Completion material integrity testing system and method of testing

Abstract

The present application relates to the technical fields of completion material sealing test, in particular to a kind of completion material sealing test system and determination method thereof, including several gas cylinders filled with different gases, gas proportioner, mixed gas bottle for buffering and storing mixed gas, compressor, sealing test container and gas chromatograph, several gas cylinders are communicated with the input end of gas proportioner, the output end of gas proportioner is communicated with mixed gas bottle, the input end of mixed gas bottle is communicated with compressor, sealing test container is equipped with packer for testing, when using, the main storage gas of current salt cavern is compressed air or natural gas, its escape coefficient is lower, if salt cavern is used as hydrogen storage or hydrogen-doped natural gas storage, the sealing property of salt cavern needs to be especially concerned, the method provides a method for determining the sealing property of completion material in advance on the ground, provides a sealing property determination method for hydrogen storage or hydrogen-doped natural gas material of salt cavern.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sealing test of completion materials, in particular to a sealing test system of completion materials and a sealing test method thereof. BACKGROUND

[0002] Before starting the water-soluble cavity, it is necessary to test the integrity of the wellbore and production casing, and the purpose of the test is to test the sealing of the well under the expected maximum brine pressure (gas storage pressure) during cavity formation. If it is a liquid cushion, a water pressure test will be performed on the borehole, and if it is a gas cushion, a gas tightness test will be performed.

[0003] The gas tightness test is performed after the cavity formation and before the gas injection, and the technical sealing of the production string casing shoe needs to be tested, especially the exposed contact part between the steel, cement and salt. If the maximum gas storage pressure is higher than the test pressure before the cavity formation, the sealing test of the production casing should also be performed. Generally, the sealing test can only be tested after completion, and the cement steel is selected based on experience and summary, and is mainly aimed at pure natural gas salt cave storage. At present, there is no sealing research on natural gas mixed with hydrogen or salt cave hydrogen storage in China, so there is no better ground test method for sealing of natural gas mixed with hydrogen or salt cave hydrogen storage related completion materials. SUMMARY

[0004] The technical problem to be solved by the present application is that the existing sealing test can only be tested after completion, and the cement steel is selected based on experience and summary, and is mainly aimed at pure natural gas salt cave storage. At present, there is no sealing research on natural gas mixed with hydrogen or salt cave hydrogen storage in China. To solve the above problems, the present application provides a sealing test system of completion materials and a sealing test method thereof.

[0005] The technical solution adopted by the present application to solve the technical problem is: a sealing test system of completion materials, comprising a plurality of gas cylinders containing different gases, a gas proportioner, a mixed gas cylinder for buffering and storing mixed gas, a compressor, a sealing test container and a gas chromatograph. The plurality of gas cylinders are in communication with the input end of the gas proportioner, the output end of the gas proportioner is in communication with the mixed gas cylinder, the mixed gas cylinder is in communication with the input end of the compressor, the sealing test container is provided with a packer for testing, the packer divides the sealing test container into two upper and lower cavities, the output end of the compressor is in communication with the lower cavity of the sealing test container, and the upper cavity of the sealing test container is in communication with the gas chromatograph.

[0006] Preferably, some embodiments further comprise a buffer tank for storing mixed gas at a certain pressure, and the buffer tank is located between the compressor and the sealing test container.

[0007] Preferably, in some embodiments, valves are arranged on the pipelines between the gas cylinders and the gas proportioner, between the gas proportioner and the mixing cylinder, between the mixing cylinder and the compressor, between the compressor and the buffer tank, between the buffer tank and the sealed test container, and between the sealed test container and the gas chromatograph.

[0008] Preferably, in some embodiments, a first branch pipe is arranged on the mixing cylinder and communicates with the outside, and a second branch pipe is arranged on both ends of the sealed test container and communicates with the upper cavity and the lower cavity, and valves are arranged on the first branch pipe and the second branch pipe.

[0009] Preferably, in some embodiments, safety valves are arranged on the buffer tank and the sealed test container.

[0010] Preferably, in some embodiments, the sealed test container comprises an outer pipe body, an upper flange cover and a lower flange cover, and the upper flange cover and the lower flange cover are respectively detachably installed on both ends of the outer pipe body.

[0011] A sealing test method using the sealing test system as described above, comprising the following steps:

[0012] S1, using the gas proportioner to proportionally mix the gases in the gas cylinders to obtain mixed gas and store the mixed gas in the mixing cylinder;

[0013] S2, using the compressor to pressurize the mixed gas in the mixing cylinder and charge the mixed gas into the buffer tank;

[0014] S3, using the pressurized mixed gas in the buffer tank to deliver the mixed gas to the sealed test container and perform a sealing test on the sample;

[0015] S4, detecting the sealed test container using the gas chromatograph and determining the sealing property.

[0016] Preferably, in some embodiments, before step S1, the valves on the first branch pipe and the second branch pipe are opened and vacuumized, the air inside the mixing cylinder, the buffer tank and the sealed test container is discharged, then the mixing cylinder and the buffer tank are charged with methane, hydrogen or a mixture of methane and hydrogen, the upper cavity of the sealed test container is charged with inert gas, and the mixing cylinder, the buffer tank and the upper cavity of the sealed test container are vacuumized again.

[0017] Preferably, in some embodiments, the sample processing step in step S3 is as follows:

[0018] S3.1, first seal the upper end of the inner pipe of the packer with a sealing flange, then seal the lower end of the inner pipe of the packer with an inner flange cover, then place the packer in the outer pipe body of the sealing test container, inject pressurized air into the inner flange cover of the packer for pressurization, and the packer expands and tightens to seal and fix the inner pipe with the outer pipe body;

[0019] S3.2, remove the sealing flange at the upper end of the inner pipe of the packer and the inner flange cover at the lower end, then install the upper positioning flange and the lower positioning flange at the upper end and the lower end of the inner pipe of the packer respectively, then block the air vent at the bottom of the lower positioning flange with filter paper, and coat the inner wall of the inner sleeve in the middle of the lower positioning flange with sealing glue, then insert the salt core into the inner pipe through the hole in the middle of the upper positioning flange until it reaches the inner sleeve in the middle of the lower positioning flange;

[0020] S3.3, add the cementing cement from the hole in the middle of the upper positioning flange into the inner pipe and the middle of the salt core, and maintain for 36h;

[0021] S3.4, install the upper flange cover and the lower flange cover at the upper end and the lower end of the outer pipe body respectively, and complete the sample processing of the sealing test container.

[0022] In some preferred embodiments, the inert gas is nitrogen.

[0023] The sealing test system for well completion materials and the sealing test method thereof have the following beneficial effects: in use, the main gas stored in the salt cavern is compressed air or natural gas, and the escape coefficient is low, if the salt cavern is used for hydrogen storage or hydrogen-doped natural gas storage, the sealing property of the salt cavern needs to be particularly concerned, the method provides a method for determining the sealing property of the well completion materials in advance on the ground, and provides a sealing property determination method for hydrogen storage or hydrogen-doped natural gas materials in the salt cavern, the method determines a plurality of leakage points, including the sealing between the inner pipe of the packer and the outer pipe body, the sealing between the inner pipe and the concrete, and the sealing between the concrete and the salt layer, in the case of the concrete and the inner pipe, the sealing property of the packer to hydrogen can be determined, in the case of the inner pipe and the concrete, the sealing effect of the pipe to hydrogen can be evaluated, and in the case of the packer and the inner pipe, the sealing property of the concrete to hydrogen can be evaluated, and in the case of the well completion materials in the salt cavern, the gas permeation under different hydrogen-doped amounts and different pressures of natural gas can also be evaluated. BRIEF DESCRIPTION OF DRAWINGS

[0024] The application will be further described below with reference to the drawings and examples.

[0025] Figure 1 is a structural schematic diagram of the sealing test system for well completion materials;

[0026] Figure 2is the assembly flow chart of the sealing test section and the packer in the application;

[0027] Figure 3 is the top view of the sealing flange in the application;

[0028] Figure 4 is the front view of the lower positioning flange in the application;

[0029] Figure 5 is the left view of the lower positioning flange in the application;

[0030] Figure 6 is the top view of the lower positioning flange in the application;

[0031] Figure 7 is the front view of the upper positioning flange in the application;

[0032] Figure 8 is the left view of the upper positioning flange in the application;

[0033] Figure 9 is the top view of the upper positioning flange in the application.

[0034] In the figure: 1, methane steel cylinder; 2, hydrogen steel cylinder; 3, gas mixer; 4, mixed gas cylinder; 5, compressor; 6, buffer tank; 7, sealing test section; 8, gas chromatograph; 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, all are valves, 19, 20 are safety valves;

[0035] Wherein A, sealing flange; B, lower positioning flange; C, upper positioning flange. DETAILED DESCRIPTION

[0036] The application is further described below in combination with embodiments:

[0037] The application is not limited to the following specific embodiments, and the person skilled in the art can implement the application by using other various specific embodiments according to the content disclosed in the application, or any simple change or modification of the design structure and idea of the application falls within the protection scope of the application. It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other in the case of no conflict.

[0038] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to. Therefore, the features defined with "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, "a plurality of" means two or more, unless otherwise specified.

[0039] In the description of the present application, it needs to be understood that the terms "installation", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] Embodiment

[0041] As Figures 1-9 shown, a completion material sealing property testing system includes two gas cylinders 1, 2 filled with different gases, a gas proportioner 3, a mixed gas cylinder 4 for buffering and storing mixed gas, a compressor 5, a sealing test container 7, a gas chromatograph 8 and a buffer tank 6 for storing mixed gas at a certain pressure, one of the two gas cylinders 1, 2 is filled with hydrogen, and the other is filled with methane, both of the two gas cylinders 1, 2 are communicated with the input end of the gas proportioner 3, the output end of the gas proportioner 3 is communicated with the mixed gas cylinder 4, the mixed gas cylinder 4 is communicated with the input end of the compressor 5, the sealing test container 7 is filled with a packer for testing, the packer is fixed with the sealing test container 7 and divides the inside of the sealing test container 7 into two upper and lower cavities separated from each other, the buffer tank 6 is located between the compressor 5 and the sealing test container 7, in this embodiment, the compressor 5 can be but is not limited to a diaphragm compressor, a liquid-driven piston compressor or an ionic liquid compressor, the output end of the compressor 5 is communicated with the buffer tank 6, the buffer tank 6 is communicated with the lower cavity of the sealing test container 7, and the upper cavity of the sealing test container 7 is communicated with the gas chromatograph 8, in this embodiment, the gas chromatograph 8 uses a thermal conductivity detector as preferred, and in this embodiment, the sealing test container includes an outer pipe body, an upper flange cover and a lower flange cover, the upper flange cover and the lower flange cover are respectively detachably installed at the two ends of the outer pipe body.

[0042] Valves 9, 10, 11, 13, 14, 15, 18 are arranged on the pipelines between the two gas cylinders 1, 2 and the gas proportioner 3, between the gas proportioner 3 and the mixed gas cylinder 4, between the mixed gas cylinder 4 and the compressor 5, between the compressor 5 and the buffer tank 6, between the buffer tank 6 and the sealed test container 7, and between the sealed test container 7 and the gas chromatograph 8, a first branch pipe communicating with the outside is arranged on the mixed gas cylinder 4, second branch pipes communicating with the upper cavity and the lower cavity are arranged at both ends of the sealed test container 7, and valves 12, 16, 17 are arranged on the first branch pipe and the second branch pipes, and safety valves 19, 20 are arranged on the buffer tank 6 and the sealed test container 7.

[0043] The outer pipe body is made of casing production material, the inner pipe material is made of injection and production pipe material, the pipe diameter and flange cover can be adjusted according to the actual situation, the pipe diameter of the outer pipe body is 330 mm, the inner pipe diameter is 240 mm, metal gaskets are arranged between the inner pipe material and the sealing flange A, and metal gaskets are arranged at the sealing positions of the pipe material, because only metal gaskets can withstand high pressure of 20 Mpa. The length of the inner pipe material can be adjusted according to the measurement accuracy, and the length of the inner pipe material is preferably 100 cm.

[0044] The lower positioning flange B is provided with a through hole for facilitating the passage of gas, and a wave-shaped concrete fixing baffle is welded on the upper surface of the lower positioning flange B, the fixing baffle is provided with an internal sleeve for limiting the displacement of the salt core, and the internal sleeve is located in the inner circle of the lower positioning flange B, in the embodiment, the fixing baffle is preferably 220 mm-240 mm in diameter, and 19 mm-22 mm in thickness, wherein the internal sleeve is 110 mm-112 mm in diameter and 50 mm-60 mm in thickness, and the structure of the upper positioning flange C is similar to that of the lower positioning flange B, and the hole diameter in the middle of the upper positioning flange C is 110 mm-120 mm.

[0045] A measurement method using the well completion material sealing property measurement system as described above, comprising the following steps:

[0046] S1, using the gas proportioner 3 to proportionally mix the gases in the two gas cylinders 1, 2, hydrogen and methane are mixed in a proportion of 1:9 to prepare natural gas mixed with hydrogen containing 10% hydrogen by volume and stored in the mixed gas cylinder 4;

[0047] S2, the mixed gas in the mixed gas cylinder 4 is pressurized by the compressor 5 and charged into the buffer tank 6, and the pressure in the buffer tank is 21 Mpa;

[0048] S3, using the pressurized mixed gas in the buffer tank 6 to deliver to the sealed test container 7 and perform sealed test on the sample, and the test pressure is controlled to be 20 Mpa;

[0049] S4, respectively, after 24h and 72h again by gas chromatograph 8 on the sealed test container 7 and determine the sealing performance.

[0050] Before step S1, open the first branch and the second branch valve 12, 16, 17 and vacuum, the air inside the gas mixing bottle 4, buffer tank 6 and sealed test container 7 is discharged, and then the gas mixing bottle 4 and the buffer tank 6 is filled with methane, hydrogen or methane and hydrogen mixture, the upper cavity of the sealed test container 7 is filled with inert gas, and the gas mixing bottle 4, buffer tank 6 and upper cavity of the sealed test container 7 are vacuumized again.

[0051] The sample processing steps in step S3 in the sealed test container 7 are as follows:

[0052] S3.1, first, the inner layer pipe of the packer is sealed with the sealing flange A, and then the inner layer flange cover of the lower end of the inner layer pipe of the packer is sealed, and then the packer is placed in the outer pipe body of the sealed test container, and the inner layer flange cover of the packer is injected with pressurized air for pressurization, and the packer is expanded and tightened to seal and fix the inner layer pipe with the outer pipe body, and in this embodiment, the outer pipe body is N80 oil casing;

[0053] S3.2, the sealing flange A at the upper end of the inner layer pipe of the packer and the inner layer flange cover at the lower end are removed, and the upper positioning flange C and the lower positioning flange B are respectively installed at the upper end and the lower end of the inner layer pipe of the packer, and then the air vent at the bottom of the lower positioning flange B is blocked with filter paper, and the inner wall of the inner sleeve in the middle of the lower positioning flange B is coated with sealing glue, and then the salt core is inserted into the inner layer pipe through the hole in the middle of the upper positioning flange C until it reaches the inner sleeve in the middle of the lower positioning flange B;

[0054] S3.3, the cement is added into the inner layer pipe and the salt core through the hole in the middle of the upper positioning flange C, and is maintained for 36h;

[0055] S3.4, the upper flange cover and the lower flange cover are installed at the upper end and the lower end of the outer pipe body, and the sample processing of the sealed test container is completed.

[0056] The upper cavity of the sealed test container 7 is first vacuumized before detection, and then nitrogen is filled into the upper cavity, and after several times of filling nitrogen and vacuumizing, nitrogen is filled into the upper cavity with a pressure greater than atmospheric pressure, preferably 150Kpa-200Kpa, and in this embodiment, the inert gas can be but is not limited to nitrogen, helium and argon, and the inert gas in this embodiment is pure gas, and the purity requirement is 99.99-99.999%.

[0057] The sealing test system and the sealing test method thereof are used as follows: the outlet of the gas cylinder 1 containing methane and the outlet of the gas cylinder 2 containing hydrogen are opened, the mixing ratio of the gas mixer 3 is started and adjusted, the valves 9, 10 and 11 are opened, the compressor 5 is started after the pressure in the mixing cylinder 4 is between 0.5-1Mpa, the valve 14 is opened in advance, the valve 13 is slowly started, the initial opening degree of the valve 13 is not too high, and the opening degree of the valve 13 is preferably 5%-10%, the valve 13 is opened while the vent valve of the compressor 5 is slowly closed, the valve 13 is continuously opened slowly after the compressor 5 is started and stabilized, the vent valve of the compressor 5 is closed, the valve 15 is opened after the pressure in the buffer tank 6 is higher than 10Mpa, the valves 14 and 15 are closed after the pressure in the buffer tank 6 is higher than 21Mpa, the gas cylinder 1 containing methane, the gas cylinder 2 containing hydrogen, the valve 9, the valve 10, the gas mixer 3 and the valve 11 are closed in sequence, the compressor 5 is stopped, the inlet valve 13 is slowly closed, the vent valve of the compressor 5 is slowly opened, the valve 13 of the inlet of the compressor 5 is closed after the pressure is stabilized, the vent valve of the compressor 5 is fully opened and the compressor 5 is closed, the lower pressure gauge is observed, the valve 15 is opened and closed in time to control the pressure in the lower cavity of the sealing test container 7 to be stabilized at the test pressure, the test pressure in the lower cavity is preferably 20Mpa, the upper end pressure of the sealing test container 7 is obviously increased, or after the test is completed, the valve 18 is opened, the gas composition and content of the leakage are accurately obtained through the gas chromatograph 8, and the rate of the leakage gas is quantitatively obtained in combination with the pressure and the time.

[0058] The above-mentioned ideal embodiments according to the present application are for illustration, and related personnel can make various changes and modifications without departing from the technical idea of the present application. The technical scope of the present application is not limited to the content in the specification, and must be determined according to the scope of claims.

Claims

1. A completion material integrity determination system, characterized by: The device comprises several gas cylinders filled with different gases, a gas proportioner (3), a mixed gas cylinder (4) for buffering and storing mixed gas, a compressor (5), a sealed test container (7) and a gas chromatograph (8). The gas cylinders are in communication with the input end of the gas proportioner (3), the output end of the gas proportioner (3) is in communication with the mixed gas cylinder (4), the mixed gas cylinder (4) is in communication with the input end of the compressor (5), the sealed test container (7) is internally provided with a packer for testing, the packer divides the sealed test container (7) into two upper and lower cavities, the output end of the compressor (5) is in communication with the lower cavity of the sealed test container (7), and the upper cavity of the sealed test container (7) is in communication with the gas chromatograph (8). The device further comprises a buffer tank (6) for storing mixed gas under pressure, which is located between the compressor (5) and the sealed test container (7). Valves are arranged on the pipelines between each of the gas cylinders and the gas proportioner (3), between the gas proportioner (3) and the mixed gas cylinder (4), between the mixed gas cylinder (4) and the compressor (5), between the compressor (5) and the buffer tank (6), between the buffer tank (6) and the sealed test container (7), and between the sealed test container (7) and the gas chromatograph (8). The mixed gas cylinder (4) is provided with a first branch pipe in communication with the outside, and the sealed test container (7) is provided with second branch pipes at both ends, the second branch pipe at the upper end is in communication with the upper cavity, and the second branch pipe at the lower end is in communication with the lower cavity. Valves are arranged on the first branch pipe and the second branch pipes.

2. The completion material integrity determination system of claim 1, wherein: Safety valves are arranged on the buffer tank (6) and the sealed test container (7).

3. The completion material integrity determination system of claim 1, wherein: The sealed test container comprises an outer pipe body, an upper flange cover and a lower flange cover, which are respectively detachably installed at both ends of the outer pipe body.

4. A method of testing the tightness of a well completion material using the system according to any one of claims 1 to 3, characterized in that, The device comprises the following steps: S1. The gas in each of the gas cylinders is mixed by the gas proportioner (3) to obtain mixed gas, which is stored in the mixed gas cylinder (4); S2. The mixed gas in the mixed gas cylinder (4) is pressurized by the compressor (5) and charged into the buffer tank (6); S3. The mixed gas pressurized in the buffer tank (6) is delivered to the sealed test container (7) for sealed testing of a sample; S4. The sealed test container (7) is detected by the gas chromatograph (8) to determine the sealing property.

5. The assay method according to claim 4, characterized in that: Before step S1, the valves on the first branch pipe and the second branch pipes are opened and vacuumized, the air in the mixed gas cylinder (4), the buffer tank (6) and the sealed test container (7) is discharged, then the mixed gas cylinder (4) and the buffer tank (6) are charged with methane, hydrogen or mixed gas of methane and hydrogen, and the upper cavity of the sealed test container (7) is charged with inert gas. The mixed gas cylinder (4), the buffer tank (6) and the upper cavity of the sealed test container (7) are vacuumized again.

6. The assay method according to claim 4 or 5, characterized in that, The sample in the sealed test container (7) in step S3 is processed as follows: S3.1, first seal the upper end of the inner layer pipe of the packer with a sealing flange (A), then seal the lower end of the inner layer pipe of the packer with an inner layer flange cover, then place the packer in the outer pipe body of the sealing test container, inject pressurized air into the inner layer flange cover of the packer for pressurization, and the packer expands and tightens to seal and fix the inner layer pipe and the outer pipe body; S3.2, remove the sealing flange (A) at the upper end and the inner layer flange cover at the lower end of the inner layer pipe of the packer, install the upper positioning flange (C) and the lower positioning flange (B) at the upper end and the lower end of the inner layer pipe of the packer respectively, then block the air vent at the bottom of the lower positioning flange (B) with filter paper, smear sealant on the inner wall of the inner sleeve in the middle of the lower positioning flange (B), then insert the salt core into the inner layer pipe from the hole in the middle of the upper positioning flange (C) until it reaches the inner sleeve in the middle of the lower positioning flange (B); S3.3, add the cement from the hole in the middle of the upper positioning flange (C) into the inner layer pipe and the middle of the salt core, and maintain for 36 hours; S3.4, install the upper flange cover and the lower flange cover corresponding to the upper end and the lower end of the outer pipe body, and complete the sample treatment of the sealing test container.

7. The assay method of claim 5, wherein: The inert gas is nitrogen.

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