CN-116816297-B - Soluble branch well temporary plugging tool and branch well temporary plugging construction method

CN116816297BCN 116816297 BCN116816297 BCN 116816297BCN-116816297-B

Abstract

The invention provides a soluble temporary plugging tool for a branch well, which comprises a cylindrical body, a temporary plug, a fixing sleeve and a first dissolution starting area, wherein a limiting step with the end face facing upwards is arranged in the cylindrical body, a shearing ring extending outwards in the radial direction is arranged on the outer wall surface of the temporary plug, a first joint surface is formed on the outer surface of the temporary plug, the fixing sleeve is used for fixedly mounting the temporary plug, a second joint surface is formed on the inner wall surface of the fixing sleeve, an anti-corrosion coating is arranged on the outer surface of the temporary plug, a first dissolution starting area is arranged on the first joint surface, the shearing ring is pressed on the limiting step by the fixing sleeve in a first state, the first joint surface is matched with the second joint surface, a seal is formed on the first dissolution starting area, so that the temporary plug is fixed in the cylindrical body, and in a second state, the temporary plug is enabled to descend by applying pressure to the shearing ring, so that the first dissolution starting area is contacted with solution in the well, and the temporary plug is dissolved. The invention also provides a temporary plugging construction method for the branch well.

Inventors

ZHU HEMING
SHAO ZHIXIANG
CHEN WUJUN
LI HANG
HOU NAIHE
LIAO HONGQIAN

Assignees

中国石油化工股份有限公司
中石化石油工程技术研究院有限公司

Dates

Publication Date: 20260512
Application Date: 20220321

Claims (7)

1. A soluble branch well temporary plugging tool comprising: the device comprises a cylindrical body (1), wherein a limiting step (11) with an upward end face is arranged in the cylindrical body; A temporary plug (2), the outer wall surface of which is provided with a shearing ring (21) extending outwards along the radial direction, the outer surface of which is provided with a first joint surface (22), the outer surface of which is provided with an anti-corrosion coating, and a first dissolution start zone (23) is arranged on the first joint surface, the first joint surface is configured to comprise an outer cylindrical surface (221) and an outer conical surface (222), the outer conical surface is formed at the edge of the upper end of the temporary plug, the outer conical surface is longitudinally inclined upwards, the outer conical surface is longitudinally upwards relative to the first dissolution start zone, the shearing ring is longitudinally downwards relative to the first dissolution start zone, the front end of the temporary plug is provided with a guide head (25) for guiding the temporary plug to descend, the guide head is configured to be a conical structure, and the end part of the guide head forms a guide spherical surface; A second joint surface (32) is formed on the inner wall surface of the fixed sleeve, an anti-corrosion coating is arranged on the inner wall surface and the outer wall surface of the fixed sleeve, a second dissolution starting area (33) is arranged on the second joint surface, and the second joint surface is configured to comprise an inner cylindrical surface (321) and an inner conical surface (322) matched with the outer conical surface, and the inner conical surface is longitudinally inclined downwards; In a first state, the fixing sleeve presses the shearing ring on the limit step, the first joint surface is matched with the second joint surface, and the first joint surface is sealed with the first dissolution starting area, so that the temporary plug is fixed in the cylindrical body, wherein the second dissolution starting area corresponds to the first dissolution starting area in the first state, and is matched with the second joint surface to form a seal through the first joint surface, the temporary plug enables the inner conical surface to be matched with the outer conical surface, so that the temporary plug bears the pressure inside a branch well hole, In a second state, causing the temporary plug to descend by applying pressure to the temporary plug to shear the shear ring so as to bring the first and second dissolution initiation zones into contact with the well solution, thereby dissolving the temporary plug and the fixed sleeve; wherein the first dissolution start zone and the second dissolution start zone are configured as annular grooves.
2. The soluble branch well temporary plugging tool of claim 1, wherein the first dissolution initiation zone and the second dissolution initiation zone are disposed on the outer cylindrical surface and the inner cylindrical surface, respectively.
3. A tool for temporary plugging of a soluble branch well according to claim 1 or 2, characterized in that said first joint face is upstream of said shear ring, on which there are provided at least two sealing grooves (24) axially spaced apart from each other, in which sealing grooves there are mounted seals (4), said first dissolution start zone being located axially between said sealing grooves.
4. A soluble branch well temporary plugging tool according to claim 1 or 2, wherein said shear ring extends radially outwardly in a dimension of 5-10mm and said shear ring has a thickness of 3-5mm.
5. The soluble branch wellbore temporary plugging tool of claim 4, wherein the cross-sectional shape of the shear ring is configured as a rectangle.
6. A tool for temporary plugging of a soluble branch well according to claim 1 or 2, wherein an upper joint (5) is fixedly connected to the upper end of the tubular body, the lower end face of the upper joint extending into the interior of the tubular body and defining the axial direction of the fixed sleeve.
7. A temporary plugging construction method for a branch well comprises the following steps: step one, providing a soluble branch well temporary plugging tool according to any one of claims 1 to 6; After the branch well bores are drilled, the soluble branch well temporary plugging tool is lowered into the well along with the branch well completion pipe string to a target stratum, and the branch well completion pipe string is plugged through the temporary plugging, so that the corresponding branch well bores are temporarily plugged; drilling the next branch well hole of the branch well, and repeating the step two to temporarily plug the corresponding branch well hole until all branch well holes of the branch well are drilled; step four, releasing temporary plugs of the soluble branch well temporary plug tools on corresponding branch well bores, applying pressure to the corresponding temporary plugs to shear the shear ring, so that the temporary plugs descend, and enabling the first dissolution starting area and the second dissolution starting area corresponding to the temporary plugs and the fixed sleeve to be respectively contacted with solution in the well to be dissolved, opening the branch well bores, and further establishing branch well bore production; In the fourth step, pressure is applied to the temporary plugging in a wellhead pressure-holding manner or in a loading manner of the lower oil pipe.

Description

Soluble branch well temporary plugging tool and branch well temporary plugging construction method Technical Field The invention belongs to the technical field of well completion tools of oil and gas fields, and particularly relates to a soluble temporary plugging tool for a branch well. The invention also relates to a temporary plugging construction method for the branch well. Background In the operation of drilling and completing branch well, after one branch well is drilled, temporary blocking is often needed to be carried out on the branch well, then window opening sidetrack drilling operation is carried out so as to carry out drilling operation of other branch well, and after all branch well are drilled, temporary blocking of the branch well is eliminated, and production is realized for each branch well. Currently, the most common temporary plugging tools are those employing rupture discs, or removable bridge plugs. The temporary plugging mode of the rupture disc is simple, but the rupture disc is broken by a well head running tool, so that the problem that the rupture disc is incomplete to influence the passage of subsequent tools of a shaft exists. The later stage of removable bridging plug needs to salvage the bridging plug, has the unsuccessful risk of salvaging, influences the subsequent instrument of pit shaft and passes through, and in addition, salvage operation makes the temporary blocking technology of branch well complicated, salvages the operation difficulty, and is not only inefficiency, has increased the working cost moreover. Therefore, a safe, reliable and simple to operate branch well temporary plugging tool is needed. Disclosure of Invention Aiming at the technical problems, the invention aims to provide a soluble temporary plugging tool for a branch well, which can realize effective temporary plugging of the branch well, can precisely control the temporary plugging removal of the branch well, can realize the full drift diameter in the branch well, and greatly improves the safety and reliability of operation. According to a first aspect of the invention, there is provided a soluble type temporary plugging tool for a branch well, comprising a cylindrical body, a temporary plug, a fixing sleeve and a first dissolution start zone, wherein the cylindrical body is internally provided with a limiting step with an upward end face, the outer wall face of the temporary plug is provided with a shearing ring extending outwards along the radial direction, the outer surface of the temporary plug is provided with a first joint face, the fixing sleeve is used for fixedly mounting the temporary plug, the inner wall face of the fixing sleeve is provided with a second joint face, the outer surface of the temporary plug is provided with an anti-corrosion coating, the first joint face is provided with a first dissolution start zone, the shearing ring is pressed on the limiting step by the fixing sleeve in a first state, the first joint face is matched with the second joint face, and a seal is formed on the first dissolution start zone, so that the temporary plug is fixed in the cylindrical body, and in a second state, the temporary plug is enabled to descend by applying pressure to the shearing ring, so that the first dissolution start zone is contacted with the temporary plug in the well. In one embodiment, the inner wall surface and the outer wall surface of the fixing sleeve are both provided with an anti-corrosion coating, the second joint surface is provided with a second dissolution starting area, the second dissolution starting area corresponds to the first dissolution starting area in a first state, a seal is formed through the adaptation of the first joint surface and the second joint surface, and the fixing sleeve can be dissolved through the dissolution contact of the second dissolution starting area and the inside of a well in a second state. In one embodiment, the first engagement surface is configured to include an outer cylindrical surface and an outer conical surface, and the second engagement surface is configured to include an inner cylindrical surface and an inner conical surface, the temporary plug being capable of adapting the inner conical surface to the outer conical surface in a first state such that the temporary plug is subjected to pressure inside the branch wellbore. In one embodiment, the first dissolution start section and the second dissolution start section are disposed on the outer cylindrical surface and the inner cylindrical surface, respectively. In one embodiment, the first joint surface is upstream of the shear ring, at least two sealing grooves axially spaced apart from each other are provided on the first joint surface, a seal is installed in the sealing grooves, and the first dissolution start zone is located between the axial directions of the sealing grooves. In one embodiment, the shear ring extends radially outwardly in the range of 5-10mm in size and the shea