Device and method for multi-channel same-shaft partial-pressure and partial-production of tight gas and deep coal bed gas

Abstract

The invention discloses a multi-channel same-shaft partial-pressure and partial-production device and method for tight gas and deep coal bed gas. Comprising ground lifting equipment, a sleeve, an oil pipe, a hollow sucker rod, a packer, an open-hole type suspension device, a special drainage and mining pump, a coal seam water output multi-way, a coal seam gas output multi-way, a tight gas output multi-way, a suspension outer pipe, a dynamic sealing mechanism in a wellhead, a polished rod and a functional joint. In a wellbore area, the packer packs an annulus between the casing pipe and the oil pipe, the hole-opening type suspension device is installed on the pipe wall of the oil pipe, the hole-opening type suspension device is lower than the packer, and a plunger of the special drainage pump is connected with the hollow sucker rod. In a wellhead area, a hollow sucker rod is communicated with a suspended outer pipe through an inner channel of a functional connector, a first annulus formed by the suspended outer pipe and a polished rod is communicated with an output port of a coal seam water output multi-way, and a second annulus formed by an oil pipe and the suspended outer pipe is communicated with an output port of a coal seam water 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 valve.

Description

Technical Field

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

[0002] China is rich in unconventional oil and gas resources. With the continuous deepening of coal-measure gas exploration and development, the current coal-measure strata mostly present a vertical multi-layer superimposed geological structure with upper tight gas production layers and lower deep coal-bed methane production layers. Coal-bed methane is an adsorbed gas, which requires drainage and decompression for desorption production. The corresponding coal reservoir is an organic reservoir with relatively low pressure. Tight gas is free gas, which can be produced naturally with low water production. The corresponding tight gas reservoir is an inorganic reservoir with relatively high pressure. The joint production of tight gas and coal-bed methane and other reservoirs in the same wellbore has become a technical difficulty.

[0003] Regarding the three-dimensional development of the combination of tight gas and deep coalbed methane production layers, due to the large differences in reservoir properties and pressures, the production layer combination with tight gas layers above and coalbed methane layers below, the current joint production process and technology of oil fields and coalbed methane cannot meet the needs of separate pressure and separate production of tight gas and deep coalbed methane in the same wellbore. The separate pressure and separate production process and technology of reservoirs with different properties, different pressure systems and at least three fluids in the same wellbore has become a bottleneck problem that needs to be urgently solved in the development of coal-measure gas. Summary of the invention

[0004] In order to solve the above problems, the present application provides equipment and methods for the pressure-separation and production of tight gas and deep coalbed methane in multiple channels and in the same wellbore.

[0005] The present application provides a device for the pressure-separation and production of dense gas and deep coalbed methane in multiple channels in the same wellbore, including ground lifting equipment, casing, oil pipe, hollow sucker rod, packer, perforated suspension device, special drainage pump, coalbed water production multi-channel, coalbed gas production multi-channel, dense gas production multi-channel, suspension outer pipe, dynamic sealing mechanism in wellhead, bare rod and functional joint, casing, oil pipe and hollow sucker rod are coaxially arranged and arranged in sequence from outside to inside, the device includes a wellbore area and a wellhead area; in the wellbore area, the packer is installed on the oil pipe, and the annulus between the casing and the oil pipe is sealed when the packer is set, the perforated suspension device is installed on the wall of the oil pipe, and the perforated suspension device is lower than the packer, the pump barrel of the special drainage pump is connected to the bottom end of the oil pipe, and the plunger of the special drainage pump is connected to the hollow sucker rod; in the wellhead area, the coalbed water production multi-channel, the coalbed gas production multi-channel and dense The gas production multi-way is connected in sequence from top to bottom, the hanging outer tube and the bare rod are coaxially arranged with the casing, the casing, the oil pipe, the hanging outer tube and the hollow sucker rod are spaced in sequence from outside to inside, the bare rod is inserted into the hanging outer tube, the ground lifting equipment is connected to the bare rod through a suspension rope, the casing, the oil pipe and the hanging outer tube are relatively fixed to the tight gas production multi-way, the bottom end of the hanging outer tube is dynamically sealed with the hollow sucker rod through a dynamic sealing mechanism in the wellhead, the bottom end of the bare rod is connected to the top of the hollow sucker rod through a functional joint, the lumen of the hollow sucker rod is connected with 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 coal seam water production multi-way, the second annulus formed by the oil pipe and the hanging outer tube is connected to the output port of the coal seam gas production multi-way, and the third annulus formed by the casing and the oil pipe is connected to the output port of the tight gas production multi-way.

[0006] The beneficial effects of this application are as follows:

[0007] The innovative design concept of using the internal cavity of the hollow sucker rod as the channel for the produced liquid solves the problem of the liquid in the moving pipe string being discharged through the process pipeline at the wellhead during stratified production, and solves the problem of the wellhead production of three types of fluids, tight gas and coalbed methane, produced separately at the same wellbore under different pressures;

[0008] In the limited space of the wellbore, according to the requirements of the drainage characteristics of coalbed methane and tight gas, the hollow sucker rod is fully utilized, and two pressure system gas channels and at least one pressure system liquid channel are innovatively designed to achieve the simultaneous pressure and production of tight gas and lower coalbed methane in the wellbore, and avoid interference in the wellbore. Tight gas, coalbed methane, and coalbed water are produced separately and measured separately at the wellhead;

[0009] This equipment realizes the separate development of multiple fluids in reservoirs with different properties and pressure systems, increases the controlled reserves of a single well, and reduces development costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention.

[0011] Figure 1 A schematic diagram of the structure of the wellhead area in the equipment for pressure-separate production of tight gas and deep coalbed methane in the same wellbore through multiple channels provided in this application;

[0012] Figure 2 for Figure 1 A first partial schematic diagram of;

[0013] Figure 3 for Figure 1 A second partial schematic diagram of;

[0014] Figure 4 for Figure 1 A third partial schematic diagram of ;

[0015] Figure 5 A schematic diagram of a dynamic seal-related structure in the wellhead area of ​​the equipment provided in this application;

[0016] Figure 6 A top view of a well seal compression sleeve in the wellhead area of ​​the equipment provided in this application;

[0017] Figure 7 Schematic diagram of the relevant annulus in the wellhead area of ​​the equipment provided for this application;

[0018] Figure 8 A cross-sectional view of a functional joint in the wellhead area of ​​the equipment provided for this application;

[0019] Fig. 9 A schematic diagram of a dynamic seal adjustment mechanism in a wellhead area provided in the present application;

[0020] Fig.10 A schematic diagram of a first structure of a wedge adjustment hoop in the wellhead area of ​​the equipment provided in this application;

[0021] Fig.11 A schematic diagram of a second structure of a wedge adjustment collar in a wellhead area of ​​the equipment provided by the present application in a first state;

[0022] Fig.12 A schematic diagram of a second structure of a wedge adjustment collar in a wellhead area of ​​the equipment provided by the present application in a second state;

[0023] Fig.13 The overall schematic diagram of the equipment for multi-channel and same-wellbore pressure-separation and production of tight gas and deep coalbed methane provided in this application;

[0024] Fig.14A schematic diagram of the ground lifting device in the equipment provided for this application;

[0025] Fig.15 A schematic diagram of the wellhead area of ​​the equipment provided for this application;

[0026] Fig.16 A schematic diagram of the wellbore area of ​​the equipment provided for this application;

[0027] Fig.17 Schematic diagram of the flow direction of fluid in the wellbore area of ​​the equipment provided for this application during operation.

[0028] Figures are marked: 1-bare rod, 2-second rope joint, 3-sealing adjustment disk, 4-wedge adjustment hoop, 4a-adjustment outer bracket, 4aa-ring frame, 4ab-bolt mounting seat, 4b-adjustment bolt, 4c-wedge, 5-bare rod sealing box, 6-coal seam water production multi-way, 7-external pipe hanger, 8-coal seam gas production multi-way, 9-oil pipe hanger, 10-tight gas production multi-way, 11-rope, 12-clamp ring, 13-first sealing member, 14-second sealing ring , 15-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-suspended outer pipe, 22-ground lifting equipment, 23-rope hanger, 24-packer, 25-opening suspension device, 26-special drainage pump, 27-tight gas production layer, 28-coalbed methane production layer, 100-first annulus, 200-second annulus, 300-third annulus. DETAILED DESCRIPTION

[0029] With the continuous deepening of coal-measure gas exploration and development, the current coal-measure strata mostly present a vertical multi-layer superimposed geological structure with upper tight gas production layers and lower deep coalbed methane production layers. In view of the superimposed coal-measure geological structure, multi-gas commingled production technology came into being, that is, tight gas and coalbed methane are developed in the same wellbore, and a single wellbore controls two reservoirs. This can increase controlled reserves, reduce development costs, and improve production capacity and efficiency, thereby effectively promoting the large-scale development of unconventional gas. The commingled production technology of superimposed coal-measure strata has brought new opportunities for the efficient development of unconventional resources, and related research has also become the key to increasing domestic unconventional oil and gas production.

[0030] Coalbed methane is an adsorbed gas, which requires drainage and pressure reduction for desorption production. The corresponding coal reservoir is an organic reservoir with relatively low pressure. Tight gas is free gas, which can be produced naturally with low water production. The corresponding tight gas reservoir is an inorganic reservoir with relatively high pressure. Due to the different occurrence mechanisms and pressure systems of coalbed methane and tight gas (high pressure in the upper part and low pressure in the lower part) and obvious differences in reservoir properties, the mining processes and output rules of coalbed methane and tight gas are quite different. The joint production of tight gas and coalbed methane and other reservoirs in the same wellbore has become a technical difficulty.

[0031] At present, multi-reservoir commingled production is mainly divided into the same-wellbore same-pressure commingled production, the same-wellbore divided-pressure commingled production and the same-wellbore divided-pressure divided production according to the pressure system in the wellbore. The same-wellbore same-pressure commingled production is suitable for two reservoirs with similar pressure systems, but the pressure systems of the coalbed methane layer and the tight gas layer are quite different, so it is not applicable. The same-wellbore divided-pressure commingled production is a mode of drainage and mixed production in the wellbore divided pressure system. This mode cannot measure the contribution of each production layer and control each production layer separately. The requirements for well conditions are extremely strict. At present, the same-wellbore divided-pressure divided production is limited to the liquid production of two pressure systems, but the coalbed methane and tight gas production fluids contain at least three fluids such as two pressure system gases and at least one liquid. In the limited space of the wellbore, the existing gas production technology and equipment cannot meet the requirements of the same-wellbore divided-pressure divided production of tight gas and deep coalbed methane. Therefore, for the three-dimensional development of tight gas and deep coalbed methane production layers, the technology of pressure-separation and production in the same wellbore with different reservoir properties, different pressure systems and at least three fluids has become a bottleneck problem that needs to be solved urgently in the development of coal-bearing gas.

[0032] In order to solve the above problems, a method of differential pressure and production in the same wellbore with three channels constructed in the limited space of the wellbore was established. The three channels correspond to three different pressure fluids, namely tight gas, coalbed methane, and coalbed produced water, so as to increase the controlled reserves, reduce development costs and increase the single well production.

[0033] The study found that the existing joint production with pressure separation in the same wellbore and the joint production with pressure separation in the same wellbore with multiple strings did not consider the casing size, multiple strings running, multiple valve opening and other issues. Due to the different properties of the reservoirs and the large difference in pressure, the combination of tight gas layers above and coalbed methane layers below, the current joint production process and technology of oilfield and coalbed methane cannot meet the needs of joint production with pressure separation in the same wellbore for tight gas and deep coalbed methane.

[0034] At present, the same-wellbore and same-pressure co-production is applicable to two production layers with similar reservoir pressure systems or similar reservoir pressure systems after transformation. In this way, the liquids of the two production layers are mixed in the same channel of the wellbore, and it is difficult to measure the contribution of different production layers. The same-wellbore separate-pressure co-production technology is aimed at relatively shallow burials with large underground space. By constructing different pressure systems, the upper and lower oil layers are separated and produced through separate channels. The oil layers with different pressures are adjusted through the production distributor through the constant-pressure distributor technology and the proportional pump separate production technology, so that the pressure is consistent and co-production can be achieved. The same-wellbore separate-pressure co-production is a mode of drainage and mixed production in the wellbore with separate pressure systems. This mode cannot measure the contribution of each production layer and control each production layer separately. The same-wellbore separate-pressure and separate-pressure production is limited to the liquid production of two pressure systems.

[0035] However, the reservoir properties and pressure systems of coalbed methane and tight gas are quite different, and the produced fluid contains at least three kinds of fluids. In the limited space of the wellbore, the existing gas production technology and equipment cannot meet the requirements of separate pressure and separate production of tight gas and deep coalbed methane in the same wellbore. Therefore, for the three-dimensional development of tight gas and deep coalbed methane production layers, the separate pressure and separate production technology for reservoirs with different properties, different pressure systems and at least three kinds of fluids in the same wellbore has become a technical problem that needs to be solved in the development of coal-measure gas.

[0036] To this end, the present invention discloses a device for the pressure-dividing and production of tight gas and deep coalbed methane in the same wellbore through multiple channels, including wellbore area-related structures and wellhead area-related structures, as well as ground-related production and drainage equipment.

[0037] Example 1

[0038] For the wellhead area related structures in the equipment for multi-channel and multi-channel pressure and production of tight gas and deep coalbed methane in the same wellbore (hereinafter referred to as wellhead equipment), please refer to Figures 1 to 12 A total of three production outlets were designed, including a water outlet, a high-pressure tight gas outlet and a low-pressure coalbed methane outlet. An innovative design concept of using the internal cavity of the hollow sucker rod 19 as a channel for the output liquid was proposed.

[0039] For details, please refer to Figure 1 The 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, and serve as a water production outlet, a low-pressure coalbed methane production outlet and a high-pressure tight gas production outlet, respectively.

[0040] 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 bare rod 1. The casing 17, the oil pipe 18, the hanging outer pipe 21, the hollow sucker rod 19 and the bare 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 sequentially spaced from the outside to the inside, and the bare rod 1 is inserted into the hanging outer pipe 21.

[0041] 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 coal seam water production multi-way 6 and the coal seam 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, and the dynamic sealing connection between the bottom end of the hanging outer pipe 21 and the hollow sucker rod 19 is realized through the dynamic sealing mechanism in the wellhead. The dynamic sealing design ensures that the hollow sucker rod column moves up and down as a power column and 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.

[0042] To achieve 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 bare 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 lumen of the hanging outer tube 21 through the inner channel 20a of the functional joint 20, and the first annulus 100 formed by the hanging outer tube 21 and the bare rod 1 is connected to the output port of the coal seam water production multi-port 6. During the deep coal seam gas drainage process, the coal seam produced water enters the hollow sucker rod 19 through the downhole drainage equipment, reaches the functional joint 20 from the internal lumen of the hollow sucker rod 19, and then enters the first annulus 100 area formed by the hanging outer tube 21 and the bare rod 1, and is discharged through the coal seam 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.

[0043] 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 7 The 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.

[0044] 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.

[0045] The upper tight gas is produced through the oil casing annulus and the lower tight gas production spool; the hanging outer tube 21 is added to the oil pipe 18, and the coal seam gas is produced through the oil pipe 18-hanging outer tube 21 annulus and the middle coal seam gas production spool; since the hollow sucker rod string is used as a power string and the internal space is a liquid channel, the internal liquid of the hollow sucker rod string passes through the functional joint of the hollow sucker rod 19 and the light rod, and the liquid channel is transferred from the inside of the hollow sucker rod 19 to the annulus formed by the solid light rod 1 and the hanging outer tube 21, and is discharged through the upper coal seam water production spool. The hollow sucker rod 19 and the hanging outer tube 21 are sealed by the dynamic sealing structure in the wellbore, forming a wellhead production channel for the moving liquid inside the hollow sucker rod 19.

[0046] 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 of using the internal cavity of the hollow sucker rod 19 as the output liquid channel is proposed, 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 wellhead production of three types 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 three different pressure systems at the wellhead, which is beneficial to the separate metering of fluids produced from multiple reservoirs.

[0047] Including from the perspective of installation, in some implementations, please refer to Figure 1 , Figure 2 and Figure 3 The top of the casing 17 is relatively fixedly connected to the tight gas production multi-way 10, and the top of the casing 17 is the casing head. The oil pipe 18 is fixedly connected to the tight gas production multi-way 10 through the oil pipe hanger 9, and the top outer periphery of the oil pipe 18 is connected to the inner periphery of the oil pipe hanger 9 through threads. The hanging outer pipe 21 is fixedly connected to the coalbed gas production multi-way 8 through the outer pipe hanger 7, and the top outer periphery of the hanging outer pipe 21 is connected to the outer pipe hanger 7 through threads.

[0048] In some embodiments, see Figure 7 and Figure 8 The functional joint 20 is connected to the polished rod 1 and the hollow sucker rod 19 by threads, and the inner channel 20a forms an opening 20b on the peripheral side of the functional joint 20. The functional joint 20 realizes the docking of the polished rod 1 and the hollow sucker rod 19, and realizes the conversion of the liquid in the moving string to the production channel of the annulus.

[0049] In some embodiments, the coalbed water output multi-port 6, the coalbed gas output multi-port 8 and the tight gas output multi-port 10 are respectively arranged in a three-way or four-way configuration, such as Figure 1 The diagrams in the figure are all in a four-way configuration. When in a three-way configuration, each includes one output port; when in a four-way configuration, each includes two output ports, one of which is used for testing.

[0050] The present invention innovatively proposes a design concept of using the internal cavity of the hollow sucker rod 19 as a channel for producing liquid. Since the liquid is in the hollow sucker rod string, and the hollow sucker rod string also moves up and down as a power string, and since the space in the wellbore is small, it is difficult to adjust the dynamic seal in the wellbore.

[0051] In some embodiments, see Figure 5 and Figure 7 The hanging outer tube 21 is provided with a circumferential clamping ring 12 at a position near the lower end of the inner periphery, and the inner periphery of the clamping ring 12 is spaced from the hollow sucker rod 19 and the functional joint 20. The dynamic sealing mechanism in the wellhead includes a rope 11, a first rope joint 16, an inner well sealing sleeve 15 and a first sealing member 13. The dynamic sealing mechanism in the wellhead cooperates with the clamping ring 12 to realize the dynamic sealing connection between the bottom end of the hanging outer tube 21 and the hollow sucker rod 19.

[0052] 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 11 is provided with a first rope joint 16, the top end of the rope 11 is fixedly arranged, and the rope 11 is partially arranged in the first annulus 100 between the suspension outer tube 21 and the polished rod 1. It is understood that the rope 11 has a non-elastic property so as to be able to maintain a sealed connection. In a preferred embodiment, the rope 11 is a steel wire rope.

[0053] The wellhead device includes an annular well seal pressure sleeve 15. The structure of the well seal pressure sleeve 15 is shown in FIG. Figure 5 and Figure 6 , the top surface of the well sealing sleeve 15 is provided with an annular step. The well sealing sleeve 15 is arranged below the clamping ring 12 at intervals, and the well sealing sleeve 15 is provided with a hole for the rope 11 to pass through. The first rope joint 16 abuts against the bottom side of the well sealing sleeve 15. Under the action of the rope 11, the well sealing sleeve 15 abuts against the bottom end of the hanging outer tube 21. The bottom side of the clamping ring 12, the top side of the well 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 device includes a first sealing member 13 arranged in the annular area, and the rope 11 is passed through the first sealing member 13. In a preferred embodiment, the first sealing member 13 is provided with a sealing filler.

[0054] 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 sealed with a sealing ring.

[0055] In some embodiments, see Figure 1 and Figure 4 A polished rod sealing box 5 is installed at the top of the coal seam water output multi-channel 6, and a dynamic sealing adjustment mechanism is installed above the polished rod sealing box 5.

[0056] Please refer to Fig. 9 and Fig.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 an odd number. All wedges 4c are evenly spaced along the inner periphery of the annular frame 4aa. The bare rod 1 and the rope 11 are inserted into the enclosed area of ​​the annular frame 4aa. The adjustment bolt 4b is installed on the bolt mounting seat 4ab. The annular frame 4aa can be retracted and expanded by controlling the tightness of the adjustment bolt 4b.

[0057] Please compare Fig.10 and Fig.11 , Fig.10 The middle wedge adjustment hoop 4 is provided with a bolt mounting seat 4ab and an adjustment bolt 4b. Fig.11 The middle wedge adjustment hoop 4 is provided with a pair of bolt mounting seats 4ab and a pair of adjustment bolts 4b, and the pair of adjustment bolts 4b are arranged on opposite sides of the annular frame 4aa. Fig.11 and Fig.12 , adjusting bolt 4b from Fig.11 Adjust to the loose position shown Fig.12 After the tighter state shown, the ring frame 4aa moves inwards with the wedge block 4c.

[0058] Please refer to Fig. 9 The sealing adjustment disk 3 is sleeved outside the polished rod 1. The sealing adjustment disk 3 is provided with an inclined surface on the bottom side that matches the inclined surface of the wedge 4c. The sealing adjustment disk 3 is provided with a channel for the rope 11 to pass through. The top of the rope 11 is provided with a second rope joint 2, which abuts against the top side of the sealing adjustment disk 3. The height of the sealing adjustment disk 3 changes under the condition that the annular frame 4aa shrinks and expands. For example, the annular frame 4aa moves inward with the wedge 4c, prompting the sealing adjustment disk 3 to move up, thereby driving the rope 11 to move up, and the rope 11 moves up to pull the sealing sleeve 15 in the well upward, so as to achieve the adjustment of the dynamic seal in the wellbore.

[0059] The rope 11 is lifted up through the dynamic seal 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 as the first seal 13, which can enhance the overall sealing performance and realize the seal adjustment.

[0060] 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 three rope members 11 are shown.

[0061] By applying the above embodiment, three fluid production channels are constructed in the wellhead, which can meet the discharge of fluids of three different pressure systems from the wellhead; it is conducive to the separate metering of fluids produced by multiple reservoirs; and it realizes the wellhead discharge of liquid inside the moving hollow sucker rod 19. At the same time, an adjustable dynamic sealing mechanism in the wellbore is adopted, and the dynamic seal in the wellbore is easy to adjust, which can effectively improve the sealing performance of the limited space in the wellbore.

[0062] The above-mentioned 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, avoids the interference of tight gas and coalbed methane in the same wellbore during joint production in the same wellbore, and will break the current situation that 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 scheme will solve the problem of difficulty in measuring the contribution of different production layers in 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 separate pressure and separate production in the wellbore 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 production, and extends the stable and high-yield cycle of tight gas and coalbed methane, with significant economic benefits and good promotion value.

[0063] By applying the above-mentioned embodiment scheme, a gas well suitable for the simultaneous exploitation of tight gas and deep coalbed methane in the same wellbore is formed during the coal-bearing gas production process. The gas well has the characteristics of different pressure systems and production in the same wellbore, no interference in the wellbore, different production layers can be controlled separately, the contribution of the production layers can be measured separately, the development cost is low, and the development efficiency is high. It is conducive to accelerating the progress of large-scale development of unconventional gas, and has significant economic benefits and good promotion value.

[0064] Example 2

[0065] The above-mentioned equipment for multi-channel and same-wellbore pressure-separation and production of tight gas and deep coalbed methane includes wellbore area-related structures and wellhead area-related structures, as well as ground-related production and drainage equipment, wherein the wellhead area-related structures are as shown in Example 1.

[0066] For relevant structures in the wellbore area, please refer to Fig.16 , Fig.16 This is a schematic diagram of the wellbore area of ​​the equipment provided in this application, in which the casing 17, the oil pipe 18 and the hollow sucker rod 19 are coaxially arranged, and the casing 17, the oil pipe 18 and the hollow sucker rod 19 are sequentially spaced from the outside to the inside.

[0067] Please compare Fig.16 and Fig.17 ,in Fig.17 Arrows are used to illustrate the flow direction of fluids in the three channels during operation. The packer 24 is connected to the oil pipe 18, and seals the annulus between the casing 17 and the oil pipe 18 when setting. The oil pipe 18 is installed with an open hole type suspension device 25 on the pipe wall, and the open hole type suspension device 25 has an opening, and the open hole type suspension device 25 is lower than the packer 24.

[0068] In the working state, the tight gas production layer 27 adopts gas-carrying liquid production, and the tight gas passes through the annulus of the casing 17 and the oil pipe 18, along the wellbore area and the wellhead area, and is finally output from the tight gas production multi-channel 10.

[0069] In the working state, the coalbed methane production layer 28 uses drainage equipment to drain water, constructing the coalbed gas channel and the coalbed output water channel. For coalbed gas channels, please refer to Fig.13 , Fig.15 and Fig.17 The coalbed methane enters the casing 17, passes through the annulus area between the casing 17 and the oil pipe 18, enters the annulus area between the oil pipe 18 and the hollow sucker rod 19 through the open-hole suspension device 25, is transported from the wellbore area to the wellhead area, and continues to be output from the coalbed methane production multi-channel 8 along the second annulus 200 of the wellhead area.

[0070] The pump barrel of the special drainage pump 26 is connected to the bottom end of the oil pipe 18, and the plunger of the special drainage pump 26 is connected to the hollow sucker rod 19, and the surface lifting device 22 is connected to the bare rod 1 through the rope hanger 23 to drive the special drainage pump 26 to work. The surface lifting device 22 is such as a pumping unit, and the reference Fig.13 The upper graph and Fig.14 , illustrating the ground lifting device 22.

[0071] Regarding the coal seam produced water channel, please refer to Fig.13 , Fig.15 and Fig.17 The coal seam produced water moves upward along the inner tube cavity of the hollow sucker rod 19 through the special drainage pump 26, enters the wellhead area through the wellbore area, reaches the functional joint 20 through the inner tube cavity of the hollow sucker rod 19, and then enters the first annulus 100 area formed by the hanging outer tube 21 and the bare rod 1, and is discharged through the coal seam water production multi-channel 6.

[0072] Compared with the method of directly drilling a hole on the wall of the oil pipe 18, a hole-type suspension device 25 is installed on the wall of the oil pipe 18. By manufacturing the hole-type suspension device 25 in advance and then installing it, the strength requirement of the pipe wall after the opening 20b is met, and it is also convenient to select the hole-drilling method and hole-drilling arrangement.

[0073] Due to the deep wellbore, a multi-stage hollow sucker rod string design can be adopted. According to the equal strength design principle, the diameter of the multi-stage sucker rod string increases from bottom to top. According to the pumping depth, a two-stage hollow sucker rod string combination or a three-stage or four-stage hollow sucker rod string combination can be adopted.

[0074] The present invention innovatively designs a device for separate pressure and production in the same wellbore. Within the limited space of the wellbore, the equipment makes full use of the hollow sucker rod string according to the requirements of the coalbed methane and tight gas production characteristics, and innovatively designs two pressure system gas channels and at least one pressure system liquid channel, thereby completing the separate pressure and production of tight gas and lower coalbed methane in the wellbore at the same time and avoiding interference in the wellbore. Tight gas, coalbed methane and coalbed water are produced separately and individual metering is achieved at the wellhead.

[0075] Compared with the existing wellhead devices, the present invention realizes the production of multiple fluids such as tight gas, coalbed methane and coalbed water from multiple channels at the wellhead. At the same time, the dynamic seal in the wellbore solves the problem of discharge of liquid in the moving pipe column at the wellhead, and also realizes the adjustment of the dynamic seal in the limited space in the wellbore. The dynamic seal in the wellbore is easy to adjust, and there is no need to disassemble the wellhead for adjustment, which saves time and cost and has low well control risk.

[0076] The present invention avoids the mutual interference of tight gas and deep coalbed methane in the wellbore during joint production in the same wellbore, and realizes the development effect of "1+1=2" that cannot be achieved in the current joint production in the same wellbore, thereby improving the development income; after using this technical solution, the problem of fuzzy contribution measurement of different production layers in the joint production in the same wellbore is solved, which is convenient for separate measurement of each production layer and beneficial for separate control of production of different production layers; the dynamic seal adjustment in the wellhead device of the same wellbore pressure-separation and production does not require disassembly of the wellhead, and the adjustment is convenient and simple, saving construction time, and there is no need to stop the well for adjustment, which ensures the continuity of the production of tight gas and coalbed methane, and extends the stable and high-yield cycle of tight gas and coalbed methane, with significant economic benefits and good promotion value.

[0077] Example 3

[0078] A method for pressure-separated production of dense gas and deep coalbed methane in multiple channels in the same wellbore is disclosed, which involves the equipment for pressure-separated production of dense gas and deep coalbed methane in multiple channels in the same wellbore in Example 2. Please refer to Fig.17 In specific applications, the packer 24 and the open-hole suspension device 25 are both located between the coalbed methane production layer and the tight gas production layer 27 to smoothly separate the coalbed methane and the tight gas.

[0079] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other 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.

[0080] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. Equipment for the separate pressure and separate production of tight gas and deep coalbed methane in multiple channels in the same wellbore, characterized in that: The equipment includes ground lifting equipment, casing, tubing, hollow sucker rod, packer, open-hole suspension device, special drainage pump, coal seam water output multi-way, coal seam gas output multi-way, tight gas output multi-way, suspension outer pipe, wellhead internal dynamic sealing mechanism, polished rod and functional joint. The casing, tubing and hollow sucker rod are coaxially arranged and sequentially spaced from outside to inside. The equipment includes a wellbore area and a wellhead area. In the wellbore area, the packer is installed on the oil pipe and seals the annulus between the casing and the oil pipe when setting. The oil pipe is installed with an open-hole suspension device on the pipe wall, and the open-hole suspension device is lower than the packer. The pump barrel of the special drainage pump is connected to the bottom end of the oil pipe, and the plunger of the special drainage pump is connected to the hollow sucker rod. In the wellhead area, the coalbed water production multi-way, the coalbed gas production multi-way and the tight gas production multi-way are connected in sequence from top to bottom, the hanging outer tube and the bare rod are coaxially arranged with the casing, the casing, the oil pipe, the hanging outer tube and the hollow sucker rod are arranged in sequence from outside to inside, the bare rod is inserted into the hanging outer tube, the ground lifting equipment is connected to the bare rod through a hanging rope, the casing, the oil pipe and the hanging outer tube are all relatively fixed to the tight gas production multi-way, and the bottom end of the hanging outer tube is fixed to the hollow sucker rod. The rod is dynamically sealed and connected through the dynamic sealing mechanism in the wellhead, the bottom end of the bare rod is connected to the top end of the hollow sucker rod through the functional joint, 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 pipe 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 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 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 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 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 device comprises at least three ropes evenly spaced along the circumference of the suspension outer tube, the bottom end of the rope is provided with a first rope joint, the top end of the rope is fixedly arranged, and the rope part is arranged in the first annulus between the suspension outer tube and the polished rod; The device comprises an annular well sealing sleeve, which is arranged below the clamping ring at intervals, and is provided with a hole for a 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 tube; 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 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 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 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 device according to claim 5, characterized in that The first sealing member is provided in the form of a sealing filler.

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

10. A method for producing tight gas and deep coalbed methane in multiple channels and in the same wellbore by pressure separation, characterized in that: Under the condition of separate pressure and separate production of tight gas and deep coalbed methane in multiple channels in the same wellbore, the packer and the open-hole suspension device are located between the coalbed methane producing layer and the tight gas producing layer.

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