Gas storage injection-production cooperative operation method

Abstract

The invention discloses a gas storage injection-production cooperative operation method. The method comprises the following steps: taking two gas wells with good connectivity as a group of collaborative injection and production wells in a well site; a gas injection facility consisting of a gas injection manifold and a gas injection valve group and a gas production facility consisting of a gas production manifold and a gas production valve group are arranged in the well site; in the gas injection period of a gas storage, natural gas is injected into a gas injection drive oil well by means of a gas injection system and a gas injection facility, and meanwhile, well flow produced by a gas production well is conveyed to a ground produced gas-liquid treatment process system by means of a gas production system and a gas production facility for gas-liquid separation; separated produced gas is injected into a gas injection system and a gas injection facility for circulation, and produced liquid is conveyed to a downstream treatment station through a condensate outward conveying pipeline. The method has the advantages that the gas injection period collaborative gas production and oil production operation mode is adopted, the purposes of improving the recovery efficiency through gas drive oil production and shortening the capacity expansion and standard production period of the gas storage can be achieved, and collaborative development of the gas storage and oil and gas development is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of gas injection and production in underground natural gas storage, and in particular relates to a gas storage injection and production coordinated operation method. Background Art

[0002] With the rapid development of my country's economy, the demand for natural gas has continued to grow. In order to resolve the contradiction between pipeline gas transmission capacity and the unbalanced peak-valley gas consumption of downstream users, gas storage has become the most important and effective means of peak regulation and supply guarantee.

[0003] The traditional operation mode of gas storage is that during the low gas consumption period, usually in summer and autumn, the surplus natural gas in the gas pipeline is pressurized by the gas injection compressor and then injected into the gas wells in the underground gas storage for storage. This is the gas injection period. During the peak gas consumption period, usually in winter and spring, the natural gas stored in the gas storage is produced from the gas wells, processed by the ground gas-liquid production process system, and then merged into the gas transmission system for downstream gas supply. This is the gas production period.

[0004] As a gas storage for seasonal peak regulation, the ground process supporting facilities include a gas injection system and a gas production system. The gas injection system and the gas production system are independent of each other and adopt a cyclic alternating operation mode. During the low gas consumption period, all gas wells in the gas storage are injected with gas at the same time. The natural gas from the gas pipeline enters the gas injection system, and after separation by the filter, it enters the gas injection compressor unit for pressurization and is injected into the gas well; during the peak gas consumption period, all gas wells in the gas storage simultaneously produce gas and carry out condensate. The well flow produced by a single well enters the gas production system, and then flows into the ground gas and liquid processing process system. The ground gas and liquid processing process system performs throttling and pressure reduction, normal temperature separation, dew point control, low temperature separation, metering and pressure regulation, and then the gas and liquid are transported out separately. The devices in the gas injection system and the gas production system are matched according to the total gas volume scale during the working period, and the injection and production are repeated in cycles.

[0005] The traditional independent operation mode of gas storage during the injection and production periods limits the recovery rate of condensate oil during the gas injection period. In order to improve the oil recovery efficiency of gas wells during the gas injection period and shorten the expansion and production cycle of gas storage, it is urgent to conduct research on a new mode of coordinated gas and oil production during the gas storage production injection period. The purpose of increasing the recovery rate can be achieved through coordinated oil production in the gas injection production stage, so as to realize the coordinated development of gas storage and oil and gas development.

[0006] By searching relevant literature, it is found that the existing technologies mainly involve four aspects: gas storage gas injection system and gas injection method, gas storage gas production device and gas production method, gas storage ground gathering and transportation system and gathering and transportation device, and gas storage construction with gas injection and production. The relevant patent search results are as follows:

[0007] [1] Gas injection system and method for underground natural gas storage, CN115680769A

[0008] This invention solves the problem of low gas injection efficiency caused by downtime maintenance when a single compressor is set up. The centrifugal compressor and the reciprocating compressor are connected in parallel. The gas storage stratum absorption performance is better in the early stage of gas injection in the natural gas underground gas storage, and the gas injection efficiency is improved by centralized injection of the centrifugal compressor. In the later stage of the gas injection period, when the formation pressure of the natural gas underground gas storage increases and the demand for gas injection decreases, the reciprocating compressor unit is used for fine supplementary gas injection, which can greatly reduce the number of compressor units to be built and reduce operation and maintenance costs. At the same time, the service life of the reciprocating compressor can be effectively extended. This method can significantly reduce greenhouse gas emissions and achieve energy conservation and environmental protection. However, this method only involves the improvement of the gas storage gas injection compressor system upgrade.

[0009] [2] A salt cavern gas storage and a method for injecting and extracting gas from a salt cavern gas storage, CN110645047A

[0010] The invention provides a method for injecting and extracting gas from a salt cavern gas storage. By setting up a gas bag, a first pipeline, and a second pipeline, all the natural gas in the gas bag can be extracted without leaving any bottom gas, thereby avoiding waste of natural gas. However, the method only involves improving the gas extraction aspect of a salt cavern gas storage with bottom gas.

[0011] [3] Liquid drainage and gas production device and method for underground natural gas storage, CN106761608A

[0012] The invention relates to a device and method for draining and producing gas from an underground natural gas storage reservoir, which has a cylindrical main body, a rotary atomizing device, and a draining and producing head. The device and method for draining and producing gas from an underground natural gas storage reservoir are used to produce natural gas from the underground natural gas storage reservoir, which can directly and effectively reduce the formation of liquid accumulation in the wellbore of the production well, timely and efficiently drain the wellbore liquid accumulation, and ensure the efficient operation of the gas storage reservoir production well. However, this method only involves ensuring the efficient operation of the gas storage reservoir production well and increasing the output of the gas production well.

[0013] [4] Method for alternating injection and production of gas wells in gas storage, CN108629471A

[0014] The invention provides a method for interactive injection and production of gas wells in a gas storage reservoir, establishes a gas production model according to relevant parameters, uses the gas production model to perform gas production operations on gas wells, and can timely perform peak-shaving operations on gas wells. The reliability and safety of gas supply from gas wells are increased. However, this method only involves effectively reducing the cost of gas production and solving the problem that the existing technology cannot quickly perform peak-shaving operations on gas wells.

[0015] [5] For ground gathering and transportation systems of depleted gas reservoirs, CN111256036A

[0016] The invention uses the same set of pipelines and devices as the gas storage gas injection and gas production process transportation system, realizing the reuse of the gas injection and production pipelines and devices, greatly reducing the construction volume and construction costs. However, the system only involves the realization of the shared use of pipelines and equipment for the ground gas injection and gas production processes of the depleted gas reservoir gas storage, optimizing the gathering and transportation process, and reducing engineering costs.

[0017] [6] Gas collection and transportation device for underground gas storage, CN218439327U

[0018] The utility model provides an underground gas storage gas collection and transportation device, which can filter out the moisture in the natural gas as fully as possible to prevent water vapor from being output together with the natural gas, and at the same time can quickly gather water droplets together to form a larger water flow flowing downward, so as to prevent the sticky water droplets on the inner wall of the liquid removal pipe from flowing upward with the natural gas under the rapid flow of natural gas, affecting the water collection efficiency, and effectively improving the separation effect of natural gas and water, and the collection efficiency of separated water. However, the device only involves the content of effectively improving the separation effect of natural gas and water, increasing the collection amount of natural gas and the purity of natural gas.

[0019] [7] A design method for improving oil recovery by gas injection in oil reservoirs, CN116025313A. This invention relates to the technical field of oil reservoir type gas storage construction. On the basis of determining that the oil reservoir plugging property meets the requirements, the gas injection source is guaranteed, and the oil reservoir gas injection is feasible, the optimization of the injection and production well network supporting oil reservoir gas injection to improve oil recovery, injection and production allocation are designed, and the construction and operation parameters and injection and production capacity of the oil reservoir type gas storage are evaluated, and then the oil reservoir gas injection to improve oil recovery and the construction of oil reservoir type gas storage are carried out. However, this method only involves the content of achieving a significant increase in oil reservoir recovery by gas injection during the construction period of the gas storage, and building a gas storage to ensure energy security. Summary of the invention

[0020] In order to solve the above problems, the purpose of the present invention is to provide a method for coordinated operation of injection and production of a gas storage facility.

[0021] In order to achieve the above object, the gas storage injection and production coordinated operation method provided by the present invention comprises the following steps performed in sequence:

[0022] 1) Two gas wells with good connectivity are used as a group of coordinated injection and production wells at the well site, one of which is used as a gas and oil production well, and the other is used as a gas injection and oil drive well;

[0023] 2) Install gas injection facilities consisting of a gas injection manifold and a gas injection valve group and gas production facilities consisting of a gas production manifold and a gas production valve group at the well site, connect the gas injection facilities with the equipment in the gas injection system, and connect the gas production facilities with the equipment in the gas production system and the surface gas and liquid processing process system;

[0024] 3) During the gas injection period of the gas storage reservoir, natural gas is injected into the gas injection drive oil wells with the help of the gas injection system and gas injection facilities. At the same time, the well flow produced by the gas and oil production wells is transported to the ground gas-liquid processing process system for gas-liquid separation with the help of the gas production system and gas production facilities. The separated produced gas is then injected into the gas injection system and gas injection facilities for circulation, and the produced liquid is transported to the downstream processing station through the condensate transmission pipeline.

[0025] In step 1), the method of using two gas wells with good connectivity as a group of coordinated injection and production wells at the well site, wherein one gas well with good production conditions is used as a gas and oil production well, and the other gas well is used as a gas injection and oil drive well is:

[0026] In order to meet the needs of coordinated injection and production operation of gas storage, two gas wells with good connectivity are selected as a group of coordinated injection and production wells according to the production conditions of the gas wells. The gas well with good production conditions is selected as the gas and oil production well, and the other gas well connected to it is used as a gas injection and oil drive well. The two wells, one injection and one production, realize cyclic gas injection development.

[0027] In step 2), the gas injection facility consisting of a gas injection manifold and a gas injection valve group and the gas production facility consisting of a gas production manifold and a gas production valve group are arranged at the well site, and the gas injection facility is connected to the equipment in the gas injection system. The method of connecting the gas production facility to the equipment in the gas production system and the ground gas and liquid processing process system is as follows:

[0028] Two sets of facilities are set up at the well site, one of which is a gas injection facility consisting of a gas injection manifold and a gas injection valve group, and the other is a gas production facility consisting of a gas production manifold and a gas production valve group; one end of the gas injection manifold is connected to the outlet of the gas injection compressor unit in the gas injection system through a pipeline, and the other end is connected to the gas injection valve group, and the gas injection valve group is also connected to multiple gas injection pipes leading to the underground gas storage; the gas production valve group is connected to the ESDV valve in the gas production system and to one end of the gas production manifold, and the other end of the gas production manifold is connected to the ground produced gas and liquid processing process system through a pipeline.

[0029] In step 3), during the gas injection period of the gas storage reservoir, natural gas is injected into the gas injection drive oil well by means of the gas injection system and the gas injection facilities, and at the same time, the well flow produced by the gas production well is transported to the ground gas-liquid processing process system for gas-liquid separation by means of the gas production system and the gas production facilities, and the separated produced gas is then injected into the gas injection system and the gas injection facilities for circulation, and the produced liquid is transported to the downstream processing station through the condensate external transmission pipeline. The method is:

[0030] During the gas injection period of the gas storage, the natural gas from the gas transmission pipeline is separated by the filter separator in the gas injection system and then enters the gas injection compressor unit for pressurization. The pressurized natural gas is transported to the gas injection manifold through the pipeline, and then distributed to each gas injection pipe through the gas injection valve group, and finally injected into each gas injection oil well of the underground gas storage for storage; while injecting gas into the gas injection oil well, the well flow produced by the gas production well enters the gas production valve group located at the wellhead through the wellhead Christmas tree and the ESDV valve, enters the gas production manifold after throttling and reducing pressure by the gas production valve group, and then is transported to the ground produced gas and liquid processing process system through pipelines; the ground produced gas and liquid processing process system performs throttling and reducing pressure, normal temperature separation, dew point control, low temperature separation, metering and pressure regulation to obtain produced gas and produced liquid, and then the produced gas that meets the injection quality requirements is injected into the gas injection system and gas injection facilities together with the gas from the gas transmission pipeline through the bypass for circulation, and the produced liquid is transported to the downstream processing station through the condensate external transmission pipeline for treatment, so as to achieve the purpose of gas drive to improve the condensate oil recovery rate.

[0031] The gas storage injection and production coordinated operation method provided by the present invention has the following beneficial effects:

[0032] (1) During the gas injection period of the gas storage, for gas wells with large condensate production potential, according to the traditional operation mode of the gas storage, production can only be carried out in the next gas production period, which limits the condensate production of the gas wells to a certain extent. The use of the gas injection period coordinated gas and oil production operation mode can achieve the purpose of gas drive oil production to improve the recovery rate and shorten the gas storage expansion and production cycle, thus realizing the coordinated development of gas storage and oil and gas development.

[0033] (2) In order to ensure the normal production of the gas storage reservoir, the well site is equipped with an injection-production separation process to achieve gas and oil production in some gas wells during the gas injection period, coordinate injection and production, and increase condensate production. The produced gas is circulated and injected into the gas injection drive wells. At the same time, the produced liquid during the gas injection period is separated by the ground gas-liquid processing system and then transported to the outside, ensuring that gas drive can improve the condensate recovery rate.

[0034] (3) During the gas injection period of the gas storage, the gas produced by some gas wells is processed by the gas production process system in the station to achieve autonomous circulation in the station, self-production and self-injection, which not only plays the role of gas drive oil production, but also can be circulated and injected into the underground to expand the capacity of the gas storage and shorten the expansion cycle of the gas storage. Gas injection is an effective method to improve crude oil recovery. Gas injection and production are coordinated with the expansion of gas storage to achieve full production, forming a larger gas storage scale to play the role of seasonal peak regulation, coordinating the two-way development of gas drive oil production and coordinated expansion and construction of gas storage, and has a good effect of improving quality and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a flow chart of the gas storage injection and production coordinated operation method provided by the present invention.

[0036] Figure 2This is a schematic diagram of the well site injection-production separation process system provided by the present invention.

[0037] Figure 3 This is a schematic diagram of the ground circulating gas injection process system provided by the present invention. DETAILED DESCRIPTION

[0038] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] like Figure 1 As shown, the gas storage injection and production coordinated operation method provided by the present invention comprises the following steps performed in sequence:

[0040] 1) Two gas wells with good connectivity are used as a group of coordinated injection and production wells at the well site, one of which is used as a gas and oil production well, and the other is used as a gas injection and oil drive well;

[0041] For a gas storage in an oil field, two gas wells, gas well 1 and gas well 2, are selected as a group of coordinated injection and production wells. During the gas production period of gas well 1, gas well 2 is in a shut-in state, but its oil pressure drops synchronously with that of gas well 1. At the end of the gas production period, the formation pressure of the two wells is basically the same, indicating that the dynamic connectivity of gas well 1 and gas well 2 is good. At the same time, gas well 1 obtains high-yield oil and gas flow during production and has a large potential for producing gas and liquid (production for 32 days, and a periodic oil production of 2558 cubic meters). According to the operation mode of the gas storage, it can only be produced again at the end of the year after participating in the gas injection period, which limits the condensate oil recovery rate of gas well 1 to a certain extent.

[0042] According to research, gas well 1 and gas well 2 have good connectivity. In order to ensure the condensate oil production of gas well 1, gas well 1 is used for gas production and oil production during the gas injection period of gas well 2, realizing one injection and one production cycle of gas injection development. After gas injection of gas well 2, when the wellhead pressure of gas well 1 rises to above 13.5MPa, the well is opened to produce gas and oil at an appropriate time, achieving the effect of gas drive oil production to improve the recovery rate.

[0043] 2) Install gas injection facilities consisting of a gas injection manifold and a gas injection valve group and gas production facilities consisting of a gas production manifold and a gas production valve group at the well site, connect the gas injection facilities with the equipment in the gas injection system, and connect the gas production facilities with the equipment in the gas production system and the surface gas and liquid processing process system;

[0044] like Figure 2As shown, two sets of facilities are arranged at the well site, one of which is a gas injection facility consisting of a gas injection manifold 2-2 and a gas injection valve group 2-3, and the other is a gas production facility consisting of a gas production manifold 2-8 and a gas production valve group 2-7; wherein one end of the gas injection manifold 2-2 is connected to the outlet of the gas injection compressor group 2-1 in the gas injection system through a pipeline, and the other end is connected to the gas injection valve group 2-3, and the gas injection valve group 2-3 is also connected to multiple gas injection pipes leading to the underground gas storage; the gas production valve group 2-7 is connected to the ESDV valve 2-6 in the gas production system, and is also connected to one end of the gas production manifold 2-8, and the other end of the gas production manifold 2-8 is connected to the ground produced gas and liquid processing process system 2-9 through a pipeline.

[0045] 3) During the gas injection period of the gas storage reservoir, natural gas is injected into the gas injection drive oil wells with the help of the gas injection system and gas injection facilities. At the same time, the well flow produced by the gas production wells is transported to the ground gas-liquid processing system for gas-liquid separation with the help of the gas production system and gas production facilities. The separated produced gas is then injected into the gas injection system and gas injection facilities for circulation, and the produced liquid is transported to the downstream processing station through the condensate transmission pipeline;

[0046] like Figure 2 As shown, during the gas injection period of the gas storage reservoir, the gas from the gas injection compressor 2-1 enters the gas injection manifold 2-2, and is distributed to each gas injection well through the gas injection valve group 2-3 and injected into the ground. In this embodiment, while the gas injection drive oil well 2-4 is injecting gas, another gas production and oil production well 2-5 is producing gas and oil. The well flow produced by the gas production and oil production well 2-5 enters the gas production valve group 2-7 through the wellhead oil tree and the ESDV valve 2-6, and enters the gas production manifold 2-8 after throttling and reducing pressure by the gas production valve group 2-7, and is then transported to the production separator of the ground gas-liquid processing system 2-9. The injection and production separation process is set up at the well site to realize the gas injection and oil production mode of the gas injection drive oil well 2-4 and the gas production and oil production mode of the gas production and oil production well 2-5. The gas injection volume of the gas injection drive oil well 2-4 is 450,000 cubic meters / day, and the gas production of the gas production and oil production well 2-5 is 175,000 cubic meters / day, and the oil production is 132m 3 / d, with a water content of 1.2%, which can improve the crude oil recovery rate and accelerate the speed of reaching full capacity and production of the gas storage.

[0047] like Figure 3 As shown, during the gas storage injection period, natural gas is mainly received from the gas transmission pipeline 4-1, and enters the gas injection compressor unit 4-5 after being processed by the cyclone separator 4-3 and the filter separator 4-4. After being pressurized by the gas injection compressor unit 4-5 and cooled by the air cooler, it is transported to the well site 4-6 for injection.

[0048] In order to achieve the coordinated production gas cycle injection during the gas injection period, the produced gas from the gas injection oil well is treated by the ground produced gas and liquid treatment process system to meet the quality requirements of the produced gas injection, and then it does not enter the external transmission pipeline but enters the gas injection system and gas injection facilities for circulation through the bypass. The produced liquid is transported to the downstream processing station for treatment through the condensate external transmission pipeline. During the gas injection period, the produced gas from a single well is processed by the gas production process system in the station to achieve autonomous circulation in the station, self-production and self-injection, which not only plays the role of gas drive oil production, but also can be circulated and injected into the underground to expand the capacity of the gas storage, and can achieve the coordinated development of gas storage and oil and gas development.

Claims

1. A method for coordinated operation of gas storage injection and production, characterized in that: The gas storage reservoir injection and production coordinated operation method comprises the following steps performed in sequence: 1) Two gas wells with good connectivity are used as a group of coordinated injection and production wells at the well site, one of which is used as a gas and oil production well, and the other is used as a gas injection and oil drive well; 2) Install gas injection facilities consisting of a gas injection manifold and a gas injection valve group and gas production facilities consisting of a gas production manifold and a gas production valve group at the well site, connect the gas injection facilities with the equipment in the gas injection system, and connect the gas production facilities with the equipment in the gas production system and the surface gas and liquid processing process system; 3) During the gas injection period of the gas storage reservoir, natural gas is injected into the gas injection drive oil wells with the help of the gas injection system and gas injection facilities. At the same time, the well flow produced by the gas and oil production wells is transported to the ground gas-liquid processing process system for gas-liquid separation with the help of the gas production system and gas production facilities. The separated produced gas is then injected into the gas injection system and gas injection facilities for circulation, and the produced liquid is transported to the downstream processing station through the condensate transmission pipeline.

2. The gas storage reservoir injection and production coordinated operation method according to claim 1, characterized in that: In step 1), the method of using two gas wells with good connectivity as a group of coordinated injection and production wells at the well site, wherein one gas well with good production conditions is used as a gas and oil production well, and the other gas well is used as a gas injection and oil drive well is: In order to meet the needs of coordinated injection and production operation of gas storage, two gas wells with good connectivity are selected as a group of coordinated injection and production wells according to the production conditions of the gas wells. The gas well with good production conditions is selected as the gas and oil production well, and the other gas well connected to it is used as a gas injection and oil drive well. The two wells, one injection and one production, realize cyclic gas injection development.

3. The gas storage reservoir injection and production coordinated operation method according to claim 1, characterized in that: In step 2), the gas injection facility consisting of a gas injection manifold and a gas injection valve group and the gas production facility consisting of a gas production manifold and a gas production valve group are arranged at the well site, and the gas injection facility is connected to the equipment in the gas injection system. The method of connecting the gas production facility to the equipment in the gas production system and the ground gas and liquid processing process system is as follows: Two sets of facilities are set up at the well site, one of which is a gas injection facility consisting of a gas injection manifold and a gas injection valve group, and the other is a gas production facility consisting of a gas production manifold and a gas production valve group; one end of the gas injection manifold is connected to the outlet of the gas injection compressor unit in the gas injection system through a pipeline, and the other end is connected to the gas injection valve group, and the gas injection valve group is also connected to multiple gas injection pipes leading to the underground gas storage; the gas production valve group is connected to the ESDV valve in the gas production system and to one end of the gas production manifold, and the other end of the gas production manifold is connected to the ground produced gas and liquid processing process system through a pipeline.

4. The gas storage reservoir injection and production coordinated operation method according to claim 1, characterized in that: In step 3), during the gas injection period of the gas storage reservoir, natural gas is injected into the gas injection drive oil well by means of the gas injection system and the gas injection facilities, and at the same time, the well flow produced by the gas production well is transported to the ground gas-liquid processing process system for gas-liquid separation by means of the gas production system and the gas production facilities, and the separated produced gas is then injected into the gas injection system and the gas injection facilities for circulation, and the produced liquid is transported to the downstream processing station through the condensate external transmission pipeline. The method is: During the gas injection period of the gas storage, the natural gas from the gas transmission pipeline is separated by the filter separator in the gas injection system and then enters the gas injection compressor unit for pressurization. The pressurized natural gas is transported to the gas injection manifold through the pipeline, and then distributed to each gas injection pipe through the gas injection valve group, and finally injected into each gas injection oil well of the underground gas storage for storage; while injecting gas into the gas injection oil well, the well flow produced by the gas production well enters the gas production valve group located at the wellhead through the wellhead Christmas tree and the ESDV valve, enters the gas production manifold after throttling and reducing pressure by the gas production valve group, and then is transported to the ground produced gas and liquid processing process system through pipelines; the ground produced gas and liquid processing process system performs throttling and reducing pressure, normal temperature separation, dew point control, low temperature separation, metering and pressure regulation to obtain produced gas and produced liquid, and then the produced gas that meets the injection quality requirements is injected into the gas injection system and gas injection facilities together with the gas from the gas transmission pipeline through the bypass for circulation, and the produced liquid is transported to the downstream processing station through the condensate external transmission pipeline for treatment, so as to achieve the purpose of gas drive to improve the condensate oil recovery rate.

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