Self-sealing device for top-drive casing running

Abstract

The invention discloses a self-sealing device for a top-drive lower casing. The problems that the sealing diameter range of an existing top drive lower casing pipe sealing device cannot be adjusted, and replacement needs to be conducted according to the diameter of a casing pipe are mainly solved. Which comprises a leather cup frame (6) which is connected outside a sealing section of the top-drive lower casing device, and is characterized in that a rotating sleeve (5) is connected outside the leather cup frame (6), a sealing leather cup (3) is arranged outside the rotating sleeve (5), and the inner wall of the front end of the sealing leather cup (3) is a conical surface. According to the top drive lower casing pipe self-sealing device, the sealing diameter range of the top drive lower casing pipe device can be adjusted, the sealing leather cup of one type can adapt to casing pipes of several sizes, the leather cup does not need to be replaced frequently, and sealing of the casing pipes of different specifications and models can be achieved only by adjusting the spacer bush.

Description

Technical Field

[0001] The invention relates to the field of oil drilling, in particular to a top drive casing self-sealing device. Background Art

[0002] With the continuous deepening of oil exploration and development, the number of horizontal wells in China is increasing, especially in the exploration and development of shale oil and gas. Since its completion method is mainly based on long horizontal sections combined with multi-stage hydraulic fracturing, the well types mined are basically horizontal wells, and the horizontal sections will gradually become longer. During the casing operation, it is easy to encounter problems such as difficulty in casing, untimely handling of downhole abnormalities, and damage to the casing caused by the axial impact load generated by the conventional casing lowering method. It is necessary to improve the level of safe casing lowering technology. The top drive casing lowering device can smoothly rotate the casing, lift and lower the casing string, and circulate the drilling fluid at any time. These advantages can avoid more complex accidents caused by untimely handling of downhole abnormalities. At present, the sealing diameter range of the top drive casing lowering sealing device cannot be adjusted and needs to be replaced according to the casing diameter. In this way, multiple sets of sealing devices need to be prepared, which is not conducive to production management. Summary of the invention

[0003] In order to overcome the problem that the sealing diameter range of the existing top drive casing sealing device cannot be adjusted and needs to be replaced according to the casing diameter, the present invention provides a top drive casing self-sealing device, the top drive casing self-sealing device can adjust the sealing diameter range of the top drive casing device, one model of sealing leather cup can adapt to several sizes of casings, there is no need to frequently replace the leather cup, and the sealing of casings of different specifications and models can be achieved by adjusting the spacer.

[0004] The technical solution of the present invention is: a top drive casing self-sealing device, including a leather cup frame, the leather cup frame is connected to the outside of the sealing section of the top drive casing device, the leather cup frame is connected to the outside of a rotating sleeve, a sealing leather cup is arranged on the outside of the rotating sleeve, and the inner wall of the front end of the sealing leather cup is a conical surface.

[0005] A spacer is arranged outside the front end of the rotating sleeve, the spacer is located inside the sealing leather cup, and there is a gap between the outer wall of the spacer and the inner wall of the sealing leather cup.

[0006] A guide sleeve is arranged on the front outer wall of the spacer sleeve, a boss is arranged on the front outer wall of the leather cup rack, and the guide sleeve is located between the boss and the spacer sleeve.

[0007] A boss is arranged at the rear end of the rotating sleeve, and a leather cup gasket is arranged between the boss and the sealing leather cup.

[0008] The sealing leather cup comprises a plurality of sealing rubbers and skeleton spring pieces, and the skeleton spring pieces are evenly embedded in the sealing rubber along the circumferential direction.

[0009] The skeleton spring piece is a steel sheet.

[0010] The leather cup rack is connected to the outside of the sealing section of the top drive casing device, and the sealing leather cup is adjusted to the casing sealing size by adjusting the position of the spacer; when the casing device is inserted into the casing, the pump is turned on to circulate the drilling fluid, and the drilling fluid pushes the sealing leather cup to expand, sealing the inner wall of the casing, and achieving self-sealing under the action of the circulating pressure.

[0011] The present invention has the following beneficial effects: due to the adoption of the above scheme, the sealing device is connected to the outside of the casing device, and when the drilling fluid circulates, the sealing cup is pushed to expand by the drilling fluid to achieve self-sealing, thereby meeting the circulation requirements when the grouting and processing are complicated during the casing operation, and ensuring the safety of the casing operation. Since the outer diameter adjustment range of the sealing cup is large during the expansion process, a type of sealing cup can adapt to several sizes of casings, and there is no need to frequently replace the cup. The sealing of casings of different specifications and models can be achieved by adjusting the spacer. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the structure of the present invention;

[0013] Figure 2 This is the left side view of the sealing leather cup;

[0014] Figure 3 This is a parts diagram of the skeleton shrapnel.

[0015] In the figure, 1-guide sleeve, 2-spacer sleeve, 3-sealing leather cup, 4-leather cup gasket, 5-rotating sleeve, 6-leather cup frame, 31-sealing rubber, 32-skeleton shrapnel. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings:

[0017] Depend on Figures 1 to 3 As shown, a self-sealing device for top drive casing includes a cup frame 6, which is connected to the outside of the sealing section of the top drive casing device. A guide head is provided at the front end of the cup frame 6, and the front end of the guide head is a conical surface, which can guide the sealing section and the insertion section of the top drive casing device to enter the casing smoothly. A rotating sleeve 5 is connected to the outside of the cup frame 6, which is connected to the cup frame 6 by threads, and a sealing ring is provided between the two, and a boss is provided at the rear of the rotating sleeve 5. A sealing cup 3 is provided on the outside of the front end of the rotating sleeve 5, and the inner wall of the front end of the sealing cup 3 is a conical surface, that is, the front end of the sealing cup 3 is a bell mouth, so that drilling fluid can enter the sealing cup and open the cup.

[0018] A spacer sleeve 2 is provided on the outside of the front end of the rotating sleeve 5. The spacer sleeve 2 is located inside the bell mouth of the sealing leather cup 3. There is a gap between the outer wall of the spacer sleeve 2 and the inner wall of the sealing leather cup 3, and a sealing ring is provided between the inner wall of the spacer sleeve 2 and the rotating sleeve 5. In this way, when the drilling fluid flows through the spacer sleeve 2, it passes through the shunt of the spacer sleeve 2 and enters the sealing leather cup through the gap between the spacer sleeve and the sealing leather cup. At the same time, the axial position of the spacer sleeve 2 on the rotating sleeve 5 is adjusted by rotating the spacer sleeve 2, so that the radial sealing range of the sealing leather cup 3 can be adjusted. A guide sleeve 1 is provided on the outer wall of the front end of the spacer sleeve 2, and a sealing ring is provided between the spacer sleeve 2 and the guide sleeve 1. A boss is formed between the guide head and the outer wall at the front end of the leather cup frame 6. The guide sleeve 1 is located between the boss and the spacer sleeve 2, and the boss can limit the guide sleeve 1. The guide sleeve 1 can shunt the drilling fluid, so that a part of it enters the sealing leather cup 3.

[0019] The sealing leather cup 3 includes a plurality of sealing rubbers 31 and skeleton springs 32, and the skeleton springs 32 are evenly embedded in the sealing rubber 31 along the circumferential direction. The skeleton springs 32 are steel sheets, and the front end of each spring is bent outward to form a bell-mouth shape. The outer surface of the spring is vulcanized rubber, so that the sealing leather cup has elasticity as a whole. The rear end of the rotating sleeve 5 is provided with a boss, and a leather cup gasket 4 is provided between the boss and the sealing leather cup 3. The rear end of the sealing leather cup 3 is located inside the leather cup gasket 4, which can prevent uneven force on the sealing leather cup when it expands.

[0020] During operation, first check whether the sealing leather cup 3 is damaged. If damaged, replace it in time. Connect the leather cup frame 6 to the outside of the sealing section of the top drive casing device, and first adjust the position of the spacer 2 to make the sealing leather cup 3 reach the casing sealing size. After the casing device is inserted into the casing and connected to the casing, the pump is turned on to circulate the drilling fluid. The drilling fluid pushes the sealing leather cup 3 to expand, thereby sealing the inner wall of the casing and achieving self-sealing under the action of the circulating pressure.

[0021] Since the outer diameter of the sealing cup can be adjusted when it expands, one type of sealing cup can adapt to several sizes of casings. There is no need to frequently replace the cup. The sealing of casings of different specifications and models can be achieved by simply adjusting the spacer. See the table below for details, which are the sealing cup models corresponding to different types of casings and the number of turns of the spacer required for sealing.

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

Claims

1. A top drive casing self-sealing device, comprising a leather cup frame (6), the leather cup frame (6) being connected to the outside of a sealing section of the top drive casing device, characterized in that: The outer portion of the leather cup frame (6) is connected to a rotating sleeve (5), and the outer portion of the rotating sleeve (5) is provided with a sealing leather cup (3), and the inner wall of the front end of the sealing leather cup (3) is a conical surface.

2. The top drive casing self-sealing device according to claim 1, characterized in that: A spacer sleeve (2) is provided on the outside of the front end of the rotating sleeve (5), and the spacer sleeve (2) is located inside the sealing leather cup (3), and a gap is provided between the outer wall of the spacer sleeve (2) and the inner wall of the sealing leather cup (3).

3. The top drive casing self-sealing device according to claim 2, characterized in that: A guide sleeve (1) is provided on the front outer wall of the spacer sleeve (2), a boss is provided on the front outer wall of the leather cup rack (6), and the guide sleeve (1) is located between the boss and the spacer sleeve (2).

4. The top drive casing self-sealing device according to claim 3, characterized in that: The rear end of the rotating sleeve (5) is provided with a boss, and a leather cup gasket (4) is provided between the boss and the sealing leather cup (3).

5. The top drive casing self-sealing device according to claim 4, characterized in that: The sealing leather cup (3) comprises a plurality of sealing rubbers (31) and skeleton spring pieces (32), wherein the skeleton spring pieces (32) are evenly embedded in the sealing rubbers (31) along the circumferential direction.

6. The top drive casing self-sealing device according to claim 5, characterized in that: The skeleton spring piece (32) is a steel sheet.

7. The top drive casing self-sealing device according to claim 6, characterized in that: The cup holder (6) is connected to the outside of the sealing section of the top drive casing device, and the sealing cup (3) is adjusted to the casing sealing size by adjusting the position of the spacer (2); after the casing device is inserted into the casing, the pump is turned on to circulate drilling fluid, and the drilling fluid pushes the sealing cup (3) to expand, sealing the inner wall of the casing, and achieving self-sealing under the action of the circulating pressure.

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