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CN-121993042-A - Tubular column combination for floating casing and construction method

CN121993042ACN 121993042 ACN121993042 ACN 121993042ACN-121993042-A

Abstract

The invention belongs to the technical field of casing running and discloses a tubular column combination for floating casing running and a construction method thereof, wherein the tubular column combination comprises a floating shoe, a collision pressing short circuit, a casing sliding sleeve, a throw-in type floating collar positioning short circuit, a floating coupling, a flexible reducing rubber plug and a throw-in type check valve core; the floating shoes, the bumping short circuit, the sleeve sliding sleeve, the input type floating collar positioning short circuit and the floating collar are sequentially connected to form a pipe column combination, the flexible reducing rubber plug is used for cleaning the inner wall of the pipe column combination, and the input type check valve core is arranged in the input type floating collar positioning short circuit to form a check valve. The pipe column combination design of the invention also focuses on improving the well cementation quality. Through reliable non-return function and well bore cleaning and debris handling measures, one-way flow of drilling fluid and well bore unobstructed is ensured. The method is favorable for improving the success rate and the well cementation quality of well cementation operation, and provides powerful guarantee for long-term stable and high yield of the oil-gas field.

Inventors

  • YANG LE
  • HUANG ZHANYING
  • TIAN DELIANG
  • OUYANG YONG
  • LU HONGJUN
  • XIE YONGGANG
  • SI DAICHUN
  • XU XIAOYUE
  • GAO YUNWEN

Assignees

  • 中国石油天然气集团有限公司

Dates

Publication Date
20260508
Application Date
20241104

Claims (10)

  1. 1. A tubular column combination capable of floating and casing running is characterized by comprising a floating shoe (14), a collision pressing short joint (13), a casing sliding sleeve (12), an input type float collar positioning short joint (11), a floating coupling (9), a flexible reducing rubber plug and an input type check valve core, wherein the floating shoe (14), the collision pressing short joint (13), the casing sliding sleeve (12), the input type float collar positioning short joint (11) and the floating coupling (9) are sequentially connected to form the tubular column combination, the flexible reducing rubber plug is used for cleaning the inner wall of the tubular column combination, and the input type check valve core is arranged in the input type float collar positioning short joint (11) to form a single-flow valve.
  2. 2. A floating casing pipe string assembly according to claim 1, characterized in that the joints of the floating shoes (14), the impact pressure short joint (13), the casing sliding sleeve (12), the input type floating collar positioning short joint (11) and the floating coupling (9) are all connected through the short casing pipe (10).
  3. 3. The floating casing pipe column combination according to claim 1, wherein the inner diameter of the input type floating collar positioning short joint (11) is larger than the inner diameter of the casing sliding sleeve (12), and the inner diameter of the casing sliding sleeve (12) is larger than the inner diameter of the collision pressing short joint (13).
  4. 4. A floating casing string assembly according to claim 1, wherein the casing sliding sleeve (12) comprises an inner sleeve and an outer sleeve, the inner sleeve and the outer sleeve being connected by a pin, the inner sleeve being provided with a ball seat, the upper part of the outer sleeve being provided with a through hole.
  5. 5. The floating casing pipe column combination according to claim 1 is characterized in that the flexible reducing rubber plug comprises a main body, a C-shaped ring (1), small rubber bowls (2) and large rubber bowls (3), wherein the C-shaped ring (1) is arranged at the end part of the main body, the small rubber bowls (2) and the large rubber bowls (3) are sleeved on the main body at intervals, and the flexible reducing rubber plug is a hydrogenated butyl cyanide rubber plug.
  6. 6. The floating casing pipe column combination according to claim 1, wherein the input type check valve core comprises a valve body, a slip body (5), slips (4) and a check valve, one end of the valve body is connected with the slips (4) through the slip body (5), and the check valve is arranged in the other end of the valve body.
  7. 7. A floating casing string assembly according to claim 6, wherein the single flow valve comprises a steel ball (7) and a spring (8), the steel ball (7) being located at the outlet inside the valve body, the steel ball (7) being fixed to the spring (8).
  8. 8. A floating casing pipe string assembly according to claim 6, characterized in that the outside of the valve body is sleeved with a cylindrical sealing ring (6).
  9. 9. A construction method of a floating cased pipe string combination, characterized by comprising the following steps based on the floating cased pipe string combination of any one of claims 1 to 8: sequentially discharging a tubular column combination from a well bottom to a well head according to the sequence of a floating shoe (14), a collision pressure short joint (13), a sleeve sliding sleeve (12), a throwing type floating collar positioning short joint (11) and a floating coupling (9); When the casing is put down, the grouting is stopped until the floating coupling (9) is put down into the well, the pressure is suppressed after the floating coupling (9) is drilled down, the blind plate of the floating coupling (9) is broken, and the drilling fluid forms circulation; The flexible reducing rubber plug is put into a wellhead, the inner wall of a pipe column assembly is cleaned, blind plate fragments are pushed to descend, and after the flexible reducing rubber plug is locked to the touch-press short circuit (13), the blind plate fragments are sealed between the touch-press short circuit (13) and the float shoe (14); the well mouth is thrown into a ball, the ball is seated on an inner sleeve ball seat of a sleeve sliding sleeve (12), after the pressure is increased, a pin between the inner sleeve and the outer sleeve is sheared off, the inner sleeve descends, and a through hole of the outer sleeve leaks out; And (3) conveying the valve core of the input check valve to the position of the input float collar positioning short circuit (11), and combining and locking the slips (4) with the screw threads on the input float collar positioning short circuit (11), so that the steel ball and the spring form a check valve.
  10. 10. The construction method of the pipe column combination of the floating casing pipe according to claim 9, wherein the C-shaped ring (1) on the flexible reducing rubber piston is contracted after being contacted with the collision and pressing short joint (13), and the collision and pressing short joint (13) is locked, so that floating coupling fragments are prevented from entering the pipe backwards.

Description

Tubular column combination for floating casing and construction method Technical Field The invention belongs to the technical field of casing running, and particularly relates to a tubular column combination for floating casing running and a construction method. Background In recent years, with the continuous progress of unconventional oil and gas field development technologies, the combined technology of 'long horizontal section well and volume fracturing' has become an indispensable important means in the field because of its ability to effectively improve oil and gas yield and recovery. However, in practical applications, as the length of the horizontal segment increases, the frictional resistance encountered during casing running during completion operations increases significantly, which poses serious challenges to the safety and efficiency of the drilling operation. To overcome this difficulty, the industry has begun to use floating casing techniques extensively to ensure that the stringent requirements of drilling operations are met under complex geological conditions. Against this background, a series of innovative solutions emerge in the field of chinese patent applications. The invention of patent application number CN201810124417.7 provides a mechanical floating coupling design, which ingeniously utilizes a shear pin to fixedly install a differential pressure sleeve on a coupling body, so that a slidable cavity is formed among the coupling body, the differential pressure sleeve and the fixed sleeve. When the casing is put in place, the pressure of drilling fluid in the casing gradually builds up until the pressure reaches a preset value, and at the moment, the pressure difference sleeve can shear the shear pin under the action of the pressure and smoothly slide downwards along the sliding cavity. When the sleeve is contacted with the sliding circular plate, the shearing pin is triggered to break again, so that complete communication inside the sleeve is finally realized, and the problem of friction caused by the running of the sleeve in the long horizontal section well is effectively solved. Another patent application, numbered cn202011442660. X, discloses a crushable blind plate floating collar with a more elaborate structural design. The coupling consists of three core components, namely a crushable blind plate, a limiting ring and a firing pin ring, wherein the lower end face of the crushable blind plate is tightly attached to the upper end face of the limiting ring, and a certain gap is reserved between the limiting ring and the firing pin ring, so that a plurality of firing pins on the firing pin ring can accurately penetrate through the limiting ring and crush the crushable blind plate when needed. When the operation condition is met, the firing pin can quickly strike the blind plate to enable the blind plate to be instantaneously crushed into fine powder, so that a circulation channel in the casing string is quickly restored, and the continuity and the high efficiency of drilling operation are ensured. Nevertheless, these two floating collars still face a series of non-negligible challenges in the application context of practical oil and gas field development. While providing significant advantages in solving the problem of long horizontal section casing running friction, the resulting wellbore diameter change after wellbore operations are a new challenge for mechanical floating collars. Such a variation not only increases the complexity of the subsequent hydrocarbon recovery operations, but may also adversely affect the recovery efficiency and safety of the equipment, thereby increasing the cost and risk of the overall operation. As for the blind plate type floating coupling, the design is exquisite in that the breakable blind plate can be instantaneously crushed through the impact of the firing pin ring, and the circulation channel in the casing is restored. However, the implementation of this process places extremely high demands on the degree of fine crushing of the crushed material. Once broken, the remaining pieces of material may adhere to the spring portions of the float shoe, causing the spring mechanism to jam or fail to open properly. The method can directly influence the quality and success rate of well cementation operation, and can also cause potential threat to the integrity and the tightness of a shaft, thereby influencing the development benefit of the whole oil-gas field. Therefore, in the current unconventional oil and gas field development field, the continuous optimization of the design of the floating collar, and the improvement of the adaptability and the reliability thereof are still a key problem to be solved urgently. Disclosure of Invention The invention aims to provide a tubular column combination for floating casing running and a construction method, which are used for solving the problems of complex operation and low quality and success rate of well cementatio