Double-rubber-cylinder expansion type packer

Abstract

The utility model provides an expansion type packer with double rubber cylinders. The packer comprises an upper connector, an upper central pipe, a connecting shaft, an adapter and a lower central pipe which are connected in sequence, an upper rubber sleeve sealing unit, a lower rubber sleeve sealing unit, a locking ring, a pressure transmission sleeve and a control piston, wherein the upper rubber sleeve sealing unit and the lower rubber sleeve sealing unit are arranged on the upper central pipe and the lower central pipe in a sleeving mode respectively, and the connecting shaft is sleeved with the locking ring and the pressure transmission sleeve. A movable cavity is defined by the pressure transmission sleeve, the connecting shaft and the adapter; the locking ring is positioned at the tail part of the movable cavity; the control piston is located in the movable cavity and can be fixed to the front section of the movable cavity through the shear pin, and at the moment, a first pressure transmission channel leading to the lower rubber sleeve sealing unit is opened; after the shear pin is sheared off, the control piston can move to the rear section of the movable cavity and is meshed with the locking ring, and at the moment, a second pressure transmission channel leading to the upper rubber sleeve sealing unit is opened. The two sets of sealing units can be started to work step by step, multiple times of setting and unsetting can be carried out under high temperature and high pressure, and the problem that an expansion type packer restricts the performance of a whole tool pipe column and the field construction efficiency is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of downhole tools in the petroleum industry, in particular to a double-rubber-tube expandable packer. Background Art

[0002] Packers are commonly used downhole tools in oil and gas field development. However, during field use, problems such as deformation of the packer rubber sleeve and damage to the rubber sleeve shoulder often occur. A single expandable packer is difficult to meet the requirements of repeated setting work under 70MPa high-pressure conditions. The overall expandable packer has problems such as low pressure rating and insufficient repeatable setting performance, which restricts the performance of the overall tool string and on-site construction efficiency. Utility Model Content

[0003] The purpose of the utility model is to improve the repeatable setting performance of the expandable packer and solve the problem that the expandable packer restricts the performance of the entire tool string.

[0004] In order to achieve the above-mentioned purpose, the utility model provides a double-rubber-tube expandable packer.

[0005] The seal includes: an upper joint, an upper center pipe, a connecting shaft, an adapter and a lower center pipe connected in sequence, an upper rubber cylinder sealing unit sleeved on the upper center pipe, a lower rubber cylinder sealing unit sleeved on the lower center pipe, a locking ring and a pressure transmission sleeve sleeved on the connecting shaft, and a control piston; wherein, a movable cavity is surrounded by the pressure transmission sleeve, the connecting shaft and the adapter; the locking ring is located at the tail end of the movable cavity; the control piston is located in the movable cavity and can be fixed to the front section of the movable cavity by shear pins, in which case, the first pressure transmission channel leading to the lower rubber cylinder sealing unit is opened, and the first pressure transmission channel includes part of the air holes on the connecting shaft and the air holes on the adapter; the control piston can move to the rear section of the movable cavity and engage with the locking ring after the shear pins are cut off. In this case, the first pressure transmission channel is closed, and the second pressure transmission channel leading to the upper rubber cylinder sealing unit is opened, and the second pressure transmission channel includes another part of the air holes on the connecting shaft and the air holes on the pressure transmission sleeve.

[0006] Alternatively, the upper rubber cylinder sealing unit may include a first upper rubber cylinder seat, an upper rubber cylinder and a first lower rubber cylinder seat connected in sequence; the first upper rubber cylinder seat is threadedly connected to the upper joint and a sealing member is provided therebetween.

[0007] Optionally, the lower rubber cylinder sealing unit includes a lower rubber cylinder, a second upper rubber cylinder seat and a second lower rubber cylinder seat.

[0008] Optionally, the packer further comprises a lower connecting sleeve threadedly connected to the lower central pipe and located at the tail thereof, the lower connecting sleeve being in clearance with the inner circumference of the second lower rubber cylinder seat and a sealing member being provided therebetween.

[0009] Optionally, the upper joint, the upper central tube, the connecting shaft, the adapter and the lower central tube are threadedly connected in sequence.

[0010] Optionally, a sealing member is provided between any two of the upper joint, the upper central tube, the connecting shaft, the adapter and the lower central tube that are in contact with each other.

[0011] Optionally, along the direction from the upper end to the lower end, the connecting shaft is provided with a first pressure transmission hole, a second pressure transmission hole, a third pressure transmission hole and a fourth pressure transmission hole, each of which is at least 1 in number; the first pressure transmission hole is connected to the second pressure transmission hole, and the opening of the first pressure transmission hole is formed on the end face of the upper end of the connecting shaft, and the opening of the second pressure transmission hole is formed on the outer surface of the shaft body of the connecting shaft; the third pressure transmission hole and the fourth pressure transmission hole are both through holes, and both can connect the inner cavity of the connecting shaft with the movable cavity.

[0012] Optionally, the pressure transmission sleeve is provided with fifth pressure transmission holes, the same number as the first pressure transmission holes and corresponding one-to-one, and both openings of the fifth pressure transmission holes are formed on the inner surface of the pressure transmission sleeve, with one opening communicating with the opening corresponding to the first pressure transmission hole and the other opening communicating with the movable cavity. The second pressure transmission channel includes the first pressure transmission hole, the second pressure transmission hole, the third pressure transmission hole, and the fifth pressure transmission hole.

[0013] Optionally, a sixth pressure transmission hole is provided on the adapter, two openings of the sixth pressure transmission hole are respectively formed on the front and rear end surfaces of the adapter, and the first pressure transmission channel includes the fourth pressure transmission hole and the sixth pressure transmission hole.

[0014] Optionally, a step is provided on the inner circumference of the connecting shaft, and the step is located between the third pressure transmission hole and the fourth pressure transmission hole. After pitching, the ball sits on the step.

[0015] Optionally, sealing elements are provided on both the inner and outer sides of the control piston.

[0016] Optionally, both the outer circumferential surface of one end of the control piston facing the locking ring and the inner circumferential surface of the locking ring are provided with serrated threads.

[0017] Alternatively, the sealing member may comprise a sealing ring.

[0018] The beneficial effects of the present invention include: the double-rubber-tube expandable packer of the present invention has two groups of rubber-tube sealing units, the two groups of sealing units can be started to work step by step, and can be set and unsealed multiple times under high-temperature and high-pressure working conditions, thereby solving the problem of the expandable packer restricting the performance of the overall tool string and improving on-site construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other objects and / or features of the present invention will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0020] Figure 1 The overall structure of the double-rubber expansion packer of the present invention is shown.

[0021] Figure 2 The figure shows a schematic diagram of the pressure transmission structure in the double-rubber-tube expandable packer of the present invention.

[0022] Figure 3 A schematic diagram of a connecting shaft in a double-rubber-tube expandable packer of the present invention is shown.

[0023] Figure 4 The figure shows a schematic diagram of an adapter in a double-rubber expansion packer of the present invention.

[0024] Figure 5 The figure shows a schematic diagram of a pressure transmission sleeve in a double-rubber expansion packer of the present invention.

[0025] Description of main reference numerals:

[0026] 1- upper connector;

[0027] 2-upper center tube;

[0028] 3-connecting shaft, 31-first pressure transmission hole, 32-second pressure transmission hole, 33-third pressure transmission hole, 34-fourth pressure transmission hole;

[0029] 4- adapter, 41- sixth pressure transmission hole;

[0030] 5- lower center tube;

[0031] 61-first upper rubber cylinder seat, 62-upper side rubber cylinder, 63-first lower rubber cylinder seat;

[0032] 7-locking ring;

[0033] 8-pressure transmission sleeve, 81-fifth pressure transmission hole;

[0034] 9-control piston;

[0035] 10-lower connecting sleeve;

[0036] a-sealing ring, b-shear nail. DETAILED DESCRIPTION

[0037] The following describes an embodiment of the double-rubber expansion packer of the present invention in conjunction with the accompanying drawings.

[0038] Example 1

[0039] The following combination Figures 1 to 5 To further illustrate this embodiment.

[0040] The double-rubber-tube expansion packer rubber tube of the utility model comprises:

[0041] Upper joint 1, upper center tube 2, connecting shaft 3, adapter 4, lower center tube 5, upper rubber cylinder sealing unit, lower rubber cylinder sealing unit, locking ring 7, pressure transmission sleeve 8 and control piston 9.

[0042] The upper central pipe 2 is connected to the upper joint 1 through threads and is provided with a sealing ring a.

[0043] The upper rubber cylinder sealing unit includes a first upper rubber cylinder seat 61, an upper rubber cylinder 62, and a first lower rubber cylinder seat 63. The first upper rubber cylinder seat 61 is threadedly connected to the upper connector 1 and is equipped with a sealing ring a. The upper rubber cylinder 62 is threadedly connected to the first upper rubber cylinder seat 61 and the first lower rubber cylinder seat 63, and the contact seal is achieved at the rubber cylinder step end surface. The structure of the lower rubber cylinder sealing unit can be the same as that of the upper rubber cylinder sealing unit.

[0044] One end of the connecting shaft 3 is threadedly connected to the upper center tube 2 and is provided with a sealing ring a. The other end is threadedly connected to the adapter 4 and is also provided with a sealing ring a. The outer sleeve of the connecting shaft 3 is provided with a control piston 9, a pressure transmission sleeve 8, and a locking ring 7. The sealing ring a is provided at the joint between the connecting shaft 3 and the pressure transmission sleeve 8.

[0045] Sealing rings a are provided on both the inside and outside of the control piston 9. Sawtooth threads are provided on the outer circumference of the control piston 9 and the inner circumference of the lock ring 7.

[0046] One end of the adapter 4 is connected to the lower center pipe 5 through a thread and is provided with a sealing ring a.

[0047] The lower connecting sleeve 10 is connected to the lower center pipe 5 by threads and is provided with a sealing ring. The outer circumference of the lower connecting sleeve 10 is clearance-matched with the inner circumference of the lower rubber cylinder seat of the lower rubber cylinder sealing unit and is provided with a sealing ring.

[0048] In this embodiment, the upper rubber sleeve 62 of the upper rubber sleeve sealing unit can be made of a rubber material. It can expand and swell outward under internal pressure, ultimately clinging to the inner wall of the casing, thereby sealing the fluid flow path within the casing. It can also rebound to its original shape when internal pressure decreases. However, the present invention is not limited to this. The material of the upper rubber sleeve 62 can also be other elastic materials besides rubber, as long as it can expand under internal pressure and rebound after pressure relief. This is not a specific limitation of the present invention.

[0049] In this embodiment, the connecting shaft 3, the control piston 9, the pressure transmission sleeve 8, the locking ring 7 and the adapter 4 can form a pressure transmission control mechanism. By controlling the movement of the piston 9, the upper liquid inlet can be opened and the lower liquid inlet can be blocked, thereby controlling the switching of the working states of the two groups of rubber cylinders, that is, realizing the step-by-step operation of the two groups of rubber cylinder sealing units.

[0050] In this embodiment, a movable cavity is formed between the connecting shaft 3 , the pressure transmission sleeve 8 and the adapter 4 .

[0051] The connecting shaft 3 is provided with a first pressure transmission hole 31, a second pressure transmission hole 32, a third pressure transmission hole 33, and a fourth pressure transmission hole 34, each of which is at least one. The first pressure transmission hole 31 is provided on the end surface of the upper end of the connecting shaft 3, and the second pressure transmission hole 32, the third pressure transmission hole 33, and the fourth pressure transmission hole 34 are provided on the outer circumferential surface of the connecting shaft 3.

[0052] Among them, the first pressure transmission hole 31 and the second pressure transmission hole 32 are connected, the opening of the first pressure transmission hole 31 is formed on the end face of the upper end of the connecting shaft 3, and the opening of the second pressure transmission hole 32 is formed on the outer surface of the shaft body of the connecting shaft 3. The third pressure transmission hole 33 and the fourth pressure transmission hole 34 are both through holes, and the two can connect the inner cavity of the connecting shaft 3 with the movable cavity.

[0053] The pressure-transmitting sleeve 8 is provided with fifth pressure-transmitting holes 81, which are identical in number to the first pressure-transmitting holes 31 and correspond one-to-one. Both openings of the fifth pressure-transmitting holes 81 are formed on the inner surface of the pressure-transmitting sleeve 8, with one opening communicating with the corresponding opening of the first pressure-transmitting hole 31 and the other opening communicating with the active cavity.

[0054] The first pressure transmission hole 31, the second pressure transmission hole 32 and the fifth pressure transmission hole 81 are connected in sequence, and the three can form a channel for transmitting pressure to the upper rubber cylinder sealing unit. The pressure can be transmitted to the inner surface of the rubber cylinder, and the inside of the rubber cylinder is pressurized to expand and swell outward.

[0055] The adapter 4 begins with a sixth pressure-transmitting hole 41, with two openings formed on the front and rear ends of the adapter 4. In other words, the adapter 4 has a sixth pressure-transmitting hole 41 extending from one end to the other. There is at least one sixth pressure-transmitting hole 41. This hole 41 communicates with the rear end of the active cavity, transmitting pressure to the lower rubber cartridge seal. This pressure is transmitted to the inner surface of the rubber cartridge, causing the interior of the rubber cartridge to expand and swell outward.

[0056] In this embodiment, a shear pin b is provided at one end of the control piston 9 and is threadedly connected (i.e., the piston and the shear pin are threaded together). The cylindrical end of the shear pin b is embedded in the connecting shaft 3. The other end of the control piston 9 is provided with a sawtooth thread that engages with the sawtooth thread on the inside of the lock ring 7. The lock ring 7 has a circumferential cutout.

[0057] In this embodiment, a pressure transmission hole is provided on one end face of the pressure transmission sleeve 8, the depth of which reaches the position of the inner circle expansion diameter, that is, Figure 2 and Figure 5 As shown in FIG, a pressure transmission hole is provided at the first step end face on the left side of the pressure transmission sleeve 8, and the pressure transmission hole extends axially to the next step position. The number of pressure transmission holes on the pressure transmission sleeve 8 is at least one.

[0058] In this embodiment, the connecting shaft 3, control piston 9, pressure transmission sleeve 8, lock ring 7, and adapter 4 constitute a pressure transmission control mechanism, which controls the operating state of the two rubber-sleeve sealing units by controlling the movement of the piston 9. For example, by opening the pressure transmission channel consisting of the first pressure transmission hole 31, the second pressure transmission hole 32, the fifth pressure transmission hole 81, and the third pressure transmission hole 33 on the upper side, the upper rubber-sleeve 62 at the upper end starts operating, while simultaneously blocking the pressure transmission channel consisting of the sixth pressure transmission hole 41 and the fourth pressure transmission hole 34 on the lower side, the rubber-sleeve of the lower rubber-sleeve sealing unit at the lower end stops operating, thereby controlling the switching of the operating states of the two rubber-sleeve groups.

[0059] In order to better understand the above embodiment, the working process of the double-rubber tube expandable packer is further described below.

[0060] After the double-rubber expansion packer is installed in the tool string, it is lowered into the well. Hydraulic pressure is applied to the double-rubber expansion packer from the inner cavity of the tool string. The pressure is transmitted to the inner wall of the rubber cylinder of the lower rubber cylinder sealing unit through the fourth pressure transmission hole 34 on the connecting shaft 3 and the sixth pressure transmission hole 41 on the adapter 4, thereby causing the rubber cylinder to expand radially outward. The outer cylindrical surface of the rubber cylinder contacts and seals the well wall, and normal construction is carried out.

[0061] When the rubber cylinder of the lower rubber cylinder sealing unit repeatedly works until it is damaged, a ball of corresponding size is put into the tube and sits on the inner step of the connecting shaft 3. At the same time, hydraulic pressure is applied in the tube to cut the shear pin b and push the control piston 9 downward. At this time, the pressure transmission channel composed of the sixth pressure transmission hole 41 and the fourth pressure transmission hole 34 is blocked, and the pressure transmission channel composed of the first pressure transmission hole 31, the second pressure transmission hole 32, the fifth pressure transmission hole 81 and the third pressure transmission hole 33 is opened. After taking out the ball in the tube, hydraulic pressure is applied again in the tube. The pressure is transmitted to the inner wall of the upper rubber cylinder 62 of the upper rubber cylinder sealing unit through the first pressure transmission hole 31, the second pressure transmission hole 32 and the third pressure transmission hole 33 on the connecting shaft 3 and the fifth pressure transmission hole 81 on the pressure transmission sleeve 8, thereby causing the upper rubber cylinder 62 to expand radially outward. The outer cylindrical surface of the upper rubber cylinder 62 contacts and seals the well wall, and normal construction continues.

[0062] The double-rubber-tube expandable packer of the utility model has two groups of expandable rubber-tube sealing units, which can control the blocking and opening of the pressure transmission hole by throwing a ball and holding the pressure, thereby controlling the two groups of expandable rubber-tube sealing units to work alternately, effectively extending the overall pressure-bearing capacity and service life of the expandable packer. For example, under the high-pressure working condition of 70MPa, the number of effective repeated sealing times can reach more than 10 times, realizing the repeated effective sealing of the expandable packer under high pressure. Compared with conventional expandable packers, it has the advantage of being reusable multiple times, solves the problem of insufficient repeatable sealing performance of general expandable packers, and improves on-site production efficiency.

[0063] Although the present invention has been described above with reference to the exemplary embodiments and the accompanying drawings, it should be apparent to those skilled in the art that various modifications may be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A double-tube expandable packer, characterized in that: The packer comprises: The upper joint, upper center tube, connecting shaft, adapter and lower center tube connected in sequence, the upper rubber cylinder sealing unit sleeved on the upper center tube, the lower rubber cylinder sealing unit sleeved on the lower center tube, the locking ring and pressure transmission sleeve sleeved on the connecting shaft, and the control piston; wherein, A movable cavity is formed between the pressure transmission sleeve, the connecting shaft and the adapter; The locking ring is located at the tail end of the movable cavity; The control piston is located in the movable cavity and can be fixed to the front section of the movable cavity by shear pins. In this case, the first pressure transmission channel leading to the lower rubber cylinder sealing unit is opened, and the first pressure transmission channel includes part of the air holes on the connecting shaft and the air holes on the adapter; after the shear pins are cut off, the control piston can move to the rear section of the movable cavity and engage with the locking ring. In this case, the first pressure transmission channel is closed, and the second pressure transmission channel leading to the upper rubber cylinder sealing unit is opened, and the second pressure transmission channel includes another part of the air holes on the connecting shaft and the air holes on the pressure transmission sleeve.

2. The double-tube expandable packer according to claim 1, characterized in that: The upper rubber cylinder sealing unit includes a first upper rubber cylinder seat, an upper rubber cylinder and a first lower rubber cylinder seat connected in sequence; the first upper rubber cylinder seat is threadedly connected to the upper joint and a sealing member is provided between the two; and / or, The lower rubber cylinder sealing unit includes a lower rubber cylinder, a second upper rubber cylinder seat and a second lower rubber cylinder seat.

3. The double-tube expandable packer according to claim 2, characterized in that: The packer further comprises a lower connecting sleeve which is threadedly connected to the lower central pipe and is located at the tail thereof. The lower connecting sleeve is fitted with an inner circumferential clearance of the second lower rubber cylinder seat and a sealing member is provided between the two.

4. The double-tube expandable packer according to claim 1, characterized in that: The upper joint, the upper center tube, the connecting shaft, the adapter and the lower center tube are threadedly connected in sequence.

5. The double-tube expandable packer according to claim 1, characterized in that: A sealing element is provided between any two of the upper joint, the upper central tube, the connecting shaft, the adapter and the lower central tube that are in contact with each other.

6. The double-tube expandable packer according to claim 1, characterized in that: From the upper end to the lower end, the connecting shaft is provided with a first pressure transmission hole, a second pressure transmission hole, a third pressure transmission hole, and a fourth pressure transmission hole, each of which is at least one; the first pressure transmission hole is connected to the second pressure transmission hole, the opening of the first pressure transmission hole is formed on the end surface of the upper end of the connecting shaft, and the opening of the second pressure transmission hole is formed on the outer surface of the shaft body of the connecting shaft; the third pressure transmission hole and the fourth pressure transmission hole are both through holes, and can connect the inner cavity of the connecting shaft with the movable cavity; The pressure transmission sleeve is provided with fifth pressure transmission holes, the same number as the first pressure transmission holes and corresponding one to one, and two openings of the fifth pressure transmission holes are formed on the inner surface of the pressure transmission sleeve, and one opening is connected to the opening corresponding to the first pressure transmission hole, and the other opening is connected to the movable cavity; The second pressure transmission channel includes a first pressure transmission hole, a second pressure transmission hole, a third pressure transmission hole and a fifth pressure transmission hole.

7. The double-tube expandable packer according to claim 6, characterized in that: The adapter begins to have a sixth pressure transmission hole, and two openings of the sixth pressure transmission hole are respectively formed on the front and rear end surfaces of the adapter, and the first pressure transmission channel includes the fourth pressure transmission hole and the sixth pressure transmission hole.

8. The double-tube expandable packer according to claim 6, characterized in that: A step is provided on the inner circumference of the connecting shaft, and the step is located between the third pressure transmission hole and the fourth pressure transmission hole. After pitching, the ball sits on the step.

9. The double-tube expandable packer according to claim 1, characterized in that: Sealing elements are provided on both the inner and outer sides of the control piston.

10. The double-tube expandable packer according to claim 1, characterized in that: The outer circumferential surface of one end of the control piston facing the lock ring and the inner circumferential surface of the lock ring are both provided with serrated threads.

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