CN-121993095-A - Removable-connectable bridge plug and operation method

CN121993095ACN 121993095 ACN121993095 ACN 121993095ACN-121993095-A

Abstract

The invention discloses a removable-connectable bridge plug and an operation method, and belongs to the technical field of downhole tools of oil and gas wells. The bridge plug comprises a main body, a fixing device, a linkage mechanism and a connecting device. The slips of the fixing device are hinged to the main body, and the slips can be driven to radially expand by descending of the tile supporting cone so as to anchor the well wall. The slip is characterized in that a sliding body of the linkage mechanism is fixed in the main body through a shearing pin, two ends of the sliding body are conical inclined planes, and when the slip expands, a hinged plate is pulled by a steel cable to swing radially inwards and squeeze the sliding body, and the sliding body is driven to descend after the shearing pin is damaged. The mushroom nails of the connecting device are radially arranged on the side wall of the base, the return spring enables the mushroom nails to have a retraction trend, and when the sliding body descends, the conical surface at the lower end of the sliding body overcomes the spring force to eject the mushroom nails so as to provide a connecting structure. The invention realizes the functions of active recovery of bridge plugs and serial connection in the pit, greatly improves the staged fracturing operation efficiency and reduces the cost and the well bore risk.

Inventors

HOU ZHAOKAI
ZHAO JIAZI
HUANG SIYANG
SUN XIAOFENG
YAN TIE
QU JINGYU
YAO DI
HU QIAOBO

Assignees

东北石油大学

Dates

Publication Date: 20260508
Application Date: 20260324

Claims (10)

1. A removable-connectable bridge plug comprising a body, further comprising: The fixing device comprises a slip, a tile supporting cone, a fixing device and a fixing device, wherein the slip is axially arranged along the main body, one end of the tile supporting cone is hinged with the main body, and the other end of the tile supporting cone is a free end; The linkage mechanism comprises a sliding body, a hinged plate, a traction mechanism and a pull mechanism, wherein the sliding body is axially fixed on the main body through a shear pin, both ends of the sliding body are configured to be conical inclined planes, one end of the hinged plate is hinged with the main body, the other end of the hinged plate moves radially towards the inside of the main body at a hinged position and is in sliding contact with the conical inclined planes at one end of the sliding body when moving radially, the traction mechanism comprises a steel rope connected between the free end of a slip and the hinged plate and a pulley used for guiding the steel rope, and the path of the steel rope is set to be capable of pulling the hinged plate to move radially inwards and abut against the top of the sliding body when the slip expands outwards; The connecting device is arranged at the base end of the main body and comprises mushroom nails which radially penetrate through the side wall of the base, the heads of the mushroom nails are in sliding contact with the conical inclined surfaces at the other ends of the sliding bodies, and one ends of the reset springs act on the inner wall of the main body, and the other ends of the reset springs act on the heads of the mushroom nails.
2. The removable-connectable bridge plug of claim 1, wherein the inner surface of the shoe taper is keyed or splined to the outer surface of the body such that the shoe taper is only axially movable along the body.
3. The bridge plug according to claim 2, further comprising a sealing and force transmitting device, wherein the sealing and force transmitting device comprises a drum sleeve sleeved outside the main body, a bearing ring sleeved outside the main body and positioned between the drum sleeve and the support tile cone, an upper pressing ring and a lower pressing ring respectively positioned at the upper end and the lower end of the drum sleeve, and the lower pressing ring is connected with the bearing ring, and the bearing ring is in driving contact with or fixedly connected with the upper end of the support tile cone.
4. A removable-connectable bridge plug according to claim 3, wherein the sealing and force transmitting means further comprises a sealing cap fixedly connected to the top end of the main body for receiving the sealing force of an external sealing tool, and a pressure transmitting ring sleeved outside the main body and located between the sealing cap and the pressure transmitting ring for transmitting the sealing force from the sealing cap to the pressure transmitting ring.
5. A removable-connectable bridge plug according to claim 3, wherein the end face of the upper pressure ring opposite the lower pressure ring is tapered for radially compressing the drum envelope when axially compressed.
6. A removable-connectable bridge plug according to claim 1, wherein a plurality of said slips are provided and a corresponding plurality of hinged plates and traction mechanisms are provided which mate with the slips, and wherein the slips and the hinged plates are all equidistantly disposed along the circumference of the body.
7. The removable-connectable bridge plug of claim 6, wherein the outer surface of each slip is provided with a second anchor and the tapered surface of the support cone is provided with a first anchor.
8. A method of operating a removable-connectable bridge plug, based on any one of claims 1-7, comprising the steps of: The expansion of the slips pulls the hinged plates to swing radially inwards through the traction mechanism and give the sliding body a downward driving force, when the driving force reaches a certain degree, the shearing pin is cut off, the sliding body continues to move downwards, and the mushroom nails are radially ejected out of the base through the conical inclined surface at the other end of the sliding body, so that the mushroom nails extend out of the base to provide a connecting structure for connecting with the top of a second bridge plug; The method comprises the steps of putting an unsealing tool into a bridge plug from a wellhead, operating the unsealing tool to lift the sliding body upwards, releasing extrusion of the mushroom nails by a conical inclined surface at the other end when the sliding body is upwards, driving the mushroom nails to radially retract to disconnect with a second bridge plug by a reset spring, simultaneously, radially expanding the hinged plates by the conical inclined surface at one end of the sliding body, further pulling the slips to radially retract to release anchoring by a traction mechanism, and finally lifting the bridge plug in the unsealed state out of a shaft.
9. The method of operation of claim 8 wherein the applied axial setting force simultaneously drives radial expansion of the drum envelope to form a seal at the anchoring location of the slips.
10. A tandem-connectable bridge plug system comprising at least two removable-connectable bridge plugs according to any one of claims 1-7, and wherein the mushroom peg extending from the base of the previous bridge plug is connected to the top end of the body of the next bridge plug, so that a plurality of bridge plugs are secured in tandem within the wellbore.

Description

Removable-connectable bridge plug and operation method Technical Field The invention relates to the technical field of efficient development of unconventional oil and gas reservoirs, in particular to a removable-connectable bridge plug and an operation method. Background In the staged fracturing operation of horizontal wells of unconventional hydrocarbon reservoirs, bridge plugs are key tools for sealing wellbores and realizing section-by-section reconstruction. In the prior art, a single bridge plug step-by-step setting and perforation combined process mode is generally adopted, a bridge plug tool is usually designed to be disposable, namely, after setting through a hydraulic or mechanical mode, slips and a rubber cylinder of the bridge plug are permanently anchored and sealed on a casing, and after the fracturing of the section is completed, the drilling and grinding tool is required to be put into for drilling and removing, so that the next section of operation can be carried out. However, this approach presents a fundamental bottleneck in that the set bridge plug does not have the downhole active unsetting and resetting functions and cannot be retrieved or repositioned once set. Therefore, each stage of fracturing needs to complete cycles of 'setting bridge plug-setting-perforating-fracturing-drilling', so that when 15-25 stages of fracturing are carried out in a horizontal stage which is several kilometers long, the working period is long, the number of times of tripping is frequent, the cost of drilling is high, and the drilling and grinding process forms a potential risk for the integrity of the casing. More importantly, the existing bridge plugs have single functions, can only realize the packing of the current well section, and cannot form reliable mechanical series connection with other bridge plugs underground, so that a multistage packing system with stronger integrity cannot be constructed, and the efficient implementation of the ultra-long horizontal section and large-displacement fracturing process is restricted. Disclosure of Invention The invention aims to provide a removable-connectable bridge plug and an operation method thereof, which have the functions of active recovery and reliable connection and disassembly among a plurality of bridge plugs. The technical scheme of the invention is as follows: A removable-connectable bridge plug comprises a main body, a fixing device, a tile supporting cone, a linkage mechanism and a traction mechanism, wherein the tile supporting cone is axially arranged along the main body, one end of the tile supporting cone is hinged with the main body, the other end of the tile supporting cone is a free end, the tile supporting cone is sleeved outside the main body and is positioned at the free end position of the tile supporting cone, the tile supporting cone is matched with the inner surface of the tile supporting cone to enable the tile supporting cone to expand radially outwards by taking the hinged end of the tile supporting cone as an axis, the linkage mechanism comprises a sliding body axially fixed on the main body through a shearing pin, both ends of the sliding body are configured to be conical inclined surfaces, one end of the sliding body is hinged with the main body, the other end of the sliding body moves radially towards the inside of the main body at the hinged position and is in sliding contact with the conical inclined surface at one end of the sliding body, the traction mechanism comprises a steel cable connected between the free end of the tile supporting cone and the hinge plate, and a pulley used for guiding the steel cable, the pulley is fixedly arranged inside the main body, and the path of the steel cable is arranged to enable the hinge plate to move radially inwards and to abut against the top of the sliding body when the tile supporting cone is expanded outwards, the hinge plate is arranged on the hinge plate, the hinge pin, the connecting device comprises a mushroom pin, and a mushroom pin connecting device is arranged on the side wall and a mushroom pin. Further, the inner surface of the tile supporting cone is matched with the outer surface of the main body through a key groove or a spline, so that the tile supporting cone can only move along the axial direction of the main body and cannot rotate relatively. The circumferential rotation or deflection of the tile supporting cone in the setting process is prevented, and the accuracy of the descending track is ensured, so that the radial expansion of the slips is uniform and reliable, and the setting success rate and the anchoring stability are improved The sealing and force transferring device comprises a drum sleeve sleeved outside the main body, a bearing ring sleeved outside the main body and positioned between the drum sleeve and the tile supporting cone, an upper pressing ring and a lower pressing ring which are respectively positioned at the upper end and the lower end of the dr