Multifunctional wellhead equipment for well cluster gathering and transportation and cross-season stratum heat storage

Abstract

The invention discloses multifunctional wellhead equipment for well cluster gathering and transportation and cross-season stratum heat storage. Comprising a heat preservation inner pipe G1, a geothermal circulation water supply pipeline G2, a wellhead equipment main body pipe J2, a geothermal circulation water return pipeline G3, a bypass pipeline G4, a wellhead equipment upper end cover J1, a heat exchange well casing pipe J3, a geothermal circulation water supply pipeline pressure gauge P1 and a geothermal circulation water supply pipeline temperature transmitter T1. The geothermal circulating water supply system comprises a geothermal circulating water return pipeline, a geothermal circulating water return pipeline pressure gauge P2, a geothermal circulating water return pipeline temperature transmitter T2, a heat meter HM, a heat storage small-power circulating water pump WP, a Y-shaped filter V1, an energy valve V2, a geothermal circulating water return pipeline valve V3, a blow-down valve V5, a geothermal circulating water return pipeline control butterfly valve V6, a sight glass V7, a bypass pipeline bypass valve V8, a geothermal circulating water supply pipeline control butterfly valve V9 and a geothermal circulating water supply pipeline. And the heat storage circulating water pump bypasses a control valve V10. Accurate flow transmission and distribution of multiple heat exchange wells, fluid parameter monitoring, water quality observation and flexible sealing of temperature measurement optical fibers can be achieved, and stable change of the fluid flow speed is ensured.

Description

Technical Field

[0001] The invention belongs to the field of group well heating in the process of medium and deep geothermal development and utilization, and relates to a multi-functional wellhead device for well group gathering and transportation and seasonal stratum heat storage. Background Art

[0002] In northern China, winter heating mainly relies on methods such as cogeneration and coal-fired boilers. As a rich renewable energy source in China, geothermal energy has now been strongly promoted and widely applied in related industries such as the building energy conservation field. The exploitation depth of geothermal energy has expanded from shallow to medium and deep layers. Among them, due to advantages such as small floor area and no need to consider cold and heat balance, the medium and deep geothermal downhole heat exchange heating technology has developed rapidly in northern China.

[0003] With the rapid development of the urbanization construction progress in China, the current heating communities under construction are all above several hundred thousand square meters. However, due to the low heat extraction power of a single medium and deep geothermal downhole heat exchange well, a heating community needs to be equipped with several or even dozens of medium and deep heat exchange wells to meet the heating demand of the community. In the process of multi-well fluid transportation and distribution, the wells close to the heat exchange station are allocated more flow, while the wells far from the heat exchange station are allocated less flow, resulting in the problem of unbalanced fluid transportation and distribution, which leads to inconsistent heat extraction power of each heat exchange well, and the actual operating conditions deviate greatly from the designed conditions. To solve such problems, relevant scholars have carried out optimized designs since the project design stage. Although such problems can be solved, the increased investment cost is very high, and this method can only solve the problems that occur in newly built communities, and cannot solve the problem of using medium and deep geothermal group wells for heating in old communities. Therefore, a solution with low cost and capable of solving the problem of unbalanced multi-well fluid distribution in old communities is needed.

[0004] The wellhead equipment of the medium and deep geothermal downhole heat exchange well can only realize the function of fluid transportation and distribution, and cannot realize other functions at the wellhead of the medium and deep heat exchange well. Therefore, there is an urgent need for a new wellhead equipment that can realize functions such as fluid monitoring, control, water quality monitoring, and pipeline cleaning.

[0005] During the operation of the medium and deep geothermal well downhole heat exchange heating technology in the heating season, with the operation time, the heat exchange power of the heat exchange well shows a downward trend. Although most of the heat can be restored through the geothermal temperature recovery during the non-heating season, from the perspective of long-term operation, the heat exchange power of the heat exchange well still decreases year by year in each heating season. To solve this phenomenon, a technical means is needed to realize seasonal conversion and the technology of storing deep high-temperature geothermal energy in shallow low-temperature strata.

[0006] With the development of the downhole heat exchange technology for medium and deep geothermal energy, in order to better monitor the temperature of formation rock and soil, it is necessary to lower a temperature-measuring optical fiber from the wellhead equipment into the medium and deep geothermal downhole heat exchange well for monitoring the temperature of formation rock and soil. Currently, the sealing of the temperature-measuring optical fiber at the lowering port of the wellhead equipment generally uses a rigid seal. As the service time increases, the sealing port will damage the temperature-measuring optical fiber. Therefore, a new optical fiber sealing method is needed to solve this problem. Summary of the Invention

[0007] Aiming at the deficiencies existing in the prior art, the purpose of the present invention is to provide a multifunctional wellhead equipment for well group gathering and transportation and cross-seasonal formation heat storage, which can achieve accurate distribution of the flow rates of multiple heat exchange wells, monitor the fluid temperature, flow rate, single-well heat extraction power, and inlet and outlet temperatures of the heat exchange wells during the heating season, observe the water quality in the pipeline during the operation of the heating season, perform backwashing according to the water quality of the circulating water to ensure the cleanliness of the circulating water in the heat exchange wells, use a flexible seal for the temperature-measuring optical fiber to avoid damaging the optical fiber, and achieve a smooth change in the fluid flow rate between the heat preservation inner pipe of the medium and deep heat exchange well and the water supply pipeline to avoid sudden changes in the fluid flow rate.

[0008] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0009] A multifunctional wellhead equipment for well group gathering and transportation and cross-seasonal formation heat storage includes a heat preservation inner pipe G1, a geothermal circulation water supply pipeline G2 connected to the heat preservation inner pipe G1, a geothermal circulation return water pipeline G3 connected to the wellhead equipment main pipe J2 outside the heat preservation inner pipe G1, a bypass pipeline G4 connecting the geothermal circulation water supply pipeline G2 and the geothermal circulation return water pipeline G3, a wellhead equipment upper end cover J1 provided at the top of the wellhead equipment main pipe J2, a heat exchange well casing J3 provided outside the wellhead equipment main pipe J2, a geothermal circulation water supply pipeline pressure gauge P1 and a geothermal circulation water supply pipeline temperature transmitter T1 provided on the geothermal circulation water supply pipeline G2, a geothermal circulation return water pipeline pressure gauge P2 and a geothermal circulation return water pipeline temperature transmitter T2 provided on the geothermal circulation return water pipeline G3, a heat metering table HM and a heat storage small power circulating water pump WP, a Y-shaped filter V1 provided on the geothermal circulation return water pipeline G3, an energy valve V2, geothermal circulation return water pipeline valves V3 provided on both sides of the heat storage small power circulating water pump WP, a sewage valve V5 provided on the geothermal circulation return water pipeline G3, a geothermal circulation return water pipeline control butterfly valve V6 and a sight glass V7, a bypass pipeline bypass valve V8 provided on the bypass pipeline G4, a geothermal circulation water supply pipeline control butterfly valve V9 provided on the geothermal circulation water supply pipeline G2, and a heat storage circulating water pump bypass control valve V10 provided on the bypass of the heat storage small power circulating water pump WP; a buffer cavity H is provided between the heat preservation inner pipe G1 and the geothermal circulation water supply pipeline G2 to achieve a smooth change in the fluid flow rate and avoid sudden changes in the fluid flow rate.

[0010] The present invention further includes the following technical features:

[0011] Specifically, the heat exchange well casing J3 includes an upper heat exchange well casing J3-1 and a lower heat exchange well casing J3-2; between the upper heat exchange well casing J3-1 and the lower heat exchange well casing J3-2 is the connection JLJ between the upper and lower parts of the heat exchange well; on the side wall of the heat exchange well casing J3 is provided a flow channel JLD on the inner wall of the heat exchange well casing, and the flow channel JLD on the inner wall of the heat exchange well casing includes an upper heat exchange well casing inner wall flow channel JLD-1 and a lower heat exchange well casing inner wall flow channel JLD-2.

[0012] Specifically, the heat preservation inner pipe G1 includes an upper heat exchange well heat preservation inner pipe G1-1 and a lower heat exchange well heat preservation inner pipe G1-2; between the upper heat exchange well heat preservation inner pipe G1-1 and the lower heat exchange well heat preservation inner pipe G1-2 is the connection GLJ between the upper and lower parts of the heat exchange well heat preservation inner pipe; on the side wall of the heat preservation inner pipe G1 is provided a flow channel GLD on the outer wall of the heat exchange well pipe heat preservation inner pipe, and the flow channel GLD on the outer wall of the heat exchange well pipe heat preservation inner pipe includes an upper heat exchange well pipe heat preservation inner pipe outer wall flow channel GLD-1 and a lower heat exchange well heat preservation inner pipe outer wall flow channel GLD-2.

[0013] Specifically, at the upper end cover J1 of the wellhead equipment through which the geothermal circulation water supply pipe G2 passes, a wellhead sealing device X1 and a heat exchange well annulus air exhaust device X2 are provided; at the top of the geothermal circulation water supply pipe G2, a heat preservation inner pipe air exhaust device X3 is provided;

[0014] Between the top of the heat preservation inner pipe G1 and the geothermal circulation water supply pipe G2 is a metal flexible connection R1 for the geothermal circulation water supply pipe; between the main pipe J2 of the wellhead equipment and the geothermal circulation return water pipe G3 is a metal flexible connection R2 for the geothermal circulation return water pipe.

[0015] For the control method of the multi-functional wellhead equipment for well group gathering and transportation and cross-seasonal formation heat storage, during the heating season, the energy valve V2, the bypass control valve V10 of the heat storage circulation water pump, the control butterfly valve V6 of the geothermal circulation return water pipe, and the control butterfly valve V9 of the geothermal circulation water supply pipe are opened. Among them, the flow characteristic curve of the energy valve V2 is a linear relationship, and it can achieve a linear relationship between the valve opening and the flow rate; the geothermal circulation return water pipe valve V3, the sewage valve V5, and the bypass valve V8 of the bypass pipe are closed; after the used geothermal circulation return water enters the heat exchange well through the geothermal circulation return water pipe G3 for heat exchange, it enters the geothermal circulation water supply pipe G2 through the heat preservation inner pipe G1 and is transported to users for utilization;

[0016] The heat meter HM can monitor the temperature of the geothermal circulation water supply pipe G2 and the flow rate of the geothermal circulation return water pipe G3 in real time, and adjust the opening of the energy valve V2 according to the flow rate, control the flow rate entering each well during group well heating, can make the flow rate entering each well consistent, and can also accurately adjust the flow rate entering each well according to the demand, so as to realize the distribution of the flow rate according to the demand during group well heating.

[0017] Specifically, the sewage discharge valve V5 can achieve the cleaning of a single well during the heating operation, before the start of the heating operation, and after the end of the heating operation. When the wellhead equipment is cleaning a single well, it can perform reverse circulation cleaning. The control process is as follows: During reverse circulation cleaning, the circulating water pressure in the geothermal circulation water supply pipeline G2 is used for cleaning. Open the control butterfly valve V9 of the geothermal circulation water supply pipeline, the bypass control valve V10 of the heat storage circulating pump, the energy valve V2, and the sewage discharge valve V5, and close the valve of the geothermal circulation return water pipeline V3, the control butterfly valve V6 of the geothermal circulation return water pipeline, and the bypass valve V8 of the bypass pipeline. The clean geothermal cleaning water enters the medium-deep heat exchange well from the geothermal circulation water supply pipeline G2 for cleaning, and the cleaned water is discharged through the sewage discharge valve V5 via the geothermal circulation return water pipeline G3 until the water quality of the cleaned water is the same as that of the cleaning clean water, then the cleaning stops.

[0018] Specifically, a fiber optic perforated male pipe X1-3 is provided on the upper end cover JI of the wellhead equipment. The optical fiber passes through the fiber optic hole and enters the well to monitor the well wall temperature. The sealing of the optical fiber of the wellhead equipment is a flexible seal, and the implementation process is as follows: A sealing ring X1-1 is provided in the male pipe X1-3, and a hole is provided at the center position of the sealing ring X1-1 for the optical fiber to pass through. During installation, the optical fiber passes through the female pipe X1-2 and then continues to pass through the sealing ring X1-1. After the optical fiber is completely lowered into the well, during sealing, the sealing ring X1-1 is inserted into the male pipe X1-3. The length of the sealing ring X1-1 is less than or equal to two-thirds of the length of the male pipe X1-3. After the sealing ring X1-1 is inserted, the female pipe X1-2 and the male pipe X1-3 are tightened. The female pipe X1-2 gradually squeezes the sealing ring X1-1, and the sealing ring X1-1 is deformed by the extrusion, completely sealing the optical fiber.

[0019] Specifically, the wellhead equipment can perform cross-season intermittent heat storage during the non-heating season, achieving cross-season intermittent heat storage in two working conditions, namely pump-free cross-season heat storage and micro-power long-time circulation cross-season heat storage. The control process is as follows: During cross-season heat storage, when the heat storage requirement is small, pump-free cross-season heat storage is carried out. Open the energy valve V2, the bypass valve V8 of the bypass pipeline, and the bypass control valve V10 of the heat storage circulating pump, and close the valve of the geothermal circulation return water pipeline V3, the sewage discharge valve V5, the control butterfly valve V6 of the geothermal circulation return water pipeline, and the control butterfly valve V9 of the geothermal circulation water supply pipeline. When the heat storage requirement is large, micro-power long-time circulation cross-season heat storage is carried out. Open the energy valve V2, the bypass valve V8 of the bypass pipeline, and the valve of the geothermal circulation return water pipeline V3, and close the bypass control valve V10 of the heat storage circulating pump, the sewage discharge valve V5, the control butterfly valve V6 of the geothermal circulation return water pipeline, and the control butterfly valve V9 of the geothermal circulation water supply pipeline.

[0020] Specifically, when the heat storage capacity is small, during the non-heating season, the heat exchange well, the geothermal circulation water supply pipe G2, and the geothermal circulation water return pipe G3 are filled with clean water before the geothermal circulation water return pipe control butterfly valve V6 and the geothermal circulation water supply pipe control butterfly valve V9. The deep high-temperature formation GW transfers heat to the clean water in the well. The clean water in the heat exchange well transfers heat from the deep part to the shallow part of the well. After the temperature of the shallow clean water in the heat exchange well rises, it transfers heat to the shallow low-temperature formation DW for heat storage;

[0021] When the heat storage capacity is large, during the non-heating season, the heat exchange well, the geothermal circulation water supply pipe G2, and the geothermal circulation water return pipe G3 are filled with clean water before the geothermal circulation water return pipe control butterfly valve V6 and the geothermal circulation water supply pipe control butterfly valve V9; open the geothermal circulation water return pipe valve V3 and the bypass pipe bypass valve V8, close the heat storage circulation water pump bypass control valve V10, and the deep high-temperature formation GW transfers heat to the clean water in the well. Turn on the heat storage micro-power circulation pump WP, and the deep high-temperature formation GW continuously transfers heat to the clean water in the well. After the temperature of the clean water in the well rises, it stores heat from the shallow formation DW to the shallow low-temperature formation; the heat meter HM monitors the heat stored in the shallow formation;

[0022] When storing heat during the non-heating season, an intermittent method is adopted to increase the heat storage influence radius and store more heat. The daily heat storage time does not exceed 12h, and heat storage is not carried out at other times.

[0023] Specifically, high heat dissipation fins GSR are provided on the outer wall of the heat exchange well casing J3 of the wellhead equipment. Reinforcing ribs JQJ are provided on the outer wall of the heat exchange well casing J3 and the high heat dissipation fins GSR. A flow channel is provided on the inner wall of the heat exchange well casing J3; a flow channel is provided on the outer wall of the inner pipe of the heat preservation inner pipe G1.

[0024] The cross-sectional area of the flow channel on the inner wall of the heat exchange well casing J3 decreases from bottom to top. During heat storage in the non-heating season, the flow velocity of the circulating water in the heat exchange well changes in the flow channel. The surface of the flow channel is treated as a smooth surface to reduce the circulating resistance of the circulating water in the heat exchange well; the small cross-sectional area opening of the lower casing flow channel JLD-2 is connected to the large cross-sectional area opening of the upper casing flow channel JLD-2, and the center lines of the large and small openings are on the same center.

[0025] The cross-sectional area of the flow channel on the outer wall of the heat preservation inner pipe G1 decreases from bottom to top. During heat storage in the non-heating season, the flow velocity of the circulating water in the heat exchange well changes in the flow channel. The surface of the flow channel is treated as a smooth surface to reduce the circulating resistance of the circulating water in the heat exchange well; the small cross-sectional area opening of the lower heat preservation inner pipe flow channel GLD-2 is connected to the large cross-sectional area opening of the upper heat preservation inner pipe flow channel GLD-2, and the center lines of the large and small openings are on the same center.

[0026] Compared with the prior art, the present invention has the following technical effects:

[0027] The present invention can achieve precise distribution of the flow rate of multiple heat exchange wells; during the heating season, it can monitor the fluid temperature, flow rate, heat extraction power of a single well, and inlet and outlet temperatures of the heat exchange wells; during the operation in the heating season, it can observe the water quality inside the pipeline through the V7 sight glass on the pipeline; it can perform backwashing according to the water quality of the circulating water to ensure the cleanliness of the circulating water in the heat exchange wells; it can achieve flexible sealing of the temperature-measuring optical fiber to avoid damage to the optical fiber; between the thermal insulation inner pipe of the medium-deep heat exchange well and the water supply pipeline, a buffer chamber is used to achieve a smooth change in the fluid flow rate and avoid sudden changes in the fluid flow rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a comparison chart of the flow rate characteristic curves of the energy valve.

[0029] Figure 2 It is the front view of the wellhead equipment in the heating season of the present invention.

[0030] Figure 3 It is the three-view drawing of the wellhead seal of the present invention.

[0031] Figure 4 It is the front view of the exhaust device of the present invention.

[0032] Figure 5 It is the front view of the wellhead equipment during heat storage in the non-heating season of the present invention.

[0033] Figure 6 It is the front view, sectional view and partial enlarged view of the heat exchange well casing of the present invention.

[0034] Figure 7 It is the front view, sectional view and partial enlarged view of the thermal insulation inner pipe of the present invention.

[0035] The meanings of the various reference numerals in the figures are as follows:

[0036] G1. Thermal insulation inner pipe; G2. Geothermal circulation water supply pipeline; G3. Geothermal circulation water return pipeline; G4. Bypass pipeline; J1. Upper end cover of wellhead equipment; J2. Main pipe of wellhead equipment; J3. Heat exchange well casing; J3-1. Upper casing of heat exchange well; J3-2. Lower casing of heat exchange well; JLD. Flow channel on the inner wall of heat exchange well casing; JLD-1. Flow channel on the inner wall of upper casing of heat exchange well; JLD-2. Flow channel on the inner wall of lower casing of heat exchange well; JLJ. Connection between upper and lower casings of heat exchange well; G1-1. Upper thermal insulation inner pipe of heat exchange well; G1-2. Lower thermal insulation inner pipe of heat exchange well; GL. Flow channel on the outer wall of thermal insulation inner pipe of heat exchange well; GLD-1. Flow channel on the outer wall of upper thermal insulation inner pipe of heat exchange well; GLD-2. Flow channel on the outer wall of lower thermal insulation inner pipe of heat exchange well; GLJ. Connection between upper and lower thermal insulation inner pipes of heat exchange well; X1. Wellhead sealing device; X2. Annulus exhaust device of heat exchange well; X3. Exhaust device of thermal insulation inner pipe; R1. Metal flexible connection of geothermal circulation water supply pipeline; R2. Metal flexible connection of geothermal circulation water return pipeline; P1. Pressure gauge of geothermal circulation water supply pipeline; P2. Pressure gauge of geothermal circulation water return pipeline; T1. Temperature transmitter of geothermal circulation water supply pipeline; T2. Temperature transmitter of geothermal circulation water return pipeline; HM. Heat metering table; WP. Small power circulating pump for heat storage; JQJ. Reinforcing rib, GSR. High heat dissipation fin, X1-1. Sealing ring, X1-2. Female threaded pipe, X1-3. Male threaded pipe, GW. Deep high-temperature formation, DW. Shallow low-temperature formation; V1. Y-type filter; V2. Energy valve; V3. Valve of geothermal circulation water return pipeline; V5. Drain valve; V6. Control butterfly valve of geothermal circulation water return pipeline; V7. Sight glass, V7-1. Lower viewing window, V7-2. Upper viewing window; V8. Bypass valve of bypass pipeline; V9. Control butterfly valve of geothermal circulation water supply pipeline; V10. Bypass control valve of heat storage circulating pump. Detailed implementation manners

[0037] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent transformations made on the basis of the technical solutions of this application fall within the protection scope of the present invention.

[0038] Embodiment 1:

[0039] As Figures 1 to 7As shown in the figure, this embodiment provides a multi-functional wellhead device for well group gathering and transportation and cross-season formation heat storage, including a heat-insulating inner pipe G1 extending from the formation, a geothermal circulation water supply pipe G2 connected to the heat-insulating inner pipe G1, a geothermal circulation water return pipe G3 connected to the main pipe J2 of the wellhead device outside the heat-insulating inner pipe G1, a bypass pipe G4 connecting the geothermal circulation water supply pipe G2 and the geothermal circulation water return pipe G3, an upper end cover J1 of the wellhead device arranged at the top of the main pipe J2 of the wellhead device, a heat exchange well casing J3 arranged outside the main pipe J2 of the wellhead device, a geothermal circulation water supply pipe pressure gauge P1 and a geothermal circulation water supply pipe temperature transmitter T1 arranged on the geothermal circulation water supply pipe G2, a geothermal circulation water return pipe pressure gauge P2 and a geothermal circulation water return pipe temperature transmitter T2 arranged on the geothermal circulation water return pipe G3, a heat meter HM and a small power heat storage circulation pump WP, a Y-type filter V1 arranged on the geothermal circulation water return pipe G3, an energy valve V2, geothermal circulation water return pipe valves V3 arranged on both sides of the small power heat storage circulation pump WP, a blowdown valve V5 arranged on the geothermal circulation water return pipe G3, a geothermal circulation water return pipe control butterfly valve V6 and a sight glass V7, a bypass valve V8 of the bypass pipe arranged on the bypass pipe G4, a geothermal circulation water supply pipe control butterfly valve V9 arranged on the geothermal circulation water supply pipe G2, and a heat storage circulation pump bypass control valve V10 arranged on the bypass of the small power heat storage circulation pump WP.

[0040] The heat exchange well casing J3 includes an upper heat exchange well casing J3-1 and a lower heat exchange well casing J3-2; between the upper heat exchange well casing J3-1 and the lower heat exchange well casing J3-2 is the connection JLJ of the upper and lower parts of the heat exchange well casing; on the side wall of the heat exchange well casing J3 is provided a flow channel JLD on the inner wall of the heat exchange well casing, and the flow channel JLD on the inner wall of the heat exchange well casing includes an upper heat exchange well casing inner wall flow channel JLD-1 and a lower heat exchange well casing inner wall flow channel JLD-2.

[0041] The heat-insulating inner pipe G1 includes an upper heat exchange well heat-insulating inner pipe G1-1 and a lower heat exchange well heat-insulating inner pipe G1-2; between the upper heat exchange well heat-insulating inner pipe G1-1 and the lower heat exchange well heat-insulating inner pipe G1-2 is the connection GLJ of the upper and lower parts of the heat exchange well heat-insulating inner pipe; on the side wall of the heat-insulating inner pipe G1 is provided a flow channel GLD on the outer wall of the heat-insulating inner pipe of the heat exchange well pipe, and the flow channel GLD on the outer wall of the heat-insulating inner pipe of the heat exchange well pipe includes an upper heat exchange well pipe heat-insulating inner pipe outer wall flow channel GLD-1 and a lower heat exchange well heat-insulating inner pipe outer wall flow channel GLD-2.

[0042] At the place where the geothermal circulation water supply pipe G2 passes through the upper end cover J1 of the wellhead device, there are provided a wellhead sealing device X1 and a heat exchange well annulus exhaust device X2; at the top of the geothermal circulation water supply pipe G2 is provided a heat-insulating inner pipe exhaust device X3; between the top of the heat-insulating inner pipe G1 and the geothermal circulation water supply pipe G2 is a metal flexible connection R1 of the geothermal circulation water supply pipe; between the main pipe J2 of the wellhead device and the geothermal circulation water return pipe G3 is a metal flexible connection R2 of the geothermal circulation water return pipe.

[0043] The present invention also provides a control method for a multi-functional wellhead device for well group gathering and transportation and cross-season formation heat storage. During the heating season, the energy valve V2, the bypass control valve V10 of the heat storage circulating water pump, the control butterfly valve V6 of the geothermal circulating return water pipeline, and the control butterfly valve V9 of the geothermal circulating supply water pipeline are opened, and the geothermal circulating return water pipeline valve V3, the blowdown valve V5, and the bypass valve V8 of the bypass pipeline are closed. After the used geothermal circulating return water enters the heat exchange well through the geothermal circulating return water pipeline G3 for heat exchange, it enters the geothermal circulating supply water pipeline G2 through the heat preservation inner pipe G1 and is transported to users for utilization.

[0044] During the heating season, when the heating area of the heating community is large and the required heat load is large, due to the low single-well heat extraction power of the medium-deep geothermal heat exchange well, a heating community needs multiple medium-deep geothermal wells as heat sources for heating. When arranging the well positions of multiple heat exchange wells, the distances from each heat exchange well to the heating station building of the heating community are different, resulting in different frictional resistances along the way from each geothermal well to the energy station. As a result, the flow rates from each well to the heating community are different due to inconsistent frictional resistances, and then the heat extraction powers of each well are different, seriously deviating from the original design conditions. To solve this problem, the present invention sets a heat meter HM and an energy valve V2 in the geothermal circulating return water pipeline G3. The heat meter can monitor the temperature of the geothermal circulating supply water pipeline G2 and the flow rate of the geothermal circulating return water pipeline G3 in real time. The energy valve V2 adjusts the opening degree of the energy valve according to the detected flow signal to control the flow rate entering each well during group well heating. It can achieve the same flow rate entering each well, and can also accurately adjust the flow rate entering each well according to requirements; it realizes the distribution of the flow rate according to requirements during group well heating.

[0045] The heat meter HM of the present invention sets a temperature sensor T1 in the geothermal circulating supply water pipeline G2 and a temperature sensor T2 in the geothermal circulating return water pipeline G3 to measure the temperature of the geothermal supply and return water, and transmits the temperature signal to the heat meter HM. The heat meter converts according to the collected geothermal supply and return water temperatures and the flow rate measured by itself, and displays the heat collected by a single well. The heat meter HM can realize the long-term storage of the supply and return water temperatures and heat. During the heating period or after the heating ends, the staff can analyze according to the stored data to determine the operation parameters of the wells in the next heating season, that is, adjust the flow rate entering the medium-deep heat exchange well in this heating season according to the heat extraction amount of a single well in the previous heating season, and then control the heat extraction power of a single heat exchange well in this heating season, and finally realize the same heat extraction power for each medium-deep heat exchange well during long-term operation, ensuring the long-term stable operation of medium-deep geothermal energy.

[0046] The energy valve V2 of the present invention is different from ordinary valves. The flow characteristic curve of this valve is a linear relationship, which can achieve a linear relationship between the valve opening and the flow rate, that is, a linear relationship between the valve opening ratio and the flow percentage. For example, when the valve opening is 50%, the flow rate is 50% of the designed flow rate. For details, see the flow characteristic curve table in the linear relationship. Different from the characteristic curves of quick-opening and equal-percentage valves, it is impossible to achieve linear adjustment of the flow percentage and the valve opening.

[0047] A sight glass V7 is provided on the wellhead equipment to observe the flow of circulating water in the pipeline, the water quality, etc. Observe the water quality through the sight glass V7 and decide whether to clean the pipeline during the heating operation according to the water quality. The sight glass V7 is provided with an upper viewing window V7-2 and a lower viewing window V7-1. The viewing window material is made of tempered borosilicate glass, quartz glass, etc., with a thickness of not less than 100mm; since the outdoor temperature is relatively low during the heating period, in extreme cases, the outdoor temperature can be below minus 20-30°C or even lower. Therefore, the allowable sudden temperature change of the viewing window material can be divided into six series: less than 60°C, less than 80°C, less than 100°C, less than 120°C, less than 140°C, and less than 160°C. The working temperature of the viewing window material is divided into five series: 0°C to 80°C, 0°C to 100°C, 0°C to 120°C, 0°C to 140°C, and 0°C to 160°C. The pressure resistance level of the viewing window material is three series: 1.0MPa, 1.6MPa, and 2.5MPa. The sealing material of the viewing window material is nitrile rubber and polytetrafluoroethylene. The above parameters of the sight glass can be selected according to the characteristics of the circulating medium in the medium-deep heat exchange well.

[0048] The sight glass V7 is arranged on the G3 geothermal circulation return water pipeline, which is different from the general situation of being arranged on G2. It can observe the water quality through the sight glass. If the water quality is observed to be poor, the work can be stopped to clean the heat exchange well and the pipeline.

[0049] The sight glass V7 of the present invention is provided with an upper viewing window V7-2 and a lower viewing window V7-1, which is different from common sight glasses. Common sight glasses generally only have one viewing window. In actual production, the effect of observing water quality with one viewing window is very poor and the water quality cannot be well observed. The present invention is provided with upper and lower viewing windows, and the center lines of the two viewing windows are on the same line and have the same size. During production, when observing water quality, shine strong light on the upper lens of the sight glass to observe the water quality, and at the same time, the water quality can also be observed according to the light transmittance. High light transmittance proves good water quality, and low light transmittance proves poor water quality.

[0050] Conventional wellhead equipment cannot achieve the cleaning of a single well. The wellhead equipment is provided with a blowdown valve V5 in the geothermal circulation return water pipeline G3. The specifications and models of the blowdown valve are five series of DN80, DN100, DN150, DN200, and DN250. The specification of the blowdown valve is one specification smaller than that of the geothermal circulation return water pipeline G3. The blowdown valve V5 can achieve the cleaning of a single well during the heating operation, before the start of the heating operation, and after the end of the heating operation. Moreover, the model of the blowdown valve is larger, which is different from the conventional blowdown valve. Since it is necessary to quickly clean the pipeline within a short time during the heat exchange well circulation, especially when the water quality of the heat exchange well does not meet the standard during the heating period, the cleaning of a single well can be realized, avoiding the heating failure of the entire community due to the cleaning of the heat exchange well and causing a heating accident.

[0051] When the wellhead equipment cleans a single well, it can perform reverse circulation cleaning. Specifically, during reverse circulation cleaning, the internal circulation water pressure in the geothermal circulation water supply pipeline G2 is used for cleaning. Open the control butterfly valve V9 of the geothermal circulation water supply pipeline, the bypass control valve V10 of the heat storage circulation water pump, the energy valve V2, and the blowdown valve V5, and close the valve V3 of the geothermal circulation return water pipeline, the control butterfly valve V6 of the geothermal circulation return water pipeline, and the bypass valve V8 of the bypass pipeline; the clean geothermal cleaning water enters the medium-deep heat exchange well from the geothermal circulation water supply pipeline G2 for cleaning. The cleaned water passes through the geothermal circulation return water pipeline G3 and is discharged through the blowdown valve V5 until the water quality of the cleaned water is the same as that of the clean geothermal cleaning water, and then the cleaning stops. Since the internal circulation water pressure in the geothermal circulation water return pipeline G3 is much greater than the internal circulation water pressure in the geothermal circulation water supply pipeline G2, after cleaning is completed using the internal circulation water pressure in the geothermal circulation water return pipeline G3, to ensure the cleaning effect. After cleaning is completed, close the blowdown butterfly valve and resume heating. According to this method, the cleaning of multiple heat exchange wells in a heating community can be realized.

[0052] The connection between the heat preservation inner pipe G1 of the wellhead equipment and the geothermal circulation water supply pipeline G2 is a flange connection. A buffer cavity H is provided between the heat preservation inner pipe G1 and the geothermal circulation water supply pipeline G2. This buffer cavity is different from the conventional connection method. Conventionally, the connection between the heat preservation inner pipe G1 and the geothermal circulation water supply pipeline G2 directly changes from a small specification of the heat preservation inner pipe G1 to a large specification pipeline. The flow rate of the geothermal circulation water changes suddenly here, resulting in the extremely easy occurrence of air bags here. After the air bags appear, since the internal circulation water pressure in the external geothermal circulation water return pipeline G3 is much greater than the internal circulation water pressure in the geothermal circulation water supply pipeline G2, and the material of the heat preservation inner pipe G1 is generally a plastic pipeline, the heat preservation inner pipe will be flattened here, damaging the heat preservation inner pipe G1. Through the buffer cavity H, such problems can be completely avoided.

[0053] On the upper end cover JI of the wellhead equipment, a fiber-optic perforated male pipe X1-3 is provided. The optical fiber passes through the fiber-optic hole and enters the well to monitor the temperature of the well wall. After the optical fiber penetrates, in order to prevent the circulating water in the well from flowing out through the gap between the fiber-optic hole and the optical fiber, it is necessary to seal this gap. The conventional sealing method is rigid sealing. During operation, it is found that the optical fiber is extremely easy to be damaged at the sealing point, and the price of the optical fiber is expensive, resulting in huge losses. Therefore, the sealing of the optical fiber of the wellhead equipment is changed from rigid sealing to flexible sealing. Specifically: Weld the finished fiber-optic perforated male pipe X1-3 on the upper end cover J of the wellhead equipment, manufacture the female pipe X1-2, the model of the female pipe is matched with that of the male pipe. The female pipe X1-2 is a finished steel bar with threads cut on a lathe, and a hole is drilled at the center position of the female pipe X1-2. The diameter of the hole is larger than the diameter of the optical fiber. The optical fiber passes through the hole in the female pipe X1-2 and enters the heat exchange well; To solve the sealing problem, a sealing ring X1-1 is arranged in the male pipe X1-3, and a hole is arranged at the center position of the sealing ring X1-1 for the optical fiber to pass through; During installation, the optical fiber passes through the female pipe X1-2 and then continues to pass through the sealing ring X1-1. After the optical fiber is completely lowered into the well, during sealing, the sealing ring X1-1 is stuffed into the male pipe X1-3. The length of the sealing ring X1-1 is less than or equal to two-thirds of the length of the male pipe X1-3. After the sealing ring X1-1 is stuffed in, the female pipe X1-2 is tightened with the male pipe X1-3. As the threads of the female pipe X1-2 and the male pipe X1-3 are gradually tightened, the female pipe X1-2 will gradually squeeze the sealing ring X1-1, and the sealing ring X1-1 will be deformed by extrusion, completely sealing the optical fiber.

[0054] The material of the sealing ring X1-1 of the wellhead equipment is: natural rubber, silicone rubber, ethylene propylene rubber, fluorinated rubber, nitrile rubber, fluororubber, etc. The sealing ring material has high temperature resistance and can maintain good use elasticity in the temperature range of -30°C to +250°C, and has the characteristics of resistance to strong oxidants, oil, acid and alkali, and aging resistance.

[0055] An exhaust valve is provided on the upper end cover JI of the wellhead equipment to discharge the gas in the inner annulus between the well casing and the heat preservation inner pipe G1. An exhaust valve is provided at the highest point of the geothermal circulating water supply pipe G2 to discharge the gas in the heat preservation inner pipe G2. The setting of the exhaust valve is different from the conventional wellhead equipment that only sets an exhaust valve on the geothermal circulating water supply pipe G2. By setting the exhaust valve at the highest point of the geothermal circulating water supply pipe G2, it can ensure the discharge of the gas in the inner annulus between the well casing and the heat preservation inner pipe G1 and the gas in the heat preservation inner pipe G2.

[0056] The wellhead equipment can realize heat storage from the deep high-temperature formation GW to the shallow low-temperature formation DW in the non-heating season. The heat stored in the shallow low-temperature formation DW in the non-heating season transfers heat to the circulating water in the heat exchange well in the heating season, improving the heat extraction power of the heat exchange well.

[0057] The wellhead equipment can achieve cross-season intermittent heat storage in the non-heating season, and can achieve cross-season intermittent heat storage in two working conditions, namely pump-free cross-season heat storage and micro-power long-time circulating cross-season heat storage. Specifically: during cross-season heat storage, when the required heat storage capacity is small, pump-free cross-season heat storage is carried out. Open the energy valve V2, the bypass valve V8 of the bypass pipeline, and the bypass control valve V10 of the heat storage circulating water pump, and close the valve V3 of the geothermal circulation return water pipeline, the blowdown valve V5, the control butterfly valve V6 of the geothermal circulation return water pipeline, and the control butterfly valve V9 of the geothermal circulation supply water pipeline; when the required heat storage capacity is large, micro-power long-time circulating cross-season heat storage is carried out. Open the energy valve V2, the bypass valve V8 of the bypass pipeline, and the valve V3 of the geothermal circulation return water pipeline, and close the bypass control valve V10 of the heat storage circulating water pump, the blowdown valve V5, the control butterfly valve V6 of the geothermal circulation return water pipeline, and the control butterfly valve V9 of the geothermal circulation supply water pipeline.

[0058] When the heat storage capacity is small, specifically in the non-heating season, the heat exchange well, the geothermal circulation supply water pipeline G2, and the geothermal circulation return water pipeline G3 are filled with clean water before the control butterfly valve V6 of the geothermal circulation return water pipeline and the control butterfly valve V9 of the geothermal circulation supply water pipeline. The deep high-temperature formation GW transfers heat to the clean water in the well. The clean water in the heat exchange well transfers heat from the deep part to the shallow part of the heat exchange well. After the temperature of the shallow clean water in the heat exchange well rises, the shallow clean water transfers heat to the shallow low-temperature formation DW for heat storage; the heat meter HM monitors the heat stored in the shallow formation.

[0059] When the heat storage capacity is large, specifically in the non-heating season, the heat exchange well, the geothermal circulation supply water pipeline G2, and the geothermal circulation return water pipeline G3 are filled with clean water before the control butterfly valve V6 of the geothermal circulation return water pipeline and the control butterfly valve V9 of the geothermal circulation supply water pipeline. Open the valve V3 of the geothermal circulation return water pipeline and the bypass valve V8 of the bypass pipeline, and close the bypass control valve V10 of the heat storage circulating water pump. The deep high-temperature formation GW transfers heat to the clean water in the well. Turn on the heat storage micro-power circulation pump WP. The deep high-temperature formation GW continuously transfers heat to the clean water in the well. After the temperature of the clean water in the well rises, heat is stored from the shallow formation DW to the shallow low-temperature formation; the heat meter HM monitors the heat stored in the shallow formation.

[0060] During heat storage in the non-heating season, in an intermittent manner, it will increase the heat storage influence radius, that is, more heat can be stored. The daily heat storage time does not exceed 12 hours, and no heat storage is carried out for the rest of the time.

[0061] On the outer wall of the heat exchange well casing J3 of the wellhead equipment, there are high heat dissipation fins GSR. On the outer wall of the heat exchange well casing J3 and the high heat dissipation fins GSR, there are stiffeners JQJ. On the inner wall of the heat exchange well casing J3, there is a flow channel LD. On the outer wall of the inner pipe G1 of the heat preservation inner pipe, there is a flow channel. On the outer wall of the heat exchange well casing J3, there is a GSR high heat dissipation fin casing. The lowering position of this casing is in the DW shallow low-temperature formation, which can increase the heat exchange power of the heat exchange well during the heating season and accelerate the heat dissipation to the shallow low-temperature formation during the non-heating season. On the outer wall of the heat exchange well casing J3, there are GSR high heat dissipation fins, and stiffeners JQJ are arranged on the outside to ensure the quality of the GSR high heat dissipation fins on the outer wall of the heat exchange well casing J3 when they are lowered into the heat exchange well and during the long-term production process.

[0062] On the inner wall of the heat exchange well casing J3 of the wellhead equipment, there is a speed-regulating flow channel. The cross-sectional area of the flow channel decreases from bottom to top. During heat storage in the non-heating season, the flow velocity of the circulating water in the heat exchange well changes in the speed-regulating flow channel. The surface treatment of the flow channel is a smooth surface, which reduces the roughness of the flow channel surface and the circulating resistance of the circulating water in the heat exchange well. For the speed-regulating flow channel provided on the inner wall of the heat exchange well casing J3, at the connection GLJ of each casing to the casing, the speed-regulating flow channel goes from bottom to top, and the small cross-sectional area of the lower casing flow channel JLD-2 is connected to the large cross-sectional area of the upper casing flow channel JLD-2, and the center lines of the small and large openings are on the same center.

[0063] On the outer wall of the heat preservation inner pipe G1 of the wellhead equipment, there is a speed-regulating flow channel. The cross-sectional area of the flow channel decreases from bottom to top. During heat storage in the non-heating season, the flow velocity of the circulating water in the heat exchange well changes in the speed-regulating flow channel. The surface treatment of the flow channel is a smooth surface, which reduces the roughness of the flow channel surface and the circulating resistance of the circulating water in the heat exchange well. For the speed-regulating flow channel provided on the outer wall of the heat preservation inner pipe G1, at the connection GLJ of each heat preservation inner pipe to the heat preservation inner pipe, the speed-regulating flow channel goes from bottom to top, and the small cross-sectional area of the lower heat preservation inner pipe flow channel GLD-2 is connected to the large cross-sectional area of the upper heat preservation inner pipe flow channel GLD-2, and the center lines of the small and large openings are on the same center.

[0064] The preferred embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0065] In addition, it should be noted that, in the above specific embodiments, the various specific technical features described can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0066] In addition, any combination can be made between various different embodiments of the present invention as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. A multi-functional wellhead device for well cluster gathering and cross-season formation heat storage, characterized in that, It includes a heat-insulating inner pipe G1, a geothermal circulation water supply pipe G2 connected to the heat-insulating inner pipe G1, a geothermal circulation water return pipe G3 connected to the wellhead equipment main pipe J2 outside the heat-insulating inner pipe G1, a bypass pipe G4 connecting the geothermal circulation water supply pipe G2 and the geothermal circulation water return pipe G3, a wellhead equipment upper end cover J1 provided at the top of the wellhead equipment main pipe J2, a heat exchange well casing J3 provided outside the wellhead equipment main pipe J2, a geothermal circulation water supply pipe pressure gauge P1 and a geothermal circulation water supply pipe temperature transmitter T1 provided on the geothermal circulation water supply pipe G2, a geothermal circulation water return pipe pressure gauge P2 and a geothermal circulation water return pipe temperature transmitter T2 provided on the geothermal circulation water return pipe G3, as well as a heat meter HM and a heat storage small-power circulation pump WP, a Y-type filter V1 provided on the geothermal circulation water return pipe G3, an energy valve V2, a geothermal circulation water return pipe valve V3 provided on both sides of the heat storage small-power circulation pump WP, a blowdown valve V5 provided on the geothermal circulation water return pipe G3, a geothermal circulation water return pipe control butterfly valve V6 and a sight glass V7, a bypass pipe bypass valve V8 provided on the bypass pipe G4, a geothermal circulation water supply pipe control butterfly valve V9 provided on the geothermal circulation water supply pipe G2, and a heat storage circulation pump bypass control valve V10 provided on the bypass of the heat storage small-power circulation pump WP; a buffer cavity H is provided between the heat-insulating inner pipe G1 and the geothermal circulation water supply pipe G2 to achieve a smooth change in the fluid flow rate and avoid sudden changes in the fluid flow rate.

2. The multifunctional wellhead equipment for well cluster gathering and cross-season formation heat storage according to claim 1, characterized in that, The heat exchange well casing J3 includes an upper heat exchange well casing J3-1 and a lower heat exchange well casing J3-2; the connection between the upper heat exchange well casing J3-1 and the lower heat exchange well casing J3-2 is the connection JLJ between the upper and lower parts of the heat exchange well casing; the side wall of the heat exchange well casing J3 is provided with a heat exchange well casing inner wall flow channel JLD, and the heat exchange well casing inner wall flow channel JLD includes an upper heat exchange well casing inner wall flow channel JLD-1 and a lower heat exchange well casing inner wall flow channel JLD-2.

3. The multifunctional wellhead equipment for well cluster gathering and cross-season formation heat storage according to claim 2, characterized in that, The heat-insulating inner pipe G1 includes an upper heat-insulating inner pipe G1-1 of the heat exchange well and a lower heat-insulating inner pipe G1-2 of the heat exchange well; the connection between the upper heat-insulating inner pipe G1-1 of the heat exchange well and the lower heat-insulating inner pipe G1-2 of the heat exchange well is the connection GLJ between the upper and lower parts of the heat-insulating inner pipe of the heat exchange well; the side wall of the heat-insulating inner pipe G1 is provided with a heat exchange well pipe heat-insulating inner pipe outer wall flow channel GLD, and the heat exchange well pipe heat-insulating inner pipe outer wall flow channel GLD includes an upper heat exchange well pipe heat-insulating inner pipe outer wall flow channel GLD-1 and a lower heat-insulating inner pipe outer wall flow channel GLD-2 of the heat exchange well.

4. The multi-functional wellhead equipment for well cluster gathering and cross-season formation heat storage according to claim 3, characterized in that, At the place where the geothermal circulation water supply pipe G2 penetrates through the wellhead equipment upper end cover J1, a wellhead sealing device X1 and a heat exchange well annulus exhaust device X2 are provided; at the top of the geothermal circulation water supply pipe G2, a heat-insulating inner pipe exhaust device X3 is provided. Between the top of the heat-insulating inner pipe G1 and the geothermal circulation water supply pipe G2 is a geothermal circulation water supply pipe metal soft connection R1; between the wellhead equipment main pipe J2 and the geothermal circulation water return pipe G3 is a geothermal circulation water return pipe metal soft connection R2.

5. The control method of the multifunctional wellhead equipment for well cluster gathering and cross-season formation heat storage according to claim 4, characterized in that, During the heating season, the energy valve V2, the bypass control valve V10 of the heat storage circulating water pump, the control butterfly valve V6 of the geothermal circulating return water pipeline, and the control butterfly valve V9 of the geothermal circulating supply water pipeline are opened. Among them, the flow characteristic curve of the energy valve V2 is a linear relationship, and it can achieve a linear relationship between the valve opening and the flow rate; the geothermal circulating return water pipeline valve V3, the drain valve V5, and the bypass valve V8 of the bypass pipeline are closed; after the used geothermal circulating return water enters the heat exchange well through the geothermal circulating return water pipeline G3 for heat exchange, it enters the geothermal circulating supply water pipeline G2 through the insulated inner pipe G1 and is transported to users for utilization; The heat meter HM can monitor the temperature of the geothermal circulating supply water pipeline G2 and the flow rate of the geothermal circulating return water pipeline G3 in real time, and adjust the opening of the energy valve V2 according to the flow rate, control the flow rate entering each well during group well heating, and can achieve the same flow rate entering each well. It can also accurately adjust the flow rate entering each well according to the demand, and realize the distribution of the flow rate according to the demand during group well heating.

6. The control method of the multifunctional wellhead equipment for well cluster gathering and cross-season formation heat storage according to claim 5, characterized in that, The drain valve V5 can realize the cleaning of a single well during the heating operation, before the heating operation starts, and after the heating operation ends; when the wellhead equipment is cleaning a single well, it can perform reverse circulation cleaning. The control process is as follows: during reverse circulation cleaning, use the internal circulation water pressure in the geothermal circulating supply water pipeline G2 for cleaning, open the control butterfly valve V9 of the geothermal circulating supply water pipeline, the bypass control valve V10 of the heat storage circulating water pump, the energy valve V2, the drain valve V5, and close the geothermal circulating return water pipeline valve V3, the control butterfly valve V6 of the geothermal circulating return water pipeline, and the bypass valve V8 of the bypass pipeline; the geothermal cleaning clean water enters the medium-deep heat exchange well from the geothermal circulating supply water pipeline G2 for cleaning, and the cleaned water passes through the geothermal circulating return water pipeline G3 and is discharged through the drain valve V5 until the water quality of the cleaned water is the same as that of the cleaning clean water, and then the cleaning stops.

7. The control method of the multi-functional wellhead equipment for well cluster gathering and cross-season formation heat storage according to claim 5, characterized in that, A fiber optic perforated male pipe X1-3 is set on the upper end cover JI of the wellhead equipment, and the optical fiber passes through the fiber optic hole and enters the well to monitor the well wall temperature; the sealing of the optical fiber of the wellhead equipment is a flexible seal, and the implementation process is as follows: a sealing ring X1-1 is set in the male pipe X1-3, and a hole is set at the center position of the sealing ring X1-1 for the optical fiber to pass through; during installation, the optical fiber passes through the female pipe X1-2 and then through the sealing ring X1-1. After the optical fiber is completely lowered into the well, during sealing, the sealing ring X1-1 is inserted into the male pipe X1-3, and the length of the sealing ring X1-1 is less than or equal to two-thirds of the length of the male pipe X1-3. After the sealing ring X1-1 is inserted, the female pipe X1-2 and the male pipe X1-3 are tightened, and the female pipe X1-2 gradually squeezes the sealing ring X1-1, and the sealing ring X1-1 is deformed by extrusion to completely seal the optical fiber.

8. The control method of the multi-functional wellhead equipment for well cluster gathering and cross-season formation heat storage according to claim 5, characterized in that, The wellhead equipment can store heat intermittently across seasons during the non-heating season, achieving cross-seasonal intermittent heat storage in two operating conditions, namely pump-free cross-seasonal heat storage and low-power long-cycle cross-seasonal heat storage; the control process is as follows: during cross-seasonal heat storage, when the required heat storage is small, pump-free cross-seasonal heat storage is carried out. Open the energy valve V2, the bypass valve V8 of the bypass pipeline, and the bypass control valve V10 of the heat storage circulating pump, and close the valve V3 of the geothermal circulation return pipeline, the drain valve V5, the control butterfly valve V6 of the geothermal circulation return pipeline, and the control butterfly valve V9 of the geothermal circulation supply pipeline; when the required heat storage is large, low-power long-cycle cross-seasonal heat storage is carried out. Open the energy valve V2, the bypass valve V8 of the bypass pipeline, and the valve V3 of the geothermal circulation return pipeline, and close the bypass control valve V10 of the heat storage circulating pump, the drain valve V5, the control butterfly valve V6 of the geothermal circulation return pipeline, and the control butterfly valve V9 of the geothermal circulation supply pipeline.

9. The control method of the multi-functional wellhead equipment for well cluster gathering and cross-season formation heat storage according to claim 8, characterized in that, When the heat storage is small, during the non-heating season, the heat exchange well, the geothermal circulation supply pipeline G2, and the geothermal circulation return pipeline G3 are filled with clean water before the control butterfly valve V6 of the geothermal circulation return pipeline and the control butterfly valve V9 of the geothermal circulation supply pipeline. The deep high-temperature formation GW transfers heat to the clean water in the well. The clean water in the heat exchange well transfers heat from the deep part to the shallow part of the heat exchange well. After the temperature of the shallow clean water in the heat exchange well rises, the shallow clean water transfers heat to the shallow low-temperature formation DW for heat storage. When the heat storage is large, during the non-heating season, the heat exchange well, the geothermal circulation supply pipeline G2, and the geothermal circulation return pipeline G3 are filled with clean water before the control butterfly valve V6 of the geothermal circulation return pipeline and the control butterfly valve V9 of the geothermal circulation supply pipeline. Open the valve V3 of the geothermal circulation return pipeline and the bypass valve V8 of the bypass pipeline, and close the bypass control valve V10 of the heat storage circulating pump. The deep high-temperature formation GW transfers heat to the clean water in the well. Turn on the low-power heat storage circulating pump WP, and the deep high-temperature formation GW continuously transfers heat to the clean water in the well. After the temperature of the clean water in the well rises, it stores heat in the shallow formation DW to the shallow low-temperature formation; the heat meter HM monitors the heat stored in the shallow formation. During heat storage in the non-heating season, an intermittent method is adopted to increase the heat storage influence radius and store more heat. The daily heat storage time does not exceed 12 hours, and no heat storage is carried out at other times.

10. The control method of the multi-functional wellhead equipment for well cluster gathering and cross-season formation heat storage according to claim 5, characterized in that, On the outer wall of the heat exchange well casing J3 of the wellhead equipment, there are high heat dissipation fins GSR. On the outer wall of the heat exchange well casing J3 and the high heat dissipation fins GSR, there are reinforcing ribs JQJ. On the inner wall of the heat exchange well casing J3, there is a flow channel. On the outer wall of the inner pipe of the heat preservation inner pipe G1, there is a flow channel. The cross-sectional area of the flow channel on the inner wall of the heat exchange well casing J3 decreases from bottom to top. During heat storage in the non-heating season, the flow velocity of the circulating water in the heat exchange well changes in the flow channel. The surface of the flow channel is treated as a smooth surface to reduce the circulating resistance of the circulating water in the heat exchange well; the small cross-sectional area opening of the lower casing flow channel JLD-2 is connected to the large cross-sectional area opening of the upper casing flow channel JLD-2, and the center lines of the large and small openings are on the same center. The cross-sectional area of the outer wall flow channel of the heat-insulating inner pipe G1 decreases from bottom to top. During heat storage in the non-heating season, the flow velocity of the circulating water in the heat exchange well changes within the flow channel. The surface of the flow channel is treated as a smooth surface to reduce the circulation resistance of the circulating water in the heat exchange well. The small cross-sectional area opening of the lower heat-insulating inner pipe flow channel GLD-2 is connected to the large cross-sectional area opening of the upper heat-insulating inner pipe flow channel GLD-2, and the centerlines of the small and large openings are on the same center.

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