CN212054539U

CN212054539U - Hydraulic rigid centralizer

Info

Publication number: CN212054539U
Application number: CN202020515823.9U
Authority: CN
Inventors: 李连杰; 曲洪坤; 张春龙; 朱健军; 张春南; 刘阳
Original assignee: Daqing Changyuan Energy Technology Co ltd
Current assignee: Daqing Changyuan Energy Technology Co ltd
Priority date: 2020-04-10
Filing date: 2020-04-10
Publication date: 2020-12-01
Anticipated expiration: 2030-04-10

Abstract

The invention belongs to corollary equipment in the horizontal well casing cementing, perforating and well completion technology, and particularly relates to a hydraulic rigid centralizer, which comprises an upper joint, a lower joint, a primary pawl, a secondary pawl and a sliding locking device, wherein the upper joint and the lower joint are hermetically connected through threads, and the primary pawl is connected to the lower part of the outer circumference of the lower joint through threads; the sliding locking device is arranged in the middle of the outer circumference of the lower joint, the secondary pawl is arranged between the sliding locking device and the primary pawl, the lower end of the sliding locking device is matched with the upper end of the secondary pawl through a wedge surface A, the lower end of the secondary pawl is matched with the upper end of the primary pawl through a wedge surface B, and the sliding locking device slides downwards to push the primary pawl and the secondary pawl to be opened. The hydraulic rigid centralizer adopts a structure of two-stage pawls and two wedge surfaces creatively, and compared with the prior art, the rigidity supporting mode not only can guarantee the centering degree of a sleeve to the maximum extent, but also reduces the running difficulty of a tubular column.

Description

Hydraulic rigid centralizer

Technical Field

The invention relates to a hydraulic rigid centralizer, belonging to supporting equipment in the horizontal well casing well cementation, perforation and completion technology.

Background

The horizontal well drilling technology is a brand new process mode for improving the exploration and development effect, the single well yield and the oil reservoir recovery ratio, promotes the development of an oil exploitation process, and is listed as one of the most important key technologies in the current oil industry. The horizontal well completion process adopts a casing cementing perforation completion technology as a main completion process.

In the horizontal well casing cementing and perforating completion technology, how to improve the displacement efficiency and strengthen the displacement effect is one of important links in horizontal well cementing, and the casing centering degree is the main reason for improving the displacement efficiency and strengthening the displacement effect. In the existing market, two centralizers, namely an elastic centralizer and a rigid centralizer, are used as the only means for improving the centering degree of the casing. The spring centralizer is influenced by factors such as the mass of the spring piece, the well diameter and the like, and can only ensure the centering degree of 67 percent or lower of the casing; although the rigid centralizer can ensure the casing centering degree of more than 67 percent of the casing, the requirement of the outer diameter of the rigid centralizer on the track and the diameter of a well hole is high, the rigidity of a pipe column cannot be increased when a hole shrinkage well section or a well section with large dog-leg degree is passed through, and the running difficulty of the pipe column is increased.

Disclosure of Invention

The invention provides a hydraulic rigid centralizer, which adopts a hydraulically-controlled outward-extending pawl structure, so that the original outer diameter of the centralizer is small, no resistance is generated during well entry, the centralizer is not influenced by well diameter change, and the outward extension of the pawl is locked, so that the setting performance is ensured.

In order to solve the problems, the invention creates the following specific technical scheme: the invention provides a hydraulic rigid centralizer, which comprises an upper joint, a lower joint, a primary pawl, a secondary pawl and a sliding locking device, wherein the upper joint and the lower joint are hermetically connected through threads to form a tubular structure; the primary pawl is connected to the lower part of the outer circumference of the lower joint through threads; the sliding locking device is arranged in the middle of the outer circumference of the lower joint, the secondary pawl is arranged between the sliding locking device and the primary pawl, the lower end of the sliding locking device is matched with the upper end of the secondary pawl through a wedge surface A, the lower end of the secondary pawl is matched with the upper end of the primary pawl through a wedge surface B, and the sliding locking device slides downwards to push the primary pawl and the secondary pawl to be opened to be attached to a well wall to realize a setting function.

As a further technical scheme, the sliding locking device mainly comprises a liquid inlet sleeve and a setting piston, wherein the upper end of the liquid inlet sleeve is in sliding insertion connection and sealing with the lower end of an upper connector, the liquid inlet sleeve is fixedly connected with the upper connector through a locking shear pin, the lower end of the liquid inlet sleeve is installed on the outer side of a lower connector in a sliding mode and is sealed in a sliding fit surface, a liquid inlet hole is formed in the lower connector, the liquid inlet hole is located above a sealing point between the liquid inlet sleeve and the lower connector, the setting piston is connected to the lower end of the liquid inlet sleeve through threads, a wedge surface A is located at the lower end of the setting piston, and a locking device used for locking the sliding locking device on the lower connector is arranged at the connecting position of the setting piston and the liquid inlet sleeve.

As a further technical scheme, the locking device is a locking ring, the locking ring is clamped between the liquid inlet sleeve and the setting piston, and one-way tooth climbing with a non-return function is arranged on the inner side of the locking ring and the outer side of the lower joint.

As a further technical scheme, the primary pawl and the secondary pawl are both composed of pawls and extension rods, and the pawls and the extension rods are of cutting structures which are uniformly distributed on the circumference; an annular cavity is formed between the extension rod of the first-level pawl and the lower joint, a limiting table is formed at the lower end of the annular cavity, and the extension rod of the second-level pawl is inserted into the annular cavity.

As a further technical scheme, the inner circumference of the pawl of the primary pawl is respectively provided with an anti-rotation column, an anti-rotation groove corresponding to the position is arranged on the wedge surface B of the secondary pawl, and the anti-rotation columns are connected with the anti-rotation grooves in a sliding mode.

The invention has the beneficial effects that: the hydraulic rigid centralizer creatively adopts a structure of two-stage pawls and two wedge surfaces, and the wedge surfaces are pushed to move downwards through hydraulic pressure, so that the function of pressing and setting with the well wall can be realized after the two-stage pawls are expanded outwards. Compared with the prior art, the rigid support mode not only can ensure the centering degree of the casing to the maximum extent, but also reduces the running difficulty of the tubular column.

Drawings

Fig. 1 is a schematic structural view of a hydraulic rigid centralizer.

Fig. 2 is a sectional view a-a of fig. 1.

Fig. 3 is a sectional view B-B of fig. 1.

Fig. 4 is a diagram showing the operation of the hydraulic rigid centralizer.

Fig. 5 is a cross-sectional view C-C of fig. 4.

In the figure: 1-upper joint, 2-liquid inlet sleeve, 3-setting piston, 4-locking ring, 5-primary pawl, 6-secondary pawl, 7-lower joint, 8-locking shear pin, 9-liquid inlet hole, 10-anti-rotation column, 11-anti-rotation groove, 12-one-way tooth climbing, 13-limit table, 14-wedge surface A and 15-wedge surface B.

Detailed Description

The invention is further described below with reference to the accompanying drawings:

as shown in fig. 1 to 3, the present embodiment includes an upper joint 1, a lower joint 7, a primary pawl 6, a secondary pawl 5 and a sliding locking device, the upper joint 1 and the lower joint 7 are connected by screw thread sealing to form a tubular structure, and when being installed, the upper joint 1 and the lower joint 7 are respectively connected with a sleeve. The primary pawl 6 is connected with the lower part of the outer circumference of the lower joint 7 through threads; the sliding locking device is arranged in the middle of the outer circumference of the lower joint 7, the secondary pawl 5 is arranged between the sliding locking device and the primary pawl 6, the lower end of the sliding locking device is matched with the upper end of the secondary pawl 5 through a wedge surface A, and the lower end of the secondary pawl 5 is matched with the upper end of the primary pawl 6 through a wedge surface B.

In the above structure, the slide lock device needs to have two functions: firstly, the primary pawl 5 and the secondary pawl 6 are forced to expand outwards through the action of the wedge surface A14; and secondly, the wedge surface A14 is automatically locked after reaching the lower limit position and cannot be reset. In order to realize above-mentioned function, the application slip locking device mainly constitute by feed liquor cover 2 and seat piston 3, the upper end of feed liquor cover 2 is pegged graft and is sealed with the lower extreme slip of top connection 1, feed liquor cover 2 is through locking shear pin 8 and 1 fixed connection of top connection, the lower extreme slidable mounting of feed liquor cover 2 is sealed in the outside of bottom connection 7 and in sliding fit face department, is equipped with feed liquor hole 9 on the bottom connection 7, feed liquor hole 9 is located more than the sealed point between feed liquor cover 2 and the bottom connection 7, seat piston 3 pass through threaded connection at the lower extreme of feed liquor cover 2, wedge surface A be located the lower extreme of seat piston 3, seat piston 3 is equipped with the locking device who is used for locking the locking device that slides on bottom connection 7 with the junction of feed liquor cover 2. The locking device is a locking ring 4 with an opening on the side surface, the locking ring 4 can be made of spring steel, and one-way climbing teeth 12 with a non-return function are arranged on the inner side of the locking ring 4 and the outer side of the lower connector 7 (the locking ring with the one-way climbing teeth 12 is common in conventional downhole tools such as packers, and the realized functions are the same, so the specific structure is not described any more here).

Before the casing is put into the well, the position states of the primary pawl 5 and the secondary pawl 6 are shown in figure 1, and in the state, the maximum outer diameters of the primary pawl 5 and the secondary pawl 6 are consistent with the overall diameter of the centralizer and smaller than the outer diameter of the existing centralizer, so that the casing pipe putting difficulty is reduced. After the centralizer is lowered to a downhole preset position, high-pressure water is injected into the casing by pressurizing, the pressure reaches the upper side of the liquid inlet sleeve 2 through the liquid inlet hole 9 to enable the liquid inlet sleeve 2 to have a downward sliding movement trend, the locking shear pin 8 is sheared under the action of the pressure, the liquid inlet sleeve 2, the setting piston 3 and the lock ring 4 move downward together, then the liquid inlet sleeve 2 and the setting piston 3 are pushed to slide downward together, and finally the primary pawl 5 and the secondary pawl 6 are expanded outwards under the action of the wedge surface A14 and the wedge surface B15 to achieve the working state shown in fig. 4.

As shown in fig. 1 or 4, the primary pawl 6 and the secondary pawl 5 are both composed of pawls and extension rods, and the pawls and the extension rods are of cutting structures which are uniformly distributed on the circumference; an annular cavity is formed between the extension rod of the primary pawl 6 and the lower joint 7, a limiting table 13 is formed at the lower end part of the annular cavity, and the extension rod of the secondary pawl 5 is inserted into the annular cavity. The structure of the extension rod realizes the transitional connection of the two pawls, and has certain sliding distance and telescopic radius.

The inner circumference of the pawl of the primary pawl 6 is respectively provided with an anti-rotation column 10, the wedge surface B of the secondary pawl 5 is provided with an anti-rotation groove 11 corresponding to the position, and the anti-rotation columns 10 are connected with the anti-rotation grooves 11 in a sliding mode.

The application states the use of fluid pressure type rigidity sleeve pipe centralizer is as follows:

step 1, an upper joint 1 and a lower joint 7 of a hydraulic rigid centralizer are respectively connected with a sleeve and are lowered to a designed position;

step 2, pressurizing the inside of the sleeve, allowing liquid to enter from the liquid inlet hole 9, applying downward thrust to the liquid inlet sleeve 2, and shearing the locking shear pin 8 when the pressure reaches a set pressure;

step 3, the liquid inlet sleeve 2 starts to move downwards, the liquid inlet sleeve 2 pushes the setting piston 3 and the secondary pawl 5 to move towards the lower joint 7 and is pushed and extruded by the secondary pawl 5, and the primary pawl 5 starts to expand outwards until an extension rod of the secondary pawl 5 is clamped at a limiting table 13 inside the primary pawl 6;

continuing pressurizing, wherein the liquid inlet sleeve 2 continues to push the setting piston 3 to move towards the lower joint 7, the setting piston 3 pushes and extrudes, the secondary pawl 5 drives the primary pawl 6 to simultaneously continue expanding outwards until the primary pawl is completely attached to the well wall, and the setting piston 3 stops moving; when the setting piston 3 stops moving, the locking ring 4 and the climbing tooth 12 are locked, so that the centralizer is in a locked state after being set, and a permanent setting is formed.

Claims

1. A hydraulic rigid centralizer, characterized by: the device comprises an upper joint (1), a lower joint (7), a primary pawl (6), a secondary pawl (5) and a sliding locking device, wherein the upper joint (1) and the lower joint (7) are hermetically connected through threads to form a tubular structure; the primary pawl (6) is connected to the lower part of the outer circumference of the lower joint (7) through threads; the sliding locking device is arranged in the middle of the outer circumference of the lower joint (7), the secondary pawl (5) is arranged between the sliding locking device and the primary pawl (6), the lower end of the sliding locking device is matched with the upper end of the secondary pawl (5) through a wedge surface A, the lower end of the secondary pawl (5) is matched with the upper end of the primary pawl (6) through a wedge surface B, and the sliding locking device slides downwards to push the primary pawl (6) and the secondary pawl (5) to be opened and is attached to the well wall to realize the sitting sealing function.

2. The rigid centralizer of claim 1, wherein: slip locking device constitute by feed liquor cover (2) and seat and seal piston (3), the upper end of feed liquor cover (2) is pegged graft and is sealed with the lower extreme slip of top connection (1), feed liquor cover (2) are through locking shear pin (8) and top connection (1) fixed connection, the lower extreme slidable mounting of feed liquor cover (2) is sealed in the outside of bottom connection (7) and in sliding fit face department, be equipped with feed liquor hole (9) on bottom connection (7), feed liquor hole (9) are located more than the sealed point between feed liquor cover (2) and bottom connection (7), seat seal piston (3) pass through the lower extreme of threaded connection at feed liquor cover (2), wedge face A be located the lower extreme of seat seal piston (3), the junction of seat seal piston (3) and feed liquor cover (2) is equipped with and is used for locking the locking device that slides on bottom connection (7).

3. The rigid centralizer of claim 2, wherein: the locking device is a locking ring (4), the locking ring (4) is clamped between the liquid inlet sleeve (2) and the setting piston (3), and the inner side of the locking ring (4) and the outer side of the lower joint (7) are provided with one-way climbing teeth (12) with a non-return effect.

4. The rigid centralizer of claim 1, wherein: the primary pawl (6) and the secondary pawl (5) are both composed of pawls and extension rods, and the pawls and the extension rods are of cutting structures which are uniformly distributed on the circumference; an annular cavity is formed between the extension rod of the primary pawl (6) and the lower joint (7), a limiting table (13) is formed at the lower end part of the annular cavity, and the extension rod of the secondary pawl (5) is inserted into the annular cavity.

5. The rigid centralizer of claim 1, wherein: the inner circumference of the pawl of the primary pawl (6) is respectively provided with an anti-rotation column (10), the wedge surface B of the secondary pawl (5) is provided with an anti-rotation groove (11) corresponding to the position, and the anti-rotation column (10) is connected with the anti-rotation groove (11) in a sliding manner.