Wellhead device and equipment for separate pressure and separate recovery of tight gas and deep coal bed gas in same shaft

Abstract

The invention discloses a well head device and equipment for tight gas and deep coal bed gas partial pressure and separate production in the same shaft, which comprises a coal bed water output multi-way, a coal bed gas output multi-way and a tight gas output multi-way which are sequentially connected from top to bottom, and a sleeve, an oil pipe, a suspension outer pipe, a hollow sucker rod and a polish rod which are coaxially arranged, the casing pipe, the oil pipe, the suspension outer pipe and the hollow sucker rod are sequentially arranged at intervals from outside to inside, the polish rod penetrates through the suspension outer pipe, the bottom end of the suspension outer pipe is connected with the hollow sucker rod in a dynamic sealing mode, and the bottom end of the polish rod is connected with the top end of the hollow sucker rod through a functional connector. A pipe cavity of the hollow sucker rod is communicated with an inner cavity of the hanging outer pipe through an inner channel of the functional connector. A first annulus formed by the suspension outer pipe and the polish rod is communicated with an output port of the coal bed gas output multi-way, a second annulus formed by the oil pipe and the suspension outer pipe is communicated with an output port of the coal bed gas output multi-way, and a third annulus formed by the sleeve and the oil pipe is communicated with an output port of the tight gas output multi-way.

Description

Technical Field

[0001] The present invention relates to the technical field of unconventional natural gas multi-gas co-production and development, and in particular to a wellhead device and equipment for separate pressure production of tight gas and deep coalbed methane in the same wellbore. Background Art

[0002] China is rich in unconventional oil and gas resources, particularly those in geological structures characterized by vertically stacked layers of high-pressure tight gas above and low-pressure deep coalbed methane below. Exploration of multi-gas production within a wellbore has begun. Due to the significant differences in the pressure systems between coalbed methane and tight gas layers, combined production within the wellbore at the same pressure is not feasible. Instead, separate production at different pressures within the wellbore is recommended.

[0003] The multi-reservoir same-wellbore pressure-separation and production technology currently used in conventional oil and gas fields is limited to the production of liquids from two pressure systems. However, the production fluids of coalbed methane and tight gas are at least three fluids in total, namely, gases from two pressure systems and at least one liquid. Therefore, the existing gas production technology and wellhead equipment cannot meet the requirements of the same-wellbore pressure-separation and production of tight gas and deep coalbed methane within the limited space of the wellbore. Summary of the Invention

[0004] The present application provides a wellhead device for separately producing tight gas and deep coalbed methane at the same wellbore under different pressures, which solves the technical problem that the existing technology cannot meet the requirements of separately producing tight gas and deep coalbed methane at the same wellbore under different pressures.

[0005] The present application provides a wellhead device for separate pressure and production of tight gas and deep coalbed methane in the same wellbore, comprising a coalbed water production multi-way, a coalbed gas production multi-way and a tight gas production multi-way connected in sequence from top to bottom, as well as a coaxially arranged casing, oil pipe, hanging outer pipe, hollow sucker rod and light rod, the casing, oil pipe, hanging outer pipe and hollow sucker rod are arranged in sequence from outside to inside, the light rod is passed through the hanging outer pipe, the casing, oil pipe and hanging outer pipe are all fixed relative to the tight gas production multi-way, and the bottom end of the hanging outer pipe is fixed relative to the tight gas production multi-way. It is dynamically sealed with the hollow sucker rod through a dynamic sealing mechanism inside the wellhead, the bottom end of the bare rod is connected to the top end of the hollow sucker rod through a functional joint, and the lumen of the hollow sucker rod is connected to the inner lumen of the hanging outer tube through the inner channel of the functional joint; the first annulus formed by the hanging outer tube and the bare rod is connected to the output port of the coalbed water production multi-channel, the second annulus formed by the oil pipe and the hanging outer tube is connected to the output port of the coalbed gas production multi-channel, and the third annulus formed by the casing and the oil pipe is connected to the output port of the tight gas production multi-channel.

[0006] In some embodiments, the top end of the casing is relatively fixedly connected to the tight gas production multi-way, the oil pipe is fixedly connected to the tight gas production multi-way through the oil pipe hanger, the top outer periphery of the oil pipe is connected to the inner periphery of the oil pipe hanger by a thread, the hanging outer pipe is fixedly connected to the coalbed gas production multi-way through the outer pipe hanger, and the top outer periphery of the hanging outer pipe is connected to the outer pipe hanger by a thread.

[0007] In some embodiments, the functional joint is connected to the polished rod and the hollow sucker rod respectively through threads, and the inner channel forms an opening on the peripheral side of the functional joint.

[0008] In some embodiments, the coalbed water production multi-port, coalbed gas production multi-port and tight gas production multi-port are respectively arranged in a three-way or four-way manner, and include one output port when arranged in a three-way manner, and include two output ports when arranged in a four-way manner, and one of the two output ports is used for testing.

[0009] In some embodiments, a circumferential clamping ring is provided at a position near the lower end of the inner periphery of the hanging outer tube, and the inner periphery of the clamping ring is spaced apart from the hollow sucker rod and the functional joint; the wellhead device includes at least three rope members evenly spaced apart along the circumference of the hanging outer tube, the bottom end of the rope member is installed with a first rope joint, the top end of the rope member is fixed, and the rope member portion is arranged in the first annulus between the hanging outer tube and the polished rod; the wellhead device includes an annular well sealing pressure sleeve, the well sealing pressure sleeve is spaced apart below the clamping ring, and the well sealing pressure sleeve is provided with a rope member for the rope member The first rope joint passes through the hole, and the first rope joint abuts the bottom side of the well sealing sleeve. Under the action of the rope, the well sealing sleeve abuts the bottom end of the hanging outer tube; the bottom side of the clamping ring, the top side of the well sealing sleeve, the inner periphery of the hanging outer tube and the outer periphery of the hollow sucker rod form an annular area. The wellhead device includes a first sealing member arranged in the annular area, and the rope member is passed through the first sealing member; the dynamic sealing mechanism in the wellhead includes a rope member, a first rope joint, an well sealing sleeve and a first sealing member to realize the dynamic sealing connection between the hanging outer tube and the hollow sucker rod.

[0010] In some embodiments, a rod sealing box is installed at the top of the coalbed water production multi-channel, and a dynamic sealing adjustment mechanism is installed above the rod sealing box, the dynamic sealing adjustment mechanism includes a sealing adjustment disk and a wedge adjustment hoop; the wedge adjustment hoop includes an adjusting outer bracket, an adjusting bolt and at least three wedges, the adjusting outer bracket includes an annular frame and a bolt mounting seat connected to the annular frame, all wedges are evenly spaced along the inner circumference of the annular frame, the rod and the rope are passed through the enclosed area of ​​the annular frame, the adjusting bolt is installed on the bolt mounting seat, and the annular frame is retracted and expanded by controlling the tightness of the adjusting bolt; the sealing adjustment disk is sleeved on the outside of the rod, and the sealing adjustment disk is provided with an inclined surface on the bottom side that matches the inclined surface of the wedge, the sealing adjustment disk is provided with a channel for the rope to pass through, and a second rope joint is installed on the top of the rope, the second rope joint abuts against the top side of the sealing adjustment disk, and the height of the sealing adjustment disk changes under the condition of the annular frame retracting and expanding.

[0011] In some embodiments, a second sealing ring is further installed at the area where the bottom end of the hanging outer tube faces the sealing sleeve in the well.

[0012] In some embodiments, the first sealing member is provided as a sealing packing.

[0013] In some embodiments, the wellhead assembly includes three ropes, which are evenly spaced apart along the circumference of the suspended outer pipe.

[0014] A device for separately producing tight gas and deep coalbed methane by pressure separation in the same wellbore comprises the above-mentioned wellhead device.

[0015] The beneficial effects of the present application are as follows: a wellhead device for separately producing tight gas and deep coalbed methane in the same wellbore by pressure division is provided, comprising a coalbed water production multi-way, a coalbed gas production multi-way, a tight gas production multi-way, a casing, an oil pipe, a hanging outer pipe, a hollow sucker rod and a polished rod; a first annulus formed by the hanging outer pipe and the polished rod is connected to the output port of the coalbed water production multi-way, a second annulus formed by the oil pipe and the hanging outer pipe is connected to the output port of the coalbed gas production multi-way, and a third annulus formed by the casing and the oil pipe is connected to the output port of the tight gas production multi-way. Through the establishment of two pressure systems in the wellbore, a high-pressure tight gas channel, a low-pressure coalbed methane gas channel and a liquid channel are established. The innovative design concept of using the internal cavity of the hollow sucker rod as the output liquid channel is proposed, which solves the problem of the liquid in the moving pipe string being discharged at the wellhead through the process pipeline during stratified mining, and solves the problem of the wellhead production of three kinds of fluids, tight gas and coalbed methane, which are produced separately at different pressures in the same wellbore; it can meet the discharge of fluids from the wellhead of three different pressure systems, which is conducive to the separate measurement of fluids produced in multiple reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention.

[0017] Figure 1 This is a schematic diagram of the overall structure of the wellhead device for separate pressure and production of tight gas and deep coalbed methane in the same wellbore provided by this application;

[0018] Figure 2 for Figure 1 A first partial schematic diagram of;

[0019] Figure 3 for Figure 1 A second partial schematic diagram of

[0020] Figure 4 for Figure 1 A third partial schematic diagram of ;

[0021] Figure 5 A schematic diagram of the dynamic seal-related structure in the wellhead device provided in this application;

[0022] Figure 6 A top view of the sealing sleeve in the wellhead device provided in this application;

[0023] Figure 7 A schematic diagram of the relevant annulus in the wellhead device provided for this application;

[0024] Figure 8 A cross-sectional view of a functional joint in a wellhead device provided in this application;

[0025] Figure 9 A schematic diagram of the dynamic seal adjustment mechanism in the wellhead device provided in this application;

[0026] Figure 10 This is a schematic diagram of the first structure of the wedge adjustment collar in the wellhead device provided by this application;

[0027] Figure 11 A schematic diagram of the second structure of the wedge adjustment collar in the wellhead apparatus provided by the present application in a first state;

[0028] Figure 12 This is a schematic diagram of the second structure of the wedge adjustment collar in the wellhead device provided in the present application in the second state.

[0029] The accompanying drawings are marked with: 1-light rod, 2-second rope joint, 3-sealing adjustment disk, 4-wedge adjustment hoop, 4a-adjusting outer bracket, 4aa-annular frame, 4ab-bolt mounting seat, 4b-adjusting bolt, 4c-wedge, 5-light rod sealing box, 6-coalbed water production multi-way, 7-external pipe hanger, 8-coalbed gas production multi-way, 9-oil pipe hanger, 10-tight gas production multi-way, 11-rope member, 12-clamping ring, 13-first sealing member, 14-second sealing ring, 15-in-well sealing sleeve, 16-first rope joint, 17-casing, 18-oil pipe, 19-hollow sucker rod, 20-functional joint, 20a-inner channel, 20b-opening, 21-hanging outer pipe, 100-first annulus, 200-second annulus, 300-third annulus. DETAILED DESCRIPTION

[0030] Multi-reservoir commingling methods are categorized by wellbore pressure system into two main types: same-wellbore, same-pressure commingling and same-wellbore, different-pressure, and different-pressure commingling. Same-wellbore, same-pressure commingling is primarily suitable for developing producing layers with similar pressure systems. However, coalbed methane, as an adsorbed gas, requires desorption and decompression to produce it, resulting in relatively low pressures. Tight gas, on the other hand, is free gas and can be produced naturally, resulting in relatively high pressures. The pressure systems of coalbed methane and tight gas layers differ significantly, making same-wellbore, same-pressure commingling unsuitable.

[0031] The current multi-reservoir, same-wellbore, pressure-separated production process used in conventional oil and gas fields is limited to the production of liquids from two pressure systems. However, the production fluids of coalbed methane and tight gas are at least three fluids: two gases from two pressure systems and at least one liquid. Therefore, existing gas production processes and wellhead equipment cannot meet the requirements of same-wellbore pressure-separated production of tight gas and deep coalbed methane within the limited space of the wellbore. Coalbed methane and tight gas have different occurrence mechanisms, significantly different reservoir properties, and different pressure systems (high-pressure tight gas in the upper part and low-pressure coalbed methane in the lower part), resulting in significantly different production processes and output patterns. Therefore, the development of a same-wellbore pressure-separated production process involving at least three fluids in different reservoir properties and pressure systems, and the provision of wellhead equipment that provides at least three fluid pathways, have become key issues that urgently need to be addressed in the development of same-wellbore pressure-separated production.

[0032] Therefore, the present invention discloses a wellhead device for separately extracting tight gas and deep coalbed methane from the same wellbore by pressure division. Figures 1 to 12 , designed a total of three production outlets, including water outlet, high-pressure tight gas outlet and low-pressure coalbed methane outlet, and innovatively proposed the design concept of using the internal cavity of the hollow sucker rod 19 as the output liquid channel.

[0033] For details, please refer to Figure 1The wellhead device includes a coalbed water production multi-way 6, a coalbed gas production multi-way 8 and a tight gas production multi-way 10. The coalbed water production multi-way 6, the coalbed gas production multi-way 8 and the tight gas production multi-way 10 are connected in sequence from top to bottom, serving as a water production outlet, a low-pressure coalbed gas production outlet and a high-pressure tight gas production outlet respectively.

[0034] Please refer to Figure 1 、 Figure 2 and Figure 5 The wellhead device includes a casing 17, an oil pipe 18, a hanging outer pipe 21, a hollow sucker rod 19 and a polished rod 1. The casing 17, the oil pipe 18, the hanging outer pipe 21, the hollow sucker rod 19 and the polished rod 1 are all coaxially arranged, and the casing 17, the oil pipe 18, the hanging outer pipe 21 and the hollow sucker rod 19 are arranged in sequence from the outside to the inside, and the polished rod 1 is inserted into the hanging outer pipe 21.

[0035] Among them, the casing 17, the oil pipe 18 and the hanging outer pipe 21 are all relatively fixed to the tight gas production multi-way 10, which is equivalent to being relatively fixed to the coalbed water production multi-way 6 and the coalbed gas production multi-way 8. The specific connection method is illustrated below. In the wellhead device, a dynamic sealing mechanism is set up in the wellhead. The dynamic sealing mechanism in the wellhead realizes the dynamic sealing connection between the bottom end of the hanging outer pipe 21 and the hollow sucker rod 19. The dynamic sealing design ensures that the hollow sucker rod 19 column moves up and down as a power column and that the liquid in the hollow sucker rod is discharged during movement. Regarding the hollow sucker rod column, the hollow sucker rod column is composed of a plurality of hollow sucker rods 19 connected and combined.

[0036] To realize the coal seam water production path, please refer to Figure 7 and Figure 8 , and combined with reference Figure 1 and Figure 3 The bottom end of the light rod 1 is connected to the top end of the hollow sucker rod 19 through a functional joint 20. The lumen of the hollow sucker rod 19 is connected to the inner lumen of the hanging outer tube 21 through the inner channel 20a of the functional joint 20. The first annulus 100 formed by the hanging outer tube 21 and the light rod 1 is connected to the output port of the coalbed water production multi-port 6. During the deep coalbed methane drainage process, the coalbed produced water enters the hollow sucker rod 19 through the downhole drainage equipment, reaches the functional joint 20 from the inner lumen of the hollow sucker rod 19, and then enters the first annulus 100 area formed by the hanging outer tube 21 and the light rod 1, and is discharged through the coalbed water production multi-port 6. This solution realizes the conversion of the liquid in the moving pipe string to the production channel of the first annulus 100 through the functional joint 20 and the dynamic seal in the well.

[0037] In order to realize the coalbed gas production path, the second annulus 200 formed by the oil pipe 18 and the hanging outer pipe 21 is connected to the output port of the coalbed gas production multi-channel 8. Please refer to Figure 1 、 Figure 2 and Figure 7The coalbed gas enters the coalbed gas production multi-channel 8 along the second annulus 200 area and is output through the coalbed gas production multi-channel 8.

[0038] In order to realize the tight gas production path, the third annulus 300 formed by the casing 17 and the oil pipe 18 is connected to the output port of the tight gas production multi-channel 10. The tight gas enters the tight gas production multi-channel 10 through the third annulus 300 area and is output through the tight gas production multi-channel 10.

[0039] The upper tight gas passes through the oil casing annulus and is produced through the lower tight gas production spool. A hanging outer tube 21 is added to the oil pipe 18, and coalbed gas passes through the annulus between the oil pipe 18 and the hanging outer tube 21 and is produced through the middle coalbed gas production spool. Since the hollow sucker rod 19 string serves as the power string and its internal space is a liquid channel, the internal liquid of the hollow sucker rod string is transferred from the inside of the hollow sucker rod 19 to the annulus formed by the solid polished rod 1 and the hanging outer tube 21 through the functional joint between the hollow sucker rod 19 and the polished rod, and is discharged through the upper coalbed water production spool. The hollow sucker rod 19 and the hanging outer tube 21 are sealed by a dynamic sealing structure in the wellbore, forming a wellhead production channel for the moving liquid inside the hollow sucker rod 19.

[0040] In summary, two pressure systems are established in the wellbore through the wellhead device in conjunction with the wellbore, special production pumps, etc., and a high-pressure tight gas channel, a low-pressure coalbed methane gas channel and a liquid channel are established. An innovative design concept is proposed to use the internal cavity of the hollow sucker rod 19 as the production liquid channel, which solves the problem of liquid in the moving pipe string being discharged through the process pipeline at the wellhead during stratified mining, and solves the problem of three kinds of fluid production from the wellhead of tight gas and coalbed methane with different pressures and production in the same wellbore; it can meet the discharge of fluids from the wellheads of three different pressure systems, which is conducive to the separate metering of fluids produced from multiple reservoirs.

[0041] Including from the perspective of installation, in some implementations, please refer to Figure 1 、 Figure 2 and Figure 3 The top of casing 17 is fixedly connected to tight gas production manifold 10, and the top of casing 17 serves as the casing head. Oil tubing 18 is fixedly connected to tight gas production manifold 10 via tubing hanger 9. The top outer periphery of oil tubing 18 is threadedly connected to the inner periphery of tubing hanger 9. Suspension outer tube 21 is fixedly connected to coalbed methane production manifold 8 via outer tube hanger 7. The top outer periphery of suspension outer tube 21 is threadedly connected to outer tube hanger 7.

[0042] In some embodiments, see Figure 7 and Figure 8The functional joint 20 is threadedly connected to the polished rod 1 and the hollow sucker rod 19, respectively. The inner channel 20a forms an opening 20b around the functional joint 20. The functional joint 20 connects the polished rod 1 and the hollow sucker rod 19, and transfers the liquid in the moving string to the production channel in the annulus.

[0043] In some embodiments, the coalbed water output multi-way 6, the coalbed gas output multi-way 8 and the tight gas output multi-way 10 are respectively arranged in a three-way or four-way configuration. Figure 1 The diagrams in the figure all show a four-way configuration. In a three-way configuration, each includes one output port; in a four-way configuration, each includes two output ports, one of which is used for testing.

[0044] The present invention innovatively proposes a design concept of using the internal cavity of the hollow sucker rod 19 as the output liquid channel. Since the liquid is in the hollow sucker rod string, and the hollow sucker rod string also moves up and down as a power pipe string, and since the space in the wellbore is small, it is more difficult to adjust the dynamic seal in the wellbore.

[0045] In some embodiments, see Figure 5 and Figure 7 A circumferentially extending retaining ring 12 is provided near the lower end of the inner periphery of the suspension outer tube 21. The inner periphery of retaining ring 12 is spaced from both the hollow sucker rod 19 and the functional joint 20. The wellhead dynamic sealing mechanism includes a rope member 11, a first rope joint 16, an in-well sealing sleeve 15, and a first sealing member 13. The wellhead dynamic sealing mechanism cooperates with retaining ring 12 to achieve a dynamic sealing connection between the bottom end of the suspension outer tube 21 and the hollow sucker rod 19.

[0046] The wellhead device includes at least three ropes 11 arranged evenly spaced along the circumference of the hanging outer tube 21. The number of ropes 11 is an odd number. The ropes 11 can be combined Figure 4 and Figure 5 It is understood that the bottom end of the rope member 11 is mounted with a first rope connector 16, the top end of the rope member 11 is fixed, and the rope member 11 is partially disposed in the first annulus 100 between the suspension outer tube 21 and the polished rod 1. It is understood that the rope member 11 is non-elastic to maintain a sealed connection. In a preferred embodiment, the rope member 11 is a steel wire rope.

[0047] The wellhead device includes an annular well sealing sleeve 15. The structure of the well sealing sleeve 15 is shown in FIG. Figure 5 and Figure 6The top surface of the wellbore sealing sleeve 15 is provided with an annular step. The wellbore sealing sleeve 15 is spaced below the retaining ring 12. The wellbore sealing sleeve 15 is provided with a hole for the rope 11 to pass through. The first rope joint 16 abuts the bottom side of the wellbore sealing sleeve 15. Under the action of the rope 11, the wellbore sealing sleeve 15 abuts the bottom end of the hanging outer tube 21. The bottom side of the retaining ring 12, the top side of the wellbore sealing sleeve 15, the inner periphery of the hanging outer tube 21, and the outer periphery of the hollow sucker rod 19 enclose an annular area. The wellhead assembly includes a first seal 13 disposed in the annular area. The rope 11 is passed through the first seal 13. In a preferred embodiment, the first seal 13 is provided in the form of a sealing filler.

[0048] In some embodiments, see Figure 5 A second sealing ring 14 is also installed at the bottom end of the hanging outer tube 21 and the area facing the well sealing sleeve 15. The well sealing sleeve 15 and the hanging outer tube 21 are matched with the shaft hole and are sealed with a sealing ring.

[0049] In some embodiments, see Figure 1 and Figure 4 A polished rod sealing box 5 is installed on the top of the coal seam water production multi-channel 6, and a dynamic sealing adjustment mechanism is installed above the polished rod sealing box 5.

[0050] Please refer to Figure 9 and Figure 10 The dynamic seal adjustment mechanism includes a seal adjustment disk 3 and a wedge adjustment hoop 4. The wedge adjustment hoop 4 includes an adjustment outer bracket 4a, an adjustment bolt 4b and at least three wedges 4c. The adjustment outer bracket 4a includes an annular frame 4aa and a bolt mounting seat 4ab connected to the annular frame 4aa. The number of wedges 4c is odd, and all wedges 4c are evenly spaced along the inner circumference of the annular frame 4aa. The polished rod 1 and the rope 11 are passed through the enclosed area of ​​the annular frame 4aa. The adjusting bolt 4b is installed in the bolt mounting seat 4ab. The annular frame 4aa is retracted and expanded by controlling the tightness of the adjusting bolt 4b.

[0051] Please compare Figure 10 and Figure 11 , Figure 10 The middle wedge adjustment hoop 4 is provided with a bolt mounting seat 4ab and an adjusting bolt 4b. Figure 11 The middle wedge adjustment hoop 4 is provided with a pair of bolt mounting seats 4ab and a pair of adjustment bolts 4b, which are arranged on opposite sides of the annular frame 4aa. Figure 11 and Figure 12 , adjusting bolt 4b from Figure 11 Adjust to the loose position shown Figure 12 After the tight state shown, the ring frame 4aa moves inwards with the wedge block 4c.

[0052] Please refer to Figure 9 The sealing adjustment disk 3 is sleeved over the polished rod 1. The bottom of the sealing adjustment disk 3 features an inclined surface that mates with the inclined surface of the wedge 4c. The sealing adjustment disk 3 also includes a channel for the passage of a rope 11. A second rope connector 2 is mounted on the top of the rope 11, which abuts the top side of the sealing adjustment disk 3. The height of the sealing adjustment disk 3 changes as the annular frame 4aa contracts and expands. For example, the annular frame 4aa, carrying the wedge 4c inward, causes the sealing adjustment disk 3 to move upward, thereby driving the rope 11 upward. This upward movement of the rope 11 pulls the sealing sleeve 15 upward, achieving dynamic seal adjustment within the wellbore.

[0053] The rope 11 is lifted up by the dynamic sealing adjustment mechanism at the wellhead. When the rope 11 is pulled upward, the sealing sleeve 15 in the well is driven to compress the sealing filler of the first sealing member 13, thereby enhancing the overall sealing performance and realizing the adjustment of the seal.

[0054] In order to make the seal adjustment balance in the well move upward uniformly, the three-point stability principle is used. In some embodiments, the wellhead device includes three rope members 11, and the three rope members 11 are evenly spaced along the circumference of the hanging outer tube 21. Figure 6 The holes provided for the three rope members 11 are shown.

[0055] The present invention also provides a device for separately producing tight gas and deep coalbed methane at different pressures in the same wellbore, including the above-mentioned wellhead device, which can realize the separate production of tight gas and deep coalbed methane at different pressures in the same wellbore within the limited space of the wellbore.

[0056] In this application example, three fluid production channels are constructed within the wellhead, enabling the discharge of fluids from three different pressure systems. This facilitates the separate metering of fluids produced from multiple reservoirs and enables the wellhead discharge of liquids from the moving hollow sucker rod 19. Furthermore, an adjustable dynamic seal mechanism is employed within the wellbore, making it easy to adjust and effectively improving the sealing performance within the confined space within the wellbore.

[0057] The embodiment scheme provides an equipment basis for realizing the separate pressure and separate production of tight gas and deep coalbed methane in the same wellbore, and avoids the interference of tight gas and coalbed methane in the same wellbore during the joint production in the same wellbore, which will break the current situation that the joint production in the same wellbore cannot achieve the development effect of "1+1=2", and promote the improvement of development benefits; the use of this technical solution will solve the problem of difficulty in measuring the contribution of different production layers in the joint production in the same wellbore, facilitate separate measurement, and be conducive to separate control of production of different production layers; the dynamic seal adjustment in the wellhead device of the same wellbore separate pressure and separate production does not require disassembly of the wellhead, and the adjustment is convenient and simple, saving construction time. There is no need to stop the well during adjustment, which ensures the continuity of tight gas and coalbed methane drainage and production, and extends the stable and high production cycle of tight gas and coalbed methane, with significant economic benefits and good promotion value.

[0058] The application embodiment scheme is formed during the coal-bearing gas production process, and is suitable for the simultaneous partial pressure production of tight gas and deep coalbed methane in the same wellbore. The partial pressure production in the same wellbore has the characteristics of no interference in the wellbore of the production layers with different pressure systems, independent control of different production layers, independent measurement of production layer contributions, low development cost, and high development efficiency. It is conducive to accelerating the progress of large-scale development of unconventional gas, and has significant economic benefits and good promotion value.

[0059] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0060] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A wellhead device for separately producing tight gas and deep coalbed methane in the same wellbore under different pressures, characterized in that: It comprises a coal seam water production multi-way, a coal seam gas production multi-way and a tight gas production multi-way connected in sequence from top to bottom, and a coaxially arranged casing, oil pipe, hanging outer pipe, hollow sucker rod and light rod, wherein the casing, the oil pipe, the hanging outer pipe and the hollow sucker rod are arranged in sequence from outside to inside, the light rod is inserted into the hanging outer pipe, the casing, the oil pipe and the hanging outer pipe are all relatively fixed to the tight gas production multi-way, the bottom end of the hanging outer pipe is dynamically sealed with the hollow sucker rod through a dynamic sealing mechanism in a wellhead, the bottom end of the light rod is connected with the top end of the hollow sucker rod through a functional joint, and the lumen of the hollow sucker rod is communicated with the inner lumen of the hanging outer pipe through the inner channel of the functional joint; The first annulus formed by the hanging outer tube and the bare rod is connected to the output port of the coalbed water production multi-channel, the second annulus formed by the oil pipe and the hanging outer tube is connected to the output port of the coalbed gas production multi-channel, and the third annulus formed by the casing and the oil pipe is connected to the output port of the tight gas production multi-channel.

2. The wellhead device according to claim 1, characterized in that: The top end of the casing is relatively fixedly connected to the tight gas production multi-way, the oil pipe is fixedly connected to the tight gas production multi-way through a oil pipe hanger, the top outer periphery of the oil pipe is threadedly connected to the inner periphery of the oil pipe hanger, the suspended outer pipe is fixedly connected to the coalbed gas production multi-way through an outer pipe hanger, and the top outer periphery of the suspended outer pipe is threadedly connected to the outer pipe hanger.

3. The wellhead device according to claim 1, characterized in that: The functional joint is respectively connected to the polished rod and the hollow sucker rod through threads, and the inner channel forms an opening on the peripheral side of the functional joint.

4. The wellhead device according to claim 1, characterized in that: The coalbed water output multi-port, the coalbed gas output multi-port and the tight gas output multi-port are respectively arranged in a three-way or four-way configuration, and include one output port when arranged in a three-way configuration, and include two output ports when arranged in a four-way configuration, and one of the two output ports is used for testing.

5. The wellhead device according to any one of claims 1 to 4, characterized in that: The hanging outer tube is provided with a circumferential clamping ring at a position near the lower end of the inner periphery, and the inner periphery of the clamping ring is spaced from the hollow sucker rod and the functional joint; The wellhead device comprises at least three rope members evenly spaced along the circumference of the suspension outer tube, the bottom end of the rope member is installed with a first rope joint, the top end of the rope member is fixedly arranged, and the rope member is partially arranged in the first annulus between the suspension outer tube and the polished rod; The wellhead device comprises an annular well sealing sleeve, the well sealing sleeve is arranged below the clamping ring at intervals, the well sealing sleeve is provided with a hole for the rope to pass through, the first rope joint abuts against the bottom side of the well sealing sleeve, and under the action of the rope, the well sealing sleeve abuts against the bottom end of the hanging outer pipe; The bottom side of the clamp ring, the top side of the well sealing sleeve, the inner periphery of the hanging outer tube and the outer periphery of the hollow sucker rod enclose an annular area, the wellhead device includes a first sealing member arranged in the annular area, and the rope member is passed through the first sealing member; The dynamic sealing mechanism in the wellhead includes the rope member, the first rope joint, the wellbore sealing sleeve and the first sealing member to achieve a dynamic sealing connection between the hanging outer tube and the hollow sucker rod.

6. The wellhead device according to claim 5, characterized in that: A polished rod sealing box is installed at the top of the coal seam water output multi-channel, and a dynamic sealing adjustment mechanism is installed above the polished rod sealing box, and the dynamic sealing adjustment mechanism includes a sealing adjustment disk and a wedge block adjustment hoop; The wedge block adjustment hoop comprises an adjustment outer bracket, an adjustment bolt and at least three wedge blocks, the adjustment outer bracket comprises an annular frame and a bolt mounting seat connected to the annular frame, all the wedge blocks are evenly spaced along the inner periphery of the annular frame, the light rod and the rope member are inserted into the enclosed area of ​​the annular frame, the adjustment bolt is mounted on the bolt mounting seat, and the annular frame is retracted and expanded by controlling the tightness of the adjustment bolt; The sealing adjustment disk is sleeved outside the bare rod, and the sealing adjustment disk is provided with an inclined surface on the bottom side that matches the inclined surface of the wedge block. The sealing adjustment disk is provided with a channel for the rope member to pass through, and a second rope joint is installed at the top end of the rope member, and the second rope joint abuts against the top side of the sealing adjustment disk. When the annular frame shrinks inward and expands outward, the height of the sealing adjustment disk changes.

7. The wellhead device according to claim 5, characterized in that: A second sealing ring is also installed at the bottom end of the hanging outer tube and the area facing the sealing sleeve in the well.

8. The wellhead device according to claim 5, characterized in that: The first sealing member is provided in the form of a sealing filler.

9. The wellhead device according to claim 5, characterized in that: The wellhead device comprises three rope members, and the three rope members are evenly spaced along the circumference of the hanging outer pipe.

10. A device for separately producing tight gas and deep coalbed methane in the same wellbore by pressure separation, characterized in that: The wellhead device comprises the wellhead device described in any one of claims 1 to 9.

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