CN-117552731-B - Coiled tubing gas injection completion string and use method thereof

Abstract

The invention provides a coiled tubing gas injection well completion string and a use method thereof, wherein the string comprises a large-diameter anchor sealer, a coiled tubing and a connector, the large-diameter anchor sealer is arranged at a wellhead, the lower end of the continuous pipe is sequentially connected with a double-insurance shearing joint, an airtight packer, a setting ball seat and a reverse blocking sliding sleeve through a connector. The coiled tubing is adopted as a well completion oil pipe, leakage points are reduced to the greatest extent, the airtight performance of a tubular column is improved, the reverse plugging sliding sleeve meets the function of pressing down a drill under a belt, the setting ball seat realizes the setting packer through the ball throwing shearing sliding sleeve, the airtight packer meets the airtight performance, the double-insurance shearing joint designs two modes of ball throwing hydraulic shearing and lifting load shearing, double insurance is provided for handling accidents, the large-drift-diameter anchor packer ensures the falling-in of a large-diameter packing tool, and the hanging and sealing performance are considered, meanwhile, the coiled tubing body is formed by processing materials with good corrosion resistance, and the underground service life can be expected to be prolonged to more than 8 years.

Inventors

• LV WEI
• HE HUA
• WANG ZAIQIANG
• WANG ZHIGUO
• LIU ZHONGNENG
• LIU YANG
• MENG XIN
• REN YONG
• ZHANG HUAGUANG
• FENG CHANGQING

Assignees

• 中国石油天然气股份有限公司

Dates

Publication Date

20260508

Application Date

20220803

Claims (4)

1. 1. The continuous pipe gas injection well completion pipe column is characterized by comprising a large-drift-diameter anchor sealer, a continuous pipe and a connector, wherein the large-drift-diameter anchor sealer is arranged at a wellhead and sleeved on the continuous pipe, and the lower end of the continuous pipe is sequentially connected with a double-insurance shear joint, a gas-tight packer, a setting ball seat and a reverse blocking sliding sleeve through the connector; The double-insurance shearing connector comprises an upper connector and a second body, wherein the upper connector is connected with the second body through a first shearing structure, the second body is provided with a second shearing structure, and the first shearing structure and the second shearing structure are sheared under the action of external force; The sliding sleeve core II is arranged in the body II, the shearing structure I comprises a shearing pin and an elastic claw, the elastic claw is arranged at the lower part of the upper joint, the inner side of the elastic claw is in sealing connection with the sliding sleeve core II through a sealing ring II, and the outer side of the elastic claw is fixedly connected with the body II through the shearing pin; The second shearing structure comprises a setting shear pin, and the second sliding sleeve core is fixedly connected with the second body through the setting shear pin; When the tubular column can not be successfully drilled, lifting the tubular column, and shearing the shearing pin when a certain load is exceeded, so that the second upper joint is separated from the second body, and releasing is realized; when releasing can not be realized through lifting the tubular column, the setting ball is firstly thrown into the sliding sleeve core II, then the oil pipe is used for pressing, the setting shear pin is sheared, the setting ball drives the sliding sleeve core II to descend together, a space is reserved, the elastic claw is contracted inwards under the elastic action, the shear pin is lost to be fixed, the upper joint is separated from the body II, and releasing is realized.
2. 2. The coiled tubing gas injection completion string of claim 1, wherein the reverse plugging sliding sleeve comprises a first body, a sliding sleeve core I and a shear pin, the sliding sleeve core I is fixedly arranged in the first body through the shear pin, the sliding sleeve core I and the first body are sealed through a sealing ring I, a step is arranged at the inner upper part of the first body, and the sliding sleeve core I is positioned below the step.
3. 3. The coiled tubing gas injection completion string according to claim 1, wherein the large-drift-diameter anchor sealer comprises a shell, a threaded ejector rod and cone slips, the lower structure in the shell is matched with the cone slips, a coiled tubing channel is arranged in the shell, the cone slips are arranged in the shell and located in the circumferential direction of the coiled tubing channel, the inclined lower end of the threaded ejector rod is inserted into the shell and connected with the shell through threads, the inclined lower end of the threaded ejector rod is connected with the cone slips, and a metal sealing piece is arranged at the bottom end of the cone slips.
4. 4. The method of using a coiled tubing gas injection completion string according to claim 1, wherein when the annulus is filled with the protection fluid, a setting ball is put in, the inside of the oil pipe is pressurized, the airtight packer is sealed and set, and then the protection fluid is injected.

Description

Coiled tubing gas injection completion string and use method thereof Technical Field The invention belongs to the technical field of enhanced oil recovery of oil fields, and particularly relates to a continuous pipe gas injection completion pipe string and a use method thereof, which are suitable for the situation that a gas injection well is required to be completed in the oil field for implementing gas injection development oil reservoirs such as CO 2 flooding, foam-assisted oxygen reduction air flooding, hydrocarbon gas flooding and the like. Background Gas flooding has become increasingly widely used in recent years as one of the key technologies for enhanced recovery. In the early gas flooding test process, the well completion operation of the injection well is mostly implemented by adopting a conventional airtight oil pipe or a common oil pipe, taking the airtight oil pipe as an example, the tubular column structure generally comprises a bell mouth, a sieve tube, a shearing sliding sleeve, a blanking plug working cylinder, an airtight packer, the airtight oil pipe, an oil pipe hanger and an air injection wellhead, and the annular space is filled with anti-corrosion protection liquid. In view of the injection well with completed well operation, the oil pipe is more in threads and high in leakage probability, and meanwhile, when the oil pipe is buckled, the airtight detection device is adopted to carry out the sealing detection of each buckle, so that the implementation cost is high, the well completion period is long, and in addition, when the well is completed again or maintained, the pressure relief is difficult due to the fact that the well shaft is pressurized, a gas well pressurized working machine needs to be introduced, the cost is high, and the safety risk is high. The investigation results at home and abroad show that the coiled tubing can be widely applied to a plurality of technical operation fields of drilling, well completion, oil extraction, well repair and the like in the oil and gas industry, has the advantages of short operation period, low accident rate, small formation damage, good reentrant and the like, but has fresh reports on the application of gas injection flooding, and because the underground is matched with a large-diameter packing tool, the mechanical property of the coiled tubing is inferior to that of a conventional oil pipe to a certain extent, so that the completion operation of introducing the coiled tubing into the gas injection well needs to break through the prior technical obstacle, the coiled tubing can be shortened, the maximum advantage of the coiled tubing is brought into play, and the technical requirement of the site is met. The national intellectual property is published by the year 2016, 12 and 21 under the publication number CN106246148A, the patent name is an invention patent of an oil extraction method for injecting air into a horizontal well by adopting a continuous pipe, the patent sequentially comprises a shearing ball valve, a sectional packer, a ball throwing sliding sleeve and a sectional packer, and a permanent packer, a sliding sleeve, a movable nipple and a downhole safety valve are arranged in a straight well section to carry out high-pressure gas injection well completion, but the patent does not consider that the yield strength of the continuous pipe is limited, and when the lifting tonnage required by the packer is over the strength of the continuous pipe, the pipe body is broken. Disclosure of Invention The invention aims to provide a coiled tubing gas injection completion string, which overcomes the technical problems in the prior art. The invention further aims to provide a using method of the coiled tubing gas injection well completion string, which provides technical support for handling accidents when accidents occur in the process of tripping the string. Therefore, the technical scheme provided by the invention is as follows: the utility model provides a coiled tubing gas injection well completion tubular column, includes big latus rectum anchor seal ware, coiled tubing and connector, big latus rectum anchor seal ware is located the well head and is established on the coiled tubing in the cover, the coiled tubing lower extreme has connected gradually double insurance shear joint, airtight packer, setting ball seat and reverse shutoff sliding sleeve through the connector. The reverse blocking sliding sleeve comprises a first body, a first sliding sleeve core and a shear pin, wherein the first sliding sleeve core is fixedly arranged in the first body through the shear pin, the first sliding sleeve core and the first body are sealed through a first sealing ring, a step is arranged on the upper portion in the first body, and the first sliding sleeve core is located below the step. The double-insurance shearing connector comprises an upper connector and a second body, wherein the upper connector is connected with the second body through a f