Floating coupling device

Abstract

The present invention relates to the technical field of drilling tools, specifically to a floating coupling device, including a coupling body; the coupling body is cylindrical with an installation cavity that is transparent from top to bottom, and a pressure differential sleeve is fixedly installed on the upper part of the installation cavity of the coupling body through a pin hole and a shear pin, and the pressure differential sleeve is cylindrical with a larger upper part and a smaller lower part. The present invention forms a temporary barrier in the casing, the casing column below the sliding circular plate is filled with air, and the casing column above the sliding circular plate is filled with drilling fluid, thereby increasing the buoyancy of the casing column below the sliding circular plate, so that the lower casing string is in a floating state during the casing lowering process. After the casing string reaches a predetermined position, the sliding sleeve and the sliding circular plate cut off the shear pin and move downward, so that the drilling fluid of the upper casing enters the lower casing, making it easier to lower the casing string, effectively reducing the resistance of the casing lowering, and improving the working efficiency of the casing lowering and the cementing quality.

Description

Technical Field

[0001] The invention relates to the technical field of drilling tools and relates to a floating coupling device. Background Art

[0002] In the cementing and completion methods of oil, natural gas and geological exploration, whether the casing is lowered smoothly is the last process before cementing. Casing is the most common tool accessory for the completion string. However, in the wells with long horizontal sections, the longer the horizontal section of the casing is lowered, the greater the friction resistance it will bear. Once a resistance point is encountered or the well wall has irregular changes, it will cause difficulty in lowering the completion string, lowering stuck, and low efficiency of casing lowering, which will have a great impact on the cementing quality. Summary of the invention

[0003] The present invention provides a floating coupling device, which overcomes the shortcomings of the above-mentioned prior art and can effectively solve the problem that when a casing string is lowered into a well with a long horizontal section, the longer the horizontal section of the casing is lowered, the greater the friction resistance it will bear. Once a resistance point is encountered or an irregular change occurs in the well wall, the completion pipe string will be difficult to lower, the casing will get stuck, and the efficiency of the casing lowering will be low, which will have a great impact on the cementing quality.

[0004] The technical solution of the present invention is achieved through the following measures: a floating coupling device, including a coupling body and a fixed sleeve; the coupling body is a cylindrical shape with an installation cavity that is transparent from top to bottom inside, a pressure differential sleeve is fixedly installed on the upper part of the coupling body installation cavity through a pin hole and a shear pin, the pressure differential sleeve is a cylindrical shape with a larger upper part and a smaller lower part, a vertical through hole is provided in the pressure differential sleeve, the fixed sleeve is a barrel shape with an opening upward and an upper outer diameter greater than a lower outer diameter, the upper outer side of the fixed sleeve is fixedly installed in the middle of the coupling body installation cavity, and the lower outer side of the pressure differential sleeve is sleeved On the upper inner side of the fixed sleeve, a sliding cavity is formed between the coupling body, the pressure differential sleeve and the fixed sleeve, a sliding circular plate is fixedly installed on the middle inner side of the fixed sleeve through shear pins and pin holes, the bottom of the fixed sleeve is provided with a connecting hole connected with the lower part of the mounting cavity of the coupling body, and the lower part of the fixed sleeve is evenly provided with at least two flow holes connected with the lower part of the mounting cavity of the coupling body, the height between the upper end of the sliding circular plate and the bottom end of the pressure differential sleeve is smaller than the height of the sliding cavity, and the thickness of the sliding circular plate is smaller than the distance between the flow hole of the fixed sleeve and the bottom end of the fixed sleeve.

[0005] The following are further optimizations and / or improvements to the above technical solutions:

[0006] The upper part of the above-mentioned differential pressure sleeve is sleeved on the upper part of the installation cavity of the coupling body. The upper part of the coupling body is provided with at least two evenly distributed horizontal pin holes. The outer side of the upper part of the differential pressure sleeve is provided with pin holes corresponding to the pin holes of the coupling body. The differential pressure sleeve is fixedly installed on the upper part of the installation cavity of the coupling body through the pin holes and shear pins.

[0007] The upper part of the above-mentioned fixing sleeve is sleeved in the middle part of the installation cavity of the coupling body. The middle part of the coupling body is provided with two groups of corresponding through holes in the upper and lower directions along the circumferential direction. Each group of through holes has at least two and are evenly distributed along the circumferential direction. The fixing sleeve is provided with corresponding bolt holes at the positions of the through holes of the coupling body. The fixing sleeve is fixedly installed in the middle part of the installation cavity of the coupling body through the through holes, fixing bolts and bolt holes.

[0008] The above-mentioned sliding circular plate is sleeved in the middle part of the inner cavity of the fixed sleeve. At least two evenly distributed horizontal pin holes are provided in the middle part of the fixed sleeve. The sliding circular plate is provided with corresponding pin holes at the positions corresponding to the pin holes of the fixed sleeve. The sliding circular plate is fixedly installed in the middle part of the inner cavity of the fixed sleeve through shear pins and pin holes.

[0009] The upper part of the through hole of the above-mentioned differential pressure sleeve is funnel-shaped with a larger upper part and a smaller lower part; or / and, sealing rings are respectively installed above and below the shear pin connection between the differential pressure sleeve and the coupling body, and sealing rings are respectively installed above and below the connection between the fixed sleeve and the coupling body fixing bolt; or / and, a thread is provided on the inner side of the upper part of the coupling body, and a thread is provided on the outer side of the lower part of the coupling body.

[0010] The invention has a reasonable and compact structure and is easy to use. A temporary barrier is formed in the casing, the casing column below the sliding circular plate is filled with air, and the casing column above the sliding circular plate is filled with drilling fluid, thereby increasing the buoyancy of the casing column below the sliding circular plate, so that the lower casing string is in a floating state during the casing lowering process. After the casing string reaches a predetermined position, the sliding sleeve and the sliding circular plate cut off the shear pin and move downward, so that the drilling fluid of the upper casing enters the lower casing, making it easy to lower the casing string, effectively reducing the resistance of lowering the casing, and improving the working efficiency of casing lowering and the cementing quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Attached Figure 1 It is a schematic diagram of the main cross-sectional structure of the best embodiment of the present invention.

[0012] The codes in the attached drawings are: 1 is the coupling body, 2 is the pressure difference sleeve, 3 is the fixed sleeve, 4 is the sliding circular plate, 5 is the sliding cavity, 6 is the connecting hole, 7 is the flow hole, 8 is the shear pin, and 9 is the fixing bolt. DETAILED DESCRIPTION

[0013] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0014] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached Figure 1The layout is described in detail, such as the positional relationship of front, back, top, bottom, left, right, etc., which is based on the attached manual. Figure 1 It is determined by the layout direction.

[0015] The present invention will be further described below in conjunction with embodiments and drawings:

[0016] As attached Figure 1 As shown, the floating coupling device comprises a coupling body 1 and a fixed sleeve 3; the coupling body 1 is a cylinder with an installation cavity that is transparent from top to bottom inside, and a pressure differential sleeve 2 is fixedly installed on the upper part of the installation cavity of the coupling body 1 through a pin hole and a shear pin 8, the pressure differential sleeve 2 is a cylinder with a larger upper part and a smaller lower part, and a vertical through hole is provided in the pressure differential sleeve 2, the fixed sleeve 3 is a barrel with an opening facing upward and an upper outer diameter greater than a lower outer diameter, the upper outer side of the fixed sleeve 3 is fixedly installed in the middle of the installation cavity of the coupling body 1, and the lower outer side of the pressure differential sleeve 2 is sleeved on the upper inner side of the fixed sleeve 3, A sliding cavity 5 is formed between the hoop body 1, the pressure differential sleeve 2 and the fixed sleeve 3. A sliding circular plate 4 is fixedly installed on the inner side of the middle part of the fixed sleeve 3 through a shear pin 8 and a pin hole. The bottom of the fixed sleeve 3 is provided with a connecting hole 6 connected with the lower part of the installation cavity of the coupling body 1. The lower part of the fixed sleeve 3 is evenly provided with at least two flow holes 7 connected with the lower part of the installation cavity of the coupling body 1. The height between the upper end of the sliding circular plate 4 and the bottom end of the pressure differential sleeve 2 is smaller than the height of the sliding cavity 5, and the thickness of the sliding circular plate 4 is smaller than the distance between the flow hole 7 of the fixed sleeve 3 and the bottom end of the fixed sleeve 3. In this way, when working, the present invention is fixedly installed in the middle position of the casing string, the sliding circular plate 4 forms a temporary barrier in the casing string, the casing above the sliding circular plate 4 is filled with drilling fluid, and the casing below the sliding circular plate 4 is filled with air, which increases the buoyancy of the casing below the sliding circular plate 4, so that the lower casing string is in a floating state during the lowering process, effectively reducing the lowering resistance of the casing string, and when the casing string reaches the expected position, the pressure of the drilling fluid in the upper casing is increased, so that the pressure difference sleeve 2 can shear the shear pin The nail 8 slides downward along the sliding cavity 5, and finally the bottom end of the pressure difference sleeve 2 touches the upper end of the sliding circular plate 4, so that the sliding circular plate 4 cuts the shear pin 8 and moves downward to make way for the flow hole 7. Because the upper outer diameter of the fixed sleeve 3 is larger than the lower outer diameter, there is a gap between the lower outer side of the fixed sleeve 3 and the coupling body 1, so that the drilling fluid can flow into the lower casing through the flow hole 7 and the gap between the fixed sleeve 3 and the coupling body 1 in turn, thereby completing the casing string lowering work and effectively improving the work efficiency and cementing quality.

[0017] The above-mentioned floating coupling device can be further optimized and / or improved according to actual needs:

[0018] As attached Figure 1As shown, the upper part of the differential pressure sleeve 2 is sleeved on the upper part of the installation cavity of the coupling body 1, the upper part of the coupling body 1 is provided with at least two evenly distributed horizontal pin holes, the outer side of the upper part of the differential pressure sleeve 2 is provided with pin holes corresponding to the pin holes of the coupling body 1, and the differential pressure sleeve 2 is fixedly installed on the upper part of the installation cavity of the coupling body 1 through the pin holes and the shear pins 8. In this way, the differential pressure sleeve 2 can be effectively fixed on the coupling body 1.

[0019] As attached Figure 1 As shown, the upper part of the fixing sleeve 3 is sleeved in the middle of the installation cavity of the coupling body 1, and the middle of the coupling body 1 is provided with two groups of corresponding through holes in the circumferential direction, each group of through holes is at least two and evenly distributed in the circumferential direction, and the fixing sleeve 3 is provided with corresponding bolt holes at the positions of the through holes of the coupling body 1, and the fixing sleeve 3 is fixedly installed in the middle of the installation cavity of the coupling body 1 through the through holes, the fixing bolts 9 and the bolt holes. In this way, the fixing sleeve 3 can be effectively fixedly installed in the coupling body 1.

[0020] As attached Figure 1 As shown, the sliding circular plate 4 is sleeved in the middle of the inner cavity of the fixed sleeve 3, and at least two evenly distributed horizontal pin holes are provided in the middle of the fixed sleeve 3. The sliding circular plate 4 is provided with corresponding pin holes at positions corresponding to the pin holes of the fixed sleeve 3, and the sliding circular plate 4 is fixedly installed in the middle of the inner cavity of the fixed sleeve 3 through the shear pins 8 and the pin holes. In this way, the sliding circular plate 4 can be effectively fixed in the fixed sleeve 3.

[0021] As attached Figure 1 As shown, the upper part of the through hole of the differential pressure sleeve 2 is a funnel shape with a larger upper part and a smaller lower part; or / and, sealing rings are respectively installed above and below the connection between the differential pressure sleeve 2 and the shear pin 8 of the coupling body 1, and sealing rings are respectively installed above and below the connection between the fixing sleeve 3 and the fixing bolt 9 of the coupling body 1; or / and, the inner side of the upper part of the coupling body 1 is provided with a thread, and the outer side of the lower part of the coupling body 1 is provided with a thread. In this way, the sealing ring can enhance the sealing performance of the present invention.

[0022] The above technical features constitute the best embodiment of the present invention, which has strong adaptability and best implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

[0023] The use process of the best embodiment of the present invention is as follows: during operation, the casing of the present invention enters the well, and the sliding circular plate 4 forms a temporary barrier in the casing. The casing below the sliding circular plate 4 is filled with air, and the casing above the sliding circular plate 4 is filled with drilling fluid. This increases the buoyancy of the casing below the present invention, and enables the lower casing to be in a floating state during the casing lowering process, effectively reducing the resistance during casing lowering. Moreover, since the casing above the present invention is filled with drilling fluid, the pressure for pushing the casing into the wellbore is increased, and the casing is smoothly lowered. When the casing enters the appropriate position, the pressure difference sleeve 2 will shear the shear pin 8 under the action of pressure and move downward, thereby connecting with the sliding circular plate 4, so that the sliding circular plate 4 also shears the shear pin 8 and moves downward under the action of the pressure difference sleeve 2, and then allows the flow hole 7 to allow the drilling fluid to smoothly enter the casing below the present invention, and finally complete the casing lowering.

Claims

1. A floating coupling device, characterized in that The invention comprises a coupling body and a fixed sleeve; the coupling body is a cylinder with an installation cavity which is transparent from top to bottom inside; a pressure differential sleeve is fixedly installed on the upper part of the installation cavity of the coupling body through a pin hole and a shear pin; the pressure differential sleeve is a cylinder with a larger upper part and a smaller lower part; a vertical through hole is arranged in the pressure differential sleeve; the fixed sleeve is a barrel with an upward opening and an upper outer diameter larger than a lower outer diameter; the upper outer side of the fixed sleeve is fixedly installed in the middle part of the installation cavity of the coupling body; the lower outer side of the pressure differential sleeve is sleeved on the upper inner side of the fixed sleeve; a sliding cavity is formed between the coupling body, the pressure differential sleeve and the fixed sleeve; the middle of the fixed sleeve A sliding circular plate is fixedly installed on the inner side of the coupling body through shear pins and pin holes, a connecting hole is provided at the bottom of the fixed sleeve which is connected to the lower part of the installation cavity of the coupling body, and at least two flow holes which are connected to the lower part of the installation cavity of the coupling body are evenly distributed at the lower part of the fixed sleeve. The height between the upper end of the sliding circular plate and the bottom end of the pressure differential sleeve is less than the height of the sliding cavity, and the thickness of the sliding circular plate is less than the distance between the flow hole of the fixed sleeve and the bottom end of the fixed sleeve; the upper part of the pressure differential sleeve is sleeved on the upper part of the installation cavity of the coupling body, and the upper part of the coupling body is provided with at least two evenly distributed horizontal pin holes. A pin hole corresponding to the pin hole of the coupling body is provided on the outer side of the coupling body, and the differential pressure sleeve is fixedly installed in the upper part of the installation cavity of the coupling body through the pin hole and the shear pin; the upper part of the fixed sleeve is sleeved in the middle part of the installation cavity of the coupling body, and the middle part of the coupling body is provided with two groups of corresponding through holes in the circumferential direction, each group of through holes is at least two and is evenly distributed in the circumferential direction, and the fixed sleeve is provided with corresponding bolt holes at the positions of the through holes of the coupling body, and the fixed sleeve is fixedly installed in the middle part of the installation cavity of the coupling body through the through holes, the fixing bolts and the bolt holes; the sliding circular plate is sleeved in the middle part of the inner cavity of the fixed sleeve At least two evenly distributed horizontal pin holes are provided in the middle of the fixed sleeve, and corresponding pin holes are provided at the positions of the sliding circular plate corresponding to the pin holes of the fixed sleeve. The sliding circular plate is fixedly installed in the middle of the inner cavity of the fixed sleeve through shear pins and pin holes; the upper part of the through hole of the pressure difference sleeve is a funnel shape with a larger upper part and a smaller lower part; sealing rings are respectively installed above and below the shear pin connection between the pressure difference sleeve and the coupling body, and sealing rings are respectively installed above and below the fixing sleeve and the fixing bolt connection between the coupling body; a thread is provided on the inner side of the upper part of the coupling body, and a thread is provided on the outer side of the lower part of the coupling body.

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