CN-117627574-B - Unidirectional sealing ring, sealing mechanism, liner top packer and liner well cementation process

CN117627574BCN 117627574 BCN117627574 BCN 117627574BCN-117627574-B

Abstract

The invention provides a unidirectional sealing ring, a sealing mechanism, a liner top packer and a liner cementing process, wherein the unidirectional sealing mechanism comprises a central pipe, an upper deformation baffle sleeve sleeved on the outer wall of the central pipe, a lower deformation baffle sleeve sleeved on the outer wall of the central pipe, the upper deformation baffle sleeve and the lower deformation baffle sleeve are spaced apart in the axial direction, a sealing element sleeved on the outer wall of the central pipe, the lower end of the sealing element is propped against the upper end of the lower deformation baffle sleeve, an expansion cone arranged between the upper deformation baffle sleeve and the sealing element, a sealing groove is arranged on the circumferential direction of the inner wall of the expansion cone, a sealing ring is arranged in the sealing groove, a drainage groove is arranged on the inner wall of the expansion cone along the axial direction, fluid can only flow unidirectionally from the upper end to the lower end of the expansion cone, fluid is allowed to flow upwards from the upper end to the lower end of the expansion cone, the fluid is allowed to flow upwards, the fluid below the sealing groove is allowed to be compressed and set through a wellhead annulus before cement paste is solidified, the formation fluid is prevented from flowing downwards due to volume shrinkage, and the quality of well cementing is ensured.

Inventors

LIU YUNLOU
LI DINGXIA
WANG JUAN
TANG XIN
ZHANG JIANJUN
ZHANG YICHAO
XIE MING
ZHANG HAOYUE

Assignees

中国石油天然气集团有限公司
中国石油集团川庆钻探工程有限公司

Dates

Publication Date: 20260508
Application Date: 20220809

Claims (11)

1. A unidirectional sealing mechanism, characterized in that the unidirectional sealing mechanism comprises: a central tube; The upper deformation blocking sleeve is sleeved on the outer wall of the central tube; The lower deformation blocking sleeve is sleeved on the outer wall of the central tube and is spaced from the upper deformation blocking sleeve in the axial direction of the central tube; The sealing element is sleeved on the outer wall of the central tube, and the lower end of the sealing element is propped against the upper end of the lower deformation blocking sleeve; The expansion cone is sleeved on the outer wall of the central tube, the expansion cone is arranged between the upper deformation blocking sleeve and the sealing element at the axial position of the central tube, the lower end of the expansion cone can be tapered into a gap between the sealing element and the outer wall of the central tube, so that the sealing element is expanded, and the inner wall of an annulus needing to be sealed is tightly attached; a shearing fixing part for fixing the sealing element and the expansion cone relatively and shearing the sealing element under the action of axial shearing force, and A seal ring installed in the seal groove so that fluid can flow only in one direction from the upper end to the lower end of the expansion cone along the leakage groove; the sealing ring comprises: An upper part having an inner diameter larger than an outer diameter of the central tube, an upper end surface provided with a radial groove along a radial direction of the seal ring, the radial groove being capable of communicating with a gap between an inner wall of the upper part and an outer wall of the central tube to allow a fluid to pass therethrough, and The lower part, the lower part includes outside head and inboard head, outside head with the inner wall of seal groove closely laminates, inboard head with the outer wall of center tube closely laminates, the lower extreme of inboard head with the lower extreme of outside head is followed the radial direction of center tube is spaced apart, the length of outside head is greater than the length of inboard head.
2. The unidirectional sealing mechanism of claim 1, wherein an included angle is formed between the inner head and the outer head, the included angle being 0-90 degrees.
3. The unidirectional sealing mechanism of claim 2, wherein the upper portion of the seal groove further defines a step along the seal groove circumference, the unidirectional sealing mechanism further comprising: the limiting ring is arranged on the step, the outer diameter of the limiting ring is larger than the bottom diameter of the drainage groove and smaller than the bottom diameter of the step, the inner diameter of the limiting ring is larger than the outer diameter of the central tube, the outer edge of the limiting ring is spaced from the step, and the inner edge of the limiting ring is spaced from the outer wall of the central tube.
4. A unidirectional sealing mechanism as claimed in claim 3, wherein a shear pin through hole is formed in the upper portion of the expansion cone along the circumferential direction of the expansion cone, the shear pin through hole penetrates through the side wall of the expansion cone, a blind hole is formed in the outer wall of the central tube at a position corresponding to the shear pin through hole, the shear fixing pieces penetrate through the shear pin through hole and the blind hole at the same time, and the number of the shear fixing pieces is identical to that of the shear pin through hole and the blind hole.
5. The one-way seal mechanism of claim 4, wherein the expansion cone has an axial length greater than an axial length of the seal element, the expansion cone being movable along the center tube axis and interposed between the seal element and the outer wall of the center tube to radially expand the seal element along the center tube to abut an inner wall of an annulus to be sealed.
6. The unidirectional sealing mechanism of claim 5, wherein the outer wall of the expansion cone is divided into an upper expansion cone outer wall section, a middle expansion cone outer wall section, and a lower expansion cone outer wall section, the upper expansion cone outer wall section having a diameter greater than the middle expansion cone outer wall section, the middle expansion cone outer wall section having a diameter greater than the lower expansion cone section.
7. The unidirectional sealing mechanism of claim 6, wherein the lower deformable collar outer wall comprises, from top to bottom in the axial direction, a collar outer wall upper section and a collar outer wall lower section, the collar outer wall upper section having a diameter less than the collar outer wall lower section, the collar outer wall upper section having a diameter equal to or slightly greater than the outer diameter of the sealing element; The lower deformation retaining sleeve inner wall comprises a retaining sleeve inner wall upper section, a retaining sleeve inner wall middle section and a retaining sleeve inner wall lower section from top to bottom along the axis direction, the diameter of the retaining sleeve inner wall middle section is larger than that of the retaining sleeve inner wall upper section, and the diameter of the retaining sleeve inner wall upper section is larger than that of the retaining sleeve inner wall lower section.
8. The one-way seal mechanism of claim 7, wherein an axial cut through the inner and outer walls of the lower deformation boot is made in the lower deformation boot in the axial direction of the lower deformation boot.
9. A unidirectional sealing mechanism as claimed in any one of claims 1 to 8, wherein a "double L-shaped" cut and a split setting jaw formed by said "double L-shaped" cut are provided in the lower portion of said upper deformation boot, said "double L-shaped" cut comprising a first distance cut along the axis from the lower end face of the upper deformation boot, a second distance cut along the circumferential direction and a third distance cut along the axial direction, said first and second distances being smaller than said third distance.
10. A liner top packer, the liner top packer comprising: a one-way seal according to claim 1 to 9, and And the setting mechanism is fixedly connected with the upper end of the central tube of the unidirectional sealing mechanism.
11. A liner cementing process is characterized in that, the liner cementing process comprises the following steps: injecting cement paste into the open hole annulus; integrating a hanger joint of the liner top packer of claim 10 with a liner hanger; the setting mechanism is pressed down, and an expansion cone of the packer at the top of the tail pipe is inserted into the sealing element, so that the sealing element swells to block the annulus, and setting is completed; after setting and before cement paste is solidified, injecting fluid into the open hole and the overlapped section annular space through the well mouth annular space through the tail pipe top packer, and waiting for solidification of cement paste; after the cement paste is solidified, the gas after well cementation is prevented from channeling from bottom to top to the upper annular space of the top packer of the tail pipe by the unidirectional sealing mechanism of the top packer of the tail pipe.

Description

Unidirectional sealing ring, sealing mechanism, liner top packer and liner well cementation process Technical Field The invention relates to the technical field of manufacturing of downhole tools for oil and gas drilling, in particular to a sealing ring with one-way sealing, a sealing mechanism, a top packer of a tail pipe and a tail pipe well cementation process. Background The liner top packer is mainly used for liner cementing in the petroleum and natural gas field, is arranged at the top of a liner hanger, is connected with the liner hanger into a whole, can seal the annulus between the liner and an upper sleeve, and solves the problem of horn mouth blowby after liner cementing of wells with low pressure leakage, narrow pressure window, simultaneous spraying leakage and the like. For example, chinese patent document with publication number CN204266983U discloses a top packer structure of a tail pipe, which comprises a packer body, a rubber sleeve pushing sleeve, one or more rubber sleeves and a fixing sleeve, wherein the rubber sleeve pushing sleeve, the one or more rubber sleeves and the fixing sleeve are sequentially sleeved outside the body from top to bottom, an O-shaped sealing ring is arranged between the rubber sleeve and the body, the fixing sleeve is fixedly connected with the body, a retaining ring is arranged between the rubber sleeve pushing sleeve and the body, and circumferential grooves are processed on the surface of the rubber sleeve pushing sleeve. The packer structure can realize the function of sealing an upper annular space in well cementation operation, and better solves the technical problem, however, in the use process, because the packer structure can form a closed space between the packer after setting and the collision and pressing seat, cement slurry in the closed space can undergo volume shrinkage in the subsequent condensation process and cannot be subjected to pressure compensation through the outside, so that the absolute pressure of an open hole annular space can be reduced, fluid in a stratum below the annular space is still in a high-pressure state, and the pressure difference between the annular space and the stratum can push the fluid in the stratum to float out of the stratum along the open hole annular space, thereby influencing the well cementation quality. Disclosure of Invention The present invention aims to address at least one of the above-mentioned deficiencies of the prior art. For example, one of the purposes of the present invention is to provide a unidirectional sealing ring, a sealing mechanism, a liner top packer and a liner cementing process, so as to solve the problem of fluid channeling caused by the pressure drop of an open hole annulus. In order to achieve the above object, an aspect of the present invention provides a one-way sealing mechanism, which may include a central tube; the sealing device comprises a central tube, an upper deformation baffle sleeve, a lower deformation baffle sleeve, a sealing element, an expansion cone, a sealing groove and a sealing groove, wherein the upper deformation baffle sleeve is sleeved on the outer wall of the central tube, the lower deformation baffle sleeve is arranged on the outer wall of the central tube and is spaced from the upper deformation baffle sleeve in the axial direction of the central tube, the sealing groove is arranged on the inner wall of the expansion cone in a spaced mode, the sealing groove is arranged on the inner wall of the expansion cone in the axial direction of the central tube, the upper end of the expansion cone is in contact with the upper end of the lower deformation baffle sleeve, the expansion cone is arranged on the outer wall of the central tube in the axial position of the central tube, the lower end of the expansion cone can be tapered into a gap between the sealing element and the outer wall of the central tube, so that the sealing element can expand to be tightly adhered to the inner wall of an annular space needing to be sealed, the sealing groove is arranged on the inner wall of the expansion cone in the axial direction of the central tube, the sealing groove is penetrated through the upper and lower ends of the expansion cone, the expansion cone is arranged on the inner wall of the expansion cone along the inner wall of the expansion cone, and the sealing groove can be sheared by the sealing groove, and the sealing device can be fixed in the axial direction, and the sealing groove can be sheared by the sealing groove. Alternatively, the sealing ring may be inverted Y-shaped, and the sealing ring may include an upper portion having an inner diameter larger than an outer diameter of the central tube, an upper end surface of the upper portion being provided with a radial groove along a radial direction of the sealing ring, the radial groove being capable of communicating with a gap between an inner wall of the upper portion and an outer wall of the central tube to allow flu