Electric pump and gas lift combined lifting separate production pipe column

Abstract

The invention relates to an electric pump and gas lift combined lifting separate production pipe column which comprises an upper production pipe column body used for oil production through electric pump lifting and / or oil production through gas lift production. The upper production pipe column is connected with the lower partial production pipe column through the underground communication controller, and the lower partial production pipe column is used for dividing an oil layer where the lower partial production pipe column is located into production layers, collecting production information of the production layers and sending the collected production information to the ground system through the underground communication controller. The ground system can make a corresponding mining quantity instruction according to the mining information; the underground communication controller is used for sending a mining quantity instruction to the lower mining pipe column and supplying power to the lower mining pipe column, and the lower mining pipe column is further used for controlling the mining quantity of each production layer according to the mining quantity instruction issued by the underground communication controller. The aims of exerting the productivity of the oil well to a large extent and improving the overall development effect of the oil well are achieved, and then the productivity of the oil well is fully exerted.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field production technology, specifically relating to a production string for electric pump-gas lift combined lifting. Background Technology

[0002] A series of supporting technologies have been developed both domestically and internationally for combined electric pump extraction, and most offshore oil wells currently use combined electric pump extraction.

[0003] However, the combined production tubing of electric pumps has the following shortcomings: First, some electric pump production wells are affected by the surge in formation gas production, resulting in frequent failures and increasingly shorter pump inspection cycles, which seriously affects the production efficiency of oil wells; Second, during combined production, due to the differences in pressure and fluid properties between reservoirs, inter-layer interference will occur during production, thus failing to effectively utilize reservoir production capacity and even severely limiting the production capacity of oil wells.

[0004] Currently, these problems in offshore oil fields have not been effectively resolved. Summary of the Invention

[0005] To address all or some of the aforementioned problems, the present invention aims to provide a production string for a combined electric pump and gas lift system. This invention's production string simultaneously meets the needs of both electric pump and gas lift production; furthermore, the gas lift valve can be retrieved, adjusted, replaced, and repaired via wireline operations without requiring manual string movement; thus maximizing the oil well's productivity and improving its overall development effectiveness.

[0006] According to one aspect of the present invention, a combined electric pump and gas lift production string is provided, comprising an upper production string, the upper production string being used for oil extraction by electric pump lift and / or by gas lift production.

[0007] The upper production tubing is connected to the lower production tubing via a downhole communication controller. The lower production tubing is used to divide the oil layer it is in into various production layers and to collect production information from each production layer. The collected production information is then sent to the surface system via the downhole communication controller so that the surface system can make corresponding production volume instructions based on the production information.

[0008] The downhole communication controller is used to send production volume instructions to the lower production string and to supply power to the lower production string. The lower production string is also used to control the production volume of each production layer according to the production volume instructions issued by the downhole communication controller.

[0009] Furthermore, the downhole communication controller includes an upper part and a lower part. The upper part is fixedly connected to the upper production tubing string, and the lower part is fixedly connected to the lower production tubing string. The upper and lower parts are plugged into each other and are connected via electromagnetic coupling. The upper and lower parts are connected to a control cable, and the lower part is electrically connected to the lower production tubing string.

[0010] Furthermore, the lower part of the production string includes a positioning seal and an insertion seal disposed below the positioning seal. Both the positioning seal and the insertion seal are used to cooperate with the production packer inside the casing to divide the oil layer into various production layers. Control tools are provided between the positioning seal and the insertion seal below it, as well as below the insertion seal. The control tools are electrically connected to the lower part of the controller via a connecting cable. The control tools are used to control the production volume of their respective production layers according to the production volume instructions issued by the downhole communication controller, and to collect production information of their respective production layers.

[0011] Furthermore, the lowest insertion sealing connection has a round plug.

[0012] Furthermore, the insertion seal comprises several units, each of which is used to cooperate with the sampling packer inside the casing, and the control tool is provided below each insertion seal.

[0013] Furthermore, the upper production tubing includes an air lift valve, an electric pump unit, and a Y-connector. The electric pump unit is connected to a power cable. One inlet end of the Y-connector is connected to the upper part of the controller, and the other inlet end of the Y-connector is connected to the outlet of the electric pump unit. The outlet end of the Y-connector is connected to the lower end of the air lift valve. A cable seal is provided between the Y-connector and the air lift valve. When the electric pump lifts, the oil in the casing is lifted to the ground through the electric pump unit, the other inlet end of the Y-connector, the outlet end of the Y-connector, and the air lift valve. When the air lift is performed, the oil is lifted to the ground through one inlet end of the Y-connector, the outlet end of the Y-connector, and the air lift valve.

[0014] Furthermore, the upper production string also includes a downhole safety valve, which is located at the upper end of the gas lift valve and is connected to a hydraulic control line.

[0015] Furthermore, a circulating sleeve is connected to the lower end of the air lift valve, and the circulating sleeve is connected to the outlet end of the Y connector.

[0016] Furthermore, the gas lift valve comprises several valves connected sequentially from top to bottom, with the uppermost gas lift valve connected to the downhole safety valve and the lowermost gas lift valve connected to the circulating sleeve.

[0017] Furthermore, the air lift valve comprises four valves connected sequentially from top to bottom.

[0018] As can be seen from the above technical solution, the electro-pump air-lift combined lifting sub-production tubing provided by the present invention has the following beneficial effects:

[0019] This invention simultaneously meets the needs of electric pump production and air lift production, and the air lift valve can be adjusted, replaced and repaired through wireline operation without the need for moving the tubing.

[0020] This invention can meet the production needs of oil wells for a longer period of time, with a long maintenance-free period for the tubing string. When repairing the production tubing string, only the upper production tubing string needs to be pulled out, without having to pull out the lower production tubing string, which saves well workover costs, reduces the time occupied by operations, and has good economic benefits.

[0021] This invention effectively solves the problems of low production efficiency and low reservoir utilization in dissolved gas drive reservoirs and wells with co-production of oil and gas, thereby maximizing the production capacity of oil wells and improving the overall development effect of oil wells.

[0022] The layered mining setup of this invention reduces or eliminates inter-layer interference between production layers, optimizes production parameters, and thus fully utilizes the production capacity of oil wells, thereby increasing production capacity. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a sub-collection pipe string using an electric pump-air lift composite lifting system according to an embodiment of the present invention.

[0024] The attached diagram is labeled as follows: Upper production tubing 01, Lower production tubing 02, Hydraulic control line 1, Downhole safety valve 2, Gas lift valve 3, Power cable 4, Control cable 5, Circulating sleeve 6, Cable packer 7, Y-connector 8, Electric pump unit 9, Downhole communication controller 10, Positioning seal 11, Control tool 12, Insertion seal 13, Circular plug 14. Detailed Implementation

[0025] To better understand the purpose, structure, and function of this invention, the following detailed description of a sampling string with electric pump and air lift composite lifting, in conjunction with the accompanying drawings, is provided.

[0026] like Figure 1 As shown, it illustrates a sub-production string of an electric pump-gas lift combined lifting system according to an embodiment of the present invention, including an upper production string 01, which is used for oil extraction by electric pump lifting and / or by gas lift production.

[0027] The upper production column 01 in this embodiment of the invention is configured to select electric pump production, air lift production, or simultaneous electric pump and air lift production according to the actual situation during specific production.

[0028] In practical applications, for example, during the initial stages of oil extraction, oil is extracted using electric pumps. At this time, the gas-liquid ratio is low, and electric pump extraction can achieve high-volume liquid production. For instance, if the gas-liquid ratio increases dramatically to the point that the electric pump cannot extract oil or if the electric pump malfunctions, the wellhead gas injection line can be connected to switch from electric pump lift to gas injection lift production.

[0029] This embodiment utilizes a combined electric pump lift and gas lift method to maximize the production capacity of oil wells and improve the overall development effect of oil wells.

[0030] In this embodiment, the upper production tubing string 01 is connected to the lower production tubing string 02 via the downhole communication controller 10. The lower production tubing string 02 is used to divide the oil layer it is located into various production layers and to collect the production information of each production layer. The collected production information is then sent to the surface system via the downhole communication controller 10 so that the surface system can make corresponding production volume instructions based on the production information.

[0031] The downhole communication controller 10 is used to send production volume commands to the lower production string 02 and to supply power to the lower production string 02. The lower production string 02 is also used to control the production volume of each production layer according to the production volume commands issued by the downhole communication controller 10.

[0032] Specifically, the mining information collected by the lower mining string 02 for each production layer includes information such as pressure, temperature, and production. The ground control system then issues corresponding mining volume commands based on the mining information collected by the lower mining string 02 for each production layer. Finally, the lower mining string 02 controls the mining volume of each production layer according to the received mining volume commands.

[0033] The layered mining setup in this embodiment reduces or eliminates inter-layer interference between production layers, optimizes production parameters, and thus fully utilizes the oil well's production capacity, thereby increasing production capacity.

[0034] The embodiments of the present invention effectively solve the problems of low production efficiency and low reservoir utilization in dissolved gas drive reservoirs and wells with co-production of oil and gas.

[0035] The downhole communication controller 10 includes an upper part and a lower part. The upper part is fixedly connected to the upper production tubing string 01, and the lower part is fixedly connected to the lower production tubing string 02. The upper and lower parts are connected by a plug-in connection and are connected by electromagnetic coupling. The upper part is connected to a control cable 5, and the lower part is electrically connected to the lower production tubing string.

[0036] The downhole communication controller 10 of this invention includes an upper part and a lower part, which are connected by a plug-in connection. Therefore, when repairing the downhole production string, only the upper production string 01 needs to be removed and replaced, while the lower production string 02 is permanently placed in the well, thereby saving well repair operation costs, reducing the time occupied by the operation, and achieving good economic benefits.

[0037] Secondly, the upper part of the controller is connected to control cable 5. Therefore, control commands from the surface are transmitted to the upper part of the controller via control cable 5. The upper and lower parts of the controller are connected via electromagnetic coupling. Thus, control commands received by the upper part of the controller are transmitted to the lower part of the controller wirelessly via electromagnetic coupling. The lower part of the controller then controls the lower production tubing string 02 according to the received commands. At the same time, information collected by the lower production tubing string 02 is transmitted to the lower part of the controller, which then transmits this information to the upper part of the controller wirelessly via electromagnetic coupling. Finally, the upper part of the controller transmits this information to the surface control system. The downhole communication controller 10 here is a current technology product that is widely used in oil wells.

[0038] When lowering the tubing, first connect the lower part of the sampling tubing 02 to the lower part of the controller. After lowering the connected tubing to the predetermined position through the oil pipe, release it. Then, fix the upper part of the controller to the upper production tubing 01. Lower the connected structure to the predetermined position through the oil pipe, so that the upper part of the controller and the lower part of the controller can be inserted and connected.

[0039] The lower part of the production string 02 includes a positioning seal 11 and an insertion seal 13 located below the positioning seal 11. The positioning seal 11 is fixedly connected to the lower part of the controller. Both the positioning seal 11 and the insertion seal 13 are used to cooperate with the production packer in the casing to divide the oil layer into various production layers. Control tools 12 are provided between the positioning seal 11 and the insertion seal 13 below it, as well as below the insertion seal 13. The control tools 12 are electrically connected to the lower part of the controller through a connecting cable. The control tools 12 are used to control the production volume of the production layer they are in according to the production volume command issued by the downhole communication controller 10, and to collect the production information of the production layer they are in.

[0040] For the lower part of the sampling tube string 02 in this embodiment, from bottom to top, it consists of: control tool 12, insertion seal 13, control tool 12 and positioning seal 11. During installation, each structure and its adjacent structure are fixedly sealed together. The positioning seal 11 is fixedly connected to the lower half of the controller above. The insertion seal 13 and the positioning seal 11 cooperate with the sampling packer in the casing to achieve isolation between the upper and lower production layers.

[0041] Specifically, both the positioning seal 11 and the insertion seal 13 are used to cooperate with the production packer inside the casing. This production packer is installed after well completion. Both the positioning seal 11 and the insertion seal 13 cooperate with the production packer inside the casing, thereby dividing the oil layer where the lower production string 02 is located into two production layers: the production layer between the positioning seal 11 and the insertion seal 13, and the production layer below the insertion seal 13.

[0042] A control tool 12 is provided between the positioning seal 11 and the insertion seal 13 below it. The control tool 12 is electrically connected to the lower part of the controller via a connecting cable. The control tool 12 is used to control the production layer between the positioning seal 11 and the insertion seal 13. Specifically, it includes collecting the mining information of the production layer and transmitting the collected information to the surface system through the downhole communication controller 10, receiving the mining volume command issued by the surface system through the downhole communication controller 10, and controlling the mining volume of the production layer according to the received mining volume command.

[0043] A control tool 12 is also provided below the insertion seal 13. This control tool 12 is also electrically connected to the lower part of the controller via a connecting cable. This control tool 12 is used to control the production layer below the insertion seal 13.

[0044] Regarding control tool 12, it is a stratified extraction tool commonly used in oil fields.

[0045] The bottommost insertion seal 13 is connected to a round plug 14.

[0046] In this embodiment, the positioning seal 11 and insertion seal 13 divide the oil layer where the lower part of the production string 02 is located into two production layers. As an alternative, there can be several insertion seals 13, each of which is configured to cooperate with the production packer inside the casing, thereby dividing the oil layer where the lower part of the production string 02 is located into multiple production layers. A control tool 12 is provided below each insertion seal 13, thereby controlling the corresponding production layer through the control tool 12.

[0047] The upper production tubing 01 includes an air lift valve 3, an electric pump unit 9, and a Y-connector 8. The electric pump unit 9 is connected to a power cable 4. One inlet end of the Y-connector 8 is connected to the upper part of the controller, and the other inlet end of the Y-connector 8 is connected to the outlet of the electric pump unit 9. The outlet end of the Y-connector 8 is connected to the lower end of the air lift valve 3. A cable seal 7 is installed between the Y-connector 8 and the air lift valve 3. When the electric pump lifts, the oil in the casing is lifted to the ground through the electric pump unit 9, the other inlet end of the Y-connector 8, the outlet end of the Y-connector 8, and the air lift valve 3. When the air lift is performed, the oil is lifted to the ground through one inlet end of the Y-connector 8, the outlet end of the Y-connector 8, and the air lift valve 3.

[0048] Specifically, the upper production string 01 in this embodiment includes a gas lift valve 3, an electric pump unit 9, and a Y-connector 8. During production, the oil collected by the lower production string 02 enters the string through the corresponding control tool 12. The oil enters the string above the positioning seal 11. Since there is no seal between the upper and lower parts of the controller, the oil enters the annulus between the string and the casing. During electric pump lift production, the oil in the annulus moves upward along the string to the wellhead through the electric pump unit 9 and the Y-connector 8. During gas injection and gas lift production, the oil moves upward along the string to the wellhead through the gas lift valve 3.

[0049] The upper production string 01 also includes a downhole safety valve 2, which is located above the gas lift valve 3 and connected to the hydraulic control line 1. This downhole safety valve 2 is used to close the wellhead in special circumstances, thus providing safety protection.

[0050] The lower end of the air lift valve 3 is connected to a circulating sleeve 6, which is connected to the outlet end of the Y connector 8.

[0051] In practical implementation, for example, the gas lift valve 3 may consist of several connected sequentially from top to bottom, with the uppermost gas lift valve 3 connected to the downhole safety valve 2 and the lowermost gas lift valve 3 connected to the circulating sleeve 6. Another example is that the gas lift valve 3 may consist of four connected sequentially from top to bottom.

[0052] The specific steps for lowering the electro-pump air-lift combined lifting sub-production string according to an embodiment of the present invention include the following:

[0053] Step 1: Lowering the lower part of the sampling pipe string 02: Connect the lower half of the controller, positioning seal 11, control tool 12, insertion seal 13, control tool 12, and round plug 14 in sequence from top to bottom. Lower the above tool assembly to the designed position through the oil pipe, release the oil pipe from the lower half of the controller and pull out the oil pipe.

[0054] Step 2: Run the upper production string 01: Connect the downhole safety valve 2, gas lift valve 3, circulating sleeve 6, cable packer 7, Y-connector 8, electric pump unit 9 and the upper part of the controller in sequence from top to bottom. Run the above tool assembly to the designed position through the tubing. Debug the downhole communication controller 10 and control tool 12 at the wellhead, start the pump, set the cable packer 7, install the wellhead, and put the oil well into production.

[0055] If a sharp increase in the gas-liquid ratio during production leads to a decrease in the adaptability of the electric pump or a malfunction, the wellhead gas injection line should be switched to gas-lift production. If a gas lift valve malfunctions or its parameters need to be adjusted, the gas lift valve can be retrieved and replaced using wireline operations without moving the tubing. If the downhole production tubing needs to be repaired, only the upper production tubing needs to be retrieved and replaced.

[0056] In wellbore treatment, the integrated tubing string is processed by conventional cutting, retrieval, and milling. While ensuring the integrity of the sand control tubing string, chemical sand control or secondary filling sand control is used to reuse the sand control tubing string.

[0057] This invention simultaneously meets the needs of both electric pump production and gas lift production. The gas lift valve can be retrieved, adjusted, replaced, and repaired via wireline operations without requiring tubing string movement. This invention can meet well production needs for a longer period, with a long maintenance-free tubing period. When repairing the production tubing, only the upper production tubing needs to be retrieved, not the lower production tubing, saving well workover costs and reducing downtime, resulting in good economic benefits. This invention effectively solves the problems of low production efficiency and low reservoir utilization in dissolved gas drive reservoirs and wells with co-production of oil and gas, maximizing well productivity and improving the overall development effect. The layered production setup of this invention reduces or eliminates inter-layer interference between production layers, optimizes production parameters, and thus fully utilizes well productivity, thereby increasing production capacity.

[0058] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0059] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions 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, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A combined electric pump and air lift production line, characterized in that, Includes an upper production string, which is used for oil extraction by electric pump lifting and / or by gas lift production; The upper production tubing is connected to the lower production tubing via a downhole communication controller. The lower production tubing is used to divide the oil layer it is in into various production layers and to collect production information from each production layer. The collected production information is then sent to the surface system via the downhole communication controller so that the surface system can make corresponding production volume instructions based on the production information. The downhole communication controller is used to send production volume instructions to the lower production string and to supply power to the lower production string. The lower production string is also used to control the production volume of each production layer according to the production volume instructions issued by the downhole communication controller.

2. The sub-production tubing with electric pump and air lift combined lifting according to claim 1, characterized in that, The downhole communication controller includes an upper part and a lower part. The upper part is fixedly connected to the upper production tubing string, and the lower part is fixedly connected to the lower production tubing string. The upper and lower parts are plugged into each other and communicate with each other via electromagnetic coupling. The upper part is connected to a control cable, and the lower part is electrically connected to the lower production tubing string.

3. The sub-production tubing with electric pump and air lift combined lifting according to claim 2, characterized in that, The lower production string includes a positioning seal and an insertion seal located below the positioning seal. Both the positioning seal and the insertion seal are used to cooperate with the production packer inside the casing to divide the oil layer into various production layers. Control tools are provided between the positioning seal and the insertion seal below it, as well as below the insertion seal. The control tools are electrically connected to the lower part of the controller via a connecting cable. The control tools are used to control the production volume of their respective production layers according to the production volume instructions issued by the downhole communication controller, and to collect production information of their respective production layers.

4. The sub-production tubing with electric pump and air lift combined lifting according to claim 3, characterized in that, The bottommost insertion sealing connection has a round plug.

5. The electro-pump air-lift combined lifting sub-production tubing according to claim 3, characterized in that, The insertion seal comprises several units, each of which is used to cooperate with the sampling packer inside the casing, and the control tool is provided below each insertion seal.

6. The sub-production tubing with electric pump and air lift combined lifting according to claim 2, characterized in that, The upper production tubing includes an air lift valve, an electric pump unit, and a Y-connector. The electric pump unit is connected to a power cable. One inlet end of the Y-connector is connected to the upper part of the controller, and the other inlet end of the Y-connector is connected to the outlet of the electric pump unit. The outlet end of the Y-connector is connected to the lower end of the air lift valve. A cable seal is provided between the Y-connector and the air lift valve. When the electric pump lifts, the oil in the tubing is lifted to the ground through the electric pump unit, the other inlet end of the Y-connector, the outlet end of the Y-connector, and the air lift valve. When the air lift is performed, the oil is lifted to the ground through one inlet end of the Y-connector, the outlet end of the Y-connector, and the air lift valve.

7. The sub-production tubing with electric pump and air lift combined lifting according to claim 6, characterized in that, The upper production string also includes a downhole safety valve, which is located at the upper end of the gas lift valve and is connected to a hydraulic control line.

8. The sub-production tubing with electric pump and air lift combined lifting according to claim 7, characterized in that, The lower end of the air lift valve is connected to a circulating sleeve, which is connected to the outlet end of the Y connector.

9. The sub-production tubing with electric pump and air lift combined lifting according to claim 8, characterized in that, The gas lift valve comprises several valves connected sequentially from top to bottom. The uppermost gas lift valve is connected to the downhole safety valve, and the lowermost gas lift valve is connected to the circulating sleeve.

10. The electro-pump air-lift combined lifting sub-production tubing according to claim 9, characterized in that, The air lift valve comprises four valves connected sequentially from top to bottom.

Images