High-temperature and high-pressure phase equilibrium corrosion evaluation device and method

Abstract

The invention belongs to the technical field of phase equilibrium measurement, and discloses a high-temperature and high-pressure phase equilibrium corrosion evaluation device and method. Comprising a gas booster pump, a gas storage tank, a reaction kettle, a sampling container and a detection pipe. Through the device and the method, phase equilibrium simulation experiment analysis and evaluation under high temperature and high pressure can be carried out, and the device and the method are used for carrying out research on different corrosion relationships, deeply understanding research on corrosion mechanisms, guiding independent research and development and performance evaluation of medicaments and optimizing optimal concentration of medicaments added in a mine field; the corrosion evaluation precision is improved, the ion change condition in the experiment process is determined, the underground corrosion environment is simulated, and the corrosion condition of each underground key component is accurately reflected.

Description

Technical Field

[0001] The invention belongs to the technical field of phase equilibrium determination, and in particular relates to a high-temperature and high-pressure phase equilibrium corrosion evaluation device and method. Background Art

[0002] The oil recovery process is divided into three stages: primary oil recovery, secondary oil recovery and tertiary oil recovery. Both primary and secondary oil recovery are physical methods, which can usually recover 30%-40% of crude oil; the commonly used methods of tertiary oil recovery are gas drive, chemical drive, microbial drive and heat recovery; gas drive is an important means to improve the recovery rate, and how to quickly and accurately simulate the corrosion of gas on the wellbore through indoor experiments has become a research focus.

[0003] Gas drive is one of the important technologies to improve oil recovery. CO2 or air is prone to corrosion when in contact with water, which restricts the safe production of gas drive. Therefore, it is urgent to develop a high-temperature and high-pressure phase equilibrium corrosion evaluation device to meet the needs of corrosion reaction analysis under different temperatures and pressures, which can provide technical support for the large-scale application of gas drive technology. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a high-temperature and high-pressure phase equilibrium corrosion evaluation device and method, which can quickly and accurately analyze the wellbore corrosion situation through indoor experiments, and can provide technical support for the large-scale application of gas drive technology.

[0005] The above-mentioned object of the present invention is achieved through the following technical scheme: a high-temperature and high-pressure phase equilibrium corrosion evaluation device, including a gas booster pump, a gas storage tank, a reactor, a sampling container and a detection tube.

[0006] The output end of the gas booster pump is connected in parallel to the output end of the gas storage tank through a pipeline, and the input end of the gas booster pump is connected to a silent air compressor; a pressure regulator is arranged on the output end of the gas storage tank, and the output end of the pressure regulator is connected to the reactor; carbon dioxide gas is arranged in the gas storage tank, and the carbon dioxide gas is put into the reactor through the pressure regulator;

[0007] The reactor comprises a reactor body, a drilling motor and an electric pressure pump; a reaction chamber is arranged in the reactor body, and a sealing cover is arranged at the top; a drilling motor is installed on the sealing cover of the reactor; the side opening of the reactor is connected to the electric pressure pump, and the reactor body is pressurized by the electric pressure pump; an external heating jacket is wrapped on the outer contour of the reactor body, a discharge port is arranged at the bottom end of the reactor body, and an experimental solution, oil well pipe and experimental rock are arranged in the reaction chamber of the reactor body, and the oil well pipe is connected to the drilling motor;

[0008] The sampling container is a piston-type structure, and the sampling container is divided into a driving chamber and a liquid storage chamber by a piston; the liquid storage chamber of the sampling container is respectively connected with a sampling pipe and a detection pipe; the other end of the sampling pipe is connected to the discharge port of the reactor body; the other end of the detection pipe is connected to the detection tube; the driving chamber of the sampling container is connected to the reactor body through a back-pressure pipe, and a back-pressure valve and a buffer container are arranged on the back-pressure pipe, and a manual pump is arranged on the pipe between the buffer container and the driving chamber of the sampling container;

[0009] The detection tube is provided with a carbonate ion probe, an oxygen atom probe and an iron ion probe.

[0010] Furthermore, an air discharge pipe is provided on the input end of the reactor body, and a liquid discharge pipe is provided at the discharge port at the output end of the reactor body.

[0011] A high temperature and high pressure phase equilibrium corrosion evaluation method, the steps are as follows:

[0012] S1: System detection: Release the gas in the gas tank to detect the air tightness of the pipeline formed by the reactor, sampling container and sampling tube;

[0013] S2: Adding raw materials: Put 3L of simulated water with a mineralization of 12000mg / L into the reactor body, and add 50ml of corrosion inhibitor into the simulated water. At the same time, connect the output end of the drilling motor on the reactor body with an N80 oil well pipe segment or a P100 oil well pipe segment. The simulated water and corrosion inhibitor are hidden in the experimental rock.

[0014] S3: Test process: The reactor body is heated by the heating sleeve on the outside of the reactor body, and the heating temperature is maintained at a constant temperature of 95°C; the reactor body is pressurized by an electric pressure pump to meet the pressure in the reactor body of 15MPa; the pressure regulator in the gas storage tank is opened to release the carbon dioxide gas in the gas tank, and the carbon dioxide gas is pumped into the reactor body by the gas booster pump, and at the same time, the drilling motor drives the N80 oil well pipe segment or the P100 oil well pipe segment at the output end to drill holes on the rock; the liquid hidden in the experimental rock is displaced by carbon dioxide into the sampling container, and finally the collected liquid is pumped into the detection tube through the sampling container, and the carbonate ion probe, oxygen atom probe and iron ion probe on the detection tube are used to detect the content of each ion in the liquid.

[0015] S4: Calculation of corrosion results: According to the content of each main ion in the test tube, the corrosion rate of the oil well pipe segment of N80 material or the corrosion rate of the oil well pipe segment of P100 material is calculated.

[0016] Furthermore, during the test in step S3, the sampling container is driven through a back pressure pipeline, with the carbon dioxide gas in the gas storage tank serving as a power source.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: through the present invention, phase equilibrium simulation experiment analysis and evaluation under high temperature and high pressure can be carried out, which can be used to carry out research on different corrosion relationships, deeply understand the research on corrosion mechanism, guide independent research and development of reagents and performance evaluation, and optimize the optimal concentration of dosing in mines; this patent improves the accuracy of corrosion evaluation, determines the changes in ions during the experiment, simulates the underground corrosion environment, and accurately reflects the corrosion conditions of various key components underground. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0019] Figure 1 It is a schematic structural diagram of a high-temperature and high-pressure phase equilibrium corrosion evaluation device of the present invention.

[0020] In the figure, 1. gas booster pump; 2. gas storage tank; 3. reactor; 4. sampling container; 5. detection tube; 6. pressure regulator; 7. buffer container; 8. silent air compressor; 9. manual pump; 31. reactor body; 32. drilling motor; 33. electric booster pump; 34. external heating jacket; 51. carbonate ion probe; 52. oxygen atom probe; 53. iron ion probe. DETAILED DESCRIPTION

[0021] 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.

[0022] 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.

[0023] Example 1

[0024] like Figure 1 A high-temperature and high-pressure phase equilibrium corrosion evaluation device shown includes a gas booster pump 1, a gas storage tank 2, a reactor 3, a sampling container 4 and a detection tube 5.

[0025] The output end of the gas booster pump 1 is connected in parallel to the output end of the gas storage tank 2 through a pipeline, and the input end of the gas booster pump 1 is connected to a silent air compressor 8; a pressure regulator 6 is arranged on the output end of the gas storage tank 2, and the output end of the pressure regulator 6 is connected to the reactor 3; carbon dioxide gas is arranged in the gas storage tank 2, and the carbon dioxide gas is put into the reactor 3 through the pressure regulator 6.

[0026] The reactor 3 includes a reactor body 31, a drilling motor 32 and an electric pressure pump 33; a reaction chamber is arranged in the reactor body 31, and a sealing cover is arranged at the top; the drilling motor 32 is installed on the sealing cover of the reactor 3; the side opening of the reactor 3 is connected to the electric pressure pump 33, and the reactor body 31 is pressurized by the electric pressure pump 33; the outer contour of the reactor body 31 is wrapped with an external heating sleeve 34, and the bottom end of the reactor body 31 is provided with a discharge port, and the reaction chamber of the reactor body 31 is provided with experimental solution, oil well pipe and experimental rock, and the oil well pipe is connected to the drilling motor 32.

[0027] The sampling container 4 is a piston structure, and the sampling container 4 is divided into a driving chamber and a liquid storage chamber by the piston; the liquid storage chamber of the sampling container 4 is respectively connected to a sampling pipe and a detection pipe; the other end of the sampling pipe is connected to the discharge port of the reactor body 31; the other end of the detection pipe is connected to the detection tube 5; the driving chamber of the sampling container 4 is connected to the reactor body 31 through a back-pressure pipe, and a back-pressure valve and a buffer container 7 are provided on the back-pressure pipe, and a manual pump 9 is provided on the pipe between the buffer container 7 and the driving chamber of the sampling container 4.

[0028] The detection tube 5 is provided with a carbonate ion probe 51 , an oxygen atom probe 52 and an iron ion probe 53 .

[0029] An air discharge pipe is arranged on the input end of the reactor body 31, and a liquid discharge pipe is arranged at the discharge port at the output end of the reactor body.

[0030] A high temperature and high pressure phase equilibrium corrosion evaluation method, the specific evaluation method is as follows:

[0031] S1: System detection: Release the gas in the gas tank to detect the air tightness of the pipeline formed by the reactor, sampling container and sampling tube.

[0032] S2: Add raw materials: put 3L of simulated water with a mineralization of 12000mg / L into the reactor body, and add 50ml of corrosion inhibitor into the simulated water. At the same time, connect the output end of the motor drilled on the reactor body with an N80 oil well pipe segment or a P100 oil well pipe segment. The simulated water and corrosion inhibitor are hidden in the experimental rock.

[0033] S3: Test process: The reactor body is heated by the heating jacket on the outside of the reactor body, and the heating temperature is maintained at a constant temperature of 95°C; the reactor body is pressurized by an electric heating pump to meet the pressure in the reactor body of 15MPa; the pressure regulator in the gas storage tank is opened to release the carbon dioxide gas in the gas tank, and the carbon dioxide gas is pumped into the reactor body by the gas booster pump, and at the same time, the drilling motor drives the N80 oil well pipe segment or the P100 oil well pipe segment at the output end to drill holes on the rock; the liquid hidden in the experimental rock is displaced by carbon dioxide into the sampling container, and finally the collected liquid is pumped into the sampling tube through the sampling container, and the carbonate ion probe, oxygen atom probe and iron ion probe on the sampling tube are used to detect the content of each ion in the liquid.

[0034] S4: Calculation of corrosion results: According to the content of each main ion in the sampling tube, the corrosion rate of the oil well pipe segment of N80 material or the corrosion rate of the oil well pipe segment of P100 material is calculated.

[0035] During the S3 test, the sampling container is driven through the back pressure pipeline, using the carbon dioxide gas in the gas tank as the power source.

[0036] Average corrosion rate mm / a N8O oil well pipe segment 0.053 P100 oil well pipe segment 0.048

[0037] The above table shows that the corrosion resistance of the oil well pipe segment made of P100 material is better and consistent with the parameters of the oil well pipe segment made of this material, which proves the rationality of the high temperature and high pressure phase equilibrium corrosion evaluation device, and can be used to provide evaluation devices and evaluation methods for the subsequent detection of oil well pipes made of other drilling materials.

[0038] The above-described embodiments are only preferred embodiments of the present invention, but not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A high temperature and high pressure phase equilibrium corrosion evaluation device, characterized in that: The invention comprises a gas booster pump (1), a gas storage tank (2), a reaction kettle (3), a sampling container (4) and a detection tube (5).

2. The high temperature and high pressure phase equilibrium corrosion evaluation device according to claim 1, characterized in that: The output end of the gas booster pump (1) is connected in parallel to the output end of the gas storage tank (2) through a pipeline, and the input end of the gas booster pump (1) is connected to a silent air compressor (8); a pressure regulator (6) is arranged on the output end of the gas storage tank (2), and the output end of the pressure regulator (6) is connected to the reactor (3); carbon dioxide gas is arranged in the gas storage tank (2), and the carbon dioxide gas is put into the reactor (3) through the pressure regulator (6).

3. The high temperature and high pressure phase equilibrium corrosion evaluation device according to claim 1, characterized in that: The reactor (3) comprises a reactor body (31), a drilling motor (32) and an electric pressure pump (33); a reaction chamber is arranged in the reactor body (31), and a sealing cover is arranged at the top; the drilling motor (32) is installed on the sealing cover of the reactor (3); the side opening of the reactor (3) is connected to the electric pressure pump (33), and the reactor body (31) is pressurized by the electric pressure pump (33); the outer contour of the reactor body (31) is wrapped with an external heating sleeve (34), and the bottom end of the reactor body (31) is provided with a discharge port, and the reaction chamber of the reactor body (31) is provided with an experimental solution, an oil well pipe and an experimental rock, and the oil well pipe is connected to the drilling motor (32).

4. The high temperature and high pressure phase equilibrium corrosion evaluation device according to claim 1, characterized in that: The sampling container (4) is a piston-type structure, and the sampling container (4) is divided into a driving chamber and a liquid storage chamber by a piston; the liquid storage chamber of the sampling container (4) is respectively connected to a sampling pipeline and a detection pipeline; the other end of the sampling pipeline is connected to the discharge port of the reaction kettle body (31); the other end of the detection pipeline is connected to the detection tube (5); the driving chamber of the sampling container (4) is connected to the reaction kettle body (31) through a back-pressure pipeline, and a back-pressure valve and a buffer container (7) are arranged on the back-pressure pipeline, and a manual pump (9) is arranged on the pipeline between the buffer container (7) and the driving chamber of the sampling container (4).

5. The high temperature and high pressure phase equilibrium corrosion evaluation device according to claim 1, characterized in that: The detection tube (5) is provided with a carbonate ion probe (51), an oxygen atom probe (52) and an iron ion probe (53).

6. The high temperature and high pressure phase equilibrium corrosion evaluation device according to claim 3, characterized in that: The input end of the reactor body (31) is provided with a degassing pipeline, and the discharge port at the output end of the reactor body (31) is provided with a liquid discharge pipeline.

7. A high temperature and high pressure phase equilibrium corrosion evaluation method, characterized in that: Here are the steps: S1: System detection: by releasing the gas in the gas storage tank (2), the air tightness of the pipeline formed by the reaction kettle (3), the sampling container (4) and the sampling tube is detected; S2: Adding raw materials: 3L of simulated water with a mineralization of 12000mg / L is placed in the reactor body (31), and 50ml of corrosion inhibitor is added to the simulated water. At the same time, an oil well pipe segment made of N80 material or an oil well pipe segment made of P100 material is connected to the output end of the drilling motor (32) on the reactor body (31). The simulated water and corrosion inhibitor are hidden in the experimental rock; S3: Test process: The reactor body (31) is heated by the heating sleeve on the outside of the reactor body (31), and the heating temperature is maintained at a constant temperature of 95°C; the reactor body (31) is pressurized by the electric pressure pump (33) to meet the pressure in the reactor body (31) of 15MPa; the pressure regulator (6) on the gas storage tank (2) is opened to release the carbon dioxide gas in the gas tank, and the carbon dioxide gas is pumped into the reactor body by the gas pressure pump (1) for pressure boosting, and at the same time, the drilling motor (32) drives the N80 oil well pipe segment or the P100 oil well pipe segment at the output end to drill a hole on the rock; the liquid hidden in the experimental rock is displaced by carbon dioxide into the sampling container (4), and finally the collected liquid is pumped into the detection tube (5) through the sampling container (4), and the carbonate ion probe (51), oxygen atom probe (52) and iron ion probe (53) on the detection tube (5) are used to detect the content of each ion in the liquid. S4: Calculation of corrosion results: Based on the contents of the main ions in the detection tube (5), the corrosion rate of the oil well pipe segment made of N80 material or the corrosion rate of the oil well pipe segment made of P100 material is calculated.

8. The high temperature and high pressure phase equilibrium corrosion evaluation method according to claim 7, characterized in that: During the test in step S3, the sampling container is driven via the back pressure pipeline, with the carbon dioxide gas in the gas storage tank (2) serving as a power source.

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