A simulation and evaluation system for oil and gas wellbore corrosion

Abstract

The invention discloses a wellbore corrosion simulation evaluation system for oil and gas wells, including an oil casing evaluation module, a corrosion hanging plate module, a scaling evaluation module, an electrochemical corrosion probe module and a double-layer circulation pipeline; the oil casing evaluation module, the corrosion hanging plate module, the scaling evaluation module and the electrochemical corrosion probe module are all connected to the double-layer circulation pipeline, the oil casing evaluation module is used for fluid scouring simulation of the oil casing and the inner coating of the oil casing; the corrosion hanging plate module is used for dynamic scouring corrosion simulation of the fluid; the scaling evaluation module is used for scaling simulation of the oil casing; the electrochemical corrosion probe module is used for electrochemical corrosion simulation of the oil casing. It can simulate the corrosion and scaling factors such as fluid flow rate, pressure, temperature in the wellbore environment, and can be used to carry out oil casing corrosion rate testing, corrosion behavior and corrosion mechanism research, anti-corrosion measures effect evaluation, corrosion inhibitor optimization, scale inhibitor optimization, incompatible fluid scaling status research, etc., to provide an effective evaluation means for the anti-corrosion and anti-scaling work of oil and gas wells.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field corrosion and protection, and relates to an oil and gas wellbore corrosion simulation evaluation system. Background Art

[0002] In the process of oil production, oil casing is a bridge connecting drilling and oil production. It is of vital importance. It is used in large quantities and has high requirements for safety and stability. It needs to be used for a long time after being put into the well. It is a key part of the long-term stable and high production of oil fields. However, with the extension of oil field development time and the continuous use of more and more enhanced oil production measures in production, such as high-pressure water injection, fracturing, large-scale acidification, steam injection, etc., the working environment of oil casing has been deteriorating. The basic theory and method of oil casing strength design for many years have taken completion construction as the main consideration, and a series of factors in the process of oil production and water injection construction and ground stress changes have been considered less or not considered. The actual situation on site shows that after the oil and water wells are put into production, the corrosion environment of the oil casing gradually deteriorates, and the damage of the oil casing becomes more and more serious. It has become a major problem restricting the development of oil fields and improving the development efficiency, and it is also a common and increasingly serious problem in oil fields at home and abroad. The research and application of casing damage prevention technology is of great significance to improving the overall development efficiency of old oil fields. Therefore, it is an urgent problem to carefully analyze and study the various factors and mechanisms of oil casing damage and evaluate the effects of various anti-corrosion measures. Although a lot of research has been done on the problem of oil casing corrosion at home and abroad, the environment of different oil fields is very different, and with the deepening of development, new problems continue to emerge, which requires a cycle of recognition-improvement-re-recognition.

[0003] At present, scientific research institutes mostly use indirect evaluation methods in corrosion scaling research, such as software prediction, hanging weight loss method, electrochemical evaluation method, etc., and there is no full-scale corrosion simulation evaluation device. At present, some oil fields have carried out full-scale corrosion simulation evaluation tests, such as the full-scale test device of Jilin Oilfield focuses on evaluating high CO2 (15% to 20%) corrosion, and the full-scale test device of Puguang Gas Field focuses on evaluating high H2S corrosion.

[0004] However, the above methods are either indirect evaluation methods based on intermediate quantities, and the evaluation results have large errors relative to the actual situation, or they can only perform simple corrosion simulation. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art that the evaluation results are of poor authenticity and can only perform corrosion simulation, and to provide an oil and gas wellbore corrosion simulation evaluation system.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A wellbore corrosion simulation and evaluation system for oil and gas wells comprises an oil casing evaluation module, a corrosion hanging plate module, a scaling evaluation module, an electrochemical corrosion probe module and a double-layer circulation pipeline; the oil casing evaluation module, the corrosion hanging plate module, the scaling evaluation module and the electrochemical corrosion probe module are all connected to the double-layer circulation pipeline, and a circulating fluid is arranged inside the double-layer circulation pipeline; the oil casing evaluation module is used for fluid scouring simulation of the oil casing and the inner coating of the oil casing; the corrosion hanging plate module is used for dynamic scouring corrosion simulation of the fluid; the scaling evaluation module is used for scaling simulation of the oil casing; and the electrochemical corrosion probe module is used for electrochemical corrosion simulation of the oil casing.

[0008] The present invention is further improved in that:

[0009] It also includes a data acquisition control module, which is connected to the corrosion hanging plate module, the scaling evaluation module and the electrochemical corrosion probe module; and is used to collect the hanging plate weight of the corrosion hanging plate module, the scaling amount of the scaling evaluation module, and the electrochemical test potential of the electrochemical corrosion probe module.

[0010] The double-layer circulation pipeline includes a liquid storage tank, a circulation pump, an outer casing and an inner oil pipe; one end of the inner oil pipe is connected to the inlet of the liquid storage tank, and the other end is connected to the outlet of the liquid storage tank. The circulation pump is arranged on the inner oil pipe to drive the fluid to circulate in the inner oil pipe. The outer casing is sleeved on the outside of the inner oil pipe, and a flexible heating sleeve is sleeved on the outside of the outer casing; the oil casing evaluation module, the corrosion hanging plate module, the scaling evaluation module and the electrochemical corrosion probe module are all connected to the inner oil pipe.

[0011] The outer casing is a fully transparent PC tube, and a plurality of windows are provided on the outer casing.

[0012] It also includes a centralizer, one end of which is connected to the outer wall of the inner oil pipe and the other end is connected to the inner wall of the outer casing, so as to place the inner oil pipe on the central axis of the outer casing.

[0013] The oil casing evaluation module includes a horizontal oil casing and a vertical oil casing. Both ends of the horizontal oil casing and the vertical oil casing are connected to the inner layer oil pipe valve of the double-layer circulation pipeline.

[0014] The corrosion hanging plate module includes an upper cover, a flange and a plurality of hanging plate hanging rods; the upper cover is sealed and connected to the upper cover hole opened on the double-layer circulation pipeline through the flange, and the plurality of hanging plate hanging rods are all located inside the double-layer circulation pipeline, and one end is connected to the surface of one side of the upper cover; a plurality of corrosion hanging plates are arranged on the hanging plate hanging rods.

[0015] The scaling evaluation module includes an anion and cation tank, a scaling ion solution tank, an injection pump, a thermostat, a waste liquid tank, a capillary scale inhibitor tester and two differential pressure sensors; one end of the scaling ion solution tank is connected to the anion and cation tank, and the other end is connected to the injection pump, the capillary scale inhibitor tester and the waste liquid tank in sequence, and the injection pump is connected to the double-layer circulation pipeline; the capillary scale inhibitor tester is located inside the thermostat, and the two differential pressure sensors are respectively connected to the two ends of the capillary scale inhibitor tester.

[0016] The scaling evaluation module also includes a flow meter, a back pressure valve and a pH probe; the flow meter and the back pressure valve are both arranged on the pipeline between the injection pump and the double-layer circulation pipeline; the pH probe is sealed and inserted inside the inner layer oil pipe.

[0017] The electrochemical corrosion probe module comprises a plurality of probes, which are threadedly connected to the double-layer circulation pipeline and have one end extending into the double-layer circulation pipeline.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] By designing a double-layer circulation pipeline, the oil casing evaluation module, the corrosion hanging module, the scaling evaluation module and the electrochemical corrosion probe module are connected as a whole through the double-layer circulation pipeline, and the fluid scouring simulation of the oil casing and the inner coating of the oil casing, the dynamic scouring corrosion simulation of the fluid, the scaling simulation of the oil casing and the electrochemical corrosion simulation of the oil casing are realized; the circulating fluid is arranged inside the double-layer circulation pipeline, which can realize dynamic scale inhibition, dynamic corrosion, and dynamic scouring pipe material test, which is closer to the dynamic production status of the oil field, and can also verify the effectiveness of anti-corrosion measures, such as evaluating the anti-corrosion effect of sacrificial anodes, corrosion inhibitors, etc., to provide an effective evaluation means for the anti-corrosion work of oil and gas wells, and provide a technical basis closer to production for corrosion inhibitor optimization, corrosion environment testing, inner coating scouring test of pipes, sacrificial anode selection, etc. At the same time, the present invention is easy to assemble, the simulation process is simple, and the labor intensity of testers is low.

[0020] Furthermore, a data acquisition control module is set up to realize data collection and facilitate subsequent data analysis.

[0021] Furthermore, the double-layer circulation pipeline is provided with an outer casing and an inner oil pipe. A flexible heating jacket is provided on the outside of the outer casing. The outer casing is used to provide the simulated formation temperature, and the inner oil pipe is used to evaluate the corrosion and scale inhibition performance of the formation liquid, thereby improving the accuracy of the simulation results. At the same time, the inner oil pipe is easy to replace for multiple experiments.

[0022] Furthermore, the outer casing adopts a fully transparent PC tube, and a plurality of windows are opened on the outer casing to increase visibility without affecting the strength of the outer casing.

[0023] Furthermore, a centralizer is provided, one end of which is connected to the outer wall of the inner oil pipe and the other end is connected to the inner wall of the outer casing, so as to place the inner oil pipe on the central axis of the outer casing.

[0024] Furthermore, the oil casing evaluation module includes horizontal oil casing and vertical oil casing; it can simulate the scouring effect of horizontal and vertical formation fluids on the pipeline and evaluate the remaining life of the pipeline; both ends of the horizontal oil casing and the vertical oil casing are connected to the inner layer oil pipe valve of the double-layer circulation pipeline, so that independent simulation of the horizontal oil casing and the vertical oil casing can be realized.

[0025] Furthermore, the corrosion hanging plate module includes an upper cover, a flange and a plurality of hanging plate hanging rods, on which a plurality of corrosion hanging plates are arranged. The corrosion hanging plates can be presented at different angles around the center, and simulation tests of scouring corrosion hanging plates at different angles can be carried out. The dynamic corrosion rates of fluids in different formations can be tested, and simulation tests of multiple corrosion hanging plates can be carried out at one time, and the average value can be taken as the result, which is more accurate.

[0026] Furthermore, the scaling evaluation module includes an anion and cation tank, a scaling ion solution tank, an injection pump, a thermostat, a waste liquid tank, a capillary scale tester and two differential pressure sensors. The capillary scale tester is arranged inside the thermostat to simulate the formation temperature through the thermostat. The scaling condition is evaluated by the differential pressure sensor, which is convenient and accurate.

[0027] Furthermore, the scaling evaluation module also includes a flow meter, a back pressure valve and a pH probe; the flow meter and the back pressure valve are both arranged on the pipeline between the injection pump and the double-layer circulation pipeline; the flow meter is used to accurately measure the flow rate of the scaling ion solution injected into the inner oil pipe, and the back pressure valve is used to prevent the scaling ion solution from flowing back; the pH probe is sealed and inserted into the inner oil pipe to facilitate the testing of the pH value in the system.

[0028] Furthermore, the electrochemical corrosion probe module includes a plurality of probes, which are threadedly connected to the double-layer circulation pipeline. The connection is stable, and the probes can be directly connected to the inside of the double-layer circulation pipeline to perform electrochemical potential testing. The testing process is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0030] Among them: 1-oil casing evaluation module; 2-corrosion hanging module; 3-scaling evaluation module; 4-electrochemical corrosion probe module; 5-data acquisition control module; 6-double-layer circulation pipeline; 7-guide rail; 8-operating platform; 11-horizontal oil casing; 12-vertical oil casing; 31-anion and cation tank; 32-scaling ion solution tank; 33-horizontal flow pump; 34-constant temperature box; 35-waste liquid pool; 61-liquid storage tank; 62-circulation pump. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme 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 only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0034] See also Figure 1 The oil and gas wellbore corrosion simulation evaluation system of the present invention can evaluate the corrosion and scaling of equipment such as oil pipes and casings by simulating the real corrosion working environment in the wellbore, understand the corrosion mechanism, and propose anti-corrosion countermeasures; at the same time, it can also verify the effectiveness of anti-corrosion measures, such as evaluating the anti-corrosion effects of sacrificial anodes and corrosion inhibitors, and provide an effective evaluation method for oil and gas well anti-corrosion work.

[0035] The oil and gas wellbore corrosion simulation evaluation system comprises an oil casing evaluation module 1, a corrosion hanging plate module 2, a scaling evaluation module 3, an electrochemical corrosion probe module 4, a data acquisition control module 5, a double-layer circulation pipeline 6, a guide rail 7 and an operating platform 8. The oil casing evaluation module 1, the corrosion hanging plate module 2, the scaling evaluation module 3 and the electrochemical corrosion probe module 4 are all connected to the double-layer circulation pipeline 6; the data acquisition control module 5 is connected to the double-layer circulation pipeline 6, the oil casing evaluation module 1, the corrosion hanging plate module 2, the scaling evaluation module 3 and the electrochemical corrosion probe module 4; the guide rail 7 is fixed on the upper surface of the operating platform 8, and the double-layer circulation pipeline 6 is located inside the guide rail 7 and can slide on the guide rail 7. The oil casing evaluation module 1 is used to simulate the scouring evaluation of the oil casing and the inner coating of the oil casing. The corrosion hanging piece module 2 is used to evaluate the corrosion situation under the simulated dynamic scouring state. The scaling evaluation module 3 is used to dynamically evaluate the scaling situation of the inner oil pipe and the effect of the scale inhibitor. The electrochemical corrosion probe module 4 is used to evaluate the potential of the inner oil pipe when the sacrificial anode is externally connected and the effect of the external cathodic protection. The data acquisition control module 5 is used to collect relevant simulation data.

[0036] The double-layer circulation pipeline 6 includes a liquid storage tank 61, a circulation pump 62, an outer casing and an inner oil pipe. One end of the inner oil pipe is connected to the inlet of the liquid storage tank 61, and the other end is connected to the outlet of the liquid storage tank 61. The circulation pump 62 is arranged on the inner oil pipe to drive the fluid to circulate in the inner oil pipe. The outer casing is sleeved on the outside of the inner oil pipe. The oil casing evaluation module 1, the corrosion hanging plate module 2, the scaling evaluation module 3 and the electrochemical corrosion probe module 4 are all connected to the inner oil pipe, and the data acquisition control module 5 is connected to the circulation pump 62. The outer casing adopts a fully transparent pc tube, and is wrapped with an external flexible heating sleeve. At the same time, two radial 120° window structures are arranged on the outer casing to increase the visibility without affecting the strength of the outer casing. The inner oil pipe adopts a metal pipe, and a centralizer is installed at the same time. The centralizer is connected to the outer wall of the inner oil pipe to place the inner oil pipe on the central axis of the outer casing. The inner oil pipe is replaceable, and oil pipes of different materials can be selected according to actual needs. By designing a double-layer circulation pipeline, the outer casing is used to provide simulated formation temperature, and the inner oil pipe is used to evaluate the corrosion and scale inhibition performance of the formation liquid, thereby improving the accuracy of the simulation results; at the same time, the inner oil pipe is easy to replace for multiple experiments.

[0037] The oil casing evaluation module 1 includes a horizontal oil casing 11 and a vertical oil casing 12. Both ends of the horizontal oil casing 11 and the vertical oil casing 12 are connected to the inner oil pipe of the double-layer circulation pipeline 6, which can simulate the scouring effect of horizontal and vertical formation fluids on the pipeline and evaluate the remaining life of the pipeline. Both ends of the vertical oil casing 12 are connected to the inner oil pipe of the double-layer circulation pipeline 6 through valves, which can realize independent simulation of the horizontal oil casing 11 and the vertical oil casing 12.

[0038] The corrosion coupon module 2 adopts the design of a high-temperature and high-pressure corrosion coupon chamber, including an upper cover, a flange, a plurality of coupon hanging rods and a plurality of corrosion coupons; the upper cover is sealed and connected to the upper cover hole opened on the inner oil pipe of the double-layer circulation pipeline 6 through the flange, and the coupon hanging rod is threadedly connected to the surface of one side of the upper cover, and the coupon hanging rod is located inside the inner oil pipe; a corrosion coupon is arranged on the coupon hanging rod, and the corrosion coupon is fixedly connected to the coupon hanging rod by bolts and nuts, and both sides of the coupon hanging rod can be hung. Two hanging points are arranged on each coupon hanging rod, and five coupon hanging rods are arranged on the upper cover. A maximum of 20 corrosion coupons can be hung at one time. Pressure-resistant hoses are arranged at both ends of the corrosion coupon module 2, and the pressure-resistant hoses are connected to the inner oil pipe of the double-layer circulation pipeline 6. The corrosion coupons can present different angles around the center, and simulation tests of scouring corrosion coupons at different angles can be carried out. The dynamic corrosion rate of fluids in different formations can be tested. A simulation test of 20 corrosion coupons can be carried out at one time, and the average value is taken as the result, which is more accurate.

[0039] The scaling evaluation module 3 includes an anion and cation tank 31, a scaling ion solution tank 32, an injection pump 33, a thermostat 34, a waste liquid tank 35, a capillary scale inhibitor tester, a pH probe and two differential pressure sensors; one end of the scaling ion solution tank 32 is connected to the anion and cation tank 31, and the other end is connected to the injection pump 33, the capillary scale inhibitor tester and the waste liquid tank 35 in sequence, the injection pump 33 is connected to the inner oil pipe of the double-layer circulation pipeline 6, and is used to inject scaling ion solution into the inner oil pipe of the double-layer circulation pipeline 6, and the waste liquid tank 35 is used to collect the remaining scaling ion solution. A flow meter and a back pressure valve are set between the injection pump 33 and the inner oil pipe of the double-layer circulation pipeline 6. The flow meter is used to accurately measure the flow of the scaling ion solution injected into the inner oil pipe, and the back pressure valve is used to prevent the scaling ion solution from flowing back. The capillary scale tester is set inside the thermostat 34. The capillary of the capillary scale tester is 1m long, 1mm in inner diameter, and made of 316L. The capillary is a coil wrapped with a heating jacket to ensure uniform temperature. Two differential pressure sensors are respectively set at both ends of the capillary scale tester, and the pH probe is sealed and inserted into the inner oil pipe to test the pH in the system. The scaling of the formation fluid is dynamically tested through the scaling evaluation module 3, and the effect of the scale inhibitor is dynamically tested.

[0040] The electrochemical corrosion probe module 4 includes a number of probes made of stainless steel rods. The stainless steel rods pass through the outer casing of the double-layer circulation pipeline 6 and are threadedly connected to the inner oil pipe. A total of four sets of probe interfaces are set. The stainless steel rod has a diameter of 50 mm and a length of 20 mm. The probe threads are integrally processed on the stainless steel rod platform and the pipe body. The size of the stainless steel rod is consistent with the size of the probe interface. The stainless steel rod can be directly connected to the 4 sets of probe interfaces for electrochemical potential testing.

[0041] The data acquisition control module 5 includes an industrial computer and a host computer; one end of the industrial computer is connected to the host computer, and the other end is connected to the corrosion hanging piece module 2, the scaling evaluation module 3 and the electrochemical corrosion probe module 4; it is used to collect the weight of the hanging piece of the corrosion hanging piece module 2, by weighing the spring tension of the hanging piece or removing it for weighing, the scaling amount of the scaling evaluation module 3, the pressure difference sensor before and after the scaling pipeline measures the pressure difference change or removes it for weighing, and the electrochemical test potential of the electrochemical corrosion probe module 4, which is collected after testing by an electrochemical testing instrument.

[0042] The oil and gas wellbore corrosion simulation evaluation system of the present invention can simulate the corrosion and scaling factors such as fluid flow rate, pressure, temperature, etc. in the wellbore environment, and dynamically evaluate the effect of the corrosion inhibitor used in the oil field; it can be used to carry out oil casing corrosion rate testing, corrosion behavior and corrosion mechanism research, corrosion prevention measures effect evaluation, corrosion inhibitor optimization, scale inhibitor optimization, incompatible fluid scaling status research, etc., to provide an effective evaluation method for oil and gas well corrosion and scaling prevention work. At the same time, the system is easy to assemble, has a high degree of automation, and has low labor intensity for testers. The following are several use examples of the oil and gas wellbore corrosion simulation evaluation system of the present invention.

[0043] Example 1

[0044] Dynamic corrosion inhibitor screening and evaluation test: During operation, the oil field water sample is stored in the liquid storage tank 61, and the liquid is pumped into the inner layer of the oil pipe until the pipe is full, and the pipe circulation is started. The heating sleeve is heated to 55°C in the formation, constant temperature, pressure 3MPa, flow rate 0.1m / s, and the dynamic corrosion rate is monitored in real time by the electrochemical corrosion probe module 4. The corrosion coupons are taken out every 3 days and weighed to obtain the uniform corrosion rate of different corrosion inhibitors in this time period. In this embodiment, MH46 and YJH-10 corrosion inhibitors are used, wherein the release rate of corrosion inhibitor MH46 is 0.03mm / a, and the release rate of corrosion inhibitor YJH-10 is 0.15mm / a. The corrosion inhibitor screened out as MH46 is suitable for oil field water samples.

[0045] Example 2

[0046] Dynamic corrosion inhibitor screening and evaluation test: When working, the oil field water sample is stored in the liquid storage tank 61, the liquid is pumped into the inner layer of the oil pipe until the pipeline is full, and the pipeline circulation is started. The heating sleeve is heated to 63°C in the formation, constant temperature, pressure 5MPa, flow rate 0.2m / s, and the dynamic corrosion rate is monitored in real time by the electrochemical corrosion probe module 4. In this embodiment, KEW-227 and RX-201 corrosion inhibitors are used, wherein the corrosion inhibitor KEW-227 release rate is 0.02mm / a, and the corrosion inhibitor RX-201 release rate is 0.11mm / a. The corrosion inhibitor screened out as suitable for oil field water samples is KEW-227.

[0047] Example 3

[0048] Dynamic scale inhibitor screening and evaluation test: When working, the oil field water sample is stored in the liquid storage tank 61, and the liquid is pumped into the inner layer oil pipe until the pipeline is full, and the pipeline circulation is started. The heating jacket is heated to 46°C in the formation, constant temperature, pressure 5MPa, flow rate 0.1m / s, and the dynamic scaling rate is monitored in real time through the scaling evaluation module 3. The scaling hanging piece is taken out every 2 days and weighed to obtain the uniform scaling rate of different scale inhibitors in this time period. In this embodiment, ZG-108 and ZG-558 scale inhibitors are used, among which the scale inhibitor ZG-108 has a scale inhibition rate of 75.6%, and the scale inhibitor ZG-558 has a scale inhibition rate of 87.6%. The scale inhibitor screened out is ZG-558, which is suitable for oil field water samples.

[0049] Example 4

[0050] Fluid compatibility evaluation test: During operation, two water samples from the oil field are stored in two liquid storage tanks 61 respectively, and the liquid is pumped into the inner layer of the oil pipe until the pipe is full, and the pipe circulation is started. The heating jacket is heated to 51°C in the formation, constant temperature, pressure 5MPa, flow rate 0.1m / s, and the dynamic scaling rate is monitored in real time through the scale inhibition module. The scaling hanging piece is taken out every 2 days and weighed to obtain the uniform scaling rate of different scale inhibitors in this time period. In this embodiment, RX-211 and AD43-3 scale inhibitors are used, among which the scale inhibition rate of scale inhibitor RX-211 is 65.3%, and the scale inhibition rate of scale inhibitor AD43-3 is 83.6%. The scale inhibitor suitable for oil field water samples is screened as AD43-3; and the compatibility of the two water samples in the oil field is evaluated.

[0051] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. An oil and gas wellbore corrosion simulation evaluation system, characterized in that: The system comprises an oil casing evaluation module (1), a corrosion coupon module (2), a scaling evaluation module (3), an electrochemical corrosion probe module (4) and a double-layer circulation pipeline (6); the oil casing evaluation module (1), the corrosion coupon module (2), the scaling evaluation module (3) and the electrochemical corrosion probe module (4) are all connected to the double-layer circulation pipeline (6), and a circulating fluid is arranged inside the double-layer circulation pipeline (6); The oil casing evaluation module (1) is used for fluid erosion simulation of oil casing and oil casing internal coating; the corrosion coupon module (2) is used for dynamic erosion corrosion simulation of fluid; the scaling evaluation module (3) is used for scaling simulation of oil casing; the electrochemical corrosion probe module (4) is used for electrochemical corrosion simulation of oil casing; The oil casing evaluation module (1) comprises a horizontal oil casing (11) and a vertical oil casing (12), both ends of which are connected to the inner layer oil pipe valve of the double-layer circulation pipeline (6); The corrosion hanging sheet module (2) comprises an upper cover, a flange and a plurality of hanging sheet hanging rods; the upper cover is sealedly connected to an upper cover hole opened on a double-layer circulation pipeline (6) through the flange; the plurality of hanging sheet hanging rods are all located inside the double-layer circulation pipeline (6) and one end of the hanging sheet hanging rods is connected to a surface of one side of the upper cover; a plurality of corrosion hanging sheets are arranged on the hanging sheet hanging rods; The scaling evaluation module (3) comprises an anion and cation tank (31), a scaling ion solution tank (32), an injection pump (33), a thermostat (34), a waste liquid pool (35), a capillary scale inhibitor tester and two differential pressure sensors; one end of the scaling ion solution tank (32) is connected to the anion and cation tank (31), and the other end is connected to the injection pump (33), the capillary scale inhibitor tester and the waste liquid pool (35) in sequence; the injection pump (33) is connected to the double-layer circulation pipeline (6); the capillary scale inhibitor tester is located inside the thermostat (34), and the two differential pressure sensors are respectively connected to the two ends of the capillary scale inhibitor tester; The scaling evaluation module (3) further comprises a flow meter, a back pressure valve and a pH probe; the flow meter and the back pressure valve are both arranged on the pipeline between the injection pump (33) and the double-layer circulation pipeline (6); the pH probe is sealed and inserted into the inner layer of the oil pipe; The electrochemical corrosion probe module (4) comprises a plurality of probes, each of which is threadedly connected to the double-layer circulation pipeline (6) and has one end extending into the interior of the double-layer circulation pipeline (6); It also includes a data acquisition control module (5), which is connected to the corrosion coupon module (2), the scaling evaluation module (3) and the electrochemical corrosion probe module (4); and is used to collect the coupon weight of the corrosion coupon module (2), the scaling amount of the scaling evaluation module (3), and the electrochemical test potential of the electrochemical corrosion probe module (4); The double-layer circulation pipeline (6) comprises a liquid storage tank (61), a circulation pump (62), an outer casing and an inner oil pipe; One end of the inner oil pipe is connected to the inlet of the liquid storage tank (61), and the other end is connected to the outlet of the liquid storage tank (61). A circulation pump (62) is arranged on the inner oil pipe to drive the fluid to circulate in the inner oil pipe. The outer casing is sleeved on the outside of the inner oil pipe, and a flexible heating sleeve is sleeved on the outside of the outer casing. The oil casing evaluation module (1), the corrosion hanging plate module (2), the scaling evaluation module (3) and the electrochemical corrosion probe module (4) are all connected to the inner oil pipe.

2. The oil and gas wellbore corrosion simulation evaluation system according to claim 1, characterized in that: The outer casing is a fully transparent PC tube, and a plurality of windows are provided on the outer casing.

3. The oil and gas wellbore corrosion simulation evaluation system according to claim 1, characterized in that: It also includes a centralizer, one end of which is connected to the outer wall of the inner oil pipe and the other end is connected to the inner wall of the outer casing, so as to place the inner oil pipe on the central axis of the outer casing.

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