) facing the oil storage salt cavern (300), the injection of the displacement object is stopped through the control mechanism (200), and oil production is stopped; When the pressure of the displacement material is greater than the pressure of the stored oil, and when the liquid level of the stored oil rises to the top of the oil storage salt cavern (300), the injection of the displacement material is stopped through the control mechanism (200), and oil production is stopped; The oil injection step comprises: S21: connecting the end of the pipeline mechanism (100) away from the oil storage salt cavern (300) to a crude oil pump, and adjusting the control mechanism (200) and the crude oil pump according to the pressure of the displacement object in the oil storage salt cavern (300) relative to the stored oil in the oil storage salt cavern (300) so that the crude oil enters the oil storage salt cavern (300) along the pipeline mechanism (100); When the pressure of the crude oil is greater than the pressure of the displacement object, the crude oil enters the oil storage salt cavern (300) along the second pipeline (120); When the pressure of the crude oil is less than the pressure of the displacement material, the displacement material enters the oil storage salt cavern (300) along the first pipeline (110); S22: When the pressure of the crude oil is greater than the pressure of the displacement material, the displacement material is discharged along the first pipeline (110); When the pressure of the crude oil is less than the pressure of the displacer, the displacer is discharged along the second pipeline (120); S23: When the pressure of the crude oil is greater than the pressure of the displacement material and the liquid level of the stored oil rises to the top of the oil storage salt cavern (300), the injection of the crude oil is stopped through the control mechanism (200), and the oil injection is stopped; When the pressure of the crude oil is lower than that of the displacement material, and when the liquid level of the stored oil drops to the end of the second pipeline (120) facing the oil storage salt cavern (300), the injection of the crude oil is stopped through the control mechanism (200), and the oil injection is stopped.

8. The method for injecting and producing oil in an underground salt cavern oil depot according to claim 7, characterized in that: When the pressure of the replacement object is lower than the stored oil, when oil production starts, the fourth valve body (230), the first valve body (211), the pressure control valve (213) and the second valve body (212) are opened, and the fifth valve body (240) and the third valve body (220) are closed; when oil production ends, the first valve body (211) and the fourth valve body (230) are closed; When the pressure of the replacement object is greater than the stored oil, when oil production starts, the fourth valve body (230), the first valve body (211), the control pressure valve and the second valve body (212) are closed, and the third valve body (220) and the fifth valve body (240) are opened; when oil production ends, the third valve body (220) and the fifth valve body (240) are closed.

9. The method for injecting and producing oil in an underground salt cavern oil depot according to claim 8, characterized in that: When the pressure of the crude oil is greater than the pressure of the displacement material, when oil injection starts, the fourth valve body (230) and the third valve body (220) are opened, and the first valve body (211), the pressure control valve (213), the second valve body (212) and the fifth valve body (240) are closed; when oil injection ends, the third valve body (220) and the fourth valve body (230) are closed; When the pressure of the crude oil is lower than the pressure of the displacement material, when oil injection starts, the fifth valve body (240) and the third valve body (220) are opened, and the first valve body (211), the pressure control valve (213), the second valve body (212) and the fourth valve body (230) are closed; when oil injection ends, the fifth valve body (240) and the third valve body (220) are closed.

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