Liquid accumulation-free production and drainage system for oil-gas well

Abstract

A liquid accumulation-free production and drainage system for an oil-gas well, comprising a casing (32) and a production string (33) which are arranged in the oil-gas well, and have the bottoms thereof inserted below the oil-gas liquid level, wherein the production string is arranged in the casing, and an annular space (34) is formed between the production string and the casing; the production string is formed by sequentially connecting a plurality of oil-gas pipes (15), a plurality of anti-slip liquid accumulators (35) and a plurality of anti-slip gas injectors (36) end to end, one anti-slip controller is provided every several oil-gas pipes, one anti-slip gas injector is provided every several anti-slip liquid accumulators, and the lower the position of the production string, the fewer the number of the anti-slip liquid accumulators between adjacent anti-slip gas injectors; and each anti-slip gas injector comprises an anti-slip liquid accumulator or oil-gas pipe joint, and an anti-slip gas injection hole structure. The liquid accumulation-free production and drainage system for an oil-gas well improves the oil-gas recovery rate. The system can be applied not only to an oil well with associated gas, but also to a gas well with associated oil, and has a wide range of applications.

Description

An oil and gas well liquid-accumulation-free production and discharge system TECHNICAL FIELD

[0001] The present disclosure belongs to the field of oil and gas exploitation equipment, and particularly relates to an oil and gas well liquid-accumulation-free production and discharge system. BACKGROUND

[0002] An oil and gas well usually has a casing arranged in the well, and a production string formed by connecting a plurality of oil and gas pipes (also referred to as oil pipes in the industry) end to end is arranged in the casing. In use, the gas-liquid mixture at the bottom of the oil and gas well is usually sprayed upward to the ground through the production string under the action of pressure difference, so as to realize the exploitation of oil and gas. However, in the process of oil and gas exploitation, as the exploitation time is prolonged, the formation pressure is gradually reduced, and the water content of crude oil is gradually increased, which leads to the decrease of the pressure difference between the liquid column and the formation, and thus the slippage of the liquid column becomes more and more serious, eventually causing the oil and gas well to stop flowing, which seriously affects the output of the oil and gas well.

[0003] To solve this problem, the commonly used methods at present are to reduce the density of the gas-liquid mixture by gas lifting and foam discharge, to use an electric submersible pump, to use a plunger to discharge and lift the liquid column, and to use a small string method to increase the flow rate of the gas-liquid mixture. However, these methods have great limitations for the exploitation of natural gas. For example, the gas lifting technology injects gas into the casing and into the oil and gas pipe to reduce the density of the liquid. When natural gas is exploited, the oil and gas pipe is mainly filled with gas, and the pressure difference is very small. The opening and closing of the gas lifting valve are controlled by the pressure difference, which seriously affects the opening and closing of the gas lifting valve. Therefore, the gas lifting technology is only suitable for the exploitation of crude oil (the density of crude oil is large, and the pressure difference between the upper and lower oil and gas pipes is large), but not suitable for the exploitation of natural gas. In addition, the gas supply hole of the gas lifting valve is usually a straight-through hole, and the gas introduced into the oil and gas pipe can only reduce the density of the gas-liquid mixture in the oil and gas pipe, but cannot increase the flow rate of the gas-liquid mixture. Therefore, the effect of avoiding slippage is also general. Furthermore, a one-way valve is arranged in the oil and gas pipe to prevent the liquid column from slipping, but this method occupies the central passage of the production string, so that other downhole tools cannot be installed, and various parameters such as temperature and pressure cannot be detected.

[0004] Therefore, how to increase the flow rate of the gas-liquid mixture in the oil and gas well and improve the gas liquid-carrying capacity of the oil and gas well without occupying the central passage of the production string is crucial for improving the exploitation rate of the oil and gas well, especially the natural gas exploitation rate of the gas well. SUMMARY

[0005] The present disclosure aims to overcome the defects in the prior art, and provides an oil and gas well liquid-accumulation-free production and discharge system which improves the liquid-carrying capacity of gas by using a anti-slip accumulator, improves the flow rate of gas-liquid mixture in the production string by using an anti-slip gas injection hole structure, reduces the density of the gas-liquid mixture, and greatly improves the oil and gas recovery rate. The system can be applied not only to oil wells associated with oil and gas, but also to gas wells associated with oil and gas, and has a wide range of applications.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present disclosure is as follows:

[0007] An anti-slip gas injection hole structure comprises a gas supply channel arranged on a production string for connecting the inside and outside of the production string, and a jet hole rotating block arranged in the gas supply channel, wherein the center of the jet hole rotating block is provided with a jet hole A, the jet hole A comprises a short conical hole, a fine hole and a long conical hole arranged in sequence and connected in the gas flow direction, and the taper of the short conical hole is greater than the taper of the long conical hole.

[0008] As a further technical solution, a limiting boss is arranged in the gas supply channel, and a steel pad (a steel pad) and an annular sealing pad are arranged between the limiting boss and the jet hole rotating block.

[0009] As a further technical solution, in the vertical direction, the gas supply channel is arranged obliquely, and the distance between the top end of the gas supply channel and the central axis of the production string is less than the distance between the bottom end of the gas supply channel and the central axis of the production string.

[0010] As a further technical solution, in the horizontal direction, the gas supply channel is arranged eccentrically with the central axis of the production string as the center.

[0011] An oil and gas well liquid-accumulation-free production and discharge system comprises a casing and a production string arranged in an oil and gas well and inserted into the oil and gas liquid surface, the production string is arranged in the casing to form an annular gap between the production string and the casing; the production string is sequentially connected by a plurality of oil and gas pipes, a plurality of anti-slip accumulators and a plurality of anti-slip gas injection devices, one anti-slip accumulator or anti-slip gas injection device is arranged every several oil and gas pipes, one anti-slip gas injection device is arranged every several anti-slip accumulators, and the number of anti-slip accumulators spaced between adjacent anti-slip gas injection devices decreases as the position of the production string goes lower.

[0012] The anti-slip gas injection device comprises an anti-slip accumulator or an oil and gas pipe joint, and the anti-slip gas injection hole structure arranged on the anti-slip accumulator or the oil and gas pipe joint.

[0013] As a further technical solution, the anti-slip accumulator comprises a pipe body, a gas main passage arranged in the center of the pipe body, an annular groove arranged on the inner wall of the pipe body and communicated with the gas passage, a gas branch passage arranged in the annular groove, and an annular liquid receiving groove with an upward opening, wherein the gas branch passage passes through the annular liquid receiving groove.

[0014] As a further technical solution, an annular flow guide plate is further arranged on the top wall of the annular groove, the inner wall of the annular flow guide plate is smoothly connected with the inner wall of the upper part of the pipe body, and the lower part of the annular flow guide plate is inserted into the annular liquid receiving groove, so as to form a bending passage in the annular liquid receiving groove.

[0015] As a further technical solution, an annular cylinder is arranged on the inner wall of the pipe body, the annular cylinder and the inner wall of the pipe body enclose an annular cavity, the gas main passage is arranged in the center of the annular cylinder, the annular liquid receiving groove is arranged on the annular cylinder, and a plurality of gas inlets are arranged on the annular cylinder and communicated with the gas main passage and the annular cavity.

[0016] As a further technical solution, the annular cylinder is gap-connected with the top wall of the annular groove, so as to form a first passage communicated with the annular cavity and the bending passage, and an annular gas outlet communicated with the bending passage and the gas main passage.

[0017] As a further technical solution, the gas inlets, the annular cavity, the first gap, the bending passage, and the annular gas outlet are sequentially communicated to form the gas branch passage.

[0018] As a further technical solution, the annular cylinder comprises an annular base arranged on the inner wall of the pipe body, and an annular liquid receiving groove arranged on the annular base.

[0019] As a further technical solution, the gas inlets are arranged on the annular base, and the positions of the gas inlets are higher than the lowest point of the annular cavity.

[0020] As a further technical solution, the annular liquid receiving groove is enclosed by an inner ring plate and an outer ring plate, and the upper surface of the inner ring plate is lower than the upper surface of the outer ring plate.

[0021] As a further technical solution, the pipe body comprises an upper pipe body and a lower pipe body, the outer wall of the upper pipe body is provided with an annular groove, the bottom of the lower pipe body is provided with an annular pipe matched with the annular groove, and the annular pipe is arranged in the annular groove and is bonded, welded, or threadedly connected with the annular groove.

[0022] As a further technical solution, when the anti-slip gas injection hole structure is arranged on the pipe body of the anti-slip accumulator, the two ends of the gas supply passage are respectively communicated with the annular space gap and the gas main passage or the gas branch passage.

[0023] As a further technical solution, the oil and gas pipe joint comprises a joint pipe body, a central gas passage arranged on the joint pipe body, and an external thread and an internal thread arranged at two ends of the joint pipe body, respectively.

[0024] As a further technical solution, the anti-slip gas injection hole structure is arranged on the joint pipe body, and the gas supply passages of the anti-slip gas injection hole structure are respectively communicated with the annular space gap and the central gas passage.

[0025] As a further technical solution, the bottom of the casing is provided with a perforated section communicating the oil and gas layer and the inside of the casing, the bottom of the production pipe column is provided with a screen pipe, the production pipe column is further provided with a Christmas tree after extending out of the ground, the annular space gap is provided with a gas filling port, and the gas filling port is communicated with a high-pressure gas source through a gas injection pipeline.

[0026] The oil and gas well liquid-accumulation-free production and discharge system is applied to an oil well or a gas well in which gas and liquid coexist.

[0027] As a further technical solution, the gas well comprises any one of a natural gas well, a shale gas well, and a gas-lift gas well; and the oil well comprises any one of a gas-lift oil well, an electric submersible pump oil well, and a screw pump oil well.

[0028] Compared with the prior art, the present disclosure has the following beneficial effects:

[0029] The present disclosure is provided with a jet hole rotating block in the gas supply passage communicating the inside and the outside of the production pipe column. During the process of passing through the jet hole rotating block, the gas can form a Laval effect, accelerate the gas flow entering the gas supply passage, and make the gas flow be sprayed at a high speed into the inside of the production pipe column, so as to form a negative pressure area near the jet hole A of the production pipe column, and improve the flow rate of the gas-liquid mixture in the production pipe column. Compared with the prior art, not only is the gas-liquid mixture in the production pipe column diluted and atomized by the gas, and the density of the gas-liquid mixture is reduced, but also the flow rate of the gas-liquid mixture in the production pipe column is improved, and the slip problem of the gas-liquid mixture is further avoided.

[0030] The present disclosure is provided with an eccentric gas supply passage communicating the inside of the production pipe column and the annular space gap. When the gas is sprayed into the production pipe column, the gas can move upward in a spiral manner. Compared with the vertical upward movement in the prior art, the Bernoulli principle of the supplied gas can be used to form a supporting force on the original gas-liquid mixture in the production pipe column, and the slip of the gas-liquid mixture is further avoided.

[0031] 3. When natural gas rises within the production tubing, the gas-liquid mixture experiences friction against the inner wall of the tubing, causing its velocity to gradually decrease. The frictional resistance of the production tubing is transmitted from the periphery to the center of the tubing due to the viscosity of the gas-liquid mixture. Therefore, the velocity of the gas-liquid mixture decreases rapidly near the inner wall of the tubing, while it decreases slowly at the center. This causes liquid to fall along the inner wall of the tubing, potentially leading to water flooding of the gas well. To address this issue, this disclosure adds an anti-slip device at regular intervals. The liquid accumulator is designed by installing a liquid receiving groove and a guide plate on the inner wall of the pipe. A gas branch channel is installed on the inner wall of the pipe that passes through the liquid receiving groove. The guide plate guides the liquid falling along the pipe wall to the liquid receiving groove, preventing it from sliding to the bottom of the well. As the oil and gas rise along the central gas channel, some of the gas is diverted by the gas branch channel, so that it carries the liquid in the liquid receiving groove out as it passes through the liquid receiving groove and continues to rise along the production tubing. This avoids the problem of liquid overflow and continued sliding after overflow caused by the increasing amount of liquid accumulating in the liquid receiving groove. Furthermore, when natural gas is ejected from the gas branch pipeline, the upward airflow can exert an upward force on the liquid on the pipe wall, further preventing the liquid from sliding down the pipe wall. In summary, this disclosure, by using the annular liquid receiving groove, the guide plate, and the branch gas channel in combination, greatly improves the liquid-carrying capacity of natural gas and avoids the problem of water flooding in gas wells caused by liquid sliding down. Compared with the gas lift technology for oil and gas wells, it can be applied not only to oil wells but also to gas wells, and it does not require additional energy. It can improve the liquid-carrying capacity of natural gas by utilizing the energy of the producing formation itself. It has wider applicability and lower cost.

[0032] In summary, this disclosure improves upon the structure of the anti-slip injection port to increase the flow velocity of the gas-liquid mixture within the production tubing. Furthermore, it adds an anti-slip liquid accumulator to the production tubing, which fully utilizes the formation pressure without obstructing the central channel of the production tubing, thereby enhancing the gas-liquid carrying capacity of the oil and gas well and achieving a liquid-free effect, thus improving oil and gas recovery. This disclosure can be applied not only to oil wells but also to gas wells, solving the problem of liquid slippage during oil and gas well production, as well as the problems of water flooding and low natural gas recovery rates caused by decreased liquid carrying capacity in gas wells. Attached Figure Description

[0033] Figure 1 is a structural schematic diagram of an embodiment of this disclosure;

[0034] Figure 2 is a schematic diagram of the structure of valve body A in one embodiment of this disclosure;

[0035] Figure 3 is a schematic diagram of the upper tube body in one embodiment of this disclosure;

[0036] Figure 4 is a schematic diagram of the structure of the lower tube in one embodiment of this disclosure;

[0037] Fig. 5 is a schematic view of the structure of the valve body B in one embodiment of the present disclosure;

[0038] Fig. 6 is an enlarged view of A in Fig. 5;

[0039] Fig. 7 is a schematic view of the structure of the valve body B in another embodiment of the present disclosure;

[0040] Fig. 8 is a sectional view of Fig. 7 along the direction of B-B;

[0041] Fig. 9 is a schematic view of the structure of the valve body B in another embodiment of the present disclosure;

[0042] Fig. 10 is a comparison chart of the first gas lift induced flow and the second gas lift induced flow in an effect example of the present disclosure;

[0043] Fig. 11 is a production chart 12 days after the intersection of wells in an effect example of the present disclosure.

[0044] In the drawings: 1, pipe body, 2, gas main passage, 3, annular liquid receiving groove, 4, annular flow guide plate, 5, bent passage, 6, annular cylinder, 7, annular cavity, 8, gas inlet, 9, first passage, 10, annular gas outlet; 11, annular connecting plate, 13, inner ring plate, 14, outer ring plate, 15, oil and gas pipe, 16, jet hole B, 17, upper pipe body, 18, lower pipe body, 19, annular groove, 20, annular pipe, 21, gas supply passage, 22, jet hole rotating block, 23, jet hole A, 24, short conical hole, 25, fine hole, 26, long conical hole, 27, limiting boss, 28, steel gasket, 29, annular sealing gasket, 30, annular groove, 31, anti-slip gas injection hole structure; 32, casing, 33, production string, 34, annular space; 35, anti-slip accumulator, 36, anti-slip gas injector, 37, joint pipe body, 38, central gas passage, 39, external thread, 40, internal thread; 41, perforated section, 42, screen pipe, 43, Christmas tree, 44, gas injection pipeline, 45, high-pressure gas source, 46, oil and gas layer, 47, packer. DETAILED DESCRIPTION

[0045] The technical solutions of the present disclosure will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present disclosure.

[0046] In the description of the present disclosure, it should be pointed out that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present disclosure and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present disclosure. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0047] In the description of the present disclosure, it should be pointed out that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific circumstances.

[0048] In the present disclosure, the explanation of the term "free liquid accumulation": slippage refers to the phenomenon that in gas-liquid two-phase pipe flow, due to the density difference between gas and liquid, the gas flows beyond the liquid; due to the existence of slippage, the gas phase in the wellbore of the oil and gas well is not enough to carry the liquid phase, resulting in the liquid phase falling back to the bottom of the well, accumulating step by step, and forming liquid accumulation; free liquid accumulation is to hinder the formation of liquid accumulation and avoid the influence of liquid accumulation in the production string on the production of oil and gas wells, which is called free liquid accumulation.

[0049] The present disclosure will be described in further detail below in conjunction with the drawings. Embodiment 1

[0050] An embodiment of the oil and gas well free liquid accumulation production and discharge system of the present disclosure shown in FIGS. 1-8 includes a casing 32 and a production string 33 arranged in the oil and gas well and inserted at the bottom below the oil and gas liquid level, the production string 33 is arranged in the casing 32, thereby forming an annular gap 34 between the production string 33 and the casing 32; the production string 33 is sequentially connected by a plurality of oil and gas pipes 15, a plurality of anti-slippage liquid accumulators 35 and a plurality of anti-slippage gas injectors 36, one anti-slippage liquid accumulator 35 or anti-slippage gas injector 36 is arranged every several oil and gas pipes 15, one anti-slippage gas injector 36 is arranged every several anti-slippage liquid accumulators 35, and the lower the position of the production string 33, the fewer the number of anti-slippage liquid accumulators 35 spaced between adjacent anti-slippage gas injectors 36.

[0051] The anti-slip accumulator 35 comprises a pipe body 1, a gas main passage 2 arranged at the center of the pipe body 1, an annular groove 30 arranged on the inner wall of the pipe body 1 and communicated with the gas passage, a gas branch passage and an annular liquid receiving groove 3 with an upward opening arranged in the annular groove 30, and the gas branch passage passes through the annular liquid receiving groove;

[0052] The anti-slip gas injector 36 comprises the anti-slip accumulator 35 and an anti-slip gas injection hole structure arranged on the anti-slip accumulator 35.

[0053] The anti-slip gas injection hole structure comprises a gas supply passage 21 arranged on the production pipe column 33 for communicating the inside and outside of the production pipe column 33, and a jet hole rotating block 22 arranged in the gas supply passage 21, the center of the jet hole rotating block 22 is provided with a jet hole A 23, the jet hole A 23 comprises a short conical hole 24, a fine hole 25 and a long conical hole 26 arranged in sequence and communicated in the direction of gas flow, and the taper of the short conical hole 24 is greater than the taper of the long conical hole 26.

[0054] The anti-slip gas injection hole structure is arranged on the pipe body 1 of the anti-slip accumulator 35, and the two ends of the gas supply passage 21 are communicated with the annular space gap 34 and the gas main passage 2 or the gas branch passage, respectively.

[0055] As an embodiment of the oil and gas well liquid-accumulation-free production and discharge system of the present disclosure, a limiting boss 27 is arranged in the gas supply passage 21, and a steel pad 28 (a steel pad) and an annular sealing pad 29 are arranged between the limiting boss 27 and the jet hole rotating block 22.

[0056] As an embodiment of the oil and gas well liquid-accumulation-free production and discharge system of the present disclosure, the gas supply passage 21 is arranged in an inclined manner in the vertical direction, and the distance between the upper end of the gas supply passage 21 and the central axis of the production pipe column 33 is less than the distance between the bottom end of the gas supply passage 21 and the central axis of the production pipe column 33.

[0057] As an embodiment of the oil and gas well liquid-accumulation-free production and discharge system of the present disclosure, the gas supply passage 21 is arranged in an eccentric manner with the central axis of the production pipe column 33 as the center in the horizontal direction.

[0058] As an embodiment of the oil and gas well liquid-accumulation-free production and discharge system of the present disclosure, an annular flow guide plate 4 is further arranged on the top wall of the annular groove 30, the inner wall of the annular flow guide plate 4 is smoothly connected with the inner wall of the upper part of the pipe body 1, and the lower part of the annular flow guide plate 4 is inserted into the annular liquid receiving groove 3, so as to form a bending passage 5 in the annular liquid receiving groove 3.

[0059] As one embodiment of the oil and gas well liquid-accumulation-free production system of the present disclosure, an annular cylinder 6 is arranged on the inner wall of the pipe body 1, the annular cylinder 6 and the inner wall of the pipe body 1 enclose an annular cavity 7, the gas main passage is arranged in the center of the annular cylinder 6, the annular liquid receiving groove 3 is arranged on the annular cylinder 6, and a plurality of gas inlets 8 are arranged on the annular cylinder 6 and communicate with the gas main passage and the annular cavity 7.

[0060] As one embodiment of the oil and gas well liquid-accumulation-free production system of the present disclosure, the gas inlets 8 are arranged obliquely, the inlet end of the gas inlet 8 is low, and the outlet end is high.

[0061] As one embodiment of the oil and gas well liquid-accumulation-free production system of the present disclosure, the annular cylinder 6 is connected with the gap between the top wall of the annular groove 30, thereby forming a first channel 9 connecting the annular cavity 7 and the bending passage 5 and an annular gas outlet 10 connecting the bending passage 5 and the gas main passage.

[0062] As one embodiment of the oil and gas well liquid-accumulation-free production system of the present disclosure, the gas inlets 8, the annular cavity 7, the first gap, the bending passage 5, and the annular gas outlet 10 are sequentially connected to form the gas branch passage.

[0063] As one embodiment of the oil and gas well liquid-accumulation-free production system of the present disclosure, the annular cylinder 6 includes an annular base arranged on the inner wall of the pipe body 1 and the annular liquid receiving groove 3 arranged on the annular base.

[0064] As one embodiment of the oil and gas well liquid-accumulation-free production system of the present disclosure, the gas inlets 8 are arranged on the annular base, and the position of the gas inlet 8 is higher than the lowest point of the annular cavity 7.

[0065] As one embodiment of the oil and gas well liquid-accumulation-free production system of the present disclosure, the annular liquid receiving groove 3 is enclosed by an inner ring plate 13 and an outer ring plate 14, and the upper surface of the inner ring plate 13 is lower than the upper surface of the outer ring plate 14.

[0066] As one embodiment of the oil and gas well liquid-accumulation-free production system of the present disclosure, the pipe body 1 includes an upper pipe body 17 and a lower pipe body 18, the outer wall of the upper pipe body 17 is provided with an annular groove 19, the bottom of the lower pipe body 18 is provided with an annular pipe 20 matched with the annular groove 19, and the annular pipe 20 is arranged in the annular groove 19 and is threadedly connected with the annular groove 19. In addition, as another embodiment, the annular pipe 20 and the annular groove 19 can also be fixed by bonding, welding, or the like.

[0067] As one embodiment of the liquid-accumulation-free production system for oil and gas wells of the present disclosure, the bottom of the casing 32 is provided with a perforated section 41 communicating the oil and gas layer 46 and the inside of the casing 32, the bottom of the production string 33 is provided with a screen pipe 42, the production string 33 is further provided with a Christmas tree 43 after extending out of the ground, the annular gap 34 is provided with a gas injection port, and the gas injection port is communicated with a high-pressure gas source 45 through a gas injection pipeline 44.

[0068] The perforated section 41 is provided with a plurality of jet holes B16 communicating the oil and gas layer 46 and the inside of the casing 32. Embodiment 2

[0069] Embodiment 2 is the same as Embodiment 1, except that the structure of the anti-slip gas injector 36 is different. In Embodiment 2, as shown in FIG. 9, the anti-slip gas injector 36 includes an oil and gas pipe 15 joint and an anti-slip gas injection hole structure provided on the oil and gas pipe 15 joint.

[0070] The anti-slip gas injection hole structure includes a gas supply channel 21 provided on the production string 33 for communicating the inside and outside of the production string 33, a jet hole rotating block 22 provided in the gas supply channel 21, a jet hole A 23 provided at the center of the jet hole rotating block 22, the jet hole A 23 including a short conical hole 24, a fine hole 25 and a long conical hole 26 provided in sequence and communicated in the direction of gas flow, and the taper of the short conical hole 24 is greater than the taper of the long conical hole 26.

[0071] The oil and gas pipe 15 joint includes a joint pipe body 37, a central gas channel 38 provided on the joint pipe body 37, and an external thread 39 and an internal thread 40 provided at both ends of the joint pipe body 37, respectively.

[0072] The anti-slip gas injection hole structure is provided on the joint pipe body 37 of the oil and gas pipe 15 joint, and the gas supply channel 21 of the anti-slip gas injection hole structure is communicated with the annular gap 34 and the central gas channel 38 at both ends, respectively.

[0073] As one embodiment of the liquid-accumulation-free production system for oil and gas wells of the present disclosure, a limiting boss 27 is provided in the gas supply channel 21, and an annular sealing pad 29 is provided between the limiting boss 27 and the jet hole rotating block 22.

[0074] As one embodiment of the liquid-accumulation-free production system for oil and gas wells of the present disclosure, in the vertical direction, the gas supply channel 21 is obliquely arranged, and the distance between the top end of the gas supply channel 21 and the central axis of the production string 33 is less than the distance between the bottom end of the gas supply channel 21 and the central axis of the production string 33.

[0075] As an embodiment of the liquid-accumulation-free oil and gas well production and discharge system of the present disclosure, in the horizontal direction, the gas supply passage 21 is eccentrically arranged with the axis of the production string 33 as the center. Embodiment 3

[0076] The liquid-accumulation-free oil and gas well system described in Embodiment 1 or Embodiment 2 can be applied to oil wells or gas wells with associated gas.

[0077] As an embodiment of the application of the present disclosure, the gas well includes natural gas wells, shale gas wells, gas-lift gas wells, etc.

[0078] As an embodiment of the application of the present disclosure, the oil well includes gas-lift oil wells, electric submersible pump oil wells, screw pump oil wells, etc.

[0079] As an embodiment of the application of the present disclosure, in the case where the original well production cannot be lifted, a pipe-in-pipe mode can be adopted: a production string of the present disclosure is lowered into the original well production string.

[0080] Method and principle of use of the present disclosure:

[0081] During the production of the oil and gas well, the gas-liquid mixture in the gas main passage 2 on the production string 33 is ejected upward along the production string 33 under the action of the pressure difference. As the oil and gas production time is prolonged, the pressure difference decreases, and the gas-liquid mixture in the inner wall region of the production string 33 decreases faster than in the central region under the action of the friction of the inner wall of the production string 33, which causes the liquid in the inner wall of the production string 33 to slide down along the wall. During the sliding process, when the liquid slides down to the anti-slip accumulator 35, it will drip into the annular liquid receiving groove 3 along the annular flow guide plate 4, and the gas-liquid mixture running upward along the gas main passage will have some gas entering the gas branch passage when passing through the gas inlet 8. The gas blowing out of the gas branch passage will blow out the liquid received in the annular liquid receiving groove 3 and carry it into the gas main passage 2 again, thereby avoiding the sliding of the liquid at the wall and improving the liquid carrying capacity. In addition, when the gas blows out of the gas branch passage, it also forms a supporting force on the liquid at the wall and blocks the channel for the liquid in the inner wall of the production string 33 to slide down, thereby avoiding the continuous sliding of the liquid.

[0082] In addition, during the production of oil and gas wells with low pressure and production, high-pressure gas can also be introduced into the annular space gap 34. When the high-pressure gas enters the inside of the production string 33 through the anti-slip gas injection device 36, the setting of the jet flow hole A23 on the structure of the anti-slip gas injection hole can accelerate the gas and increase the flow speed of the gas-liquid mixture in the production string 33, thereby avoiding the sliding of the gas-liquid mixture. In addition, when the gas supply passage 21 is eccentrically arranged, the gas entering the production string 33 from the annular space gap 34 will run upward in a spiral manner, forming a supporting force on the gas-liquid mixture in the production string 33, thereby further avoiding the sliding of the gas-liquid mixture.

[0083] In summary, the anti-slip gas injection hole structure is improved in one aspect of the present disclosure, which can improve the flow speed of the gas-liquid mixture in the production string 33. On the other hand, the anti-slip accumulator 35 is added to the production string 33, which can reduce the liquid slip without occupying the central passage of the production string 33, improve the gas liquid carrying capacity of the oil and gas well, fully utilize the formation pressure, and improve the oil and gas recovery. The present disclosure can not only be applied to oil wells, but also to gas wells, solving the problem of liquid slip in the production process of oil and gas wells, and the problem of gas flooding and low natural gas recovery rate caused by the decrease of gas liquid carrying capacity.

[0084] Effect example: application example of Su X-X-XXH natural gas flowing well

[0085] Due to the difference in the content of each operation section before and after construction, the time difference is large, and the liquid discharge change cannot be compared and analyzed one by one. Therefore, the gas lift liquid discharge change and the hourly liquid discharge of the traditional gas lift induced flow and the gas lift induced flow of the present disclosure are compared in the induced flow stage of the natural gas flowing well (Figure 10), and the gas production data of the stable production using the present disclosure is recorded after the well is connected (Figure 11), and the results are as follows:

[0086] 1. First gas lift induced flow (traditional gas lift induced flow before the production string of the present disclosure is lowered): 3 hours of open flow before gas lift, 4 hours of gas lift, 46 hours of open flow after stopping lift, and 53 hours of shut-in, with a maximum casing pressure of 20.8 MPa, a minimum of 2.1 MPa, a cumulative liquid discharge of 61.5 m³, a maximum hourly liquid discharge of 8.4 m³, and an average hourly liquid discharge of about 1.16 m³;

[0087] 2. Second gas lift induced flow (using the production string of the present disclosure): replacing the production string 33 in the traditional gas lift technology with the production string 33 of the present disclosure, i.e. the present disclosure technology, gas lift for 26 hours, 29 hours of open flow after stopping lift, and 55 hours of shut-in, with a cumulative liquid discharge of 129.8 m³, a maximum hourly liquid discharge of 8.1 m³, and an average hourly liquid discharge of about 2.36 m³.

[0088] From the above results, it can be seen that:

[0089] 1. After the gas lift well is modified according to the present disclosure, the average hourly liquid discharge is more than twice the average hourly liquid discharge before modification, even though the time used for gas lift is longer than before modification.

[0090] 2. In the traditional gas lift technology, the maximum pressure of the gas lift operation is 20.8 MPa, while after applying the present disclosure, the maximum gas lift pressure is only 13.58 MPa, which shows that the gas lift pressure required by the present disclosure is lower than that of the traditional gas lift technology, and the pressure required for the subsequent well start-up is lower.

[0091] 3、From Figure 10, it can be seen that when the first gas lift induced flow is conducted, the pressure of the gas lift through pipe foot casing 32 drops suddenly, and the casing 32 pressure is 5.9 MPa when the pump is stopped, thereby causing the casing 32 pressure to be insufficient when the flow is released, and when the present disclosure is used, when the pressure reaches a maximum of 13.58 MPa, a slow decline phenomenon occurs, and after the gas lift is stopped, the casing pressure is 13.05 MPa and still maintains a slow decline in pressure, and thus it can be proved that the present disclosure can fully utilize the pressure stored in the casing 32 during gas lift to ensure stable production.

[0092] 4、Figure 11 is the production situation 12 days after the intersection, which is divided into four stages from left to right: the first stage is the blue area, which is the first time to open the well after the intersection for 20 hours, and the water content is relatively large from the production temperature. The second stage is the black area, and the production situation in this area is shut-in. The third stage is the red area, and the production fluctuation in this stage is relatively large, and a large amount of gas-liquid is intermittently discharged. It is judged that the kill fluid entering the bottom layer is being produced. (After the gas lift is completed, the remaining fracturing fluid and kill fluid in the well are 201 m³); the fourth stage is the green area, and after a large amount of liquid in the well is produced, the production tends to be stable, and stable production of gas-liquid mixture begins.

[0093] The above-described embodiments are only preferred embodiments of the present disclosure, and are not an exhaustive list of the feasible implementations of the present disclosure. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present disclosure should be considered to be included in the protection scope of the claims of the present disclosure.

Claims

1. A gas injection hole structure for preventing slippage, characterized by, The gas supply channel (21) is provided with a limiting boss (27), and a steel pad (28) and an annular sealing pad (29) are arranged between the limiting boss (27) and the jet orifice rotating block (22).

2. The anti-slip gas injection hole structure according to claim 1, wherein, The gas supply channel (21) is arranged in an inclined manner in the vertical direction, and the distance from the upper end of the gas supply channel (21) to the central axis of the production pipe column (33) is smaller than the distance from the bottom end of the gas supply channel (21) to the central axis of the production pipe column (33). In the horizontal direction, the gas supply channel (21) is arranged eccentrically with the central axis of the production pipe column (33) as the center.

3. The anti-slip gas injection hole structure according to claim 1, wherein, The production pipe column (33) is sequentially connected by a plurality of oil and gas pipes (15), a plurality of anti-slip and anti-falling liquid accumulators (35) and a plurality of anti-slip and anti-falling gas injectors (36), one anti-slip and anti-falling liquid accumulator (35) or anti-slip and anti-falling gas injector (36) is arranged every several oil and gas pipes (15), one anti-slip and anti-falling gas injector (36) is arranged every several anti-slip and anti-falling liquid accumulators (35), and the lower the position of the production pipe column (33), the fewer the number of anti-slip and anti-falling liquid accumulators (35) spaced between adjacent anti-slip and anti-falling gas injectors (36).

4. A liquid-accumulation-free production system for oil and gas wells, comprising a casing (32) and a production string (33) arranged in an oil and gas well, the bottom of the casing (32) being arranged below the oil and gas level, the production string (33) being arranged in the casing (32) so that an annular space (34) is formed between the production string (33) and the casing (32); characterized in that, The anti-slip and anti-falling gas injector (36) comprises an anti-slip and anti-falling liquid accumulator (35) or an oil and gas pipe (15) joint, and the anti-slip and anti-falling gas hole structure as claimed in any one of claims 1-3 is arranged on the anti-slip and anti-falling liquid accumulator (35) or the oil and gas pipe (15) joint. The anti-slip and anti-falling liquid accumulator (35) comprises a pipe body (1), a gas main channel (2) arranged at the center of the pipe body (1), an annular groove (30) arranged on the inner wall of the pipe body (1) and in communication with the gas channel, a gas branch channel and an annular liquid receiving groove (3) with an opening facing upwards arranged in the annular groove (30), and the gas branch channel passes through the annular liquid receiving groove. An annular flow guide plate (4) is further arranged on the top wall of the annular groove (30), the inner wall of the annular flow guide plate (4) is smoothly connected with the inner wall of the upper part of the pipe body (1), and the lower part of the annular flow guide plate (4) is inserted into the annular liquid receiving groove (3), so as to form a bending passage (5) in the annular liquid receiving groove (3).

5. The liquid loading free production system for oil and gas wells according to claim 4, characterized in that, An annular cylinder (6) is arranged on the inner wall of the pipe body (1), the annular cylinder (6) and the inner wall of the pipe body (1) form an annular cavity (7), the gas main passage is arranged at the center of the annular cylinder (6), the annular liquid receiving groove (3) is arranged on the annular cylinder (6), and a plurality of gas inlets (8) for communicating the gas main passage and the annular cavity (7) are formed in the annular cylinder (6). ​ The annular cylinder (6) is connected with the top wall of the annular groove (30) in a gap, thereby forming a first channel (9) connecting the annular cavity (7) and the bending passage (5) and an annular gas outlet (10) connecting the bending passage (5) and the gas main passage. The gas inlet (8), the annular cavity (7), the first gap, the bending passage (5) and the annular gas outlet (10) are sequentially connected to form the gas branch passage.

6. The liquid loading free production system for oil and gas wells, as claimed in claim 5, wherein, The annular cylinder (6) comprises an annular base arranged on the inner wall of the pipe body (1) and an annular liquid receiving groove (3) arranged on the annular base. The gas inlet (8) is arranged on the annular base, and the position of the gas inlet (8) is higher than the lowest point of the annular cavity (7). The annular liquid receiving groove (3) is enclosed by an inner ring plate (13) and an outer ring plate (14), and the upper surface of the inner ring plate (13) is lower than the upper surface of the outer ring plate (14).

7. The liquid-accumulation-free production and extraction system for oil and gas wells according to claim 4, characterized in that, When the anti-slip gas injection hole structure is arranged on the pipe body (1) of the anti-slip liquid accumulator (35), the two ends of the gas supply passage (21) are connected with the annular space gap (34) and the gas main passage (2) or the gas branch passage, respectively.

8. The liquid loading free production system for oil and gas wells, as claimed in claim 4 wherein, The oil and gas pipe (15) joint comprises a joint pipe body (37), a central gas passage (38) arranged on the joint pipe body (37), an outer thread (39) and an inner thread (40) arranged at the two ends of the joint pipe body (37), respectively. The anti-slip gas injection hole structure is arranged on the joint pipe body (37), and the gas supply passage (21) of the anti-slip gas injection hole structure is connected with the annular space gap (34) and the central gas passage (38), respectively.

9. The liquid loading free production system for oil and gas wells of claim 4 wherein, The bottom of the casing (32) is provided with a perforated section (41) connected with the oil and gas layer (46) and the inside of the casing (32), the bottom of the production string (33) is provided with a screen pipe (42), the production string (33) is further provided with a Christmas tree (43) after extending out of the ground, the annular space gap (34) is provided with a gas filling port, and the gas filling port is connected with a high-pressure gas source (45) through a gas injection pipeline (44).

10. The application of the liquid-accumulation-free production and extraction system for oil and gas wells according to any one of claims 4-9 in oil wells or gas wells with associated gas and liquid.

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