阅读说明：本技术 一种径向锚定倒扣取换套管装置及方法 (Radial anchoring inverted-buckling casing taking and replacing device and method ) 是由 杨文东 和新鹏 张义铁 杜庆 万彬 段晓明 于 2019-10-14 设计创作，主要内容包括：本发明提出一种径向锚定倒扣取换套管装置及方法,包括换套管柱和套管液压钳,换套管柱包括钻杆、封隔器和锚定器,封隔器设于钻杆的底部,锚定器设于钻杆下部,套管液压钳的背钳在上夹持钻杆的上部,套管液压钳的主钳在下夹持待换的第一根套管,将第一根套管更换为短套管,从而实现降井口的目的。本发明安全可靠、施工成本低、作业周期短、成功率高。(The invention provides a device and a method for taking and replacing a casing pipe by radial anchoring and back-off, which comprises a casing pipe replacing string and casing pipe hydraulic tongs, wherein the casing pipe replacing string comprises a drill pipe, a packer and an anchor, the packer is arranged at the bottom of the drill pipe, the anchor is arranged at the lower part of the drill pipe, back tongs of the casing pipe hydraulic tongs clamp the upper part of the drill pipe upwards, main tongs of the casing pipe hydraulic tongs clamp a first casing pipe to be replaced downwards, and the first casing pipe is replaced by a short casing pipe, so that the purpose of lowering a well head is realized. The invention has the advantages of safety, reliability, low construction cost, short operation period and high success rate.)

1. The utility model provides a radial anchoring back-off gets and trades sleeve pipe device which characterized in that: the device comprises a casing replacing string and casing hydraulic tongs, wherein the casing replacing string comprises a drill rod, a packer and an anchor, the packer is arranged at the bottom of the drill rod, the anchor is arranged at the lower part of the drill rod, back tongs of the casing hydraulic tongs clamp the upper part of the drill rod, and a main tong of the casing hydraulic tongs clamps a first casing to be replaced.

2. A radial anchoring inverted casing device according to claim 1, wherein the distance between said back-up tong and said main tong is greater than 45 cm.

3. The radial anchoring inverted casing pipe taking-off device as claimed in claim 1, wherein the drill pipe is formed by connecting a plurality of sub drill pipes in sequence.

4. A method for taking and replacing a sleeve by radial anchoring and back-off is characterized by comprising the following steps:

s1) killing the well: pulling out the original well production pipe column, and performing well washing and killing construction;

s2) scraping the tube: a pipe scraper is put in to repeatedly scrape the well mouth to the well section of 20 meters for 3-5 times, and the pipe scraper is taken out;

s3) sand-pack: putting an optical oil pipe down, filling sand to cover a production layer, and taking out a part of the optical oil pipe after the sand detection surface is qualified;

s4) seating: lowering a casing changing string, lifting and lowering a drill rod to seal the packer, and positively rotating the drill rod to anchor the anchor to the second casing;

s5) back-off: removing a wellhead and a bottom flange, biting a drill rod by using back tongs of a special back-off casing hydraulic tong, biting and reversing a first casing by using a main tong, and removing a screw thread between the first casing and a second casing to pull out the first casing;

s6) buckling: selecting a short sleeve with proper length according to the height of the wellhead and the length of the pulled-out sleeve, putting the short sleeve into the well, and fastening the short sleeve with a second sleeve in a buckling manner;

s7) installing a wellhead and a blowout preventer: installing a casing pipe nipple, a bottom flange and a lower half casing of a wellhead, and installing a blowout preventer;

s8) testing and sand washing: and (4) taking out the casing replacing string, assembling the well mouth, flushing and removing sand covering the production layer after the pressure test is qualified at 15MPa, finishing the construction of lowering the well mouth, and turning to the next construction procedure according to the design requirement.

Technical Field

The invention belongs to the technical field of downhole tools for replacing damaged oil well casings, and relates to a radial anchoring inverted-buckling casing replacing device and method.

Background

In the oil field production, the ground sinks due to the fact that a local salt industry factory extracts underground brine for a long time to sun salt, the thick oil thermal recovery well adopts a steam injection recovery mode to enable a sleeve to stretch and deform, and the like, so that the height of a packing box at the well mouth of an oil well from the ground is too high, the operation is seriously influenced by more than 2 meters, and the too high well mouth brings very adverse influences on safety and well control in the normal production and well workover operation processes of the oil well.

Adverse effects on oil-water well production: the safety distance between the rope hanger and the packing box is insufficient, so that the oil well cannot be normally produced, and safety risks such as hand clamping and the like are easy to occur; potential safety hazards exist in daily maintenance of the oil-water well, including replacing a packing of a blowout prevention box, replacing the packing, cleaning a well head and the like; well control potential safety hazards exist due to deformation of a well head flow. Adverse effects on workover operations: the well mouth is easily hung in the process of pulling out and putting down the pipe column; the safety distance of the anti-collision crown block cannot meet the requirement, and the crown block is easy to jack in the construction process, so that equipment damage and personnel injury are caused.

Aiming at the condition of overhigh well head, the method adopted in the past is to heighten the height of a well head platform, a pumping unit or an operation team by using an earth-rock pad, but the method is easy to cause slipping and falling injury of operators, and does not fundamentally solve the potential safety and well control hazards existing in the production and well workover operation processes of oil-water wells.

To completely eliminate various adverse effects caused by the over-height of the wellhead, the most effective method is to lower the wellhead to a proper safe height. The conventional wellhead lowering method is to cut off a surface casing and an oil layer casing at a certain position below a wellhead by gas welding cutting and weld an annular steel plate and an oil layer casing coupling again to achieve the purpose of lowering the wellhead.

Disclosure of Invention

The invention aims to solve the technical problem of providing a radial anchoring inverted-buckling casing replacing device and a method, which can effectively solve the problem that the height of a packing box at the wellhead of an oil well from the ground is too high due to the reasons that the ground sinks, the casing is stretched and deformed in a steam injection exploitation mode of a heavy oil thermal recovery well and the like.

The technical scheme adopted by the invention for solving the technical problems is as follows: the device comprises a casing replacing string and casing hydraulic tongs, wherein the casing replacing string comprises a drill rod, a packer and an anchor, the packer is arranged at the bottom of the drill rod, the anchor is arranged at the lower part of the drill rod, back tongs of the casing hydraulic tongs clamp the upper part of the drill rod, and a main tong of the casing hydraulic tongs clamps a first casing to be replaced.

According to the technical scheme, the distance between the back clamp and the main clamp is larger than 45 cm.

According to the technical scheme, the drill rod is formed by sequentially connecting a plurality of sub drill rods.

A method for taking and replacing a sleeve by radial anchoring and back-off is characterized by comprising the following steps:

s1) killing the well: pulling out the original well production pipe column, and performing well washing and killing construction;

s2) scraping the tube: a pipe scraper is put in to repeatedly scrape the well mouth to the well section of 20 meters for 3-5 times, and the pipe scraper is taken out;

s3) sand-pack: putting an optical oil pipe down, filling sand to cover a production layer, and taking out a part of the optical oil pipe after the sand detection surface is qualified;

s4) seating: lowering a casing changing string, lifting and lowering a drill rod to seal the packer, and positively rotating the drill rod to anchor the anchor to the second casing;

s5) back-off: removing a wellhead and a bottom flange, biting a drill rod by using back tongs of a special back-off casing hydraulic tong, biting and reversing a first casing by using a main tong, and removing a screw thread between the first casing and a second casing to pull out the first casing;

s6) buckling: selecting a short sleeve with proper length according to the height of the wellhead and the length of the pulled-out sleeve, putting the short sleeve into the well, and fastening the short sleeve with a second sleeve in a buckling manner;

s7) installing a wellhead and a blowout preventer: installing a casing pipe nipple, a bottom flange and a lower half casing of a wellhead, and installing a blowout preventer;

s8) testing and sand washing: and (4) taking out the casing replacing string, assembling the well mouth, flushing and removing sand covering the production layer after the pressure test is qualified at 15MPa, finishing the construction of lowering the well mouth, and turning to the next construction procedure according to the design requirement.

The invention has the beneficial effects that: a second sleeve is anchored by a sleeve taking and replacing tool with an anchor, the first sleeve is replaced by a short sleeve by utilizing the reversing special sleeve hydraulic tong for reversing, so that the purpose of lowering the wellhead is realized, the problem that the height of a packing box at the wellhead of an oil well is too high from the ground due to the reasons that the ground is sunken, the thick oil thermal recovery well adopts a steam injection recovery mode to make the sleeve stretch and deform and the like can be effectively solved, and the safety and well control hidden dangers existing in the production and workover processes of the oil-water well can be eliminated.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Detailed Description

For a better understanding of the present invention, reference is made to the following description taken in conjunction with the accompanying drawings and examples.

As shown in figure 1, the radial anchoring back-off casing taking and replacing device comprises a casing replacing string and casing hydraulic tongs, wherein the casing replacing string comprises a drill rod 1, a packer 4 and an anchor 3, the packer is arranged at the bottom of the drill rod, the anchor is arranged at the lower part of the drill rod and is positioned above the packer, back tongs 9 of the casing hydraulic tongs clamp clamps the upper part of the drill rod at the upper part, and a main tong 8 of the casing hydraulic tongs clamps a first casing 2 to be replaced at the lower part.

The distance between the back-up tong and the main tong is more than 45cm, and the bottom flange can be sleeved in to carry out back-off construction under the condition that the bottom flange cannot be detached. Meanwhile, a hydraulic station is added, and hydraulic power can be provided for the special sleeve hydraulic tong for back-off.

The drill rod is formed by connecting a plurality of sub drill rods in sequence, and the requirements of different well depths are met.

The anchor is used to anchor a second casing 7, by rotating clockwise the anchor blade is extended, locking the casing. And when the anchor sheet rotates reversely, the anchor sheet loses support, and unlocking is realized.

A method for taking and replacing a sleeve by radial anchoring and back-off is characterized by comprising the following steps:

s1) killing the well: pulling out the original well production pipe column, and performing well washing and killing construction;

s2) scraping the tube: a pipe scraper is put in to repeatedly scrape the well mouth to the well section of 20 meters for 3-5 times, and the pipe scraper is taken out;

s3) sand-pack: putting the optical oil pipe 6 into the sand filling and covering the production layer, and taking out part of the optical oil pipe after the sand detection surface is qualified;

s4) seating: setting the casing pipe taking and replacing assembly, raising the drill pipe to seal the packer, and rotating the drill pipe forward to anchor the anchor to the second casing pipe;

s5) back-off: removing a wellhead and a bottom flange, biting a drill rod by using back tongs of a special back-off casing hydraulic tong, biting a first casing and reversing by using a main tong, and detaching a screw thread 5 between the first casing and a second casing to pull out the first casing;

s6) buckling: selecting a short sleeve with proper length according to the height of the wellhead and the length of the pulled-out sleeve, putting the short sleeve into the well, and fastening the short sleeve with a second sleeve in a buckling manner;

s7) installing a wellhead and a blowout preventer: installing a casing pipe nipple, a bottom flange and a lower half casing of a wellhead, and installing a blowout preventer;

s8) testing and sand washing: and (4) pulling out the replacement sleeve assembly, assembling the well mouth, flushing and removing sand covering the production layer after the pressure test is qualified at 15MPa, finishing the construction of lowering the well mouth, and turning to the next construction procedure according to the design requirement.