Liquid dense phase CO2 injection system

Abstract

The invention discloses a liquid dense phase CO2 injection system which comprises a liquid phase pressure boosting device, a phase stabilizing device, a dense phase pressure boosting injection allocation device and a controller, and the liquid phase pressure boosting device, the phase stabilizing device and the dense phase pressure boosting injection allocation device are sequentially connected through pipelines and are each provided with an adjusting device, a pressure transmitting device, a temperature transmitting device and a flow detection assembly. The adjusting device, the pressure transmitting device, the temperature transmitting device and the flow detection device are all electrically connected with the controller. The system not only can be applied to liquid-phase CO2 injection, but also can be applied to dense-phase pipeline transportation CO2 injection, so that the front-end investment during large-scale production is greatly reduced, and the condition that the pump efficiency of a secondary booster pump is low due to an unstable CO2 source is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield carbon dioxide injection, and particularly relates to a liquid dense phase CO 2 Inject into the system. Background Art

[0002] Changqing Oilfield is actively promoting the layout of tens of millions of tons of industries in the Ordos Basin, striving to build it into the largest industrial cluster in the country. The carbon dioxide flooding test in Changqing Oilfield has confirmed that CO2 has good injectability and can quickly replenish formation energy. The production of the pilot test center well group has doubled.

[0003] At present, the injection process adopted by the comprehensive test station is the "low-temperature liquid injection process". The source of CO2 and the inlet conditions of the injection pump are limited to liquid (i.e., the temperature is between -56 and 31.1℃ and the pressure is less than 7.38MPa). Its basic process is "CO2 tanker transportation - low-temperature storage in storage tanks - liquid injection pump - injection well". This process has defects such as frequent operation, high cost, and many management points, which limit the large-scale application of this process in oil fields. First, the entire process from loading and unloading vehicles, long-distance transportation, opening and closing of valves when liquid enters and exits the storage tank, to the injection pump being cooled in advance, etc., all require manual operation; secondly, CO2 must be in a low-temperature state throughout the process before injection. The high price of source materials and the cold preservation requirements during transportation require special transportation vehicles to further increase the cost. Low-temperature liquid storage tanks must be set up in the process, and the economic investment in cold preservation and pressure maintenance is large; finally, the temperature and pressure of each process must be strictly monitored, and manual leakage monitoring must be carried out at each node in the process to ensure that there is no frostbite, which is difficult to manage. Summary of the invention

[0004] The purpose of the present invention is to solve the problems in the prior art and provide a liquid dense phase CO2 injection system.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A liquid dense phase CO2 injection system comprises: a liquid phase pressurizing device, a phase stabilizing device, a dense phase pressurizing and injection device and a controller. The liquid phase pressurizing device, the phase stabilizing device and the dense phase pressurizing and injection device are connected in sequence through pipelines, and are all equipped with regulating devices, pressure transmitting devices, temperature transmitting devices and flow detection components. The regulating devices, pressure transmitting devices, temperature transmitting devices and flow detection devices are all electrically connected to the controller.

[0007] Further, the liquid phase boosting device includes a liquid feeding pump, a primary boosting pump and a first frequency conversion instrument control cabinet, one end of the liquid feeding pump is connected to the liquid carbon dioxide inlet through a liquid feeding bypass pipeline, and the other end is connected to one side of the primary boosting pump through a primary boosting pump inlet pipeline;

[0008] The other side of the primary booster pump is connected to the phase stabilizing device through the primary booster pump outlet pipeline, a primary booster pump precooling inlet pipeline is also provided on the liquid feeding bypass pipeline, the end of the primary booster pump precooling inlet pipeline is connected to the primary booster pump, a primary booster pump precooling outlet pipeline is provided on the primary booster pump, the end of the primary booster pump precooling outlet pipeline is fixedly connected with a reflux port, and the end of the primary booster pump outlet pipeline on the primary booster pump is also connected with a carbon dioxide outlet;

[0009] The regulating device, the pressure transmitting device and the temperature transmitting device respectively include a first regulating component, a first pressure transmitting component and a first temperature transmitting component, the flow detection component includes a first flow detection component and a second flow detection component, and the first regulating component, the first pressure transmitting component, the first temperature transmitting component, the first flow detection component and the second flow detection component are all connected to the first variable frequency instrument control cabinet signal.

[0010] Further, the first regulating assembly includes a first ball valve, a second ball valve, a third ball valve, a fourth ball valve, a fifth ball valve, a sixth ball valve, a seventh ball valve, an eighth ball valve, a first safety valve, a ninth ball valve, a first electric regulating valve, a tenth ball valve, a first check valve, a second electric regulating valve, an eleventh ball valve and a first electric ball valve; the first ball valve is connected between the liquid feeding pump and the liquid carbon dioxide inlet, the second ball valve is connected between the liquid feeding pump and the primary booster pump, the third ball valve is connected between the liquid feeding pump and the first booster pump precooling inlet pipeline, the fourth ball valve is connected to the liquid feeding bypass pipeline, the fifth ball valve is connected between the liquid feeding bypass pipeline and the primary booster pump precooling inlet pipeline, the sixth ball valve is connected between the primary booster pump precooling inlet pipeline and the primary booster pump, the seventh ball valve is connected to the other end of the primary booster pump precooling inlet pipeline, the eighth ball valve is connected between the primary booster pump and the primary booster pump precooling outlet pipeline, and the ninth ball valve is connected to the end of the primary booster pump precooling outlet pipeline away from the primary booster pump;

[0011] The first safety valve is connected between the eighth ball valve and the ninth ball valve, the first electric regulating valve is connected between the primary booster pump precooling outlet pipeline and the primary booster pump outlet pipeline, the tenth ball valve is connected to the primary booster pump outlet pipeline, the first check valve is also connected to the primary booster pump outlet pipeline and is located on one side of the tenth ball valve, and the second electric regulating valve, the eleventh ball valve and the first electric ball valve are all connected to the end of the primary booster pump outlet pipeline.

[0012] Furthermore, the first pressure transmitter assembly includes a first digital pressure transmitter, a second digital pressure transmitter and a third digital pressure transmitter. The first digital pressure transmitter is connected to the liquid feeding pump, the second digital pressure transmitter is connected between the primary booster pump and the primary booster pump inlet pipeline, and the third digital pressure transmitter is connected to the primary booster pump.

[0013] Furthermore, the first temperature transmitter assembly includes a first temperature transmitter, and the first temperature transmitter is connected to the outlet pipeline of the primary booster pump.

[0014] Furthermore, the phase stabilizing device includes an electromagnetic heater, an oil cooling device, a phase stabilizing system inlet pipeline, a phase stabilizing system outlet pipeline, and a phase stabilizing system bypass pipeline. One end of the electromagnetic heater is connected to the phase stabilizing system inlet pipeline, and the other end is connected to the phase stabilizing system outlet pipeline. The end of the phase stabilizing system outlet pipeline is connected to the dense phase pressurization and injection device.

[0015] The regulating device, the pressure transmitting device and the temperature transmitting device further include a second regulating component, a second pressure transmitting component and a second temperature transmitting component respectively, and the flow detection component includes a third flow detection component;

[0016] Both sides of the electromagnetic heater are connected to the oil cooling device through the second regulating assembly, the end of the second regulating assembly is connected to the inlet of the phase stabilizing device, and the inlet of the phase stabilizing device is connected to the bypass pipeline of the phase stabilizing system through the second regulating assembly, and the bypass pipeline of the phase stabilizing system is connected to the pipeline carbon dioxide inlet;

[0017] The dense phase pressurized injection device comprises a second variable frequency instrument control cabinet, and a second regulating component, a second pressure transmitting component, a second temperature transmitting component, a third flow detection component, an electromagnetic heater and an oil cooling device are all connected to the second variable frequency instrument control cabinet by signal.

[0018] Furthermore, the second regulating component includes a twelfth ball valve, a second electric ball valve, a third electric ball valve, a fourth electric ball valve, a fifth electric ball valve, a sixth electric ball valve and a seventh electric ball valve; the twelfth ball valve and the second electric ball valve are both connected to the piped carbon dioxide inlet, the third electric ball valve is connected to the inlet pipeline of the steady-state system, the fourth electric ball valve is connected between one end of the oil cooling device and the inlet pipeline of the steady-state system, the fifth electric ball valve is connected to the outlet pipeline of the steady-state system, the sixth electric ball valve is connected between the outlet pipeline of the steady-state system and the other end of the oil cooling device, and the seventh electric ball valve is connected to the bypass pipeline of the steady-state system.

[0019] Furthermore, the second pressure transmitter assembly includes a fourth digital pressure transmitter, the second temperature transmitter assembly includes a second temperature transmitter, the third flow detection component is a third flow meter, and the fourth digital pressure transmitter, the second temperature transmitter and the third flow meter are all connected to the pipeline carbon dioxide inlet.

[0020] Further, the dense phase boosting and injection device includes a dense phase boosting and injection inlet, a secondary boosting pump, a second frequency conversion instrument control cabinet, a manifold, a steady flow automatic control instrument, a single well injection pipeline inlet, a secondary boosting pump inlet pipeline, a secondary boosting pump return pipeline, a secondary boosting pump outlet pipeline and a carbon dioxide distribution pipeline, the end of the dense phase boosting and injection inlet is connected to the secondary boosting pump inlet pipeline, the end of the secondary boosting pump inlet pipeline is connected to the secondary boosting pump, the secondary boosting pump is connected to the secondary boosting pump outlet pipeline, and the secondary boosting pump outlet pipeline is connected to the secondary boosting pump return pipeline and the carbon dioxide distribution pipeline;

[0021] The regulating device, the pressure transmitting device and the temperature transmitting device further include a third regulating component, a third pressure transmitting component and a third temperature transmitting component respectively, and the flow detection component includes a fourth flow detection component;

[0022] The carbon dioxide distribution pipeline is connected to one end of the fourth flow detection component, the other end of the fourth flow detection component is connected to one end of the third regulating component, the other end of the third regulating component is connected to one end of the manifold, and the other end of the manifold is connected to the steady flow automatic control instrument.

[0023] Furthermore, the steady flow automatic control instrument is connected to the inlet of the single well injection pipeline through the third regulating component, and the end of the inlet of the single well injection pipeline is fixedly connected to the single well injection pipeline outside the station.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The system can be used for both liquid phase CO2 injection and dense phase pipeline CO2 injection, which greatly reduces the front-end investment in large-scale production (the establishment of low-temperature storage tanks and the economic investment in large-scale tank truck transportation).

[0026] 2. The system solves the problem of low efficiency of secondary booster pump caused by unstable CO2 source by adopting liquid phase booster device, phase stabilizing device and dense phase booster injection device.

[0027] 3. It ensures that the carbon dioxide at the inlet of the booster pump is in a liquid, dense phase state, meeting the starting pressure requirements at the injection end.

[0028] 4. The system collects temperature, pressure and three-phase current data to automatically adjust the frequency of the booster pump throughout the entire process. It can remotely adjust the system operating parameters based on the system device operating data and actual work needs, reducing the frequency of employee operations and achieving risk prevention and control at each node.

[0029] 5. The system is also equipped with a dense phase pressurized injection device, which can correspond to multiple injection wells.

[0030] 6. The device adopts the method of prefabrication of multiple skids in the factory and on-site installation, which reduces the construction time by 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 The liquid dense phase CO provided by the present invention 2 Schematic diagram of the overall structure of the injection system;

[0033] Figure 2 The liquid dense phase CO provided by the present invention 2 Schematic diagram of the liquid phase pressure boosting device in the injection system;

[0034] Figure 3 The liquid dense phase CO provided by the present invention 2 Schematic diagram of the phase stabilization device in the injection system;

[0035] Figure 4 The liquid dense phase CO provided by the present invention 2 Schematic diagram of dense phase pressurized injection device in injection system;

[0036] Among them: 1. Liquid carbon dioxide inlet; 2. Reflux port; 3. Carbon dioxide outlet; 4. First ball valve; 5. First digital pressure transmitter; 6. Liquid feeding pump; 7. Second ball valve; 8. Second digital pressure transmitter; 9. Primary booster pump; 10. First frequency conversion instrument control cabinet; 11. Third ball valve; 12. Fourth ball valve; 13. Fifth ball valve; 14. Sixth ball valve; 15. Seventh ball valve; 16. Eighth ball valve; 17. First safety valve; 18. Ninth ball valve; 19. First electric regulating valve; 20. Third digital pressure transmitter; 21. First Temperature transmitter; 22, the tenth ball valve; 23, the first flow meter; 24, the first check valve; 25, the second electric regulating valve; 26, the second flow meter; 27, the eleventh ball valve; 28, the first electric ball valve; 29, the primary booster pump inlet pipeline; 30, the liquid feeding bypass pipeline; 31, the primary booster pump precooling inlet pipeline; 32, the primary booster pump precooling outlet pipeline; 33, the primary booster pump outlet pipeline; 34, the phase stabilizing device inlet; 35, the pipeline carbon dioxide inlet; 36, the twelfth ball valve; 37, the fourth digital pressure transmitter; 38, the third flow ; 39, the second temperature transmitter; 40, the second electric ball valve; 41, the third electric ball valve; 42, the fourth electric ball valve; 43, the electromagnetic heater; 44, the oil cooling device; 45, the fifth electric ball valve; 46, the sixth electric ball valve; 47, the seventh electric ball valve; 48, the steady phase system inlet pipeline; 49, the steady phase system outlet pipeline; 50, the steady phase system bypass pipeline; 51, the dense phase booster injection inlet; 52, the fifth digital pressure transmitter; 53, the third temperature transmitter; 54, the secondary booster pump; 55, the second frequency conversion instrument control cabinet; 56, the Six digital pressure transmitters; 57. The third electric regulating valve; 58. The second safety valve; 59. The thirteenth ball valve; 60. The fourth flow meter; 61. The second check valve; 62. The manifold; 63. The seventh digital pressure transmitter; 64. The fourteenth ball valve; 65. The steady flow automatic controller; 66. The fourth temperature transmitter; 67. The third check valve; 68. The eighth digital pressure transmitter; 69. The inlet of the single well injection pipeline; 70. The inlet pipeline of the secondary booster pump; 71. The return pipeline of the secondary booster pump; 72. The outlet pipeline of the secondary booster pump; 73. The carbon dioxide distribution pipeline. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0040] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0041] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0042] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0044] See also Figure 1The embodiment of the present invention discloses a liquid dense phase CO2 injection system, comprising: a liquid phase pressurizing device, a phase stabilizing device, a dense phase pressurizing and injection device and a controller. The liquid phase pressurizing device, the phase stabilizing device and the dense phase pressurizing and injection device are connected in sequence through pipelines, and are all equipped with a regulating device, a pressure transmitting device, a temperature transmitting device and a flow detection component. The regulating device, the pressure transmitting device, the temperature transmitting device and the flow detection device are all electrically connected to the controller. Furthermore, the liquid phase boosting device includes a liquid feeding pump 6, a primary boosting pump 9 and a first frequency conversion instrument control cabinet 10, one end of the liquid feeding pump 6 is connected to the liquid carbon dioxide inlet 1 through a liquid feeding bypass pipeline 30, and the other end is connected to one side of the primary boosting pump 9 through a primary boosting pump inlet pipeline 29; the other side of the primary boosting pump 9 is connected to the phase stabilizing device through a primary boosting pump outlet pipeline 33, and a primary boosting pump precooling inlet pipeline 31 is also provided on the liquid feeding bypass pipeline 30, and the end of the primary boosting pump precooling inlet pipeline 31 is connected to the primary boosting pump 9, and a primary boosting pump precooling outlet pipeline 32 is provided on the primary boosting pump 9, and the end of the primary boosting pump precooling outlet pipeline 32 is fixedly connected to the reflux port 2, and the end of the primary boosting pump outlet pipeline 33 on the primary boosting pump 9 is also connected to the carbon dioxide outlet 3. In this embodiment, the regulating device, the pressure transmitting device and the temperature transmitting device respectively include a first regulating component, a first pressure transmitting component and a first temperature transmitting component, the flow detection component includes a first flow detection component and a second flow detection component, the first regulating component, the first pressure transmitting component, the first temperature transmitting component, the first flow detection component and the second flow detection component are all connected to the first variable frequency instrument control cabinet 10 by signal, and the controller is installed in the control room of the central station.

[0045] Specifically, Figure 2As shown, the first regulating assembly includes a first ball valve 4, a second ball valve 7, a third ball valve 11, a fourth ball valve 12, a fifth ball valve 13, a sixth ball valve 14, a seventh ball valve 15, an eighth ball valve 16, a first safety valve 17, a ninth ball valve 18, a first electric regulating valve 19, a tenth ball valve 22, a first check valve 24, a second electric regulating valve 25, an eleventh ball valve 27 and a first electric ball valve 28; the first ball valve 4 is connected between the liquid feeding pump 6 and the liquid carbon dioxide inlet 1, the second ball valve 7 is connected between the liquid feeding pump 6 and the primary booster pump 9, the third ball valve 11 is connected between the liquid feeding pump 6 and the primary booster pump precooling inlet pipeline 31, the fourth ball valve 12 is connected to the liquid feeding bypass pipeline 30, the fifth ball valve 13 is connected between the liquid feeding bypass pipeline 30 and the primary booster pump precooling inlet pipeline 31, the sixth ball valve 14 is connected between the primary booster pump precooling inlet pipeline 31 and the primary booster pump 9 The seventh ball valve 15 is connected to the other end of the primary booster pump precooling inlet pipeline 31, the eighth ball valve 16 is connected between the primary booster pump 9 and the primary booster pump precooling outlet pipeline 32, and the ninth ball valve 18 is connected to the end of the primary booster pump precooling outlet pipeline 32 away from the primary booster pump 9; the first safety valve 17 is connected to the primary booster pump precooling outlet pipeline 32 and is located between the eighth ball valve 16 and the ninth ball valve 18, the first electric regulating valve 19 is connected between the primary booster pump precooling outlet pipeline 32 and the primary booster pump outlet pipeline 33, the tenth ball valve 22 is connected to the primary booster pump outlet pipeline 33, the first check valve 24 is also connected to the primary booster pump outlet pipeline 33, and is located on one side of the tenth ball valve 22, and the second electric regulating valve 25, the eleventh ball valve 27 and the first electric ball valve 28 are all connected to one end of the primary booster pump outlet pipeline 33 connected to the carbon dioxide outlet.

[0046] In this embodiment, the first pressure transmitter assembly includes a first digital pressure transmitter 5, a second digital pressure transmitter 8 and a third digital pressure transmitter 20. The first digital pressure transmitter 5 is connected to the liquid feeding pump 6, the second digital pressure transmitter 8 is connected between the primary booster pump 9 and the primary booster pump inlet pipeline 29, and the third digital pressure transmitter 20 is connected to the primary booster pump 9.

[0047] In this embodiment, the first temperature transmitter assembly includes a first temperature transmitter 21 , and the first temperature transmitter 21 is connected to the outlet pipeline 33 of the primary booster pump.

[0048] In this embodiment, the first flow detection component and the second flow detection component are respectively the first flow meter 23 and the second flow meter 26. The first flow meter 23 and the second flow meter 26 are both installed on the primary boost pump outlet pipeline 33. The first flow meter 23 is located between the tenth ball valve 22 and the first check valve 24, and the second flow meter 26 is located between the second electric regulating valve 25 and the eleventh ball valve 27.

[0049] The liquid phase boosting device needs to be pre-cooled before operation. The front end of the liquid carbon dioxide inlet 1 is connected to the outlet pipeline of the low-temperature CO2 storage tank, and the other end is connected to the liquid feeding pump 6 or the liquid feeding bypass pipeline 30. The liquid feeding pump 6 is connected to the primary boosting pump inlet pipeline 29, and the primary boosting pump inlet pipeline 29 is connected to the primary boosting pump 9, and the primary boosting pump outlet pipeline 33 is connected to the phase stabilizing device inlet 34 or the second electric regulating valve 25. The second electric regulating valve 25 is connected to the second flow meter 26, and the second flow meter 26 is connected to the eleventh ball valve 27. The eleventh ball valve 27 is connected to the carbon dioxide outlet 3, and the carbon dioxide outlet 3 is connected to the CO2 injection trunk line outside the station. The other end of the liquid feeding bypass pipeline 30 is connected to the primary booster pump inlet pipeline 29 or the primary booster pump precooling inlet pipeline 31, the primary booster pump precooling inlet pipeline 31 is connected to the primary booster pump 9, the primary booster pump 9 is connected to the primary booster pump precooling outlet pipeline 32, the primary booster pump precooling outlet pipeline 32 is connected to the reflux port 2, and the reflux port 2 is connected to the low-temperature CO2 storage tank reflux pipeline.

[0050] In this embodiment, if Figure 3 As shown, the phase-stabilizing device includes an electromagnetic heater 43, an oil cooling device 44, a phase-stabilizing system inlet pipeline 48, a phase-stabilizing system outlet pipeline 49, and a phase-stabilizing system bypass pipeline 50. One end of the electromagnetic heater 43 is connected to the phase-stabilizing system inlet pipeline 48, and the other end is connected to the phase-stabilizing system outlet pipeline 49. The end of the phase-stabilizing system outlet pipeline 49 is connected to the dense phase pressurization injection device. Furthermore, in the present embodiment, the regulating device, the pressure transmitting device and the temperature transmitting device further include a second regulating component, a second pressure transmitting component and a second temperature transmitting component, respectively, and the flow detection component includes a third flow detection component; both sides of the electromagnetic heater 43 are connected to the oil cooling device 44 through the second regulating component, and the end of the second regulating component is connected to the inlet 34 of the phase stabilizing device, and the inlet 34 of the phase stabilizing device is connected to the bypass pipeline 50 of the phase stabilizing system through the second regulating component, and the bypass pipeline 50 of the phase stabilizing system is connected to the pipeline carbon dioxide inlet 35; the dense phase booster injection device includes a second variable frequency instrument control cabinet 55, and the second regulating component, the second pressure transmitting component, the second temperature transmitting component, the third flow detection component, the electromagnetic heater 43 and the oil cooling device 44 are all connected to the second variable frequency instrument control cabinet 55 by signal.

[0051] In this embodiment, the second regulating component includes a twelfth ball valve 36, a second electric ball valve 40, a third electric ball valve 41, a fourth electric ball valve 42, a fifth electric ball valve 45, a sixth electric ball valve 46 and a seventh electric ball valve 47; the twelfth ball valve 36 and the second electric ball valve 40 are both connected to the pipeline carbon dioxide inlet 35, the third electric ball valve 41 is connected to the steady-state system inlet pipeline 48, the fourth electric ball valve 42 is connected between one end of the oil cooling device 44 and the steady-state system inlet pipeline 48, the fifth electric ball valve 45 is connected to the steady-state system outlet pipeline 49, the sixth electric ball valve 46 is connected between the steady-state system outlet pipeline 49 and the other end of the oil cooling device 44, and the seventh electric ball valve 47 is connected to the steady-state system bypass pipeline 50.

[0052] In this embodiment, the second pressure transmitting assembly includes a fourth digital pressure transmitter 37, the second temperature transmitting assembly includes a second temperature transmitter 39, the third flow detection component is a third flow meter 38, and the fourth digital pressure transmitter 37, the third flow meter 38 and the second temperature transmitter 39 are all connected to the pipeline carbon dioxide inlet 35 in sequence.

[0053] Before the operation of the phase-stabilizing device, the front end of the pipeline carbon dioxide inlet 35 is connected to the carbon dioxide pipeline, and the rear end of the pipeline carbon dioxide inlet 35 is connected to the phase-stabilizing system inlet pipeline 48 or the seventh electric ball valve 47. The phase-stabilizing system inlet pipeline 48 is connected to the third electric ball valve 41 and the fourth electric ball valve 42. The third electric ball valve 41 is connected to the electromagnetic heater 43. The electromagnetic heater 43 is connected to the fifth electric ball valve 45. The fifth electric ball valve 45 is connected to the phase-stabilizing system outlet pipeline 49. The fourth electric ball valve 42 is connected to the oil cooling device 44. The oil cooling device 44 is connected to the sixth electric ball valve 46. The sixth electric ball valve 46 is connected to the phase-stabilizing system outlet pipeline 49. The phase-stabilizing system outlet pipeline 49 is connected to the dense phase pressurization and injection inlet 51; the phase-stabilizing device inlet 34 is connected to the seventh electric ball valve 47. The seventh electric ball valve 47 is connected to the phase-stabilizing system bypass pipeline 50. The phase-stabilizing system bypass pipeline 50 is connected to the dense phase pressurization and injection inlet 51.

[0054] In this embodiment, if Figure 4 As shown, the dense phase boosting and injection device includes a dense phase boosting and injection inlet 51, a secondary boosting pump 54, a second frequency conversion instrument control cabinet 55, a manifold 62, a steady flow automatic control instrument 65, a single well injection pipeline inlet 69, a secondary boosting pump inlet pipeline 70, a secondary boosting pump return pipeline 71, a secondary boosting pump outlet pipeline 72 and a carbon dioxide distribution pipeline 73, the end of the dense phase boosting and injection inlet 51 is connected to the secondary boosting pump inlet pipeline 70, the end of the secondary boosting pump inlet pipeline 70 is connected to the secondary boosting pump 54, the secondary boosting pump 54 is connected to the secondary boosting pump outlet pipeline 72, the secondary boosting pump outlet pipeline 72 is connected to the secondary boosting pump return pipeline 71 and the carbon dioxide distribution pipeline 73;

[0055] The regulating device, the pressure transmitting device and the temperature transmitting device further include a third regulating component, a third pressure transmitting component and a third temperature transmitting component respectively, and the flow detection component includes a fourth flow detection component; the carbon dioxide distribution pipeline 73 is connected to one end of the fourth flow detection component, the other end of the fourth flow detection component is connected to one end of the third regulating component, the other end of the third regulating component is connected to one end of the manifold 62, the other end of the manifold 62 is connected to the steady flow automatic control instrument 65, the steady flow automatic control instrument 65 is connected to the single well injection pipeline inlet 69 through the third regulating component, and the end of the single well injection pipeline inlet 69 is fixedly connected with the single well injection pipeline outside the station.

[0056] Furthermore, the third regulating assembly includes a third electric regulating valve 57, a second safety valve 58, a thirteenth ball valve 59, a second check valve 61, a fourteenth ball valve 64 and a third check valve 67. The third electric regulating valve 57 is connected to the secondary booster pump return pipeline 71, the second safety valve 58 is connected to the secondary booster pump 54, the thirteenth ball valve 59 and the second check valve 61 are both connected to the carbon dioxide distribution pipeline 73, and the fourteenth ball valve 64 and the third check valve 67 are both connected between the manifold 62 and the single well injection pipeline inlet 69.

[0057] The third pressure transmitter assembly includes a fifth digital pressure transmitter 52, a sixth digital pressure transmitter 56, a seventh digital pressure transmitter 63 and an eighth digital pressure transmitter 68; the fifth digital pressure transmitter 52 is connected to the dense phase booster injection inlet 51, the sixth digital pressure transmitter 56 is connected to the carbon dioxide distribution pipeline 73, the seventh digital pressure transmitter 63 is connected to the manifold 62, and the eighth digital pressure transmitter 68 is connected to the single well injection pipeline inlet 69. The third temperature transmitter assembly includes a third temperature transmitter 53 and a fourth temperature transmitter 66, the third temperature transmitter 53 is connected between the dense phase booster injection inlet 51 and the secondary booster pump inlet pipeline 70, and the fourth temperature transmitter 66 is connected to the manifold 62. The flow detection assembly includes a fourth flow detection component, which is a fourth flow meter 60, and the fourth flow meter 60 is connected to the carbon dioxide distribution pipeline 73.

[0058] Before the dense phase boosting and injection device is put into operation, the rear end of the dense phase boosting and injection inlet 51 is connected to the secondary boosting pump inlet pipeline 70, the secondary boosting pump inlet pipeline 70 is connected to the secondary boosting pump 54, the secondary boosting pump 54 is connected to the secondary boosting pump outlet pipeline 72, the secondary boosting pump outlet pipeline 72 is connected to the secondary boosting pump return pipeline 71 or the carbon dioxide distribution pipeline 73; the secondary boosting pump return pipeline 71 is plugged into the secondary boosting pump inlet pipeline 70, the carbon dioxide distribution pipeline 73 is connected to the fourth flow meter 60, the fourth flow meter 60 is connected to the second check valve 61, the second check valve 61 is connected to the manifold 62, the manifold 62 is connected to the fourteenth ball valve 64, the fourteenth ball valve 64 is connected to the steady flow automatic control instrument 65, the steady flow automatic control instrument 65 is connected to the third check valve 67, the third check valve 67 is connected to the single well injection pipeline inlet 69, and the rear end of the single well injection pipeline inlet 69 is connected to the single well CO2 injection pipeline outside the station.

[0059] In this embodiment, the liquid dense phase CO2 injection system is divided into three injection processes during the carbon dioxide injection process. The first injection process is: liquid phase carbon dioxide injection, specifically, the liquid carbon dioxide inlet 1 of the liquid phase booster device is connected from the outlet of the low-temperature liquid phase CO2 storage tank, the reflux port 2 is connected to the low-temperature liquid phase CO2 storage tank reflux pipeline, and the carbon dioxide outlet 3 is connected to the station external CO2 injection trunk line. First, precool the liquid phase booster device, close the eleventh ball valve 27 and the first electric ball valve 28, open all other valves, and precool for 5 minutes. Close the fourth ball valve 12, the fifth ball valve 13, the sixth ball valve 14 and the eighth ball valve 16; close the eleventh electric ball valve 28, open the eleventh ball valve 27, and the liquid CO2 enters the feeding pump 6 from the low-temperature liquid phase CO2 storage tank through the first ball valve 4, enters the primary booster pump 9 through the primary booster pump inlet pipeline 29, enters the primary booster pump 9 for boosting, enters the second electric regulating valve 25 through the primary booster pump outlet pipeline 33 for regulation, and then connects the station external CO2 injection trunk line through the carbon dioxide outlet 3.

[0060] The second injection process is also liquid carbon dioxide injection. Specifically, the precooling process is the same as the liquid carbon dioxide injection method in the first injection process. The second electric regulating valve 25 and the eleventh ball valve 27 are closed, and the first electric ball valve 28 is opened. The liquid CO2 enters the feeding pump 6 from the low-temperature liquid CO2 storage tank through the first ball valve 4, enters the primary booster pump 9 through the primary booster pump inlet pipeline 29 to be pressurized to the set pressure, and is measured from the primary booster pump outlet pipeline 33 through the first flow meter 23, and enters the phase stabilizing device inlet 34 through the first electric valve 28, and automatically closes the third electric ball valve 41, The fourth electric ball valve 42, the fifth electric ball valve 45 and the sixth electric ball valve 46 open the seventh electric ball valve 47, enter the dense phase pressurization and injection inlet 51 through the phase-stabilizing system bypass pipeline 50, the dense phase pressurization and injection inlet 51 is connected to the secondary booster pump inlet pipeline 70, is pressurized to the set pressure by the secondary booster pump 54, is connected to the carbon dioxide distribution pipeline 73 from the secondary booster pump outlet pipeline 72, and after being measured by the fourth flow meter 60, enters the manifold 62, and 4 branch pipelines are connected to the manifold 62, which is regulated to the set flow rate by the steady flow automatic control instrument 65 and enters the single well CO2 injection pipeline outside the station after accumulation.

[0061] The third injection process is: dense phase carbon dioxide injection, specifically, dense phase pipeline CO2 enters the phase stabilization device through the pipeline carbon dioxide inlet 35, and then enters the third flow meter 38 for measurement. The data collected by the second temperature transmitter 39 is judged and executed by the plc controller of the second frequency conversion instrument control cabinet 55: if the temperature meets the setting, the third electric ball valve 41, the fourth electric ball valve 42, the fifth electric ball valve 45 and the sixth electric ball valve 46 are automatically closed, the seventh electric ball valve 47 is opened, and the dense phase booster injection inlet 51 of the dense phase booster injection device is entered through the bypass pipeline 50 of the phase stabilization system; if the temperature is higher than the setting, it enters the inlet pipeline 48 of the phase stabilization system, automatically closes the third electric ball valve 41, the fifth electric ball valve 45 and the seventh electric ball valve 47, opens the fourth electric ball valve 42 and the sixth electric ball valve 46, and after the temperature is controlled by the oil cooling device 44 , enter the steady-phase system outlet pipeline 49, and then enter the third temperature transmitter 53 of the dense phase booster injection device; if the temperature is lower than the setting, enter the steady-phase system inlet pipeline 48, automatically close the fourth electric ball valve 42, the sixth electric ball valve 46 and the seventh electric ball valve 47, open the third electric ball valve 41 and the fifth electric ball valve 45, and after the temperature is controlled by the electromagnetic heater 43, enter the steady-phase system outlet pipeline 49, and then enter the third temperature transmitter 53; the third temperature transmitter 53 is connected to the secondary booster pump inlet pipeline 70, and the secondary booster pump 54 is pressurized to the set pressure, and the secondary booster pump outlet pipeline 72 is connected to the carbon dioxide distribution pipeline 73, and after being measured by the fourth flowmeter 60, it enters the manifold 62, and the manifold 62 is connected to 4 branch pipelines, and is adjusted to the set flow rate by the steady flow automatic control instrument 65 and accumulated before entering the single well CO2 injection pipeline outside the station.

[0062] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A liquid dense phase CO 2 Injection system, It is characterized in that include: A liquid phase pressure boosting device, a phase stabilizing device, a dense phase pressure boosting and injection device and a controller, wherein the liquid phase pressure boosting device, the phase stabilizing device and the dense phase pressure boosting and injection device are connected in sequence through pipelines, and are all equipped with a regulating device, a pressure transmitting device, a temperature transmitting device and a flow detection component, and the regulating device, the pressure transmitting device, the temperature transmitting device and the flow detection device are all electrically connected to the controller.

2. The CO according to claim 1 2 Injection system, It is characterized in that The liquid phase boosting device comprises a liquid feeding pump (6), a primary boosting pump (9) and a first frequency conversion instrument control cabinet (10); one end of the liquid feeding pump (6) is connected to the liquid carbon dioxide inlet (1) via a liquid feeding bypass pipeline (30), and the other end is connected to one side of the primary boosting pump (9) via a primary boosting pump inlet pipeline (29); The other side of the primary booster pump (9) is connected to the phase stabilizing device via a primary booster pump outlet pipeline (33); a primary booster pump precooling inlet pipeline (31) is also provided on the liquid feeding bypass pipeline (30); the end of the primary booster pump precooling inlet pipeline (31) is connected to the primary booster pump (9); a primary booster pump precooling outlet pipeline (32) is provided on the primary booster pump (9); the end of the primary booster pump precooling outlet pipeline (32) is fixedly connected to a reflux port (2); and the end of the primary booster pump outlet pipeline (33) on the primary booster pump (9) is also connected to a carbon dioxide outlet (3); The regulating device, the pressure transmitting device and the temperature transmitting device respectively comprise a first regulating component, a first pressure transmitting component and a first temperature transmitting component; the flow detection component comprises a first flow detection component and a second flow detection component; the first regulating component, the first pressure transmitting component, the first temperature transmitting component, the first flow detection component and the second flow detection component are all connected to the first variable frequency instrument control cabinet (10) by signal.

3. CO according to claim 2 2 Injection system, It is characterized in that The first regulating assembly comprises a first ball valve (4), a second ball valve (7), a third ball valve (11), a fourth ball valve (12), a fifth ball valve (13), a sixth ball valve (14), a seventh ball valve (15), an eighth ball valve (16), a first safety valve (17), a ninth ball valve (18), a first electric regulating valve (19), a tenth ball valve (22), a first check valve (24), a second electric regulating valve (25), an eleventh ball valve (27) and a first electric ball valve (28); the first ball valve (4) is connected between the liquid feeding pump (6) and the liquid carbon dioxide inlet (1), the second ball valve (7) is connected between the liquid feeding pump (6) and the primary booster pump (9), the third ball valve (11) is connected to the liquid feeding pump (6) and the primary booster pump (9), The fourth ball valve (12) is connected to the liquid feeding bypass pipeline (30), the fifth ball valve (13) is connected between the liquid feeding bypass pipeline (30) and the primary booster pump precooling inlet pipeline (31), the sixth ball valve (14) is connected between the primary booster pump precooling inlet pipeline (31) and the primary booster pump (9), the seventh ball valve (15) is connected to the other end of the primary booster pump precooling inlet pipeline (31), the eighth ball valve (16) is connected between the primary booster pump (9) and the primary booster pump precooling outlet pipeline (32), and the ninth ball valve (18) is connected to the end of the primary booster pump precooling outlet pipeline (32) away from the primary booster pump (9); The first safety valve (17) is connected between the eighth ball valve (16) and the ninth ball valve (18); the first electric regulating valve (19) is connected between the primary booster pump precooling outlet pipeline (32) and the primary booster pump outlet pipeline (33); the tenth ball valve (22) is connected to the primary booster pump outlet pipeline (33); the first check valve (24) is also connected to the primary booster pump outlet pipeline (33) and is located on one side of the tenth ball valve (22); the second electric regulating valve (25), the eleventh ball valve (27) and the first electric ball valve (28) are all connected to the end of the primary booster pump outlet pipeline (33).

4. The CO according to claim 2 2 Injection system, It is characterized in that The first pressure transmitter assembly comprises a first digital pressure transmitter (5), a second digital pressure transmitter (8) and a third digital pressure transmitter (20), wherein the first digital pressure transmitter (5) is connected to a liquid feeding pump (6), the second digital pressure transmitter (8) is connected between a primary booster pump (9) and an inlet pipeline (29) of the primary booster pump, and the third digital pressure transmitter (20) is connected to the primary booster pump (9).

5. The CO according to claim 2 2 Injection system, It is characterized in that The first temperature transmitter assembly comprises a first temperature transmitter (21), and the first temperature transmitter (21) is connected to an outlet pipeline (33) of a primary booster pump.

6. The CO according to claim 1 2 Injection system, It is characterized in that The phase stabilizing device comprises an electromagnetic heater (43), an oil cooling device (44), a phase stabilizing system inlet pipeline (48), a phase stabilizing system outlet pipeline (49), and a phase stabilizing system bypass pipeline (50); one end of the electromagnetic heater (43) is connected to the phase stabilizing system inlet pipeline (48), and the other end is connected to the phase stabilizing system outlet pipeline (49); the end of the phase stabilizing system outlet pipeline (49) is connected to the dense phase pressurization and injection device; The regulating device, the pressure transmitting device and the temperature transmitting device further include a second regulating component, a second pressure transmitting component and a second temperature transmitting component respectively, and the flow detection component includes a third flow detection component; Both sides of the electromagnetic heater (43) are connected to the oil cooling device (44) via a second regulating assembly, an end of the second regulating assembly is connected to an inlet (34) of a phase stabilizing device, the inlet (34) of the phase stabilizing device is further connected to a bypass pipeline (50) of the phase stabilizing system via the second regulating assembly, and a pipeline carbon dioxide inlet (35) is connected to the bypass pipeline (50) of the phase stabilizing system; The dense phase pressurized injection device comprises a second variable frequency instrument control cabinet (55), and the second regulating component, the second pressure transmitter component, the second temperature transmitter component, the third flow detection component, the electromagnetic heater (43) and the oil cooling device (44) are all connected to the second variable frequency instrument control cabinet (55) by signal.

7. The CO according to claim 6 2 Injection system, It is characterized in that The second regulating assembly comprises a twelfth ball valve (36), a second electric ball valve (40), a third electric ball valve (41), a fourth electric ball valve (42), a fifth electric ball valve (45), a sixth electric ball valve (46) and a seventh electric ball valve (47); the twelfth ball valve (36) and the second electric ball valve (40) are both connected to the pipeline carbon dioxide inlet (35), the third electric ball valve (41) is connected to the steady phase system inlet pipeline (48), the fourth electric ball valve (42) is connected between one end of the oil cooling device (44) and the steady phase system inlet pipeline (48), the fifth electric ball valve (45) is connected to the steady phase system outlet pipeline (49), the sixth electric ball valve (46) is connected between the steady phase system outlet pipeline (49) and the other end of the oil cooling device (44), and the seventh electric ball valve (47) is connected to the steady phase system bypass pipeline (50).

8. The CO according to claim 6 2 Injection system, It is characterized in that The second pressure transmitter assembly includes a fourth digital pressure transmitter (37), the second temperature transmitter assembly includes a second temperature transmitter (39), the third flow detection component is a third flow meter (38), and the fourth digital pressure transmitter (37), the second temperature transmitter (39) and the third flow meter (38) are all connected to the pipeline carbon dioxide inlet (35).

9. The CO according to claim 1 2 Injection system, It is characterized in that The dense phase boosting and injection device comprises a dense phase boosting and injection inlet (51), a secondary boosting pump (54), a second frequency conversion instrument control cabinet (55), a manifold (62), a steady flow automatic control instrument (65), a single well injection pipeline inlet (69), a secondary boosting pump inlet pipeline (70), a secondary boosting pump return pipeline (71), a secondary boosting pump outlet pipeline (72) and a carbon dioxide distribution pipeline (73), wherein the end of the dense phase boosting and injection inlet (51) is connected to the secondary boosting pump inlet pipeline (70), the end of the secondary boosting pump inlet pipeline (70) is connected to the secondary boosting pump (54), the secondary boosting pump (54) is connected to the secondary boosting pump outlet pipeline (72), and the secondary boosting pump outlet pipeline (72) is connected to the secondary boosting pump return pipeline (71) and the carbon dioxide distribution pipeline (73); The regulating device, the pressure transmitting device and the temperature transmitting device further include a third regulating component, a third pressure transmitting component and a third temperature transmitting component respectively, and the flow detection component includes a fourth flow detection component; The carbon dioxide distribution pipeline (73) is connected to one end of the fourth flow detection component, the other end of the fourth flow detection component is connected to one end of the third regulating component, the other end of the third regulating component is connected to one end of the manifold (62), and the other end of the manifold (62) is connected to the steady flow automatic control device (65).

10. The CO according to claim 9 2 Injection system, It is characterized in that The steady flow automatic control instrument (65) is connected to the single well injection pipeline inlet (69) via a third regulating component, and the end of the single well injection pipeline inlet (69) is fixedly connected to an off-station single well injection pipeline.

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