CN107542434A - A plunger gas lift liquid drainage device and production method for horizontal gas wells - Google Patents

Abstract

The invention discloses a plunger gas lift drainage device for a horizontal gas well and a production method thereof, and the plunger gas lift drainage device comprises a self-buffering plunger and a uniflow device which are arranged in an oil pipe, wherein the oil pipe comprises two pipelines with different pipe diameters and is connected through a reducing nipple, the self-buffering plunger is arranged in the pipeline at the upper part of the reducing nipple, the uniflow device is used for controlling the unidirectional flow of gas and liquid from bottom to top and is arranged in the pipeline at the lower part of the reducing nipple, the gas well can lift accumulated liquid in a shaft to the upper part of the uniflow device by means of self energy and stay, and the accumulated liquid is lifted to a well mouth by the self-buffering. The downhole tool of the existing plunger device is simplified; the single-flow device realizes the function of one-way gas-liquid flow, has a simple structure, is easy to put in and salvage, effectively utilizes the lifting capacity of the gas well, realizes the lifting of accumulated liquid of a part of inclined shaft sections and horizontal shaft sections at the bottom of the horizontal gas well, greatly reduces the height of a shaft liquid column, increases the gas production rate, and effectively solves the difficult problem of liquid drainage and gas production of the horizontal gas well.

Description

A plunger gas lift liquid drainage device and production method for horizontal gas wells

technical field

The invention belongs to the technical field of gas production in gas fields, and in particular relates to a plunger gas-lift liquid drainage device and a production method for horizontal gas wells.

Background technique

There are currently more than 1,300 horizontal gas wells in the Changqing gas area of the Ordos Basin, and it is estimated that the number will reach 2,700 in 10 years. Gas wells with gas production below 20,000 m3/d will account for 76.7%, and the problem of liquid accumulation is gradually emerging.

The plunger gas lift liquid drainage technology uses the plunger as the gas-liquid separation interface, which can effectively prevent the gas from moving up and the liquid from slipping, and increase the efficiency of liquid lifting. In addition, this technology does not require chemical agents and is environmentally friendly. Foreign countries believe that the plunger gas lift technology is the most economical and effective drainage gas recovery technology for low-yield and tight gas reservoirs. Gas wells increase production by 22% to 500%, and the investment recovery period is 4 months. The measures can be applied to gas well depletion. In 1991, an exploratory test of plunger gas lift technology was carried out in China. The Changqing gas area researched and developed the plunger gas lift technology with independent intellectual property rights, which realized remote real-time parameter adjustment and management of gas wells. A total of 518 wells were used, which effectively played the role of liquid drainage and gas recovery, saving manpower and material resources, and is especially suitable for tight The development status of gas fields with large areas, many wells, and few people has become the main technology for gas field drainage and gas recovery.

The existing plunger device puts the downhole tool at the bottom of the well, and mainly realizes the function of alleviating the impact force of the plunger falling. Since the horizontal well deviates gradually from the kickoff point to the window entry point at the bottom of the well, the existing downhole tools are difficult to enter the highly deviated well section, and cannot be locked in the highly deviated well section, so they can only be used in vertical wells part. In addition, the tubing of most horizontal wells in the Changqing gas area will shrink in diameter before entering the horizontal section at the bottom of the well, and the plunger cannot pass through this place during the falling process. The effusion cannot be lifted, which means that the full wellbore effusion lift of the horizontal well cannot be realized, which seriously affects the efficiency of the plunger gas lift drainage. Therefore, the existing plunger gas lift technology has limited effect in horizontal well drainage. It is of great practical significance to develop the plunger gas lift drainage technology suitable for horizontal gas wells.

Contents of the invention

The technical problem to be solved by the present invention is to provide a plunger gas-lift liquid drainage device for horizontal gas wells, a production method and supporting technologies for the above-mentioned deficiencies in the prior art, and to realize the lifting of the entire wellbore liquid accumulation of horizontal gas wells. , greatly reducing the height of the wellbore liquid column, increasing the gas production, the application effect is remarkable, and it can solve the problem of liquid drainage and gas production in horizontal gas wells.

The present invention adopts following technical scheme:

A plunger gas lift liquid drainage device for horizontal gas wells, comprising a self-buffering plunger and a single-flow device arranged in an oil pipe, the oil pipe includes two sections of pipelines with different diameters, and the two sections of pipelines pass through The self-buffering plunger is set in the oil pipe on the upper part of the reducing joint, and the single-flow device has the function of controlling the one-way flow of gas and liquid from bottom to top, and is set in the reducing In the tubing pipeline at the lower part of the pup joint, the gas well can rely on its own energy to lift the wellbore fluid to the upper part of the single-flow device and stay there, and then lift the fluid to the wellhead through the self-buffering plunger to complete the drainage production .

Further, the self-buffering plunger is a hollow structure, one end is provided with a first fishing head, and the other end is provided with a guide rod and a retaining ring, and a plurality of valves for realizing the self-buffering function of the plunger are arranged in the self-buffering plunger. The buffer spring, the guide rod and the retaining ring are used to fix and support the buffer spring.

Further, a first spring cylindrical pin and a second spring cylindrical pin are respectively arranged at the retaining ring and the guide head.

Further, a guide head for guiding and supporting the body of the self-buffering plunger at the bottom of the well is provided at the end of the guide rod.

Further, the guide rod is a hollow structure.

Further, the single-flow device includes a single-flow valve, a steel ball and a rubber cartridge, one end of the single-flow valve is connected to the second fishing head, and the other end passes through the steel ball and is arranged in the rubber cartridge The hollow channel connection.

A method for producing a plunger gas-lift liquid drainage device for a horizontal gas well, comprising the following steps:

S1. Connect the upper and lower oil pipes with different pipe diameters through the variable diameter nipple, set the self-buffering plunger in the upper oil pipe, and set the single flow device in the lower oil pipe of the variable diameter nipple;

S2. After the well is opened, the buffer plunger moves upward to lift the liquid in the upper part of the single-flow device to the wellhead, and the liquid in the lower part of the single-flow device is lifted to the upper part of the single-flow device by the energy of the gas itself;

S3. After the well is shut down, the self-buffering plunger goes down, and when it reaches the end of the reducing sub, the guide head of the self-buffering plunger encounters resistance and stops moving. The self-buffering plunger continues to go down due to inertia, and is relieved by the buffer spring. Kinetic energy until stopped;

S4. The liquid in the wellbore that has not been lifted to the surface pipeline falls back to the upper part of the single-flow device and the self-buffering plunger, and stays there;

S5. Steps S2-S4 are repeated to complete the lifting of the full wellbore fluid accumulation of the horizontal gas well.

Compared with the prior art, the present invention has at least the following beneficial effects:

The invention is a plunger gas-lift liquid drainage device for horizontal gas wells, which connects two sections of oil pipes with different diameters into one body through variable-diameter nipples, and sets a self-buffering plunger and a single-flow device in the pipelines. The self-buffering plunger not only increases the depth of the plunger, but also simplifies the downhole tools of the existing plunger device; the single-flow device realizes the function of gas-liquid one-way flow, and the structure is simple, easy to put in, easy to salvage, and effectively used The lifting capacity of the gas well itself has realized the lifting of liquid accumulation in the inclined well section and the horizontal section at the bottom of the horizontal gas well, greatly reduced the height of the wellbore liquid column, increased the gas production, and effectively solved the problem of liquid drainage and gas production in the horizontal gas well.

Further, the new self-buffering plunger with its own buffer is equipped with a spring inside to realize the self-buffering function of the plunger; the bottom guide rod and retaining ring play the role of fixing the spring position, preventing the spring from slipping, and supporting the spring; the guide head plays the role of During the falling process of the plunger, it plays the role of guiding and supporting the plunger body at the bottom of the well, and the spring cylindrical pin plays the role of fixing the retaining ring and the guide head.

Further, the single-flow device is composed of single-flow valves, steel balls, rubber tubes, etc. After the rubber tube is heated and expanded, it realizes the sealing of the outer wall of the single-flow device and the inner wall of the wellbore, and plays a positioning function; the central channel is composed of steel balls and valves. Er realizes gas-liquid flow in one direction from bottom to top. Thereby, the functions of gas-liquid lifting and stagnation to the upper part of the single-flow device are realized.

The invention also discloses a production method using a plunger gas-lift liquid drainage device of a horizontal gas well. The upper and lower sections of oil pipes with different pipe diameters are connected through variable diameter joints, and the self-buffering plunger is arranged in the upper section of the oil pipe. Set the single-flow device in the variable-diameter nipple; after the well is opened, the buffer plunger moves upward to lift the liquid in the upper part of the single-flow device to the wellhead, and the liquid in the lower part of the single-flow device is lifted to the single-flow by the energy of the gas itself. The upper part of the flow device; after the well is shut down, the self-buffering plunger goes down, and when it reaches the end of the reducing nipple, the guide head with the self-buffering plunger encounters resistance and stops moving, and the self-buffering plunger continues to go down due to inertia, and the The spring relieves its own kinetic energy until it stops; the liquid in the wellbore that has not been lifted to the surface pipeline falls back to the upper part of the single-flow device and the self-buffering plunger, and stays there, so that the reciprocating operation realizes the downhole single-flow device and the self-buffering column The plug forms a relay-type effusion lifting, which greatly reduces the wellbore effusion, realizes the lifting of the entire wellbore effusion of the horizontal gas well, opens up the gas flow channel, increases the recovery rate of the gas well, and reduces the production cost.

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Description of drawings

Fig. 1 is a schematic diagram of the high-efficiency plunger gas-lift liquid drainage production method and supporting technology used in horizontal gas wells of the present invention;

Fig. 2 is the plunger schematic diagram that the present invention is used for horizontal gas well self-buffering;

Fig. 3 is a schematic diagram of a single flow device of the present invention.

Among them: 1. oil pipe; 2. self-buffering plunger; 2-1. first fishing head; 2-2. buffer spring; 2-3. guide rod; 2-4. first spring cylindrical pin; 2-5. Retaining ring; 2-6. Second spring pin; 2-7. Guide head; 3. Reducing nipple; 4. Single flow device; 4-1. Second fishing head; ; 4-3. Steel ball; 4-4. Rubber cartridge; 4-5. Hollow channel.

detailed description

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer" and the like are based on the orientation or positional relationship shown in the drawings, and are only for It is convenient to describe the present invention and simplify the description, but does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and thus should not be construed as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

The invention discloses a plunger gas-lift liquid drainage device for horizontal gas wells and a production method. A self-buffering plunger 2 and a single-flow device 4 are used for relay-type lifting and drainage, and the single-flow device 4 is placed in the At the narrowing position of the tubing string of tubing 1, the gas well relies on its own energy to lift the wellbore effusion, and the single-flow device 4 retains the lifting liquid on its upper part, and the self-buffering plunger 2 then lifts the effusion from the narrowing position. It is lifted to the wellhead to complete the liquid drainage, and realizes the gas recovery of horizontal well plunger gas lift drainage, which can be applied to high-slope gas wells, expands the application range of plunger gas wells, and solves the production problem of horizontal gas wells.

Please refer to Fig. 1, the high-efficiency plunger gas lift drainage production method for horizontal gas wells of the present invention comprises the following steps:

S1. Connect the upper and lower oil pipes 1 with different pipe diameters through the reducing nipple 3, set the self-buffering plunger 2 in the upper oil pipe, and install the single flow device 4 in the lower oil pipe of the reducing nipple 3;

The diameter of the upper oil pipe 1 is 88.9mm, and the diameter of the lower oil pipe 1 is 73.02mm.

As shown in Figure 2, the self-buffering plunger 2 is a hollow structure, and one end is provided with a first fishing head 2-1, and several buffer springs 2 for realizing the self-buffering function of the plunger are arranged in the self-buffering plunger 2 -2, the other end is provided with a guide rod 2-3 and a retaining ring 2-5, which are used to fix the position of the buffer spring 2-2, prevent the buffer spring 2-2 from slipping, and support the buffer spring 2-2; The guide head 2-7 at the end of the guide rod 2-3 plays the role of guiding and supporting the plunger body at the bottom of the well during the falling process of the self-buffering plunger 2. 7 places are respectively provided with first spring cylindrical pin 2-4 and second spring cylindrical pin 2-6, which play a fixing role.

Preferably, the guide rod 2-3 is set as a hollow structure.

As shown in Figure 3, the single-flow device 4 includes a single-flow valve 4-2, a steel ball 4-3 and a rubber cartridge 4-4, and one end of the single-flow valve 4-2 is connected to the second fishing head 4 -1 connection, and the other end is connected to the hollow channel 4-5 provided in the rubber cartridge 4-4 through the steel ball 4-3.

The rubber tube 4-4 is used for sealing the outer wall of the single-flow device 4 and the inner wall of the wellbore after being heated and expanded, and plays a positioning function; the hollow passage 4-5 is composed of a steel ball 4-3 and a single-flow Vail 4-2 realizes the gas-liquid flow from bottom to top in one direction, so as to realize the function of gas-liquid lifting and retention to the upper part of the single-flow device.

S2. After opening the well, move upward from the buffer plunger 2 to lift the liquid in the upper part of the single-flow device 4 to the wellhead, and the liquid in the lower part of the single-flow device 4 is lifted to the upper part of the single-flow device 4 by the energy of the gas itself. The flow device 4 has the performance of one-way flow from bottom to top, and the gas and liquid will not flow back;

S3. After the well is shut down, the self-buffering plunger 2 goes down. After reaching the reduced diameter position, the guide head 2-7 of the self-buffering plunger 2 encounters resistance and stops moving, and the self-buffering plunger 2 continues to go down due to inertia. The spring 2-2 relieves its own kinetic energy until it stops;

S4. The liquid in the wellbore that has not been lifted to the surface pipeline falls back to the upper part of the single-flow device 3 and the self-buffering plunger 2, and stays there.

According to the operation of the above cycle of shutting down and shutting down wells, the horizontal gas wells have finally achieved efficient lifting of the full wellbore liquid effusion.

The above content is only to illustrate the technical ideas of the present invention, and cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solutions according to the technical ideas proposed in the present invention shall fall within the scope of the claims of the present invention. within the scope of protection.

Claims (7)

1. A plunger gas lift liquid discharge device for horizontal gas wells, characterized in that it comprises a self-buffering plunger (2) and a single-flow device (4) arranged in the oil pipe (1), the oil pipe (1 ) includes two sections of pipelines with different diameters, the two sections of pipelines are connected by a reducing joint (3), and the self-buffering plunger (2) is arranged on the oil pipe on the upper part of the reducing joint (3) In the pipeline, the single-flow device (4) has the function of controlling the one-way flow of gas and liquid from bottom to top, and is installed in the tubing pipeline at the lower part of the variable-diameter nipple (3), so that the gas well can lift the wellbore by its own energy. The accumulated liquid reaches the upper part of the single-flow device (4) and stays there, and then the accumulated liquid is lifted to the wellhead by the self-buffering plunger (2) to complete the liquid drainage production. 2. A plunger gas lift liquid drainage device for horizontal gas wells according to claim 1, characterized in that the self-buffering plunger (2) is a hollow structure, and one end is provided with a first fishing head (2 -1), the other end is provided with a guide rod (2-3) and a retaining ring (2-5), and several buffer springs ( 2-2), the guide rod (2-3) and retaining ring (2-5) are used to fix and support the buffer spring (2-2). 3. A plunger gas-lift liquid drainage device for horizontal gas wells according to claim 2, characterized in that, the retaining ring (2-5) and the guide head (2-7) are respectively provided with First spring pin (2-4) and second spring pin (2-6). 4. A plunger gas-lift liquid drainage device for horizontal gas wells according to claim 2, characterized in that, at the end of the guide rod (2-3) is provided a (2) The guide head (2-7) that guides and supports the body of the self-buffering plunger (2) at the bottom of the well during the fall. 5. A plunger gas lift liquid drainage device for horizontal gas wells according to claim 4, characterized in that the guide rod (2-3) is a hollow structure. 6. A kind of plunger gas-lift liquid drainage device for horizontal gas wells according to claim 1, characterized in that, the single-flow device (4) comprises a single-flow valve (4-2), a steel ball ( 4-3) and the rubber cartridge (4-4), one end of the single-flow valve (4-2) is connected to the second fishing head (4-1), and the other end passes through the steel ball (4-3) It is connected with the hollow channel (4-5) arranged in the said glue cartridge (4-4). 7. A method for producing by the liquid discharge device according to claim 1, characterized in that, comprising the following steps: S1. Connect the upper and lower oil pipes with different pipe diameters through the variable diameter nipple, set the self-buffering plunger in the upper oil pipe, and set the single flow device in the lower oil pipe of the variable diameter nipple; S2. After the well is opened, the buffer plunger moves upward to lift the liquid in the upper part of the single-flow device to the wellhead, and the liquid in the lower part of the single-flow device is lifted to the upper part of the single-flow device by the energy of the gas itself; S3. After the well is shut down, the self-buffering plunger goes down, and when it reaches the end of the variable diameter nipple, the guide head of the self-buffering plunger encounters resistance and stops moving, and the self-buffering plunger continues to go down due to inertia, and is relieved by the buffer spring Kinetic energy until stopped; S4. The liquid in the wellbore that has not been lifted to the surface pipeline falls back to the upper part of the single-flow device and the self-buffering plunger, and stays there; S5. Steps S2-S4 are repeated to complete the lifting of the full wellbore fluid accumulation of the horizontal gas well.