Oil field water supply and injection linkage control method

Abstract

The upstream and downstream linkage control method specifically comprises the following steps that each water supply raw water tank is communicated with all water source pumps, linkage control logic of the liquid level of the water supply raw water tank and starting and stopping of each water source pump is established in each water supply PLC system, each water injection raw water tank is communicated with all water supply pumps, and all the water supply pumps are communicated with the water supply raw water tank; linkage control logic of the liquid level of a water injection raw water tank and starting and stopping of each water supply pump is established in each water injection PLC system, a water injection frequency converter is arranged on each water injection pump, a first pressure transmitter is arranged on a water injection manifold at an outlet of each water injection pump, and the first pressure transmitter collects the pressure value of the water injection manifold and feeds back the pressure value to the water injection PLC system; linkage control logic of the pressure of the water injection pump and the frequency of the water injection frequency converter is established in the water injection PLC system; the three independent units of the water source well, the water supply station and the water injection station are subjected to linkage closed-loop control, automatic balance is achieved according to the water amount required by the ground water supply and injection technology, and whole-process automatic control is achieved.

Description

Technical Field

[0001] This invention belongs to the technical field of oilfield surface engineering construction methods, and relates to an oilfield water supply and injection linkage control method. Background Technology

[0002] Water injection in oilfields is a crucial measure for achieving efficient oilfield development. By injecting water into the reservoir, formation energy is maintained, a reasonable pressure displacement system is established, and the production potential of oil wells can be maximized to improve economic efficiency. Currently, the water injection system consists of source wells, water supply stations, water injection stations, water distribution rooms, and water injection wells. However, it faces the following problems: As source well production continues, the dynamic water level drops, leading to continuous dry pumping of the source wells. Furthermore, the source wells lack pressure and flow data uploading and remote monitoring, requiring manual on-site work for most tasks such as well inspections and production rate adjustments. While both the water supply and injection stations have PLC systems to monitor and manage their respective production processes and upload production data to the work area's SCADA system (Work Area Data Acquisition and Monitoring Control System), there is no coordinated control between the water supply stations, injection stations, and source wells. This creates a contradiction between precise water injection and the large workload and high safety risks associated with manual control. Summary of the Invention

[0003] The purpose of this invention is to provide a method for coordinated control of upstream and downstream water supply and injection in oilfields, which solves the problem of lack of coordinated control between water supply stations, water injection stations, and water source wells in existing water supply and injection systems.

[0004] The technical solution adopted in this invention is a method for coordinated control of upstream and downstream water supply and injection in oilfields, which specifically includes the following steps: Step 1: Connect each water supply tank to all water source pumps, and establish linkage control logic between the water supply tank level and the start / stop of each water source pump in each water supply PLC system; Step 2: Connect each water injection tank to all water supply pumps, and establish linkage control logic between the water injection tank level and the start / stop of each water supply pump in each water injection PLC system; Step 3: Install a water injection frequency converter on each water injection pump, and install a first pressure transmitter on the water injection manifold at the outlet of each water injection pump. The first pressure transmitter collects the pressure value of the water injection manifold and feeds it back to the water injection PLC system. Establish linkage control logic between the water injection pump pressure and the frequency of the water injection frequency converter in the water injection PLC system. The invention is further characterized in that, Step 1 is performed as follows: Step 1.1: Connect the raw water tank in each water supply station to the water source pumps in all water source wells via pipelines. Designate one water source well as a backup water source well, several water source wells as regular water source wells, and the remaining water source wells as regulating water source wells. Install a first electric ball valve on the outlet pipeline of all regular water source wells, a second electric ball valve on the outlet pipeline of all regulating water source wells, a third electric ball valve on the outlet pipeline of the backup water source well, and a fourth electric ball valve at the outlet of each water supply pump. Communicate with each water supply PLC system to all regular water source pumps, all regulating water source pumps, backup water source pumps, and water supply pumps. Communicate with each water supply PLC system to all first electric ball valves, all second electric ball valves, third electric ball valves, and fourth electric ball valves. Step 1.2: Install a first static pressure level gauge in each raw water tank, and connect each first static pressure level gauge to the corresponding water supply PLC system. Set four level limits in the water supply PLC system. The four level limits are in descending order as: first level, second level, third level, and fourth level. Step 1.3: The water supply PLC system opens all the first electric ball valves and the conventional water source pump, the second electric ball valve and the regulating water source pump, the fourth electric ball valve and the water supply pump. The first static pressure level gauge collects the water level information of the raw water tank and uploads it to the water supply PLC system. When the water level in the raw water tank is lower than the fourth level, the water supply PLC system shuts down the water supply pump and the fourth electric ball valve. When the water level in the raw water tank is between the fourth and third levels, the water supply PLC system issues an alarm. Simultaneously, the water supply PLC system adjusts the opened regulating water source well and the second... The number of electric ball valves increases the inflow of water into the raw water tank. When the raw water tank level reaches the third level, the second electric ball valve will no longer be adjusted. When the raw water tank level is between the third and second levels, the water supply PLC system operates normally. When the raw water tank level is between the second and first levels, the water supply PLC system issues an alarm and simultaneously shuts down all first electric ball valves and the conventional water source pump. When the raw water tank level is higher than the first level, the water supply PLC system shuts down all second electric ball valves and the regulating water source pump.

[0005] Step 2 is performed as follows: Step 2.1: Connect the raw water tank in each water injection station to the water supply pump in all water supply stations through pipelines, and connect each water injection PLC system to all water supply pumps, the fourth electric ball valve, and the booster pump on the clean water treatment device. Step 2.2: Install a second static pressure level gauge in each raw water tank, and connect each second static pressure level gauge to the corresponding water injection PLC system. Set four level limits in the water injection PLC system. The four level limits are in descending order as follows: fifth level, sixth level, seventh level, and eighth level. Step 2.3: The water injection PLC system monitors the operating status of all water supply pumps, the fourth electric ball valve, and the booster pump. The second static pressure level gauge collects the water level information of the raw water tank and uploads it to the water injection PLC system. When the water level in the raw water tank is lower than the eighth level, the water injection PLC system issues an alarm and shuts down the booster pump. When the water level in the raw water tank is between the eighth and seventh levels, the water injection PLC system adjusts all the fourth electric ball valves to increase the water inflow into the raw water tank. When the water level in the raw water tank reaches the seventh level, the fourth electric ball valve will no longer be adjusted. When the water level in the raw water tank is between the seventh and sixth levels, the water injection PLC system will operate normally. When the water level in the raw water tank is between the sixth and fifth levels, the water injection PLC system will alarm and simultaneously adjust all the fourth electric ball valves to reduce the water inflow into the raw water tank. When the water level in the raw water tank is greater than the fifth level, the water injection PLC system will shut down all water supply pumps and the fourth electric ball valves.

[0006] Step 3 is performed as follows: Step 3.1: Install a water injection frequency converter on each water injection pump, install a first pressure transmitter on the water injection manifold at the outlet of each water injection pump, connect the water injection PLC system to all water injection frequency converters, water injection pumps and first pressure transmitters, set a constant pressure value in the SCADA system of the work area, and turn on all water injection pumps in the water injection PLC system. Step 3.2: The pressure value of the water injection manifold is collected by the first pressure transmitter and uploaded to the SCADA system in the work area. The SCADA system in the work area compares the pressure value of the water injection manifold with the constant pressure value and feeds it back to the water injection PLC system. When the pressure value of the water injection manifold is greater than the constant pressure value, the water injection PLC system reduces the frequency of the water injection inverter. When the pressure value of the water injection manifold is less than the constant pressure value, the water injection PLC system increases the frequency of the water injection inverter.

[0007] The water injection frequency converter has a manual adjustment mode. When the water injection PLC system fails or the network is disconnected, the manual adjustment mode is activated.

[0008] In step 1.3, when a certain regulating water source pump fails, the water supply PLC system starts the backup water source pump and the third electric ball valve.

[0009] All water wellheads are equipped with flow meters, and all flow meters are connected to the SCADA system in the work area.

[0010] All water source wellheads are equipped with a second pressure transmitter, and all second pressure transmitters are connected to the SCADA system in the work area.

[0011] The beneficial effects of this invention are: This invention establishes an automatic linkage control logic for water source wells adapted to the water supply station, linking the start and stop of the water source wells with the liquid level of the raw water tank, thereby rationally controlling the operation of the water source wells, realizing intelligent management of the water source well group, and reducing the frequency of manual inspections. Through constant liquid level water supply control at the water supply station and constant pressure water injection control at the water injection station, stable water injection is achieved, improving the reliability of system operation, reducing the labor intensity of on-site employees, and eliminating the safety hazards of manual control. By optimizing the acquisition and control functions of each unit, the three independent units of water source wells, water supply station, and water injection station are linked and controlled in a closed loop, which can automatically balance the water volume required by the surface water supply and injection process, realizing full-process automatic control. Attached Figure Description

[0012] Figure 1 This is a schematic diagram illustrating the linkage between the water source well, water supply station, and water injection station in this invention; Figure 2 This is a schematic diagram of the linkage operation process between the water source pump and the raw water tank in this invention; Figure 3 This is a schematic diagram of the linkage operation process between the water supply pump and the raw water tank in this invention; Figure 4 This is a schematic diagram of the constant pressure water injection control logic of the water injection pump in this invention; Figure 5 This is a diagram of the existing SCADA system architecture in the work area; Figure 6 This is a schematic diagram of the existing water supply and injection process.

[0013] In the diagram, 1. SCADA system for the work area, 2. Communication network, 3. Water supply station, 31. Water supply PLC system, 32. Raw water tank, 33. Water supply pump, 4. Injection station, 41. Injection PLC system, 42. Raw water tank, 43. Clean water treatment device, 431. Booster pump, 44. Clean water tank, 45. Feed pump, 46. Injection pump, 47. High-pressure valve group, 5. Water source well, 51. Water source RTU system, 52. Water source pump, 6. Distribution well, 61. Distribution RTU system. TU system, 7. Injection well, 8. Conventional water source well, 81. Conventional water source pump, 9. Regulating water source well, 91. Regulating water source pump, 10. Backup water source well, 101. Backup water source pump, 11. First electric ball valve, 12. Second electric ball valve, 13. Third electric ball valve, 14. Fourth electric ball valve, 15. First static pressure level gauge, 16. Second static pressure level gauge, 17. Injection frequency converter, 18. First pressure transmitter, 19. Second pressure transmitter, 20. Flow meter. Detailed Implementation

[0014] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0015] The method for coordinated control of upstream and downstream water supply and injection in oilfields includes the following steps: Step 1, refer to Figure 1 Each water supply station 3 has its raw water tank 32 connected to the water source pumps 52 in all water source wells 5 via pipelines. One water source well 5 is designated as a backup water source well 10, several water source wells 5 are designated as regular water source wells 8, and the remaining water source wells 5 are designated as regulating water source wells 9. A first electric ball valve 11 is installed on the outlet pipeline of all regular water source wells 8, a second electric ball valve 12 is installed on the outlet pipeline of all regulating water source wells 9, a third electric ball valve 13 is installed on the outlet pipeline of the backup water source well 10, and a fourth electric ball valve 14 is installed at the outlet of each water supply pump 33. Each water supply PLC system 31 is connected to all regular water source pumps 81, all regulating water source pumps 91, backup water source pumps 101, and water supply pumps 33 via communication. Next, each water supply PLC system 31 is communicatively connected to all first electric ball valves 11, all second electric ball valves 12, third electric ball valves 13, and fourth electric ball valves 14. A first static pressure level gauge 15 is installed in each raw water tank 32, and each first static pressure level gauge 15 is communicatively connected to its corresponding water supply PLC system 31. Four level limits are set in the water supply PLC system 31, in descending order: first level, second level, third level, and fourth level. All first electric ball valves 11, conventional water source pumps 81, second electric ball valves 12, regulating water source pumps 91, fourth electric ball valves 14, and water supply pumps 33 are opened via the water supply PLC system 31, as per [reference needed]. Figure 2When a regulating water source pump 91 malfunctions, the water supply PLC system 31 starts the backup water source pump 101 and the third electric ball valve 13. The first static pressure level gauge 15 collects the water level information of the raw water tank 32 and uploads it to the water supply PLC system 31. When the water level in the raw water tank 32 is lower than the fourth level, the water supply PLC system 31 shuts down the water supply pump 33 and the fourth electric ball valve 14. When the water level in the raw water tank 32 is between the fourth and third levels, the water supply PLC system 31 issues an alarm. At the same time, the water supply PLC system 31 adjusts the number of open regulating water source wells 9 and the second electric ball valve 12 to increase the water inflow into the raw water tank 32. When the water level in the raw water tank 32 reaches the third level, the second electric ball valve 12 will no longer be adjusted. When the water level in the raw water tank 32 is between the third and second levels, the water supply PLC system 31 operates normally. When the water level in the raw water tank 32 is between the second and first levels, the water supply PLC system 31 issues an alarm and simultaneously shuts down all first electric ball valves 11 and conventional water source pumps 81. When the water level in the raw water tank 32 is greater than the first level, the water supply PLC system 31 shuts down all second electric ball valves 12 and regulating water source pumps 91. All water source wells 5 are equipped with flow meters 20, and all flow meters 20 are connected to the SCADA system of the work area. All water source wells 5 are equipped with second pressure transmitters 19, and all second pressure transmitters 19 are connected to the SCADA system of the work area.

[0016] Step 2: Refer to Figure 3Each water injection station 4 has its raw water tank 42 connected to the water supply pumps 33 in all water supply stations 3 via pipelines. Each water injection PLC system 41 is communicatively connected to all water supply pumps 33, the fourth electric ball valve 14, and the booster pump 431 on the clean water treatment device 43. A second static pressure level gauge 16 is installed in each raw water tank 42, and each second static pressure level gauge 16 is communicatively connected to the corresponding water injection PLC system 41. Four level limits are set in the water injection PLC system 41, in descending order: the fifth level, the sixth level, the seventh level, and the eighth level. The water injection PLC system 41 monitors the operating status of all water supply pumps 33, the fourth electric ball valve 14, and the booster pump 431. The second static pressure level gauge 16 collects the level information of the raw water tank 42 and uploads it to the water injection PLC system 41. In this system, when the water level in the raw water tank 42 is lower than the eighth level, the water injection PLC system 41 issues an alarm and shuts down the booster pump 431; when the water level in the raw water tank 42 is between the eighth and seventh levels, the water injection PLC system 41 adjusts all the fourth electric ball valves 14 to increase the water inlet flow of the raw water tank 42; when the water level in the raw water tank 42 reaches the seventh level, the fourth electric ball valves 14 will no longer be adjusted; when the water level in the raw water tank 42 is between the seventh and sixth levels, the water injection PLC system 41 operates normally; when the water level in the raw water tank 42 is between the sixth and fifth levels, the water injection PLC system 41 issues an alarm and simultaneously adjusts all the fourth electric ball valves 14 to reduce the water inlet flow of the raw water tank 42; when the water level in the raw water tank 42 is higher than the fifth level, the water injection PLC system 41 shuts down all the water supply pumps 33 and the fourth electric ball valves 14.

[0017] Step 3: Refer to Figure 4 A water injection frequency converter 17 is installed on each water injection pump 46, and a first pressure transmitter 18 is installed on the water injection manifold at the outlet of each water injection pump 46. The water injection PLC system 41 is communicatively connected to all water injection frequency converters 17, water injection pumps 46, and first pressure transmitters 18. A constant pressure value is set in the SCADA system of the work area. The water injection PLC system 41 turns on all water injection pumps 46, collects the pressure value of the water injection manifold through the first pressure transmitter 18, and uploads it to the SCADA system of the work area. The SCADA system of the work area compares the pressure value of the water injection manifold with the constant pressure value and feeds back to the water injection PLC system 41. When the pressure value of the water injection manifold is greater than the constant pressure value, the water injection PLC system 41 reduces the frequency of the water injection frequency converter 17. When the pressure value of the water injection manifold is less than the constant pressure value, the water injection PLC system 41 increases the frequency of the water injection frequency converter 17. The water injection frequency converter 17 is set with a manual adjustment mode. When the water injection PLC system 41 fails or is disconnected from the network, the manual adjustment mode is activated.

[0018] Example 1: The method for coordinated control of upstream and downstream water supply and injection in oilfields includes the following steps: Step 1: Connect each water supply tank 32 to all water source pumps 52 respectively, and establish linkage control logic between the water supply tank 32 level and the start and stop of each water source pump 52 in each water supply PLC system 31. Step 2: Connect the raw water tank 42 in each water injection station 4 to the water supply pumps 33 in all water supply stations 3 via pipelines. Connect each water injection PLC system 41 to all water supply pumps 33, the fourth electric ball valve 14, and the booster pump 431 on the clean water treatment device 43. Install a second static pressure level gauge 16 in each raw water tank 42 and connect each second static pressure level gauge 16 to its corresponding water injection PLC system 41. Set four level limits in the water injection PLC system 41, in descending order: fifth level, sixth level, seventh level, and eighth level. The water injection PLC system 41 monitors the operating status of all water supply pumps 33, the fourth electric ball valve 14, and the booster pump 431. The second static pressure level gauge 16 collects the level information of the raw water tank 42 and uploads it to the water injection PLC system. In step 41, when the water level in the raw water tank 42 is lower than the eighth level, the water injection PLC system 41 issues an alarm and shuts down the booster pump 431; when the water level in the raw water tank 42 is between the eighth and seventh levels, the water injection PLC system 41 adjusts all the fourth electric ball valves 14 to increase the water inlet flow of the raw water tank 42; when the water level in the raw water tank 42 reaches the seventh level, the fourth electric ball valves 14 will no longer be adjusted; when the water level in the raw water tank 42 is between the seventh and sixth levels, the water injection PLC system 41 operates normally; when the water level in the raw water tank 42 is between the sixth and fifth levels, the water injection PLC system 41 issues an alarm and simultaneously adjusts all the fourth electric ball valves 14 to reduce the water inlet flow of the raw water tank 42; when the water level in the raw water tank 42 is higher than the fifth level, the water injection PLC system 41 shuts down all the water supply pumps 33 and the fourth electric ball valves 14. Step 3: Install a water injection frequency converter 17 on each water injection pump 46, and install a first pressure transmitter 18 on the water injection manifold at the outlet of each water injection pump 46. Connect the water injection PLC system 41 to all water injection frequency converters 17, water injection pumps 46, and first pressure transmitters 18. Set a constant pressure value in the SCADA system of the work area. The water injection PLC system 41 turns on all water injection pumps 46, collects the pressure value of the water injection manifold through the first pressure transmitter 18, and uploads it to the SCADA system of the work area. The SCADA system of the work area compares the pressure value of the water injection manifold with the constant pressure value and feeds back to the water injection PLC system 41. When the pressure value of the water injection manifold is greater than the constant pressure value, the water injection PLC system 41 reduces the frequency of the water injection frequency converter 17. When the pressure value of the water injection manifold is less than the constant pressure value, the water injection PLC system 41 increases the frequency of the water injection frequency converter 17.

[0019] Example 2: The method for coordinated control of upstream and downstream water supply and injection in oilfields includes the following steps: Step 1: Connect the raw water tank 32 in each water supply station 3 to the water source pump 52 in all water source wells 5 via pipelines. Designate one water source well 5 as a backup water source well 10, three water source wells 5 as regular water source wells 8, and the remaining water source wells 5 as regulating water source wells 9. Install a first electric ball valve 11 on the outlet pipeline of all regular water source wells 8, a second electric ball valve 12 on the outlet pipeline of all regulating water source wells 9, a third electric ball valve 13 on the outlet pipeline of the backup water source well 10, and a fourth electric ball valve 14 at the outlet of each water supply pump 33. Connect each water supply PLC system 31 to all regular water source pumps 81, all regulating water source pumps 91, and the backup water source pump 10. 01. The water supply pump 33 is connected via communication. Each water supply PLC system 31 is connected to all first electric ball valves 11, all second electric ball valves 12, third electric ball valves 13, and fourth electric ball valves 14. A first static pressure level gauge 15 is installed in each water supply raw water tank 32. Each first static pressure level gauge 15 is connected to the corresponding water supply PLC system 31. Four level limits are set in the water supply PLC system 31. The four level limits are in descending order as follows: first level, second level, third level, and fourth level. The water supply PLC system 31 opens all first electric ball valves 11, conventional water source pumps 81, second electric ball valves 12, and regulating water source pumps. 91. The fourth electric ball valve 14 and water supply pump 33: When a regulating water source pump 91 malfunctions, the water supply PLC system 31 starts the backup water source pump 101 and the third electric ball valve 13. The first static pressure level gauge 15 collects the water level information of the raw water tank 32 and uploads it to the water supply PLC system 31. When the water level in the raw water tank 32 is lower than the fourth level, the water supply PLC system 31 shuts down the water supply pump 33 and the fourth electric ball valve 14. When the water level in the raw water tank 32 is between the fourth and third levels, the water supply PLC system 31 issues an alarm. At the same time, the water supply PLC system 31 adjusts the number of open regulating water source wells 9 and the second electric ball valve 12 to increase the water inflow into the raw water tank 32. When the water level in the raw water tank 32 reaches the third level, the second electric ball valve 12 will no longer be adjusted. When the water level in the raw water tank 32 is between the third and second levels, the water supply PLC system 31 will operate normally. When the water level in the raw water tank 32 is between the second and first levels, the water supply PLC system 31 will issue an alarm and simultaneously shut down all the first electric ball valves 11 and the conventional water source pump 81. When the water level in the raw water tank 32 is greater than the first level, the water supply PLC system 31 will shut down all the second electric ball valves 12 and the regulating water source pump 91. All water source wells 5 are equipped with flow meters 20, and all flow meters 20 are connected to the SCADA system of the work area. Step 2: Connect each water injection tank 42 to all water supply pumps 33 respectively, and establish linkage control logic between the water level of the water injection tank 42 and the start and stop of each water supply pump 33 in each water injection PLC system 41. Step 3: Install a water injection frequency converter 17 on each water injection pump 46, and install a first pressure transmitter 18 on the water injection manifold at the outlet of each water injection pump 46. Connect the water injection PLC system 41 to all water injection frequency converters 17, water injection pumps 46, and first pressure transmitters 18. Set a constant pressure value in the SCADA system of the work area. The water injection PLC system 41 turns on all water injection pumps 46, collects the pressure value of the water injection manifold through the first pressure transmitter 18, and uploads it to the SCADA system of the work area. The SCADA system of the work area compares the pressure value of the water injection manifold with the constant pressure value and feeds back to the water injection PLC system 41. When the pressure value of the water injection manifold is greater than the constant pressure value, the water injection PLC system 41 reduces the frequency of the water injection frequency converter 17. When the pressure value of the water injection manifold is less than the constant pressure value, the water injection PLC system 41 increases the frequency of the water injection frequency converter 17.

[0020] Example 3: The method for coordinated control of upstream and downstream water supply and injection in oilfields includes the following steps: Step 1: Connect the raw water tank 32 in each water supply station 3 to the water source pump 52 in all water source wells 5 via pipelines. Designate one water source well 5 as a backup water source well 10, four water source wells 5 as regular water source wells 8, and the remaining water source wells 5 as regulating water source wells 9. Install a first electric ball valve 11 on the outlet pipeline of all regular water source wells 8, a second electric ball valve 12 on the outlet pipeline of all regulating water source wells 9, a third electric ball valve 13 on the outlet pipeline of the backup water source well 10, and a fourth electric ball valve 14 at the outlet of each water supply pump 33. Connect each water supply PLC system 31 to all regular water source pumps 81, all regulating water source pumps 91, and the backup water source pump 101. The water supply pump 33 is connected via communication. Each water supply PLC system 31 is connected to all first electric ball valves 11, all second electric ball valves 12, third electric ball valves 13, and fourth electric ball valves 14. A first static pressure level gauge 15 is installed in each raw water tank 32, and each first static pressure level gauge 15 is connected to its corresponding water supply PLC system 31. Four level limits are set in the water supply PLC system 31, in descending order: first level, second level, third level, and fourth level. The water supply PLC system 31 opens all first electric ball valves 11, conventional water source pumps 81, second electric ball valves 12, regulating water source pumps 91, and fourth electric ball valves 14. The system includes four electric ball valves 14 and a water supply pump 33. When a regulating water source pump 91 malfunctions, the water supply PLC system 31 starts the backup water source pump 101 and the third electric ball valve 13. The first static pressure level gauge 15 collects the water level information of the raw water tank 32 and uploads it to the water supply PLC system 31. When the water level in the raw water tank 32 is lower than the fourth level, the water supply PLC system 31 shuts down the water supply pump 33 and the fourth electric ball valve 14. When the water level in the raw water tank 32 is between the fourth and third levels, the water supply PLC system 31 issues an alarm. At the same time, the water supply PLC system 31 adjusts the number of open regulating water source wells 9 and the second electric ball valve 12 to increase the water inflow into the raw water tank 32. When the water level in tank 32 reaches the third level, the second electric ball valve 12 will no longer be adjusted. When the water level in the raw water tank 32 is between the third and second levels, the water supply PLC system 31 operates normally. When the water level in the raw water tank 32 is between the second and first levels, the water supply PLC system 31 issues an alarm and simultaneously shuts down all the first electric ball valves 11 and the conventional water source pump 81. When the water level in the raw water tank 32 is greater than the first level, the water supply PLC system 31 shuts down all the second electric ball valves 12 and the regulating water source pump 91. All water source wells 5 are equipped with second pressure transmitters 19, and all second pressure transmitters 19 are connected to the SCADA system of the work area. Step 2: Connect the raw water tank 42 in each water injection station 4 to the water supply pumps 33 in all water supply stations 3 via pipelines. Connect each water injection PLC system 41 to all water supply pumps 33, the fourth electric ball valve 14, and the booster pump 431 on the clean water treatment device 43. Install a second static pressure level gauge 16 in each raw water tank 42 and connect each second static pressure level gauge 16 to its corresponding water injection PLC system 41. Set four level limits in the water injection PLC system 41, in descending order: fifth level, sixth level, seventh level, and eighth level. The water injection PLC system 41 monitors the operating status of all water supply pumps 33, the fourth electric ball valve 14, and the booster pump 431. The second static pressure level gauge 16 collects the level information of the raw water tank 42 and uploads it to the water injection PLC system. In step 41, when the water level in the raw water tank 42 is lower than the eighth level, the water injection PLC system 41 issues an alarm and shuts down the booster pump 431; when the water level in the raw water tank 42 is between the eighth and seventh levels, the water injection PLC system 41 adjusts all the fourth electric ball valves 14 to increase the water inlet flow of the raw water tank 42; when the water level in the raw water tank 42 reaches the seventh level, the fourth electric ball valves 14 will no longer be adjusted; when the water level in the raw water tank 42 is between the seventh and sixth levels, the water injection PLC system 41 operates normally; when the water level in the raw water tank 42 is between the sixth and fifth levels, the water injection PLC system 41 issues an alarm and simultaneously adjusts all the fourth electric ball valves 14 to reduce the water inlet flow of the raw water tank 42; when the water level in the raw water tank 42 is higher than the fifth level, the water injection PLC system 41 shuts down all the water supply pumps 33 and the fourth electric ball valves 14. Step 3: Install a water injection frequency converter 17 on each water injection pump 46 to collect the outlet pressure data of the water injection pump 46. The first pressure transmitter 18 collects the pressure value of the water injection manifold and feeds it back to the water injection PLC system 41. Establish the linkage control logic between the pressure of the water injection pump 46 and the frequency of the water injection frequency converter 17 in the water injection PLC system 41.

[0021] Example 4: The method for coordinated control of upstream and downstream water supply and injection in oilfields includes the following steps: Step 1: Connect the raw water tank 32 in each water supply station 3 to the water source pumps 52 in all water source wells 5 via pipelines. Designate one water source well 5 as a backup water source well 10, five water source wells 5 as regular water source wells 8, and the remaining water source wells 5 as regulating water source wells 9. Install a first electric ball valve 11 on the outlet pipeline of all regular water source wells 8, a second electric ball valve 12 on the outlet pipeline of all regulating water source wells 9, a third electric ball valve 13 on the outlet pipeline of the backup water source well 10, and a fourth electric ball valve 14 at the outlet of each water supply pump 33. Connect each water supply PLC system 31 to all regular water source pumps 81 and all regulating water source wells 9. The source pump 91, standby water source pump 101, and water supply pump 33 are communicatively connected. Each water supply PLC system 31 is communicatively connected to all first electric ball valves 11, all second electric ball valves 12, third electric ball valves 13, and fourth electric ball valves 14. A first static pressure level gauge 15 is installed in each water supply raw water tank 32, and each first static pressure level gauge 15 is communicatively connected to the corresponding water supply PLC system 31. Four level limits are set in the water supply PLC system 31, and the four level limits are in descending order as: first level, second level, third level, and fourth level. All first electric ball valves 11 and normally closed valves 14 are opened through the water supply PLC system 31. The system includes a standard water source pump 81, a second electric ball valve 12, a regulating water source pump 91, a fourth electric ball valve 14, and a water supply pump 33. When a regulating water source pump 91 malfunctions, the water supply PLC system 31 starts the backup water source pump 101 and the third electric ball valve 13. The first static pressure level gauge 15 collects the water level information of the raw water tank 32 and uploads it to the water supply PLC system 31. When the water level in the raw water tank 32 is lower than the fourth level, the water supply PLC system 31 shuts down the water supply pump 33 and the fourth electric ball valve 14. When the water level in the raw water tank 32 is between the fourth and third levels, the water supply PLC system 31 issues an alarm and simultaneously adjusts the opened... Adjust the number of water source wells 9 and the second electric ball valves 12 to increase the water inlet flow of the raw water tank 32. When the water level in the raw water tank 32 reaches the third level, the second electric ball valves 12 will no longer be adjusted. When the water level in the raw water tank 32 is between the third and second levels, the water supply PLC system 31 operates normally. When the water level in the raw water tank 32 is between the second and first levels, the water supply PLC system 31 issues an alarm and simultaneously shuts down all the first electric ball valves 11 and the conventional water source pump 81. When the water level in the raw water tank 32 is greater than the first level, the water supply PLC system 31 shuts down all the second electric ball valves 12 and the regulating water source pump 91. Step 2: Connect the raw water tank 42 in each water injection station 4 to the water supply pumps 33 in all water supply stations 3 via pipelines. Connect each water injection PLC system 41 to all water supply pumps 33, the fourth electric ball valve 14, and the booster pump 431 on the clean water treatment device 43. Install a second static pressure level gauge 16 in each raw water tank 42 and connect each second static pressure level gauge 16 to its corresponding water injection PLC system 41. Set four level limits in the water injection PLC system 41, in descending order: fifth level, sixth level, seventh level, and eighth level. The water injection PLC system 41 monitors the operating status of all water supply pumps 33, the fourth electric ball valve 14, and the booster pump 431. The second static pressure level gauge 16 collects the level information of the raw water tank 42 and uploads it to the water injection PLC system. In step 41, when the water level in the raw water tank 42 is lower than the eighth level, the water injection PLC system 41 issues an alarm and shuts down the booster pump 431; when the water level in the raw water tank 42 is between the eighth and seventh levels, the water injection PLC system 41 adjusts all the fourth electric ball valves 14 to increase the water inlet flow of the raw water tank 42; when the water level in the raw water tank 42 reaches the seventh level, the fourth electric ball valves 14 will no longer be adjusted; when the water level in the raw water tank 42 is between the seventh and sixth levels, the water injection PLC system 41 operates normally; when the water level in the raw water tank 42 is between the sixth and fifth levels, the water injection PLC system 41 issues an alarm and simultaneously adjusts all the fourth electric ball valves 14 to reduce the water inlet flow of the raw water tank 42; when the water level in the raw water tank 42 is higher than the fifth level, the water injection PLC system 41 shuts down all the water supply pumps 33 and the fourth electric ball valves 14. Step 3: Install a water injection frequency converter 17 on each water injection pump 46, and install a first pressure transmitter 18 on the water injection manifold at the outlet of each water injection pump 46. Connect the water injection PLC system 41 to all water injection frequency converters 17, water injection pumps 46, and first pressure transmitters 18. Set a constant pressure value in the work area SCADA system. The water injection PLC system 41 turns on all water injection pumps 46, collects the pressure value of the water injection manifold through the first pressure transmitter 18, and uploads it to the work area SCADA system. In the process, the SCADA system in the work area compares the pressure value of the water injection manifold with the constant pressure value and feeds it back to the water injection PLC system 41. When the pressure value of the water injection manifold is greater than the constant pressure value, the water injection PLC system 41 reduces the frequency of the water injection frequency converter 17. When the pressure value of the water injection manifold is less than the constant pressure value, the water injection PLC system 41 increases the frequency of the water injection frequency converter 17. The water injection frequency converter 17 is set with a manual adjustment mode. When the water injection PLC system 41 fails or is disconnected from the network, the manual adjustment mode is activated.

Claims

1. A method for upstream-downstream linkage control of water injection in an oil field, characterized by, Specifically, it includes the following steps: Step 1: Connect each water supply tank (32) to all water source pumps (52) respectively, and establish linkage control logic between the water supply tank (32) level and the start and stop of each water source pump (52) in each water supply PLC system (31); Step 2: Connect each water injection tank (42) to all water supply pumps (33) respectively, and establish linkage control logic between the water level of the water injection tank (42) and the start and stop of each water supply pump (33) in each water injection PLC system (41); Step 3: Install a water injection frequency converter (17) on each water injection pump (46), and install a first pressure transmitter (18) on the water injection manifold at the outlet of each water injection pump (46). The first pressure transmitter (18) collects the pressure value of the water injection manifold and feeds it back to the water injection PLC system (41). Establish the linkage control logic between the pressure of the water injection pump (46) and the frequency of the water injection frequency converter (17) in the water injection PLC system (41).

2. The water injection up / downstream linkage control method of claim 1, wherein, Step 1 is performed as follows: Step 1.1: Connect the raw water tank (32) in each water supply station (3) to the water source pump (52) in all water source wells (5) through pipelines. Designate one water source well (5) as a backup water source well (10), several water source wells (5) as regular water source wells (8), and the remaining water source wells (5) as regulating water source wells (9). Install a first electric ball valve (11) on the outlet pipeline of all regular water source wells (8) and a second electric ball valve (12) on the outlet pipeline of all regulating water source wells (9). A third electric ball valve (13) is installed on the outlet pipeline of 10), and a fourth electric ball valve (14) is installed at the outlet of each water supply pump (33). Each water supply PLC system (31) is connected to all conventional water source pumps (81), all regulating water source pumps (91), standby water source pumps (101), and water supply pumps (33) respectively. Each water supply PLC system (31) is connected to all first electric ball valves (11), all second electric ball valves (12), third electric ball valves (13), and fourth electric ball valves (14) respectively. Step 1.2: Install a first static pressure level gauge (15) in each raw water tank (32), and connect each first static pressure level gauge (15) to the corresponding water supply PLC system (31). Set four liquid level limits in the water supply PLC system (31). The four liquid level limits are in descending order as follows: first liquid level, second liquid level, third liquid level, and fourth liquid level. Step 1.3: Through the water supply PLC system (31), all the first electric ball valves (11), conventional water source pumps (81), second electric ball valves (12), regulating water source pumps (91), fourth electric ball valves (14), and water supply pumps (33) are opened. The first static pressure level gauge (15) collects the level information of the raw water tank (32) and uploads it to the water supply PLC system (31). When the level of the raw water tank (32) is lower than the fourth level, the water supply PLC system (31) shuts down the water supply pumps (33) and the fourth electric ball valve (14). When the level of the raw water tank (32) is between the fourth level and the third level, the water supply PLC system (31) issues an alarm. At the same time, the water supply PLC system (31) adjusts the opened regulating water source well ( 9) and the number of second electric ball valves (12) increase the water inlet of the raw water tank (32). When the water level of the raw water tank (32) reaches the third level, the second electric ball valve (12) will no longer be adjusted. When the water level of the raw water tank (32) is between the third level and the second level, the water supply PLC system (31) works normally. When the water level of the raw water tank (32) is between the second level and the first level, the water supply PLC system (31) issues an alarm and at the same time closes all the first electric ball valves (11) and the conventional water source pump (81). When the water level of the raw water tank (32) is greater than the first level, the water supply PLC system (31) closes all the second electric ball valves (12) and the regulating water source pump (91).

3. The water injection up / downstream linkage control method of claim 1, wherein, Step 2 is performed as follows: Step 2.1: Connect the raw water tank (42) in each water injection station (4) to the water supply pump (33) in all water supply stations (3) through pipelines, and connect each water injection PLC system (41) to all water supply pumps (33), the fourth electric ball valve (14), and the booster pump (431) on the clean water treatment device (43); Step 2.2, install a second static pressure level gauge (16) in each water injection tank (42), connect each second static pressure level gauge (16) to the corresponding water injection PLC system (41), set four liquid level limits in the water injection PLC system (41), and the four liquid level limits are in descending order as: fifth liquid level, sixth liquid level, seventh liquid level, and eighth liquid level; Step 2.3: The water injection PLC system (41) detects the operating status of all water supply pumps (33), the fourth electric ball valve (14), and the booster pump (431). The second static pressure level gauge (16) collects the level information of the water injection raw water tank (42) and uploads it to the water injection PLC system (41). When the level of the water injection raw water tank (42) is lower than the eighth level, the water injection PLC system (41) issues an alarm and shuts down the booster pump (431). When the level of the water injection raw water tank (42) is between the eighth and seventh levels, the water injection PLC system (41) adjusts all the fourth electric ball valves (14) to increase the level of the water injection raw water tank (42). When the water level in the raw water tank (42) reaches the seventh level, the fourth electric ball valve (14) will no longer be adjusted. When the water level in the raw water tank (42) is between the seventh and sixth levels, the water injection PLC system (41) will work normally. When the water level in the raw water tank (42) is between the sixth and fifth levels, the water injection PLC system (41) will alarm and adjust all the fourth electric ball valves (14) to reduce the water inflow of the raw water tank (42). When the water level in the raw water tank (42) is greater than the fifth level, the water injection PLC system (41) will shut down all the water supply pumps (33) and the fourth electric ball valves (14).

4. The method for coordinated control of upstream and downstream water supply and injection in oilfields according to claim 1, characterized in that, Step 3 is performed as follows: Step 3.1: Install a water injection frequency converter (17) on each water injection pump (46), install a first pressure transmitter (18) on the water injection manifold at the outlet of each water injection pump (46), connect the water injection PLC system (41) to all water injection frequency converters (17), water injection pumps (46) and first pressure transmitters (18) respectively, set a constant pressure value in the SCADA system of the work area, and turn on all water injection pumps (46) in the water injection PLC system (41). Step 3.2: The pressure value of the water injection manifold is collected by the first pressure transmitter (18) and uploaded to the SCADA system of the work area. The SCADA system of the work area compares the pressure value of the water injection manifold with the constant pressure value and feeds it back to the water injection PLC system (41). When the pressure value of the water injection manifold is greater than the constant pressure value, the water injection PLC system (41) reduces the frequency of the water injection inverter (17). When the pressure value of the water injection manifold is less than the constant pressure value, the water injection PLC system (41) increases the frequency of the water injection inverter (17).

5. The oilfield water supply and injection upstream and downstream linkage control method according to claim 4, characterized in that, The water injection frequency converter (17) is equipped with a manual adjustment mode. When the water injection PLC system (41) fails or the network is disconnected, the manual adjustment mode is activated.

6. The oilfield water supply and injection upstream and downstream linkage control method according to claim 2, characterized in that, In step 1.3, when a certain regulating water source pump (91) fails, the water supply PLC system (31) starts the backup water source pump (101) and the third electric ball valve (13).

7. The oilfield water supply and injection upstream and downstream linkage control method according to any one of claims 1-6, characterized in that, All the water source wells (5) are equipped with flow meters (20) at their openings, and all flow meters (20) are connected to the SCADA system of the work area.

8. The oilfield water supply and injection upstream and downstream linkage control method according to any one of claims 1-6, characterized in that, All the water source wells (5) are equipped with a second pressure transmitter (19) at the wellhead, and all the second pressure transmitters (19) are connected to the SCADA system of the work area.

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