Open hole packer with large expanding rate

Abstract

The invention discloses a large-diameter-expansion-rate open hole packer. The large-diameter-expansion-rate open hole packer comprises a rubber sleeve sealing structure and a setting locking structure. The rubber sleeve sealing structure is mainly composed of a supporting ring, a shoulder pad, an end rubber sleeve, a spacer ring and a middle rubber sleeve. The setting locking structure is mainly composed of an upper mandrel, a lock sleeve, a lock ring, an upper hydraulic cylinder, a middle mandrel, a lower hydraulic cylinder and a lower mandrel. The middle core shaft is fixedly, hermetically and buckled at the right end of the upper core shaft, the lower core shaft is fixedly, hermetically and buckled at the right end of the middle core shaft, and the lock sleeve and the lock ring are slidably sleeved on the upper core shaft; the outer diameter of the packer body is smaller than that of a conventional open hole packer body, a larger open hole annulus can be sealed with the smaller outer diameter of a product, and the packer can be put into a well more easily while the sealing performance is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of downhole tools for oil and gas field development, and particularly relates to an open hole packer with a large diameter expansion rate. Background Art

[0002] In the cementing and production process of oil and gas fields, open hole packers are the most commonly used isolation tools, especially in horizontal wells. Ordinary open hole packers support a maximum expansion rate of 8%. Therefore, when it is necessary to ensure the sealing performance, the outer diameter of the packer body needs to be increased, and no shoulder is generated when the rubber tube is under pressure, thereby ensuring the sealing performance of the packer. After the outer diameter of the packer body increases, it will be more difficult to go down the well, especially in the horizontal section. Therefore, it is necessary to study an open hole packer with a large expansion rate, which can seal a larger open hole annulus with a smaller outer diameter, ensure the sealing performance and make it easier to go down the well. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an open hole packer with a large expansion ratio to seal a larger open hole annulus with a smaller outer diameter, thereby ensuring sealing performance and being easier to lower into a well.

[0004] In order to solve the above technical problems, the present invention is implemented through the following technical solutions: a large expansion ratio open hole packer, comprising a rubber sleeve sealing structure and a seat lock tightening structure; The rubber cylinder sealing structure is mainly composed of a support ring, shoulder guard, end rubber cylinder, spacer ring, and middle rubber cylinder; The locking and tightening structure is mainly composed of an upper mandrel, a locking sleeve, a locking ring, an upper hydraulic cylinder, a middle mandrel, a lower hydraulic cylinder and a lower mandrel; The central core shaft is fixedly sealed and buckled on the right end of the upper core shaft, the lower core shaft is fixedly sealed and buckled on the right end of the central core shaft, the locking sleeve and the locking ring are both slidably sleeved and mounted on the upper core shaft, the inner surface of the locking sleeve and the outer surface of the locking ring are matched with a first annular limiting sawtooth structure that limits the locking ring to move rightward, and the inner surface of the locking ring and the outer surface of the upper core shaft are matched with a second annular limiting sawtooth structure that limits the locking ring to move rightward; A first limiting shoulder is formed on the outer surface of the upper core shaft, two support rings, two shoulder guards, two end rubber tubes, two spacer rings, and a middle rubber tube are slidably sleeved and installed on the upper core shaft, a middle rubber tube is located between the two support rings, two shoulder guards are located outside the support rings, the two shoulder guards are buckled and installed on the outer ends of the two end rubber tubes, the two support rings are buckled and installed on the outer ends of the two shoulder guards, the support rings are provided with a first slit in an annular array, the shoulder guards are provided with a second slit in an annular array, and the support ring at the left end is against the first limiting shoulder; The upper liquid cylinder sliding seal sleeve is installed on the upper core shaft and the middle core shaft, the lower liquid cylinder sliding seal sleeve is installed on the middle core shaft and the lower core shaft, the upper liquid cylinder fixed seal buckle is installed on the left end of the lower liquid cylinder, the right end of the lower core shaft is fixedly sealed with a lower joint, the right end of the lower liquid cylinder sliding seal buckle is installed on the left end of the lower joint, a first piston chamber is formed between the upper liquid cylinder and the upper core shaft and the middle core shaft, a second piston chamber is formed between the lower liquid cylinder and the middle core shaft and the lower core shaft, a first liquid inlet hole connected to the first piston chamber is provided on the upper core shaft, and a second liquid inlet hole connected to the second piston chamber is provided on the middle core shaft.

[0005] Preferably, the first slit on the support ring and the second slit on the shoulder guard are staggered.

[0006] Preferably, 4 to 10 of the first liquid inlet holes and the second liquid inlet holes are arranged in a circular array on the upper core shaft and the middle core shaft respectively.

[0007] Preferably, the lower cylinder and the lower joint are connected and fixed by shear nails.

[0008] Preferably, a fastening screw is threadedly mounted on the locking sleeve, the fastening screw presses against the outer surface of the upper core shaft, a notch is provided on the locking ring, and the inner end of the fastening screw is located in the notch.

[0009] Preferably, the outer end of the spacer ring cooperates with the end rubber sleeve to form a first inclined surface structure.

[0010] Preferably, the outer end of the end rubber sleeve is composed of a first fillet section, a first cone sleeve section, a second fillet section, and a second cone sleeve section transition from outside to inside.

[0011] Preferably, a first O-ring is provided between the upper liquid cylinder and the upper core shaft, and between the lower liquid cylinder and the middle core shaft, a second O-ring is provided between the upper liquid cylinder and the middle core shaft, and between the lower liquid cylinder and the lower core shaft, and a third O-ring is provided between the lower joint and the lower core shaft.

[0012] Preferably, an annular groove having a trapezoidal longitudinal section is provided in the middle of the inner wall of the middle rubber cylinder.

[0013] Preferably, the contact surface between the middle tube and the spacer ring is cooperatively configured as a second inclined surface structure.

[0014] Compared with the prior art, the present invention is beneficial in that: 1. The spacer ring is squeezed into the end rubber tube to prop up one end of the end rubber tube, ensuring that the expanded outer diameter of the end rubber tube is larger than that of ordinary open hole packers. The outer diameter of the packer body is smaller than that of the conventional open hole packer body, and it can seal a larger open hole annulus with a smaller product outer diameter, ensuring the sealing performance while being easier to lower into the well.

[0015] 2. The support ring and the shoulder guard are provided with slits, which have the advantage of being easy to expand. At the same time, the slits of the support ring and the shoulder guard are staggered and fixed. The inner wall of the support ring, the inner wall of the shoulder guard and the outer end of the end rubber tube adopt a multi-angle transformation design structure to ensure that the outer diameter of the end rubber tube is large enough after being expanded, and effectively ensure that the end rubber tube does not produce a shoulder protrusion when under pressure, so that the end rubber tube is compressed and expanded and expanded and tightly adheres to the open hole wall or casing wall, thereby ensuring that the sealing performance of the packer in an open hole well with a large expansion rate is not affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is further described below in conjunction with the accompanying drawings.

[0017] Figure 1 It is a perspective view of the present invention.

[0018] Figure 2 It is a cross-sectional view divided into section A + section B (the right end of section A and the left end of section B are a continuous structure).

[0019] Figure 3 It is a cross-sectional view of the cartridge assembly.

[0020] Figure 4 yes Figure 2 Enlarged structural diagram at L.

[0021] Figure 5 yes Figure 2 Enlarged structural diagram at M.

[0022] Figure 6 yes Figure 2 Schematic diagram of the enlarged structure at N.

[0023] Figure 7 is a three-dimensional diagram of the support ring.

[0024] Figure 8 It is a three-dimensional picture of the shoulder pad.

[0025] Fig. 9 It is a three-dimensional diagram of the lock ring.

[0026] Fig.10 It is a three-dimensional diagram of the septum ring.

[0027] Fig.11 It is a three-dimensional diagram of the end rubber cylinder.

[0028] Fig.12 It is the front view of the end rubber cylinder.

[0029] Fig.13 yes Fig.12 Enlarged structural diagram at P. DETAILED DESCRIPTION

[0030] The present invention is described in detail below in conjunction with specific embodiments: like Figure 1 A large expansion rate open hole packer shown includes a rubber sleeve sealing structure and a seat seal tightening structure; The rubber cylinder sealing structure is mainly composed of a support ring 2, a shoulder guard 3, an end rubber cylinder 13, a spacer ring 4, and a middle rubber cylinder 14; The locking and tightening structure is mainly composed of an upper mandrel 1, a locking sleeve 5, a locking ring 6, an upper hydraulic cylinder 7, a middle mandrel 8, a lower hydraulic cylinder 9 and a lower mandrel 10; The central core shaft 8 is fixedly sealed and buckled on the right end of the upper core shaft 1, and the lower core shaft 10 is fixedly sealed and buckled on the right end of the central core shaft 8. The locking sleeve 5 and the locking ring 6 are both slidably sleeved and mounted on the upper core shaft 1. The inner surface of the locking sleeve 5 and the outer surface of the locking ring 6 are matched with a first annular limiting sawtooth structure that limits the rightward movement of the locking ring 6, and the inner surface of the locking ring 6 and the outer surface of the upper core shaft 1 are matched with a second annular limiting sawtooth structure that limits the rightward movement of the locking ring 6; A first limiting shoulder 101 is formed on the outer surface of the upper core shaft 1, two support rings 2, two shoulder guards 3, two end rubber tubes 13, two spacer rings 4, and a middle rubber tube 14 are slidably sleeved and installed on the upper core shaft 1, a middle rubber tube 14 is located between the two support rings 2, two shoulder guards 3 are located outside the support rings 2, the two shoulder guards 3 are snap-fitted and installed on the outer ends of the two end rubber tubes 13, the two support rings 2 are snap-fitted and installed on the outer ends of the two shoulder guards 3, the support rings 2 are provided with a first slit 201 in an annular array, the shoulder guards 3 are provided with a second slit 301 in an annular array, and the support ring 2 at the left end abuts against the first limiting shoulder 101; The upper liquid cylinder 7 is installed in a sliding sealing sleeve on the upper core shaft 1 and the middle core shaft 8, and the lower liquid cylinder 9 is installed in a sliding sealing sleeve on the middle core shaft 8 and the lower core shaft 10. The upper liquid cylinder 7 is fixedly sealed and buckled on the left end of the lower liquid cylinder 9. The right end of the lower core shaft 10 is fixedly sealed with a lower joint 11, and the right end of the lower liquid cylinder 9 is slidingly sealed and buckled on the left end of the lower joint 11. A first piston chamber 701 is formed between the upper liquid cylinder 7 and the upper core shaft 1 and the middle core shaft 8, and a second piston chamber 801 is formed between the lower liquid cylinder 9 and the middle core shaft 8 and the lower core shaft 10. A first liquid inlet hole 102 connected to the first piston chamber 701 is provided on the upper core shaft 1, and a second liquid inlet hole 802 connected to the second piston chamber 801 is provided on the middle core shaft 8.

[0031] like Figure 7 , Figure 8 As shown, the first slit 201 on the support ring 2 and the second slit 301 on the shoulder guard 3 are staggered, and the first slit 201 and the second slit 301 are easy to open. At the same time, the slits of the support ring 2 and the shoulder guard 3 are staggered and fixed to each other, which effectively ensures that the end rubber tube 13 does not produce a shoulder protrusion when under pressure.

[0032] The first liquid inlet holes 102 and the second liquid inlet holes 802 are respectively arranged in a circular array of 5 or 6 on the upper core shaft 1 and the middle core shaft 8 to ensure uniform filling pressure to the first piston chamber 701 and the second liquid inlet holes 802.

[0033] The lower cylinder 9 is connected and fixed to the lower joint 11 by shear nails 12. When the packer is easy to be lowered, the lower cylinder 9 is ensured to be in a fixed state. Before the lower cylinder 9 moves under pressure, the shear nails 12 are cut off under pressure.

[0034] like Fig. 9 As shown, a fastening screw 16 is threadedly installed on the locking sleeve 5, and the fastening screw 16 presses on the outer surface of the upper core shaft 1. A notch 601 is provided on the locking ring 6, and the inner end of the fastening screw 16 is located in the notch 601. Before the locking sleeve 5 is pressed and moved, the fastening screw 16 can fix the locking sleeve 5. When the locking sleeve 5 is pressed and moved, the driving force applied to the locking sleeve 5 overcomes the friction generated by the fastening screw 16 and the outer surface of the upper core shaft 1, and pushes the locking sleeve 5 to move to the left.

[0035] like Fig.10 , Fig.13 As shown, the outer end of the spacer ring 4 cooperates with the end rubber tube 13 to form a first inclined surface structure 401, 1301, so that the spacer ring 6 can be squeezed into the end rubber tube 13 to support one end of the end rubber tube 13.

[0036] like Fig.12 As shown, the outer end of the end rubber tube 13 is composed of a first rounded section 1302, a first cone sleeve section 1303, a second rounded section 1304, and a second cone sleeve section 1305 from outside to inside. The radius of the first rounded section 1302 is set to 3mm, and the radius of the second rounded section 1304 is set to 5mm. The clamping angle between the first cone sleeve section 1303 and the center axis of the end rubber tube 13 is 40°, and the angle between the second cone sleeve section 1305 and the right straight section of the end rubber tube 13 is 10°. The above-mentioned design structure is expanded when the end rubber tube 13 is compressed and expanded, and is tightly attached to the open hole wall or casing wall. Under the buckling action of the support ring 2 and the shoulder guard 3, the end rubber tube 13 is protected from shoulder protrusion, thereby ensuring the sealing performance of the rubber tube. The multi-angle transition design ensures that the outer diameter of the end rubber tube 13 is large enough after it is expanded, thereby ensuring that the sealing performance of the packer in the open hole well with a large expansion rate is not affected.

[0037] A first O-ring 15 is provided between the upper liquid cylinder 7 and the upper core shaft 1, and between the lower liquid cylinder 9 and the middle core shaft 8. A second O-ring 17 is provided between the upper liquid cylinder 7 and the middle core shaft 8, and between the lower liquid cylinder 9 and the lower core shaft 10. A third O-ring 18 is provided between the lower joint 11 and the lower core shaft 10 to improve the sealing performance of the above-mentioned connection positions.

[0038] Figure 4As shown, an annular groove 1401 with a trapezoidal longitudinal section is provided at the middle of the inner wall of the middle rubber tube 14. The annular groove 1401 can make the hardness of the middle rubber tube 14 and the end rubber tube 13 different, and the middle rubber tube 14 is compressed and expanded first. The contact surface between the middle tube 14 and the spacer ring 4 is cooperatively set to a second inclined surface structure, and the spacer ring 4 forms a buckling effect on the middle rubber tube 14, which can prevent the end of the middle rubber tube 14 from separating from the spacer ring 4 when the middle rubber tube 14 is compressed and expanded.

[0039] Before the shear nail 12 is started to cut, the lower hydraulic cylinder 9, the upper hydraulic cylinder 7, the locking sleeve 5, and the locking ring 6 of the open hole packer remain in position. After the packer is started and sealed, the hydraulic pressure enters the first liquid inlet hole 102 and the second liquid inlet hole 802 through the first liquid inlet hole 102 and the second liquid inlet hole 802. The lower hydraulic cylinder 9 and the upper hydraulic cylinder 7 push the locking ring 6 and the locking sleeve 5 to move upward to the left under the action of the hydraulic pressure. The locking sleeve 5 pushes the locking ring 6 to move to the left through the first annular limiting sawtooth structure. When the end rubber cylinder 13 is expanded by the compression force, it first expands along the inclined surface of the spacer ring 4, and at the same time pushes the spacer ring 4 to compress the middle rubber cylinder 14. The end rubber cylinder 13 and the middle rubber cylinder 14 adopt Different hardness designs ensure that the middle rubber tube 14 is compressed and expanded first. As the main sealing structure of the packer, the middle rubber tube 14's priority expansion can ensure the annular sealing ability of the packer. The end rubber tube 13 is compressed to open the support ring 2 and the shoulder guard 3 to fit tightly against the inner wall of the casing. When the sealing pressure reaches the minimum sealing pressure of the packer, the locking ring 6 and the upper core shaft 1 lock the second annular limiting serration structure to keep the rubber tube in the sealing state. When the packer is completely sealed, the spacer ring 4 is squeezed into the end rubber tube 13, further propping up the end rubber tube 13 to fit tightly against the casing, thereby better protecting the middle rubber tube 14 and ensuring the stable sealing performance of the rubber tube.

Claims

1. A large expansion ratio open hole packer, characterized in that: It includes a rubber cylinder sealing structure and a seat lock tightening structure; The rubber cylinder sealing structure mainly consists of a support ring (2), a shoulder guard (3), an end rubber cylinder (13), a spacer ring (4), and a middle rubber cylinder (14); The locking and tightening structure mainly consists of an upper mandrel (1), a locking sleeve (5), a locking ring (6), an upper hydraulic cylinder (7), a middle mandrel (8), a lower hydraulic cylinder (9) and a lower mandrel (10); The central core shaft (8) is fixedly sealed and buckled on the right end of the upper core shaft (1); the lower core shaft (10) is fixedly sealed and buckled on the right end of the central core shaft (8); the locking sleeve (5) and the locking ring (6) are both slidably sleeved and mounted on the upper core shaft (1); the inner surface of the locking sleeve (5) and the outer surface of the locking ring (6) are cooperatively provided with a first annular limiting sawtooth structure for limiting the rightward movement of the locking ring (6); the inner surface of the locking ring (6) and the outer surface of the upper core shaft (1) are cooperatively provided with a second annular limiting sawtooth structure for limiting the rightward movement of the locking ring (6); A first limiting shoulder (101) is formed on the outer surface of the upper core shaft (1); two support rings (2), two shoulder guards (3), two end rubber tubes (13), two spacer rings (4), and a middle rubber tube (14) are slidably sleeved and mounted on the upper core shaft (1); a middle rubber tube (14) is located between the two support rings (2); the two shoulder guards (3) are located outside the support rings (2); the two shoulder guards (3) are snap-fitted and mounted on the outer ends of the two end rubber tubes (13); the two support rings (2) are snap-fitted and mounted on the outer ends of the two shoulder guards (3); the support rings (2) are provided with a first slit (201) in an annular array; the shoulder guards (3) are provided with a second slit (301) in an annular array; and the support ring (2) at the left end abuts against the first limiting shoulder (101); The upper liquid cylinder (7) is slidably and sealably mounted on the upper core shaft (1) and the middle core shaft (8); the lower liquid cylinder (9) is slidably and sealably mounted on the middle core shaft (8) and the lower core shaft (10); the upper liquid cylinder (7) is fixedly and sealably mounted on the left end of the lower liquid cylinder (9); the right end of the lower core shaft (10) is fixedly and sealably mounted with a lower joint (11); the right end of the lower liquid cylinder (9) is slidably and sealably mounted on the left end of the lower joint (11); a first piston chamber (701) is formed between the upper liquid cylinder (7) and the upper core shaft (1) and the middle core shaft (8); a second piston chamber (801) is formed between the lower liquid cylinder (9) and the middle core shaft (8) and the lower core shaft (10); a first liquid inlet hole (102) connected to the first piston chamber (701) is provided on the upper core shaft (1); and a second liquid inlet hole (802) connected to the second piston chamber (801) is provided on the middle core shaft (8).

2. The open hole packer with large expansion ratio according to claim 1, characterized in that: The first slit (201) on the support ring (2) and the second slit (301) on the shoulder guard (3) are arranged in a staggered manner.

3. The open hole packer with large expansion ratio according to claim 1, characterized in that: 4 to 10 of the first liquid inlet holes (102) and the second liquid inlet holes (802) are respectively arranged in a ring array on the upper core shaft (1) and the middle core shaft (8).

4. The open hole packer with large expansion ratio according to claim 1, characterized in that: The lower liquid cylinder (9) and the lower joint (11) are connected and fixed via shear nails (12).

5. The open hole packer with large expansion ratio according to claim 1, characterized in that: A fastening screw (16) is threadedly mounted on the locking sleeve (5), the fastening screw (16) is pressed against the outer surface of the upper core shaft (1), a notch (601) is provided on the locking ring (6), and the inner end of the fastening screw (16) is located in the notch (601).

6. The open hole packer with large expansion ratio according to claim 1, characterized in that: The outer end of the spacer ring (4) cooperates with the end rubber sleeve (13) to form a first inclined surface structure (401, 1301).

7. The open hole packer with large expansion ratio according to claim 1, characterized in that: The outer end of the end rubber cylinder (13) is composed of a first rounded corner section (1302), a first cone sleeve section (1303), a second rounded corner section (1304), and a second cone sleeve section (1305) in sequence from outside to inside.

8. The open hole packer with large expansion ratio according to claim 1, characterized in that: A first O-ring (15) is provided between the upper liquid cylinder (7) and the upper core shaft (1), and between the lower liquid cylinder (9) and the middle core shaft (8); a second O-ring (17) is provided between the upper liquid cylinder (7) and the middle core shaft (8), and between the lower liquid cylinder (9) and the lower core shaft (10); and a third O-ring (18) is provided between the lower joint (11) and the lower core shaft (10).

9. The open hole packer with large expansion ratio according to claim 1, characterized in that: An annular groove (1401) having a trapezoidal longitudinal cross-section is provided at the middle of the inner wall of the middle rubber cylinder (14).

10. The open hole packer with large expansion ratio according to claim 1, characterized in that: The contact surfaces of the middle cylinder (14) and the spacer ring (4) are cooperatively arranged to form a second inclined surface structure.

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