A sandstone gas reservoir annulus leakage monitoring system
By applying gradient distribution marking coatings in the casing joint area of the injection well of the sandstone gas reservoir, combined with the detachable filter and sampling pump device, the precise positioning of the leakage point is achieved, and the existing technology is solved The long time and high cost of monitoring of Central Sky leakage ensure the continuity of injection and procurement operations.
Patent Information
- Application Number
- CN202311850302.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-29
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2043-12-29
AI Technical Summary
The existing technology is difficult to effectively monitor the annular leakage of underground gas storage injection and mining wells, especially in sandstone gas reservoirs. Traditional methods such as gamma logging and scanning electromagnetic flaw detection logging are long and costly, which affects the injection and mining operation. continuity.
The identification coating is used to coat the casing in series area, the coating density is smaller than the annular protective liquid, and the leakage point is located through the gradient distributed particulate matter or color identification elements, and the detachable filter and sampling pump device capture the fallen identification coating. , realize accurate positioning of leakage location without affecting the continuity of injection and procurement operations.
It realizes low-cost and rapid monitoring and positioning of the annular leakage of the sandstone gas reservoir gas reservoir, avoids interference with the injection and procurement operations by traditional methods, and improves the detection efficiency and accuracy of the leakage point.
Smart Images
Figure CN118088162B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of annular pressure monitoring of injection and production wells in underground natural gas storage reservoirs, and in particular to an annular leakage monitoring system for sandstone gas reservoir gas storage reservoirs. Background Art
[0002] An underground gas storage is a gas storage facility that compresses natural gas and injects it into depleted gas (oil) reservoirs, underground salt caverns or other geological structures for storage, and then extracts it during the peak consumption period to meet the market demand for natural gas. A gas storage can solve the monthly, daily and hourly unevenness between natural gas supply and demand, and can also ensure uninterrupted gas supply when the gas source is interrupted or a technical failure occurs in the pipeline network.
[0003] As the construction of gas storage facilities develops rapidly, how to scientifically control operational risks and ensure the safe operation of gas storage facilities has also attracted increasing attention from the industry. Taking depleted oil and gas reservoir-type gas storage facilities as an example, during the periodic and large-volume throughput of injection and production wells, due to the influence of factors such as alternating loads, temperature and pressure changes, and corrosive media, the integrity of cement rings, casings, and completion pipe strings may fail, which is also the weakest unit among the various subsystems of the gas storage facility. Relevant data show that injection and production well accidents account for about 31% of all accidents in gas storage facilities. The main type of accident is gas leakage, and annular pressure is a common production problem in injection and production wells.
[0004] During the production process of natural gas cyclic injection and production, the wellbore temperature, gas internal pressure, operating pressure and ground stress field will change alternately. The tubing string is subjected to alternating pressure and temperature loads. The service conditions of the well casing cement ring are complex, which may cause continuous pressure in the annulus and even lead to problems such as integrity failure and gas leakage.
[0005] Determining the annular leakage point is the basic work for evaluating and solving the annular pressure. However, the annular depth is large, and the use of gamma logging and scanning electromagnetic flaw detection logging takes a long time and is expensive, and also affects the continuity of injection and production operations. Summary of the invention
[0006] The technical problem to be solved by the present invention is to provide a sandstone gas reservoir annulus leakage monitoring system for the above-mentioned technical deficiencies, which can monitor the leakage points of the casing string in the vertical direction and locate the leakage position of the casing string through identification elements, without affecting the continuity of the injection and production operations and with low cost.
[0007] The technical solution adopted by the present invention is: to provide a sandstone gas reservoir gas storage annulus leakage monitoring system, which is used for annulus leakage monitoring of underground gas storage injection and production wells. The underground gas storage injection and production wells include injection and production pipes and casings arranged outside the injection and production pipes. The annular space between the injection and production pipes and the casing is called annulus, and the annulus is filled with annulus protection liquid; it includes:
[0008] The marking coating for annular leakage is constructed to mark the location of the annular leakage; the marking coating is distributed and coated on the A series connection areas between the casings, and the coating of the marking coating on each A series connection area is distributed in a gradient from top to bottom in the vertical direction containing marking elements; the density of the marking coating is less than the density of the annular protection fluid;
[0009] The sampling device is constructed to obtain the marking coating that falls off and floats to the top of the annulus due to annulus leakage by collecting the annulus liquid at the top of the annulus; the collecting device includes a liquid outlet pipe connected to the annulus, and the liquid outlet pipe is connected to the input end of the sampling pump; the output end of the sampling pump is connected to the liquid inlet pipe, and a detachable filter net is provided in the liquid inlet pipe for filtering and collecting the marking coating that has fallen off.
[0010] As a preferred technical solution, the marking element is a marking coating whose particle size is distributed in a gradient from top to bottom in the vertical direction.
[0011] As a preferred technical solution, the identification element is a different distribution of the color of particles of the identification coating from top to bottom in the vertical direction.
[0012] As a preferred technical solution, the marking coating is also distributed and coated on the B series connection areas between the injection and production pipes, and the marking coating on each B series connection area is distributed in a gradient from top to bottom in the vertical direction containing marking elements.
[0013] As a preferred technical solution, the lower end of the annulus is sealed by a packer arranged between the casing and the injection and production pipe; the identification coating is also coated on the connection area between the packer and the casing, and the packer and the casing.
[0014] As a preferred technical solution, the liquid outlet pipeline is provided with a hydraulic gauge in parallel between the upstream and downstream pipelines of the detachable filter screen.
[0015] As a preferred technical solution, a switch valve is installed on the liquid inlet pipeline and the liquid outlet pipeline respectively; the opening and closing of the two switch valves are linked.
[0016] The technical solution adopted by the present invention is that when a leak occurs in the casing series connection area, the inflowing airflow causes the marking coating at the corresponding position to fall off, and the falling marking coating floats to the top of the annulus in the annulus liquid and is captured by the detachable filter of the sampling device. By detecting the marking elements of the captured marking coating, the position of the casing series connection area at the corresponding depth can be obtained according to the corresponding relationship between the gradient distribution and the corresponding depth. The entire monitoring process does not use a ray source or an electromagnetic flaw detection device to penetrate into the annulus, and does not affect the continuity of the injection and production work.
[0017] Other technical effects of the present invention will be clearly explained in the development of some embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a structural schematic diagram of the present invention;
[0019] In the figure, 1. injection and production pipe; 2. casing; 3. annulus; 4. identification coating; 5. A series connection area; 6. liquid outlet pipeline; 7. sampling pump; 8. liquid outlet pipeline; 9. removable filter screen; 10. B series connection area; 11. packer; 12. hydraulic gauge; 13. switch valve. DETAILED DESCRIPTION
[0020] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods. For the sake of simplicity, the "casing 2 string" in the specification refers to a casing 2 assembly formed by connecting multiple sections of casing 2 in series.
[0021] like Figure 1 As shown, a sandstone gas reservoir gas storage annulus leakage monitoring system is used for annulus 3 leakage monitoring of underground gas storage injection and production wells, wherein the underground gas storage injection and production wells include an injection and production pipe 1 and a casing 2 arranged outside the injection and production pipe 1, and the annular space between the injection and production pipe 1 and the casing 2 is called annulus 3; the annulus 3 is filled with annulus protection fluid; it includes an annulus 3 leakage identification coating 4, which is constructed to identify the location of the annulus 3 leakage; the identification coating 4 is distributed and coated on the A series connection areas 5 between the casings 2, and the coating of the identification coating 4 on each A series connection area 5 is distributed in a gradient distribution containing identification elements from top to bottom in the vertical direction; the density of the identification coating 4 is less than the density of the annulus protection fluid;
[0022] The sampling device is constructed to obtain the marking coating 4 that falls off and floats to the top of the annulus 3 due to leakage of the annulus 3 by collecting the annulus liquid at the top of the annulus 3; the collecting device includes a liquid outlet pipe 6 connected to the annulus 3, and the liquid outlet pipe 6 is connected to the input end of the sampling pump 7; the output end of the sampling pump 7 is connected to the liquid inlet pipe 8, and a detachable filter net 9 is provided in the pipeline of the liquid inlet pipe 8 for filtering and collecting the marking coating 4 that has fallen off.
[0023] The "element" in the "identification element" in this embodiment does not refer to a material element in the chemical concept, but rather to an identification component that constitutes monitoring. For example, the identification coating 4 is generally formed by mixing an adhesive with particulate matter, and the particle size, color, or combination of particle size or color of the particulate matter can be used as an identification element. By detecting the identification element of the identification coating 4 captured by the detachable filter 9, the gradient distribution of the corresponding identification coating 4 is determined, and the leakage position of the corresponding serial connection area of the sleeve 2 is determined.
[0024] As a preferred technical solution of the above embodiment, the marking element is a marking coating 4 whose particle size is distributed in a gradient from top to bottom in the vertical direction. In the specific construction process, the marking coatings 4 with different particle sizes should be numbered one by one with the corresponding sleeves 2. The particles can be selected from foamed silica particles with different particle sizes. In the production process, the foamed silica particles can also be mixed with fluorescent masterbatches. The marking coating 4 can be made of a mixture of heat-resistant epoxy glue and foamed silica particles.
[0025] As a preferred technical solution of the above embodiment, the marking element is the different distribution of the color of the particles of the marking coating 4 from top to bottom in the vertical direction. The particles of different colors can be achieved by the different colors of the masterbatch particles during production. The marking coatings 4 of the particles of different colors should correspond to the corresponding sleeves 2 one by one. In addition, a gradient distribution method of color and particle size composite can also be adopted, which can reduce the detection accuracy of the two elements.
[0026] As a preferred technical solution of the above embodiment, the marking coating 4 is also distributed and coated on the B series connection areas between the injection and production pipes 1. The marking coating 4 is coated on each B series connection area in a vertical direction from top to bottom with a gradient distribution containing marking elements. Using the same technical means, the marking coating 4 can also realize the monitoring and location of the injection and production pipe 1 leaking outward.
[0027] As a preferred technical solution of the above embodiment, the lower end of the annulus 3 is sealed by a packer 11 disposed between the casing 2 and the injection and production pipe 1; the marking coating 4 is also coated on the connection area between the packer 11 and the casing 2, and the packer 11 and the casing 2. Using the same technical means, the marking coating 4 can also realize the monitoring of the inward leakage of the packer 11.
[0028] As a preferred technical solution of the above embodiment, a hydraulic gauge 12 is provided in parallel in the liquid outlet pipe 6 between the upstream and downstream pipes of the removable filter screen 9. The hydraulic gauge 12 can display the pressure difference caused by the blockage of the removable filter screen 9. The capture amount of the marking coating 4 by the removable filter screen 9 can be judged by the pressure difference, which can be used as an evaluation indicator of the leakage of the annulus 3 or the pressure of the annulus 3.
[0029] As a preferred technical solution of the above embodiment, a switch valve 13 is respectively installed on the liquid inlet pipeline and the liquid outlet pipeline; the opening and closing of the two switch valves 13 are linked; when the detachable filter screen 9 is removed, the two switch valves 13 can be closed to prevent the annulus protection liquid from leaking from the pipeline due to the pressure of the annulus 3; in addition, it can also serve as an emergency closing valve when the liquid outlet pipeline 6, the liquid inlet pipeline 8, the detachable filter screen 9, and the sampling pump 7 leak.
[0030] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0031] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.
Claims
1. A sandstone gas reservoir gas storage annulus leakage monitoring system, used for annulus leakage monitoring of underground gas storage injection and production wells, wherein the underground gas storage injection and production wells include an injection and production pipe and a casing arranged outside the injection and production pipe, and the annular space between the injection and production pipe and the casing is called an annulus, and the annulus is filled with an annulus protection liquid; characterized in that: include The marking coating for annular leakage is constructed to mark the location of the annular leakage; the marking coating is distributed and coated on the A series connection areas between the casings; the marking coating is coated on each A series connection area and is distributed in a gradient from top to bottom in the vertical direction containing marking elements; the density of the marking coating is less than the density of the annular protection fluid; The sampling device is constructed to obtain the marking coating that falls off and floats to the top of the annulus due to annular leakage by collecting the annular fluid at the top of the annulus; the sampling device comprises a liquid outlet pipeline connected to the annulus, the liquid outlet pipeline is connected to the input end of the sampling pump; the output end of the sampling pump is connected to the liquid inlet pipeline, and a detachable filter screen for filtering and collecting the fallen marking coating is arranged in the pipeline of the liquid inlet pipeline; The identification coating is formed by mixing an adhesive and particulate matter, wherein the particle size, color or a combination of the particle size and color of the particulate matter serves as an identification element, and is gradient distributed according to the change in the particle size and color of the particulate matter; by detecting the identification elements of the identification coating captured by the detachable filter, the gradient distribution of the corresponding identification coating is corresponding to the determination of the leakage position of the corresponding casing series connection area.
2. The annular space leakage monitoring system for a sandstone gas reservoir according to claim 1 is characterized in that: The marking element is a particle size gradient distribution of particles of the marking coating from top to bottom in the vertical direction.
3. A sandstone gas reservoir annulus leakage monitoring system according to claim 1 or 2, characterized in that: The marking element is the different distribution of the color of the particles of the marking coating from top to bottom in the vertical direction.
4. The annular space leakage monitoring system for a sandstone gas reservoir according to claim 3 is characterized in that: The marking coating is also distributed and coated on the B series connection areas between the injection and production pipes; the marking coating is coated on each B series connection area and is distributed in a gradient from top to bottom in the vertical direction containing marking elements.
5. The annular space leakage monitoring system for a sandstone gas reservoir according to claim 4 is characterized in that: The lower end of the annulus is sealed by a packer arranged between the casing and the injection and production pipe; the marking coating is also coated on the connection area between the packer and the casing, and between the packer and the casing.
6. The sandstone gas reservoir annulus leakage monitoring system according to claim 1, characterized in that: The liquid outlet pipeline is provided with a hydraulic gauge in parallel between the upstream and downstream pipelines of the detachable filter screen.
7. The sandstone gas reservoir annulus leakage monitoring system according to claim 1, characterized in that: A switch valve is installed on the liquid inlet pipe and the liquid outlet pipe respectively; the opening and closing of the two switch valves are linked.