Integrated monitoring device for salt cavern gas storage

Abstract

The utility model relates to an integrated monitoring device for a salt-cavern gas storage and belongs to the field of salt-cavern gas storage monitoring. Comprising a monitoring mechanism, a well completion pipe string, a well sealing mechanism, a ground control cabinet, a sleeve and a cavity. The casing pipe is adaptively arranged on a well wall above the cavity, the well sealing mechanism is arranged at a well mouth at the top end of the casing pipe in a sealing manner, the monitoring mechanism and the well completion pipe string both penetrate through the well sealing mechanism and are arranged in the casing pipe, the monitoring mechanism is clamped on the well completion pipe string, and the well completion pipe string is arranged in the casing pipe. The ground control cabinet is arranged outside the casing pipe and connected with the monitoring mechanism and the well completion pipe string. The salt-cavern gas storage monitoring device is beneficial to monitoring the shaft temperature and the shaft bottom pressure of the salt-cavern gas storage in real time, timely discovers and deals with the stress fatigue and abrasion problems of a tubular column and a downhole tool, avoids the risk of integrity failure of a shaft and a cement sheath, and provides a technical means for long-acting safe production and operation of the salt-cavern gas storage.

Description

Technical Field

[0001] The utility model relates to the field of salt cavern gas storage monitoring, in particular to an integrated salt cavern gas storage monitoring device. Background Art

[0002] The production completion process of the salt cavern gas storage that has been built in China is to add gas production tubing to the production casing. Compared with oil and gas reservoir gas storage, the injection and production conversion of salt cavern gas storage is more frequent and flexible. The high-frequency and large-volume injection and production peak-shaving production leads to continuous changes in wellbore temperature and pressure and alternating stress. Under the condition of multi-cycle alternating stress changes, the integrity of the wellbore tubing and cement ring will be severely challenged. The thermodynamic effect of high-pressure natural gas injection and production at high speed leads to obvious heat exchange in the wellbore, and there is abnormal pressure in the annulus of the wellbore during gas production. It is necessary to grasp the temperature of the wellbore and the annulus in real time and evaluate the impact of thermal effects on the wellbore. The long-term production and operation of the gas storage, high-intensity and large-volume injection and production, leads to continuous changes in wellbore temperature and pressure and alternating stress, resulting in stress fatigue and wear of the tubing and downhole tools. In severe cases, it will lead to the risk of wellbore integrity failure, and the integrity of the wellbore needs to be monitored in real time.

[0003] Usually during the production process, the integrity of the wellbore and cement ring is regularly tested through logging methods. However, this regular testing method cannot detect corrosion and failure of the tubing and downhole tools in a timely manner, which poses a risk of natural gas leakage and is extremely costly. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide an integrated monitoring device for a salt cavern gas storage to solve the above-mentioned problem.

[0005] The utility model provides a technical solution to the above technical problems as follows: an integrated monitoring device for a salt cavern gas storage reservoir, comprising: a monitoring mechanism, a completion string, a sealing mechanism, a ground control cabinet, a casing and a cavity; the casing is adapted to be arranged on the well wall above the cavity, the sealing mechanism is sealingly arranged at the wellhead at the top of the casing, the monitoring mechanism and the completion string both pass through the sealing mechanism and are arranged in the casing, the monitoring mechanism is clamped on the completion string, the ground control cabinet is arranged outside the casing, and is connected to the monitoring mechanism and the completion string.

[0006] The beneficial effect of the utility model is that the monitoring mechanism is arranged on the completion string, which is conducive to real-time monitoring of the wellbore temperature and bottom hole pressure of the salt cavern gas storage on the basis of the original completion process without occupying the wellbore production time. By monitoring the changes in the wellbore temperature and bottom hole pressure, stress fatigue and wear problems of the string and downhole tools can be discovered and responded to in time, and the risk of failure of the integrity of the wellbore and cement ring can be avoided, thus providing technical means for the long-term safe production operation of the salt cavern gas storage.

[0007] On the basis of the above technical solution, the present invention can also be improved as follows.

[0008] Furthermore, the completion tubing string includes: a ball seat guide shoe, multiple oil pipes, a landing joint, a permanent packer, a pressure gauge holder, a lower flow short joint, a downhole safety valve and an upper flow short joint; the permanent packer adapter is arranged on the inner wall of the casing, the ball seat guide shoe and the landing joint are arranged below the permanent packer, the pressure gauge holder, the lower flow short joint, the downhole safety valve and the upper flow short joint are arranged above the permanent packer, the ball seat guide shoe is arranged below the landing joint and is connected to the landing joint through the oil pipe, the pressure gauge holder is connected to the landing joint, the lower flow short joint and the upper flow short joint are respectively arranged at the lower end and the upper end of the downhole safety valve, the pressure gauge holder is connected to the lower flow short joint through the oil pipe, and the upper flow short joint is connected to the outside through the oil pipe passing through the well sealing mechanism.

[0009] The beneficial effects of adopting the above further scheme are: the permanent packer has a large sealing pressure difference, reliable performance, permanent sealing, and can achieve long-term production. In combination with the ball seat guide shoe, oil pipe, landing joint, pressure gauge bracket, lower flow short joint, downhole safety valve and upper flow short joint, it is beneficial to guide the natural gas in the cavity to the outside of the wellbore.

[0010] Furthermore, the completion string also includes a safety valve hydraulic control pipeline, the safety valve hydraulic control pipeline passes through the well sealing mechanism, and the two ends are respectively connected to the downhole safety valve and the ground control cabinet.

[0011] The beneficial effect of adopting the above further solution is that the safety valve hydraulic control pipeline cooperates with the downhole safety valve to facilitate the opening and closing of the fluid inside the completion string.

[0012] Furthermore, the monitoring mechanism includes: an electronic temperature pressure gauge, a steel tube photoelectric composite cable, an optical fiber end protection tube and an optical fiber composite cable protector; the detection head of the electronic temperature pressure gauge and the optical fiber end protection tube are both installed on the pressure gauge support tube, the electronic temperature pressure gauge is connected to the steel tube photoelectric composite cable, the optical fiber end protection tube is sleeved on the end of the steel tube photoelectric composite cable, the steel tube photoelectric composite cable passes through the well sealing mechanism and is connected to the ground control cabinet, the optical fiber composite cable protector is a C-type clip, the steel tube photoelectric composite cable and the safety valve hydraulic control pipeline are both clamped on the side wall of the completion string through the optical fiber composite cable protector.

[0013] The beneficial effects of adopting the above further scheme are: the electronic temperature and pressure gauge is conducive to the real-time monitoring of the temperature and pressure of the entire wellbore without occupying the wellbore production time, and the steel tube photoelectric composite cable is conducive to the real-time evaluation of the wellbore working condition and integrity, providing technical means for the long-term safe production operation of the salt cavern gas storage.

[0014] Furthermore, an internal pressure transmission port is provided on the side wall of the pressure gauge holder, and the detection head of the electronic temperature pressure gauge is arranged in the internal pressure transmission port.

[0015] The beneficial effect of adopting the above further scheme is that it is conducive to real-time monitoring of the temperature and pressure in the wellbore through the internal pressure transmission port on the pressure gauge holder, and provides technical means for the long-term safe production operation of the salt cavern gas storage.

[0016] Furthermore, the steel tube optoelectronic composite cable includes: an outer stainless steel tube, filled aluminum, an optical fiber transmission area and a cable transmission area; the outer stainless steel tube is a tubular structure, the optical fiber transmission area and the cable transmission area are both arranged in the outer stainless steel tube, and the filled aluminum is filled in the area between the inner wall of the outer stainless steel tube and the optical fiber transmission area and the cable transmission area.

[0017] The beneficial effects of adopting the above further scheme are: the steel tube optoelectronic composite cable is conducive to ensuring the stability of signal transmission in the harsh environment underground, and the optical fiber transmission area and the cable transmission area are conducive to transmitting the optical fiber signal and the temperature and pressure signal to the ground control cabinet.

[0018] Furthermore, the optical fiber transmission area includes: an inner stainless steel tube, multiple optical fibers and hydrogen-blocking grease; the optical fiber is arranged in the inner stainless steel tube, the hydrogen-blocking grease fills the area between the optical fiber and the inner wall of the inner stainless steel tube, the end of the optical fiber is sealed and anti-reflective, the optical fiber end protection tube is sleeved on the end of the optical fiber, the area between the inner wall of the optical fiber end protection tube and the optical fiber is filled with silicone grease, and the end of the optical fiber away from the optical fiber end protection tube is connected to the ground control cabinet.

[0019] The beneficial effect of adopting the above further scheme is that the end of the sensing optical fiber is sealed and anti-reflected, which is beneficial to reduce end face reflection and improve measurement accuracy. The combination of the optical fiber end protection tube and silicone grease can not only protect the optical fiber, but also better reduce end face reflection.

[0020] Furthermore, the cable transmission area includes a cable insulation layer and a cable core wire, the cable insulation layer is sleeved on the cable core wire, and two ends of the cable core wire are respectively connected to the electronic temperature pressure gauge and the ground control cabinet.

[0021] The beneficial effect of adopting the above further scheme is that the cable insulation layer is conducive to protecting the cable core wire, and the cable core wire is conducive to transmitting the temperature and pressure signals monitored by the electronic temperature and pressure to the external ground control cabinet, thereby realizing real-time monitoring of the temperature and pressure in the wellbore.

[0022] Furthermore, the ground control cabinet includes a pressure thermometer ground data acquisition system and an optical fiber main line, and the pressure thermometer ground data acquisition system and the optical fiber main line are respectively connected to the cable core wire and the optical fiber.

[0023] The beneficial effects of adopting the above further scheme are: it is conducive to realizing functions such as ground control, data display, and data storage, providing power for downhole instruments, and at the same time collecting and storing data signals from downhole temperature and pressure gauges.

[0024] Furthermore, the well sealing mechanism includes a wellhead plug and a wellhead crossing assembly. The wellhead plug is sealingly installed at the wellhead at the top of the casing. The wellhead crossing assembly is arranged in the wellhead plug. The steel tube optoelectronic composite cable passes through the wellhead crossing assembly and is connected to the ground control cabinet.

[0025] The beneficial effects of adopting the above further solution are: the wellhead plug is helpful to prevent the downhole fluid from leaking out of the wellhead, and the wellhead crossing assembly is helpful to ensure the sealing when the steel tube optoelectronic composite cable passes through the wellhead plug. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The overall structural diagram provided for the embodiment of the utility model;

[0027] Figure 2 A cross-sectional view of a steel tube photoelectric composite cable provided in an embodiment of the utility model.

[0028] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0029] 1. Monitoring mechanism; 2. Completion string; 3. Well sealing mechanism; 4. Ground control cabinet; 5. Casing; 6. Cavity; 11. Electronic temperature and pressure gauge; 12. Steel tube photoelectric composite cable; 13. Optical fiber end protection tube; 14. Photoelectric composite cable protector; 21. Ball seat shoe; 22. Oil pipe; 23. Landing joint; 24. Permanent packer; 25. Pressure gauge support tube; 26. Lower flow nipple; 27. Downhole safety valve; 28. Upper flow nipple; 29. ​​Safety valve hydraulic control pipeline; 31. Wellhead plug; 32. Wellhead crossing assembly; 121. Outer stainless steel pipe; 122. Filling aluminum; 123. Optical fiber transmission area; 124. Cable transmission area; 1231. Inner stainless steel pipe; 1232. Optical fiber; 1233. Hydrogen barrier grease; 1241. Cable insulation layer; 1242. Cable core wire. DETAILED DESCRIPTION

[0030] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0031] like Figure 1 As shown, an integrated monitoring device for a salt cavern gas storage reservoir comprises: a monitoring mechanism 1, a completion string 2, a sealing mechanism 3, a ground control cabinet 4, a casing 5 and a cavity 6; the casing 5 is adapted to be arranged on the well wall above the cavity 6, the sealing mechanism 3 is sealingly arranged at the wellhead at the top of the casing 5, the monitoring mechanism 1 and the completion string 2 both pass through the sealing mechanism 3 and are arranged in the casing 5, the monitoring mechanism 1 is clamped on the completion string 2, and the ground control cabinet 4 is arranged outside the casing 5 and connected to the monitoring mechanism 1 and the completion string 2.

[0032] It should be noted that: in the technical solution of the present utility model, the data communication between the ground control cabinet 4 and the monitoring mechanism 1 and the completion string 2 belongs to the prior art.

[0033] The beneficial effect of the utility model is that the monitoring mechanism is arranged on the completion string, which is conducive to real-time monitoring of the wellbore temperature and bottom hole pressure of the salt cavern gas storage on the basis of the original completion process without occupying the wellbore production time. By monitoring the changes in the wellbore temperature and bottom hole pressure, stress fatigue and wear problems of the string and downhole tools can be discovered and responded to in time, and the risk of failure of the integrity of the wellbore and cement ring can be avoided, thus providing technical means for the long-term safe production operation of the salt cavern gas storage.

[0034] Preferably, Figure 1As shown, the completion string 2 includes: a ball seat guide shoe 21, a plurality of oil pipes 22, a landing joint 23, a permanent packer 24, a pressure gauge support tube 25, a lower flow short section 26, a downhole safety valve 27 and an upper flow short section 28; the permanent packer 24 adapter card is arranged on the inner wall of the casing 5, the ball seat guide shoe 21 and the landing joint 23 are arranged below the permanent packer 24, the pressure gauge support tube 25, the lower flow short section 26, the downhole safety valve 27 and the upper flow short section 28 are arranged on the permanent packer The ball seat guide shoe 21 is arranged below the seating joint 23 and is connected to the seating joint 23 through the oil pipe 22. The pressure gauge holder 25 is connected to the seating joint 23. The lower flow nipple 26 and the upper flow nipple 28 are respectively arranged at the lower end and the upper end of the downhole safety valve 27. The pressure gauge holder 25 is connected to the lower flow nipple 26 through the oil pipe 22. The upper flow nipple 28 is connected to the outside through the oil pipe 22 passing through the well sealing mechanism 3.

[0035] Among them, it should be noted that: in the technical solution of the utility model, the ball seat guide shoe 21 is a hollow short section with inner and outer chamfers at the bottom and a ball seat in the middle. The ball seat can cut off the pin under a certain pressure and separate from the guide shoe body; the seating joint 23 is a hollow short section, and its inner diameter is slightly larger than the inner diameter of the ball seat guide shoe 21. When the ball seat seal of the ball seat guide shoe 21 fails, the plugger can be dropped into the seating joint through cable operation to seal the packer; the permanent packer 24 is a hydraulic seat seal packer.

[0036] The beneficial effects of adopting the above-mentioned preferred scheme are: the permanent seal has a large sealing pressure difference, reliable performance, permanent sealing, and can achieve long-term production. In combination with the ball seat guide shoe, oil pipe, landing joint, pressure gauge support, lower flow short joint, downhole safety valve and upper flow short joint, it is beneficial to guide the natural gas in the cavity to the outside of the wellbore.

[0037] Preferably, Figure 1 As shown, the completion string 2 further includes a safety valve hydraulic control pipeline 29, which passes through the well sealing mechanism 3, and has two ends respectively connected to the downhole safety valve 27 and the ground control cabinet 4.

[0038] The beneficial effect of adopting the above preferred solution is that the safety valve hydraulic control pipeline cooperates with the downhole safety valve to facilitate the opening and closing of the fluid inside the completion string.

[0039] Preferably, Figure 1As shown, the monitoring mechanism 1 includes: an electronic temperature pressure gauge 11, a steel tube photoelectric composite cable 12, an optical fiber end protection tube 13 and an optical fiber composite cable protector 14; the detection head of the electronic temperature pressure gauge 11 and the optical fiber end protection tube 13 are both installed on the pressure gauge support tube 25, the electronic temperature pressure gauge 11 is connected to the steel tube photoelectric composite cable 12, the optical fiber end protection tube 13 is sleeved on the end of the steel tube photoelectric composite cable 12, the steel tube photoelectric composite cable 12 passes through the well sealing mechanism 3 and is connected to the ground control cabinet 4, the optical fiber composite cable protector 14 is a C-type clip, the steel tube photoelectric composite cable 12 and the safety valve hydraulic control pipeline 29 are both clamped on the side wall of the completion string 2 through the optical fiber composite cable protector 14.

[0040] It should be noted that: in the technical solution of the present utility model, the optical fiber end protection tube 13 is sleeved on the end of the steel tube optoelectronic composite cable 12 located in the wellbore.

[0041] The beneficial effects of adopting the above-mentioned preferred scheme are: the electronic temperature and pressure gauge is conducive to the real-time monitoring of the temperature and pressure of the entire wellbore without occupying the wellbore production time, and the steel tube photoelectric composite cable is conducive to the real-time evaluation of the wellbore working condition and integrity, providing technical means for the long-term safe production operation of the salt cavern gas storage.

[0042] Preferably, an inner pressure transmission port is provided on the side wall of the pressure gauge holder 25, and the detection head of the electronic temperature pressure gauge 11 is arranged in the inner pressure transmission port.

[0043] The beneficial effect of adopting the above preferred solution is that it is conducive to real-time monitoring of the temperature and pressure in the wellbore through the internal pressure transmission port on the pressure gauge holder, and provides technical means for the long-term safe production operation of the salt cavern gas storage.

[0044] Preferably, Figure 2 As shown, the steel tube optoelectronic composite cable 12 includes: an outer stainless steel tube 121, filling aluminum 122, an optical fiber transmission area 123 and a cable transmission area 124; the outer stainless steel tube 121 is a tubular structure, the optical fiber transmission area 123 and the cable transmission area 124 are both arranged in the outer stainless steel tube 121, and the filling aluminum 122 is filled in the area between the inner wall of the outer stainless steel tube 121 and the optical fiber transmission area 123 and the cable transmission area 124.

[0045] The beneficial effects of adopting the above preferred scheme are: the steel tube optoelectronic composite cable is conducive to ensuring the stability of signal transmission in the harsh environment underground, and the optical fiber transmission area and the cable transmission area are conducive to transmitting the optical fiber signal and the temperature and pressure signal to the ground control cabinet.

[0046] Preferably, Figure 2As shown, the optical fiber transmission area 123 includes: an inner stainless steel tube 1231, multiple optical fibers 1232 and a hydrogen-blocking grease 1233; the optical fiber 1232 is arranged in the inner stainless steel tube 1231, and the hydrogen-blocking grease 1233 fills the area between the optical fiber 1232 and the inner wall of the inner stainless steel tube 1231, the end of the optical fiber 1232 is sealed and anti-reflective, the optical fiber end protection tube 13 is sleeved on the end of the optical fiber 1232, and the area between the inner wall of the optical fiber end protection tube 13 and the optical fiber 1232 is filled with silicone grease, and the end of the optical fiber 1232 away from the optical fiber end protection tube 13 is connected to the ground control cabinet 4.

[0047] It should be noted that: in the technical solution of the present invention, the end of the optical fiber 1232 that has been sealed and anti-reflection treated is one end arranged in the wellbore; in the preferred embodiment of the present invention, the optical fiber 1232 is a six-core optical fiber, and the end of the six-core optical fiber is cut into sections of different lengths.

[0048] The beneficial effect of adopting the above preferred scheme is that the end of the sensing optical fiber is sealed and anti-reflected, which is beneficial to reduce end face reflection and improve measurement accuracy. The combination of the optical fiber end protection tube and silicone grease can not only protect the optical fiber, but also better reduce end face reflection.

[0049] Preferably, Figure 2 As shown, the cable transmission area 124 includes a cable insulation layer 1241 and a cable core wire 1242. The cable insulation layer 1241 is sleeved on the cable core wire 1242. The two ends of the cable core wire 1242 are respectively connected to the electronic temperature pressure gauge 11 and the ground control cabinet 4.

[0050] The beneficial effects of adopting the above-mentioned preferred scheme are: the cable insulation layer is conducive to protecting the cable core wire, and the cable core wire is conducive to transmitting the temperature and pressure signals monitored by the electronic temperature and pressure to the external ground control cabinet, thereby realizing real-time monitoring of the temperature and pressure in the wellbore.

[0051] Preferably, the ground control cabinet 4 includes a pressure thermometer ground data acquisition system and an optical fiber main line, and the pressure thermometer ground data acquisition system and the optical fiber main line are connected to the cable core wire 1242 and the optical fiber 1232 respectively.

[0052] It should be noted that: in a preferred embodiment of the present invention, the cable core wire 1242 and the optical fiber 1232 can be connected via a communication module to achieve remote data transmission.

[0053] The beneficial effects of adopting the above preferred solution are: it is conducive to realizing functions such as ground control, data display, and data storage, providing power for downhole instruments, and at the same time collecting and storing data signals from downhole temperature and pressure gauges.

[0054] Preferably, Figure 1 As shown, the well sealing mechanism 3 includes a wellhead plug 31 and a wellhead crossing assembly 32. The wellhead plug 31 is sealingly installed at the wellhead at the top of the casing 5. The wellhead crossing assembly 32 is arranged in the wellhead plug 31. The steel tube optoelectronic composite cable 12 passes through the wellhead crossing assembly 32 and is connected to the ground control cabinet 4.

[0055] The beneficial effects of adopting the above preferred solution are: the wellhead plug is helpful to prevent the downhole fluid from leaking out of the wellhead, and the wellhead crossing assembly is helpful to ensure the sealing when the steel tube optoelectronic composite cable passes through the wellhead plug.

[0056] During the lowering of the completion string 2, it is necessary to ensure that the steel tube photoelectric composite cable 12 and the safety valve hydraulic control pipeline 29 do not rub against the inner wall of the casing 5; when lowering the completion string 2, attention should be paid to the steady and uniform speed during the lowering process, and no sudden lifting, sudden braking or sudden release is allowed. The tonnage should not exceed 20KN when encountering resistance, and objects falling from the well should be strictly prevented to prevent the completion string 2 from being stuck. It is strictly forbidden to force it through when encountering resistance, which will damage the rubber cylinder of the permanent packer 24. After the completion string 2 is in place, the completion string 2 should be adjusted to ensure that the permanent packer 24 is well sealed; the electronic temperature and pressure gauge 11 is sealed and connected to the pressure transmission port in the pressure gauge support tube 25. After the connection is completed, the electronic temperature and pressure gauge 11 and the internal pressure transmission port need to be arranged and pressure tested to 35MPa. Only after the pressure test is qualified can it be lowered into the well; the photoelectric composite cable protector 14 is installed on the coupling of the oil pipe 22, and attention should be paid to the steel tube photoelectric composite cable 1 2 cannot be twisted, and then the photoelectric composite cable protector 14 is installed at each oil pipe 22 coupling in turn. The optical and cable signals are detected every 100 meters during the steel tube photoelectric composite cable 12 going down the well. Once the signal is abnormal, the construction work should be stopped immediately, the fault location should be found, the fault should be eliminated, and then the next construction plan should be determined; when the steel tube photoelectric composite cable 12 passes through the wellhead plug 31, a sufficiently long steel tube photoelectric composite cable 12 is reserved, and before the steel tube photoelectric composite cable 12 reaches the wellhead plug 31 and passes through, the steel tube photoelectric composite cable 12 is freely wound on the completion string 2 for 3-5 turns before passing through the wellhead plug 31, and the wellhead crossing assembly 32 is installed to the upper plane of the wellhead plug 31, and a sealing pressure test is performed; the steel tube photoelectric composite cable 12 is buried and pulled into the ground control cabinet 4, and the pipe string operation is completed.

[0057] The downhole pressure and temperature are monitored by an electronic temperature and pressure gauge 11. The core of the electronic temperature and pressure gauge 11 is a pressure sensor and a temperature sensor. Under the combined influence of the downhole formation pressure and temperature, the oscillation circuit of the electronic temperature and pressure gauge 11 converts the pressure and temperature values ​​of the measured formation into resistance values ​​and voltage values ​​recognizable by the circuit system, and converts the oscillation circuit into a current frequency value signal recognizable by the computer, which is then recognized and converted by software and converted into the downhole pressure and temperature data required by the tester. The electrical signal of the electronic temperature and pressure gauge 11 is transmitted to the ground control cabinet 4 through the cable core wire 1242 in the steel tube optoelectronic composite cable 12. After being processed by the system, the downhole pressure and temperature data are formed, which can be stored in the electronic temperature and pressure gauge 11 or remotely transmitted to the monitoring center.

[0058] The optical fiber 1232 in the optoelectronic composite cable 12 is used to continuously monitor the temperature and vibration of the annulus to provide favorable data support for the integrity of the wellbore. It can be monitored at any time at the ground control cabinet 4 as needed. Optical fiber monitoring is a technology that has developed rapidly along with the development of optical fiber and optical fiber communication technology. Its basic principle is to use light to transmit in the optical fiber. When affected by the change of the measured parameter, the intensity, wavelength, phase and other parameters of the light will change. Compared with traditional sensing technology, it has the advantages of small size, good electrical insulation, no electromagnetic interference from the formation, and can be used in some measurement environments with harsh conditions. The optical signal in the optical fiber 1232 is transmitted to the ground control cabinet 4. After being processed by the system, the downhole temperature and pipe string vibration data are formed, which can be stored in the acquisition system or remotely transmitted to the monitoring center.

[0059] For salt cavern gas storage, the thermodynamic effect of high-pressure natural gas high-speed injection and production leads to obvious heat exchange in the wellbore, and abnormal pressure in the annulus of the wellbore when the well is opened for gas production. It is necessary to grasp the temperature conditions of the wellbore and the annulus in real time and evaluate the impact of the thermal effect on the wellbore. The long-term production and operation of the gas storage and the high-intensity and large-volume injection and production lead to continuous changes in wellbore temperature and pressure and alternating stress, resulting in stress fatigue and wear of the tubing and downhole tools. In severe cases, there is a risk of wellbore integrity failure. It is necessary to monitor the integrity of the wellbore in real time. In terms of temperature monitoring, the electronic pressure gauge and optical fiber acquisition principles and data transmission methods are different. The dual monitoring system design ensures the normal acquisition of monitoring parameters to the greatest extent.

[0060] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0061] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying 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 the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0062] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0063] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0064] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0065] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An integrated monitoring device for salt cavern gas storage, characterized in that: include: A monitoring mechanism (1), a completion string (2), a well sealing mechanism (3), a ground control cabinet (4), a casing (5) and a cavity (6); the casing (5) is adapted to be arranged on the well wall above the cavity (6); the well sealing mechanism (3) is sealingly arranged at the wellhead at the top of the casing (5); the monitoring mechanism (1) and the completion string (2) both pass through the well sealing mechanism (3) and are arranged in the casing (5); the monitoring mechanism (1) is clamped on the completion string (2); the ground control cabinet (4) is arranged outside the casing (5) and is connected to the monitoring mechanism (1) and the completion string (2).

2. According to claim 1, the integrated monitoring device for salt cavern gas storage is characterized in that: The completion string (2) comprises: a ball seat guide shoe (21), a plurality of oil pipes (22), a landing joint (23), a permanent packer (24), a pressure gauge support (25), a lower flow nipple (26), a downhole safety valve (27) and an upper flow nipple (28); The permanent packer (24) adapter is arranged on the inner wall of the casing (5), the ball seat guide shoe (21) and the seating joint (23) are arranged below the permanent packer (24), the pressure gauge support (25), the lower flow short joint (26), the downhole safety valve (27) and the upper flow short joint (28) are arranged above the permanent packer (24), the ball seat guide shoe (21) is arranged below the seating joint (23) and is connected to the seating joint (23). 3) are connected through the oil pipe (22), the pressure gauge holder (25) is connected to the seating joint (23), the lower flow nipple (26) and the upper flow nipple (28) are respectively arranged at the lower end and the upper end of the downhole safety valve (27), the pressure gauge holder (25) is connected to the lower flow nipple (26) through the oil pipe (22), and the upper flow nipple (28) is connected to the outside through the oil pipe (22) passing through the well sealing mechanism (3).

3. According to claim 2, the integrated monitoring device for salt cavern gas storage is characterized in that: The completion string (2) further comprises a safety valve hydraulic control pipeline (29), the safety valve hydraulic control pipeline (29) passes through the well sealing mechanism (3), and the two ends are respectively connected to the downhole safety valve (27) and the ground control cabinet (4).

4. According to claim 3, the integrated monitoring device for salt cavern gas storage is characterized in that: The monitoring mechanism (1) comprises: an electronic temperature pressure gauge (11), a steel tube photoelectric composite cable (12), an optical fiber end protection tube (13) and a photoelectric composite cable protector (14); The detection head of the electronic temperature pressure gauge (11) and the optical fiber end protection tube (13) are both installed on the pressure gauge support tube (25); the electronic temperature pressure gauge (11) is connected to the steel tube photoelectric composite cable (12); the optical fiber end protection tube (13) is sleeved on the end of the steel tube photoelectric composite cable (12); the steel tube photoelectric composite cable (12) passes through the well sealing mechanism (3) and is connected to the ground control cabinet (4); the photoelectric composite cable protector (14) is a C-type clip; the steel tube photoelectric composite cable (12) and the safety valve hydraulic control pipeline (29) are both clamped on the side wall of the completion string (2) through the photoelectric composite cable protector (14).

5. The integrated monitoring device for salt cavern gas storage according to claim 4 is characterized in that: An internal pressure transmission port is arranged on the side wall of the pressure gauge holder (25), and a detection head of the electronic temperature pressure gauge (11) is arranged in the internal pressure transmission port.

6. The integrated monitoring device for salt cavern gas storage according to claim 4, characterized in that: The steel tube photoelectric composite cable (12) comprises: an outer stainless steel tube (121), filler aluminum (122), an optical fiber transmission area (123) and a cable transmission area (124); The outer stainless steel tube (121) is a tubular structure, the optical fiber transmission area (123) and the cable transmission area (124) are both arranged in the outer stainless steel tube (121), and the filling aluminum (122) fills the area between the inner wall of the outer stainless steel tube (121) and the optical fiber transmission area (123) and the cable transmission area (124).

7. The integrated monitoring device for salt cavern gas storage according to claim 6, characterized in that: The optical fiber transmission area (123) comprises: an inner stainless steel tube (1231), a plurality of optical fibers (1232) and a hydrogen-blocking paste (1233); The optical fiber (1232) is arranged in the inner stainless steel tube (1231), the hydrogen-blocking grease (1233) is filled in the area between the optical fiber (1232) and the inner wall of the inner stainless steel tube (1231), the end of the optical fiber (1232) is sealed and anti-reflection treated, the optical fiber end protection tube (13) is sleeved on the end of the optical fiber (1232), the area between the inner wall of the optical fiber end protection tube (13) and the optical fiber (1232) is filled with silicone grease, and the end of the optical fiber (1232) away from the optical fiber end protection tube (13) is connected to the ground control cabinet (4).

8. The integrated monitoring device for salt cavern gas storage according to claim 7, characterized in that: The cable transmission area (124) comprises a cable insulation layer (1241) and a cable core wire (1242), the cable insulation layer (1241) is sleeved on the cable core wire (1242), and two ends of the cable core wire (1242) are respectively connected to the electronic temperature pressure gauge (11) and the ground control cabinet (4).

9. The integrated monitoring device for salt cavern gas storage according to claim 8, characterized in that: The ground control cabinet (4) comprises a pressure thermometer ground data acquisition system and an optical fiber main line, and the pressure thermometer ground data acquisition system and the optical fiber main line are respectively connected to the cable core wire (1242) and the optical fiber (1232).

10. The integrated monitoring device for salt cavern gas storage according to claim 4, characterized in that: The well sealing mechanism (3) comprises a wellhead plug (31) and a wellhead crossing assembly (32); the wellhead plug (31) is sealingly installed at the wellhead at the top of the casing (5); the wellhead crossing assembly (32) is arranged in the wellhead plug (31); the steel tube optoelectronic composite cable (12) passes through the wellhead crossing assembly (32) and is connected to the ground control cabinet (4).

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