A monitoring system for injection and production operation of gas storage well geological bodies

Abstract

A gas storage well geological body injection and production operation monitoring system relates to the technical field of gas storage wells. The injection and production wells are installed above the salt caverns, and monitoring wells are installed in the strata around the salt caverns. The monitoring wells pass through the cap layer and rock salt layer of the salt caverns from the ground to the belly layer at the bottom of the salt caverns. A multifunctional sensor is installed in the salt cavern, and a vibration sensor and a temperature sensor are installed in the monitoring wells. The beneficial effects of the present invention are: the space where the monitoring well is located can maintain the original temperature and pressure of the formation without destroying the original state of the formation. The monitoring section detects the real formation vibration and temperature data. Through the vibration conditions of each formation, combined with previous geological and hydrological data, it can be analyzed whether the geological changes of the gas storage well at each pressure operation stage are controllable. The real-time temperature changes of each formation are monitored, and combined with the pressure changes in the salt cavern, it can be calculated whether the salt cavern has leakage, and at the same time, the credibility of the analysis is enhanced according to the data of the gas concentration sensor.

Description

Technical Field

[0001] The invention relates to the technical field of gas storage wells, and in particular to a gas storage well geological body injection and production operation monitoring system. Background Art

[0002] Salt cavern gas storage wells have the characteristics of large storage capacity, wide peak-shaving range, economic rationality, and durability. They are one of the important links in the natural gas industry chain and have become a strategic infrastructure to ensure safe and stable gas supply. In order to ensure the long-term safe and stable operation of the gas storage, the cap layer, rock salt layer and belly layer of the gas storage well are monitored in real time. The monitoring objects are mainly the micro-earthquakes of the formation, the temperature and pressure inside the gas storage well, etc., to master the internal deformation mechanism of the salt cavern, the morphological information of conductive cracks and reactivated fault structures, and the movement of the pressure front, so as to provide a decision-making basis for the production and operation management of the gas storage. In addition to the pressure change of the salt cavern with the injection and production parameters, it is also necessary to monitor the temperature change of the formation to affect the pressure change of the rock cavern. Since the volume of the salt cavern is fixed, the change of the formation temperature will cause the gas reservoir pressure in the salt cavern to change. Therefore, accurate monitoring of the formation temperature change around the salt cavern is an important monitoring data for the gas storage well.

[0003] For formation monitoring, the sensor is generally fixed to the inner wall of the monitoring well, for example, by sealing the monitoring well with sand or mud, so that the sensor and the monitoring well wall remain relatively still. This type of method has a good effect on formation vibration, but is not effective for monitoring formation temperature. Summary of the invention

[0004] In order to solve the problems of lack of existing gas storage well formation temperature monitoring and poor effect, the present invention provides a gas storage well geological body injection and production operation monitoring system.

[0005] The technical solution provided by the present invention is: a gas storage well geological body injection and production operation monitoring system, including an injection and production well, the injection and production well is installed above the salt cavern, and monitoring wells are installed in the strata around the salt cavern, the monitoring wells pass through the cap layer and the rock salt layer of the salt cavern from the ground to the belly layer at the bottom of the salt cavern, a multifunctional sensor is installed in the salt cavern, the cable of the multifunctional sensor is sealed upward and passes through the wellhead of the injection and production well, a vibration sensor and a temperature sensor are installed in the monitoring well, the signal lines of the vibration sensor and the temperature sensor are extended to the ground to connect to the control cabinet, and the cable of the multifunctional sensor is connected to the control cabinet;

[0006] The monitoring well includes a casing, a core tube is installed in the casing, a monitoring hole is opened in the core tube, a monitoring slot is opened on one side of the monitoring hole, the monitoring slots are arranged at intervals from top to bottom, the monitoring hole passes through the monitoring slot, a liquid injection hole is opened in the core tube, a side hole is opened between the liquid injection hole and the monitoring slot, a perforating tool is installed in each monitoring slot, a monitoring section is installed at each monitoring slot position of the monitoring hole, the monitoring section includes a short circuit, a vibration sensor and a temperature sensor are connected by a threaded seal on the side of the short circuit, stainless steel pipes are connected between the short circuits by threaded seals, signal lines of the vibration sensor and the temperature sensor are accommodated in the stainless steel pipe, the stainless steel pipe is connected to the monitoring hole by a sealing ring gap fit at the upper and lower parts of the monitoring slot, and the core tube is connected to the casing by a sealing ring gap fit at the upper and lower parts of the monitoring slot;

[0007] The multifunctional sensor includes a pressure sensor and a gas concentration sensor.

[0008] The wellhead of the injection and production well includes a wellbore and a well cover, which are sealed and connected by a flange. A through hole is opened on the well cover, and the cable of the multifunctional sensor passes through the through hole of the well cover. A sealing groove is opened on the upper part of the through hole of the well cover, and a sealing ring is installed in the sealing groove. An annular high-pressure capsule is installed on the upper part of the sealing ring in the sealing groove, and a pressure cap is installed on the upper part of the high-pressure capsule. The cable passes through the pressure cap, and the pressure cap is connected to the well cover by bolts. An air nozzle is installed on the high-pressure capsule, and the air nozzle extends out of the pressure cap. A pressure transmitter is installed on the pipe extending out of the pressure cap.

[0009] The lower threaded portion of the lowest short-circuit is sealed and connected to the tail pipe, and the tail pipe is connected to the monitoring hole through a sealing ring gap fit.

[0010] The perforating tool is of electric detonation type, and the power cord of the perforating tool is sealed through the short-circuited pipe wall and then extends to the ground to connect to the control cabinet.

[0011] The distance between each monitoring section is 50 to 80 meters.

[0012] Installation method of monitoring well: install perforating tools in the monitoring slot of the core pipe, put the connected monitoring sections and stainless steel pipes into the monitoring hole, the monitoring section is located at the monitoring slot, and after the casing is completed, put the core pipe in, install a bridge plug at the bottom of the lowest monitoring slot for the injection hole, first energize the lowest perforating tool to detonate the perforation, the perforating tool shoots a fracturing channel on the wall of the casing, injects fracturing fluid through the injection hole, and fractures the cement and formation outside the casing. After the fracturing is completed, a bridge plug is installed on the upper part of the monitoring slot for the injection hole, and then the perforating tool above is detonated, and the installation of the monitoring well is completed by analogy.

[0013] The beneficial effects of the present invention are as follows: the space between the monitoring section and the formation in the installed monitoring well is filled with fracturing fluid, and the fracturing fluid transmits the vibration and temperature of the formation to the monitoring section. At the same time, two bridge plugs are installed at the injection holes on the upper and lower sides of the monitoring section to seal the formation. The space where the monitoring section is located can maintain the original temperature and pressure of the formation without destroying the original state of the formation. The monitoring section detects the real formation vibration and temperature data. Through the vibration conditions of each formation, combined with previous geological and hydrological data, it can be analyzed whether the geological changes of the gas storage well at each pressure operation stage are controllable. By monitoring the real-time temperature changes of each formation and combining with the pressure changes in the salt cavern, it can be calculated whether the salt cavern has leakage, and at the same time, the credibility of the analysis is enhanced according to the data of the gas concentration sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Attached Figure 1 It is a schematic diagram of the structure of the present invention;

[0015] Attached Figure 2 It is a schematic diagram of the structure of the monitoring well in the present invention;

[0016] Attached Figure 3 Yes Figure 2 AA section view;

[0017] Attached Figure 4 is a schematic cross-sectional view of the mandrel in the present invention;

[0018] Attached Figure 5 Yes Figure 1 The enlarged view of point B;

[0019] Attached Figure 6 Yes Figure 2 Cross-sectional view at point C.

[0020] In the figure: 1-injection and production well, 2-monitoring well, 3-cap layer, 4-rock salt layer, 5-belly layer, 6-salt cavern, 7-multi-function sensor, 8-control cabinet, 9-casing, 10-core tube, 11-injection hole, 12-stainless steel pipe, 13-perforating tool, 14-bridge plug, 15-monitoring slot, 16-fracturing channel, 17-side hole, 18-monitoring hole, 19-monitoring section, 20-well cover, 21-wellbore, 22-sealing groove, 23-high-pressure capsule, 24-pressure cover, 25-gas nozzle, 26-temperature sensor, 27-short circuit, 28-vibration sensor, 29-tail pipe, 30-cable, 31-power cord, 32-pressure transmitter. DETAILED DESCRIPTION

[0021] like Figures 1 to 6As shown, a gas storage well geological body injection and production operation monitoring system includes an injection and production well 1, which is installed above a salt cavern 6. A monitoring well 2 is installed in the strata around the salt cavern 6. The monitoring well 2 passes through a cap layer 3 and a rock salt layer 4 of the salt cavern 6 from the ground to a belly layer 5 at the bottom of the salt cavern 6. A multifunctional sensor 7 is installed in the salt cavern 6. A cable 30 of the multifunctional sensor 7 seals upward and passes through the wellhead of the injection and production well 1. A vibration sensor 28 and a temperature sensor 26 are installed in the monitoring well 2. The signal lines of the vibration sensor 28 and the temperature sensor 26 extend to the ground to connect to a control cabinet 8. The cable 30 of the multifunctional sensor 7 is connected to the control cabinet 8.

[0022] The monitoring well 2 includes a casing 9, a core tube 10 is installed in the casing 9, a monitoring hole 18 is opened in the core tube 10, a monitoring slot 15 is opened on one side of the monitoring hole 18, the monitoring slots 15 are arranged at intervals from top to bottom, the monitoring holes 18 pass through the monitoring slots 15, a liquid injection hole 11 is opened in the core tube 10, a side hole 17 is opened between the liquid injection hole 11 and the monitoring slots 15, a perforating tool 13 is installed in each monitoring slot 15, and the monitoring hole 18 is located at the position of each monitoring slot 15. A monitoring section 19 is installed, the monitoring section 19 includes a short circuit 27, the side of the short circuit 27 is threaded and sealed to connect the vibration sensor 28 and the temperature sensor 26, each short circuit 27 is threaded and sealed to connect the stainless steel tube 12, the signal lines of the vibration sensor 28 and the temperature sensor 26 are accommodated in the stainless steel tube 12, the stainless steel tube 12 is connected to the monitoring hole 18 at the upper and lower parts of the monitoring slot 15 through the gap of the sealing ring, and the core tube 10 is connected to the sleeve 9 at the upper and lower parts of the monitoring slot 15 through the gap of the sealing ring;

[0023] The multifunctional sensor 7 includes a pressure sensor and a gas concentration sensor.

[0024] The wellhead of the injection and production well 1 includes a wellbore 21 and a well cover 20, which are sealed and connected by a flange. A through hole is opened on the well cover 20, and the cable 30 of the multifunctional sensor 7 passes through the through hole of the well cover 20. A sealing groove 22 is opened on the upper part of the through hole of the well cover 20, and a sealing ring is installed in the sealing groove 22. An annular high-pressure capsule 23 is installed on the upper part of the sealing ring of the sealing groove 22, and a gland 24 is installed on the upper part of the high-pressure capsule 23. The cable 30 passes through the gland 24, and the gland 24 is connected to the well cover 20 by bolts. A gas nozzle 25 is installed on the high-pressure capsule 23, and the gas nozzle 25 extends out of the gland 24. A pressure transmitter 32 is installed on the pipe extending out of the gland 24 to keep the pressure of the high-pressure capsule 23 greater than the pressure in the salt cavern 6, reduce the pressure difference on both sides of the sealing ring, and keep the cable 30 from leaking. When the air pressure of the high-pressure capsule 23 drops, the pressure transmitter 32 sends a signal to prompt the staff to compensate the gas to the gas nozzle 25.

[0025] The lower part of the lowest short-circuit 27 is threadedly sealed and connected to the tail pipe 29, and the tail pipe 29 is connected to the monitoring hole 18 through a sealing ring clearance fit.

[0026] The perforating tool 13 is of an electric detonation type. A power line 31 of the perforating tool 13 is sealed through the pipe wall of the short circuit 27 and then extends to the ground to connect to the control cabinet 8 .

[0027] According to the accuracy of the monitoring data, the distance between each monitoring section 19 is designed to be between 50 and 80 meters, so that basic data of the formation can be obtained and the monitoring cost can be reduced.

[0028] Installation method of monitoring well 2: install a perforating tool 13 in the monitoring slot 15 of the core pipe 10, and lower the connected monitoring sections 19 and stainless steel pipes 12 into the monitoring hole 18. The monitoring section 19 is located at the monitoring slot 15. After the casing 9 is completed, the core pipe 10 is lowered. A bridge plug 14 is installed at the lower part of the lowest monitoring slot 15 through the injection hole 11. First, the lowest perforating tool 13 is energized to detonate the perforation. The perforating tool 13 shoots a fracturing channel 16 on the wall of the casing 9, and fracturing fluid is injected through the injection hole 11 to fracture the cement and formation outside the casing 9. After the fracturing is completed, a bridge plug 14 is installed at the upper part of the monitoring slot 15 through the injection hole 11, and then the perforating tool 13 above is detonated. The installation of monitoring well 2 is completed by analogy.

[0029] The space between the monitoring section 19 and the formation in the installed monitoring well 2 is filled with fracturing fluid, which transmits the vibration and temperature of the formation to the monitoring section 19. At the same time, two bridge plugs 14 are installed at the injection holes 11 on the upper and lower sides of the monitoring section 19 to seal the formation. The space where the monitoring section 19 is located can maintain the original temperature and pressure of the formation without destroying the original state of the formation. The monitoring section 19 detects the real formation vibration and temperature data. Through the vibration conditions of each formation, combined with previous geological and hydrological data, it can be analyzed whether the geological changes of the gas storage well at each pressure operation stage are controllable. By monitoring the real-time temperature changes of each formation and combining the pressure changes in the salt cavern 6, it can be calculated whether the salt cavern 6 has leakage, and at the same time, the credibility of the analysis is enhanced based on the data of the gas concentration sensor.

Claims

1. A gas storage well geological body injection and production operation monitoring system, comprising an injection and production well (1), characterized in that: The injection and production well (1) is installed above the salt cavern (6), and a monitoring well (2) is installed in the strata around the salt cavern (6). The monitoring well (2) passes through the cap layer (3) and the rock salt layer (4) of the salt cavern (6) from the ground to the belly layer (5) at the bottom of the salt cavern (6). A multifunctional sensor (7) is installed in the salt cavern (6). The cable (30) of the multifunctional sensor (7) passes through the wellhead of the injection and production well (1) in a sealed manner upward. A vibration sensor (28) and a temperature sensor (26) are installed in the monitoring well (2). The signal lines of the vibration sensor (28) and the temperature sensor (26) extend to the ground to connect to the control cabinet (8), and the cable (30) of the multifunctional sensor (7) is connected to the control cabinet (8); The monitoring well (2) comprises a casing (9), a core tube (10) is installed in the casing (9), a monitoring hole (18) is opened in the core tube (10) and is connected vertically, a monitoring groove (15) is opened on one side of the monitoring hole (18), the monitoring grooves (15) are arranged at intervals from top to bottom, the monitoring holes (18) pass through the monitoring grooves (15), a liquid injection hole (11) is opened in the core tube (10) and is connected vertically, a side hole (17) is opened between the liquid injection hole (11) and the monitoring groove (15), a perforating tool (13) is installed in each monitoring groove (15), and a monitoring section (17) is installed at the position of each monitoring groove (15) in the monitoring hole (18) (19), the monitoring section (19) includes a short circuit (27), the side of the short circuit (27) is threadedly sealed to connect the vibration sensor (28) and the temperature sensor (26), each short circuit (27) is threadedly sealed to connect the stainless steel pipe (12), the signal lines of the vibration sensor (28) and the temperature sensor (26) are accommodated in the stainless steel pipe (12), the stainless steel pipe (12) is connected to the monitoring hole (18) at the upper and lower parts of the monitoring groove (15) through the gap of the sealing ring, and the core tube (10) is connected to the sleeve (9) at the upper and lower parts of the monitoring groove (15) through the gap of the sealing ring; the multifunctional sensor (7) includes a pressure sensor and a gas concentration sensor; The installation method of the monitoring well (2) is as follows: a perforating tool (13) is installed in the monitoring slot (15) of the core pipe (10), and each connected monitoring section (19) and the stainless steel pipe (12) are lowered into the monitoring hole (18), and the monitoring section (19) is located at the monitoring slot (15). After the casing (9) is completed, the core pipe (10) is lowered, and a bridge plug (14) is installed at the lower part of the injection hole (11) at the bottom of the lowest monitoring slot (15). First, The lowest perforating tool (13) is powered on to detonate the perforation, and the perforating tool (13) opens a fracturing channel (16) on the wall of the casing (9), and injects fracturing fluid through the injection hole (11) to fracture the cement and formation outside the casing (9). After the fracturing is completed, a bridge plug (14) is installed on the upper part of the monitoring slot (15) through the injection hole (11), and then the upper perforating tool (13) is detonated, and the installation of the monitoring well (2) is completed by analogy.

2. A gas storage well geological body injection and production operation monitoring system according to claim 1, characterized in that: The wellhead of the injection and production well (1) comprises a wellbore (21) and a well cover (20), the wellbore (21) and the well cover (20) are sealed and connected via a flange, a through hole is provided on the well cover (20), a cable (30) of the multifunctional sensor (7) passes through the through hole of the well cover (20), a sealing groove (22) is provided on the upper part of the through hole of the well cover (20), a sealing ring is installed in the sealing groove (22), an annular high-pressure capsule (23) is installed on the upper part of the sealing ring of the sealing groove (22), a pressure cap (24) is installed on the upper part of the high-pressure capsule (23), the cable (30) passes through the pressure cap (24), the pressure cap (24) is connected to the well cover (20) via bolts, a gas nozzle (25) is installed on the high-pressure capsule (23), the gas nozzle (25) extends out of the pressure cap (24), and a pressure transmitter (32) is installed on the pipe extending out of the pressure cap (24) of the gas nozzle (25).

3. A gas storage well geological body injection and production operation monitoring system according to claim 1, characterized in that: The lower thread of the lowest short-circuit (27) is sealed and connected to the tail pipe (29), and the tail pipe (29) is connected to the monitoring hole (18) through the gap fit of the sealing ring.

4. A gas storage well geological body injection and production operation monitoring system according to claim 1, characterized in that: The perforating tool (13) is of an electric detonation type. The power line (31) of the perforating tool (13) is sealed through the pipe wall of the short circuit (27) and then extends to the ground to connect to the control cabinet (8).

5. A gas storage well geological body injection and production operation monitoring system according to claim 1, characterized in that: The distance between each monitoring section (19) is 50 to 80 meters.

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