CN-122014169-A - Radial expander and radial expanding method

CN122014169ACN 122014169 ACN122014169 ACN 122014169ACN-122014169-A

Abstract

The invention belongs to the technical field and discloses a radial pipe expander and a radial pipe expanding method. The radial expander comprises a central tube, an upper hydraulic cylinder, a lower hydraulic cylinder, a fixed sleeve, a connecting joint, a pushing joint, an expansion cone, a first elastic piece and a second elastic piece, wherein the top end opening of the central tube is used for injecting high-pressure liquid, a first driving cavity is formed between the upper hydraulic cylinder and the central tube, a transmission cavity is formed between the lower hydraulic cylinder and the central tube, a second driving cavity is formed between the pushing joint and the lower hydraulic cylinder, the fixed sleeve is fixedly connected to the central tube, the top end of the connecting joint is connected with the upper hydraulic cylinder, the bottom end of the connecting joint is connected with the lower hydraulic cylinder, the expansion cone is connected with the bottom end of the central tube, two ends of the first elastic piece are respectively abutted against the upper hydraulic cylinder and the fixed sleeve, and two ends of the second elastic piece are respectively abutted against the pushing joint and the expansion cone. The invention provides a radial expansion pipe expanding device which can radially expand an expansion pipe again so as to improve the sealing effect of a well wall and can be recycled and reused.

Inventors

SUN LIWEI
ZHANG NAN
GUO ZIWEI
LIU JIN
XIA YU
ZHU GAOLEI
HAN DONG
LIU HONGYU
YUAN XIUFA
YANG XING
LIU JINMING
HUO AILI
WANG XUESHEN
WANG YEHAN
HUO XIN
ZHONG YONG
LI HU
SUN SHAOLIANG
LI PENG
TIAN KAIWEI
LIU YONGQUAN

Assignees

中国石油集团长城钻探工程有限公司
中国石油天然气集团有限公司

Dates

Publication Date: 20260512
Application Date: 20241112

Claims (10)

1. The radial expander is used for radially expanding and expanding an expansion pipe (100), and is characterized by comprising the following components: the device comprises a central tube (1), wherein a first through hole (11) and a second through hole (12) are sequentially formed in the tube wall of the central tube (1) from top to bottom, the bottom end of the central tube (1) is sealed, and the top end of the central tube (1) is provided with an opening for injecting high-pressure liquid into the central tube (1); The upper hydraulic cylinder (2) is sleeved on the outer side of the central tube (1) and forms a first driving cavity (13) with the outer wall of the central tube (1), and the first driving cavity (13) is communicated with the first through hole (11); the lower hydraulic cylinder (7) is sleeved on the outer side of the central tube (1) and positioned below the upper hydraulic cylinder (2), a transmission cavity (14) is formed between the lower hydraulic cylinder (7) and the outer wall of the central tube (1), a third through hole (15) is formed in the tube wall of the lower hydraulic cylinder (7), and the transmission cavity (14) is communicated with the second through hole (12) and the third through hole (15); The top end of the fixing sleeve (5) is positioned between the first through hole (11) and the second through hole (12) and is fixedly connected to the outer wall of the central tube (1), and the inner wall of the bottom end of the fixing sleeve (5) is in sliding sealing with the outer wall of the lower hydraulic cylinder (7); the top end of the connecting joint (6) is penetrated through the fixing sleeve (5) upwards and is fixedly connected with the upper hydraulic cylinder (2), and the bottom end of the connecting joint (6) is fixedly connected with the lower hydraulic cylinder (7); a second driving cavity (16) is formed between the inner wall of the pushing joint (8) and the outer wall of the lower hydraulic cylinder (7), and the second driving cavity (16) is communicated with the third through hole (15); The top end of the expansion cone (10) is of a split structure, and the bottom end of the expansion cone (10) is sleeved on the central tube (1) and fixedly connected with the central tube (1); The two ends of the first elastic piece (4) are respectively abutted against the upper hydraulic cylinder (2) and the fixed sleeve (5); The two ends of the second elastic piece (9) are respectively abutted against the pushing joint (8) and the expansion cone (10), and the pushing joint (8) is abutted against the fixing sleeve (5) to limit under the elastic action of the second elastic piece (9); the elastic force of the first elastic piece (4) is larger than that of the second elastic piece (9).
2. The radial expander according to claim 1, further comprising an upper joint (3), wherein the bottom end thread of the upper hydraulic cylinder (2) is connected with the upper joint (3), the bottom end face of the upper joint (3) is elastically abutted against the first elastic member (4), the inner wall of the upper joint (3) is in thread connection with the outer wall of the connecting joint (6), and the top end face of the upper joint (3), the outer wall of the central tube (1) and the inner wall of the upper hydraulic cylinder (2) enclose to form the first driving cavity (13).
3. Radial expander according to claim 1, characterized in that the outer wall of the fixed sleeve (5) is provided with a first limit step (17), in an initial state, under the action of the second elastic element (9), the top end of the pushing joint (8) is stopped against the first limit step (17), and the transmission cavity (14) and the second driving cavity (16) are in a communication state.
4. Radial expander according to claim 1, characterized in that the outer wall of the lower cylinder (7) is provided with a groove (18), the groove (18) being in communication with the top end face of the lower cylinder (7), and that high pressure liquid in the second drive chamber (16) is able to flow out along the groove (18) when the lower cylinder (7) moves down until the second drive chamber (16) is in communication with the groove (18).
5. The radial expander according to claim 4, wherein a first stepped groove and a second stepped groove are formed in the inner wall of the push joint (8), the push joint (8) is located at the maximum height in an initial state, part of the groove wall of the first stepped groove is in sliding sealing connection with the outer wall of the fixed sleeve (5), the groove bottom of the first stepped groove, the other part of the groove wall of the first stepped groove, the bottom end face of the fixed sleeve (5) and the groove wall of the second stepped groove are in sliding sealing connection with the outer wall of the lower hydraulic cylinder (7), and when the lower hydraulic cylinder (7) moves downwards to the position that the second driving cavity (16) is communicated with the groove (18) to release pressure, the push joint (8) resets.
6. Radial expander according to claim 1, wherein the top end of the connection joint (6) is of split construction and the fixing sleeve (5) is of split construction.
7. Radial expander according to claim 1, wherein the outer diameter of the outer wall of the bottom end of the push joint (8) gradually increases from bottom to top, the inner wall of the push joint (8) is provided with a limit groove (20), and the top end of the second elastic member (9) is abutted with the groove bottom of the limit groove (20).
8. A radial expansion method, characterized in that a radial expander according to any one of claims 1-7 is applied, said radial expansion method comprising the steps of: S1, after naked eye plugging and wall fixing are carried out through an expansion pipe (100), the expansion pipe (100) is attached to a well wall (200), and more than one expanded section (201) exists in the well wall (200); s2, the radial expander is lowered into the expansion pipe (100) according to logging data, and the expansion cone (10) is located below the expansion section (201); S3, injecting high-pressure liquid into the central tube (1) and pressing the high-pressure liquid to a first pressure, wherein the first pressure is smaller than the elastic force of the first elastic piece (4) and larger than the elastic force of the second elastic piece (9), under the action of the high-pressure liquid, the pushing joint (8) overcomes the elastic force of the second elastic piece (9) to move downwards and prop up the expansion cone (10), and the expansion cone (10) swells the expansion tube (100) and is attached to the inner wall of the expanding section (201).
9. The radial expansion method according to claim 8, further comprising the step S4 of pulling the center tube (1), and under the action of the expansion cone (10), the outer diameter of the expansion tube (100) is continuously expanded in the axial direction until the pulling resistance is suddenly increased, stopping the pulling, and ending the expansion.
10. The radial pipe expanding method according to claim 9, wherein in step S3 and step S4, when the first pressure of the high-pressure liquid is instantaneously raised to the second pressure, under the action of the high-pressure liquid, the upper hydraulic cylinder (2) overcomes the elastic force of the first elastic member (4) and moves downwards, and meanwhile, the upper hydraulic cylinder (2) drives the lower hydraulic cylinder (7) to move downwards through the connecting joint (6) until the high-pressure liquid in the second driving cavity (16) flows out through the groove (18) on the outer wall of the top end of the lower hydraulic cylinder (7), the pushing joint (8) is depressurized and is retracted under the action of the elastic force of the second elastic member (9), and the expansion cone (10) is reset to stop pipe expanding.

Description

Radial expander and radial expanding method Technical Field The invention relates to the technical field of oil and gas drilling and well repair, in particular to a radial pipe expander and a radial pipe expanding method. Background In the petroleum drilling process, when abnormal formations such as abnormal high pressure, lost circulation, water discharge, collapse and the like are encountered, the conventional mode is that a next layer of casing is sealed, but when a plurality of complex formations are encountered, the casing has multiple layers, high cost, long construction period and small well completion hole size, and the drilling to a target horizon is difficult. The expansion pipe with good characteristics is put into the well by using the open hole plugging technology of the expansion pipe, and is expanded and tightly attached to the shaft, so that complex stratum which is easy to collapse, leak, mud rock, abnormally high pressure and the like can be effectively isolated, and the size loss of the well bore is reduced to the greatest extent on the premise of ensuring smooth drilling, thereby being beneficial to the entering of subsequent tools. In practical implementations, however, the wellbore size may be enlarged or reduced due to the presence of complex formations. The size of the well hole is small, the drift diameter can be recovered through reaming and other modes, and when the expansion pipe is constructed, the expansion pipe sealing section is just positioned at the expansion section and cannot be attached to the well wall, so that the sealing is not tight, and the construction effect is affected. And the expansion section can be complemented with an expansion pipe, so that the damaged casing can be repaired, and the sealing and the integrity of the casing are restored. However, in oil and gas fields requiring large-scale fracturing operation such as shale gas and shale oil, the casing is severely damaged and deformed through the fracturing operation, and when one or more points of the inside diameter of the casing is enlarged or even overlarge, after the expansion pipe patching technology is implemented, the expansion pipe patching technology still cannot be tightly attached to the wall of the external casing, and the sealing and bearing performances cannot meet the requirements. When the borehole size is uneven or the borehole diameter is irregular, the existing casing repairing mode cannot meet the requirements of expansion pipes with all sizes at one time, and cannot be applied to the open hole sealing operation of the expansion pipes. Disclosure of Invention The invention aims to provide a radial expander and a radial expanding method, which are used for radially expanding an expansion pipe so as to improve the repairing effect. To achieve the purpose, the invention adopts the following technical scheme: a radial expander for radially expanding an expanded pipe, the radial expander comprising: The bottom end of the central tube is sealed, the top end of the central tube is provided with an opening, and the top end opening is used for injecting high-pressure liquid into the central tube; the upper hydraulic cylinder is sleeved on the outer side of the central tube and forms a first driving cavity with the outer wall of the central tube, and the first driving cavity is communicated with the first through hole; The lower hydraulic cylinder is sleeved on the outer side of the central tube and positioned below the upper hydraulic cylinder, a transmission cavity is formed between the lower hydraulic cylinder and the outer wall of the central tube, the tube wall of the lower hydraulic cylinder is provided with a third through hole, and the transmission cavity is communicated with the second through hole and the third through hole; the top end of the fixed sleeve is positioned between the first through hole and the second through hole and is fixedly connected to the outer wall of the central tube, and the inner wall of the bottom end of the fixed sleeve is in sliding seal with the outer wall of the lower hydraulic cylinder; The top end of the connecting joint upwards penetrates through the fixing sleeve and is fixedly connected with the upper hydraulic cylinder, and the bottom end of the connecting joint is fixedly connected with the lower hydraulic cylinder; the pushing joint is provided with a first driving cavity, and the first driving cavity is communicated with the first through hole; The top end of the expansion cone is of a split structure, and the bottom end of the expansion cone is sleeved on the central tube and fixedly connected with the central tube; the two ends of the first elastic piece are respectively abutted against the upper hydraulic cylinder and the fixed sleeve; The two ends of the second elastic piece are respectively abutted against the pushing joint and the expansion cone, and the pushing joint is abutted against the fixing sleeve to limit under the elastic action of t