CN114293928B - Underground stable joint for plugging operation - Google Patents

Abstract

The invention relates to the technical field of oil pipe connection in oil extraction engineering, in particular to an underground stable joint for plugging operation, wherein a high-elasticity rubber ring is sleeved in the middle of a middle working pipe column, the edges of the two side ends of the high-elasticity rubber ring are in sealing connection with the middle working pipe column, the middle working pipe column corresponds to a through hole at the position of the high-elasticity rubber ring, the outer wall of the middle working pipe column is respectively provided with a T-shaped channel close to the two ends, a T-shaped component is clamped in the T-shaped channel, a second spring is arranged in the T-shaped channel, the two ends of the second spring are respectively abutted to the tail end of the T-shaped channel and the T-shaped component, the T-shaped components on the two sides of the high-elasticity rubber ring are respectively connected through steel rings, a plurality of elastic steel sheets are in a long shape, and the two ends of the elastic steel sheets are respectively connected with the steel rings through first springs. The joint structure can solve the problem that the oil pipe collides with the inner wall of the casing when the plugging agent flows at a high speed.

Description

A downhole stable joint for plugging operations

technical field

The invention relates to the technical field of oil production engineering tubing connections, in particular to a downhole stable joint used for plugging operations.

Background technique

In recent years, with the continuous deepening of oil and gas development, major oil fields have gradually entered the middle and late stage of development, the contradiction between wellbore technical status and production has become increasingly prominent, the difficulty of mining has increased, and problems in downhole operation technology have also increased.

During the plugging operation, the process of pumping the plugging agent into the bottom of the well will cause vibration at the bottom of the tubing string due to the high-speed flow of the plugging agent fluid and the high pumping pressure. The additional dynamic load generated by the vibration at the bottom of the tubing string will change the stress distribution of the tubing string, and the tubing will hit the inner wall of the casing under the action of stress, reducing the service life of the tubing and casing or causing other engineering accidents. Based on the above reasons, there is a need for a downhole tool that can realize the stable operation of the oil pipe during the transportation of the lost circulation agent.

Contents of the invention

In order to solve the above problems, the present invention proposes a downhole stable joint for plugging operations. The joint structure can solve the problem that the tubing collides with the inner wall of the casing when the plugging agent flows at high speed.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A downhole stable joint for plugging operations, including an upper joint, an intermediate working string, a lower joint, a steel ring, a high elastic rubber ring, an elastic steel sheet, a T-shaped member, a first spring and a second spring, wherein the upper joint The upper and lower joints are respectively connected to the two ends of the middle working string and communicate with each other internally. The high elastic rubber ring is an annular structure with a certain width, and the high elastic rubber ring is set in the middle of the middle working string, and the high elastic rubber ring The edge of both sides of the middle working string is sealed and connected with the middle working string, and the middle working string is provided with a through hole as the flow channel of the plugging agent corresponding to the high elastic rubber ring. There is a T-shaped channel, the extension direction of the T-shaped channel is the axial direction of the intermediate working string, the end of the T-shaped channel extends to the middle of the intermediate working string, and the T-shaped member is clamped in the T-shaped channel , and the T-shaped member can slide in the T-shaped channel along the axial direction of the intermediate working string, the second spring is placed in the T-shaped channel, and the two ends of the second spring respectively abut against the T-shaped channel On the end and the T-shaped member, the second spring is used to push the T-shaped member away from the middle of the middle working string. The T-shaped members on both sides of the high-elastic rubber ring are respectively connected by steel rings. The elastic steel sheet There are several, the elastic steel sheets are elongated, and the two ends of the elastic steel sheets are respectively connected with the steel ring through the first spring.

Preferably, the part of the T-shaped member protrudes from the outer ring surface of the intermediate working string, and the steel ring passes through the part of the T-shaped member that protrudes from the outer ring surface of the intermediate working string; the T-shaped member has a The through hole through which the steel ring passes, and the diameter of the through hole of the T-shaped member is consistent with the diameter of the open steel ring, so as to ensure that the T-shaped member will not slip around the steel ring.

Preferably, the main body of the lower joint is a conical structure, the maximum outer diameter of the lower joint is larger than the diameter of the intermediate working string, and the conical surface of the lower joint is provided with an external thread structure protruding from the conical surface.

Preferably, the main body of the upper joint is a tubular structure, and the inner ring surface of the upper joint has internal threads.

Preferably, there are multiple through-holes and they are equally spaced and uniformly distributed around the circumference of the intermediate working string.

Preferably, the outer ring surface of the intermediate working string is provided with two inverted triangular grooves opened in the circumferential direction, and the ends on both sides of the high elastic rubber ring are respectively embedded in the two inverted triangular grooves. The contact part of the rubber and the inverted triangular groove is installed with an annular sealing ring.

Preferably, the inverted triangular grooves are respectively arranged at a position of 1/4 length and a position 3/4 of the length in the axial direction of the intermediate working string.

Preferably, there are several elastic steel sheets, and the several elastic steel sheets are equally spaced; there are several sets of T-shaped channels and T-shaped members, and the number of elastic steel sheets is greater than the number of T-shaped members.

Preferably, the upper joint, the intermediate working string and the lower joint are integrally welded.

Preferably, the length of the T-shaped channel does not exceed one-third of the length of the intermediate working string.

The beneficial effect of using the present invention is:

In the present invention, a through hole is opened in the middle part of the working pipe string, wrapped with high elastic rubber, and an elastic steel sheet and a limit device are added outside the high elastic rubber to form a ball cage. The high elastic rubber ring enters into the high elastic rubber ring under the action of the ball cage, so that the high elastic rubber ring expands evenly inside the ball cage, fills a part of the gap between the oil pipe and the casing, increases the stability of the oil pipe during the plugging operation, and avoids the collision between the oil pipe vibration and the casing. To protect the casing and improve the service life of joints and oil pipes, increase the safety of operations, and improve the delivery efficiency of the plugging agent.

Description of drawings

Fig. 1 is a schematic structural view of the downhole stable joint used in the plugging operation of the present invention.

Fig. 2 is a schematic longitudinal sectional view of the downhole stabilizing joint used in the plugging operation of the present invention.

Fig. 3 is a schematic longitudinal sectional view of the working state of the downhole stabilizing joint used in the plugging operation of the present invention.

Fig. 4 is a schematic top view of the intermediate working string used for the downhole stable joint in the plugging operation of the present invention.

Reference signs include:

1-upper joint, 2-steel ring, 3-T-shaped groove, 4-inverted triangular groove, 5-high elastic rubber ring, 6-elastic steel sheet, 7-middle working string, 8-T-shaped member, 9-first spring, 10-through hole, 11-annular sealing ring, 12-second spring, 13-lower joint, 14-external thread, 15-stopping agent.

Detailed ways

In order to make the purpose, technical solution and advantages of the technical solution clearer, the technical solution will be further described in detail below in conjunction with specific embodiments. It should be understood that these descriptions are only exemplary, and are not intended to limit the scope of the technical solution.

As shown in Figures 1-4, this embodiment proposes a downhole stable joint for plugging operations, including an upper joint 1, an intermediate working string 7, a lower joint 13, a steel ring 2, a high-elastic rubber ring 5, an elastic Steel sheet 6, T-shaped member 8, first spring 9 and second spring 12, wherein the upper joint 1 and the lower joint 13 are respectively connected to the two ends of the middle working column 7 and communicate with each other internally, and the high elastic rubber ring 5 has An annular structure with a certain width, the high-elastic rubber ring 5 is set in the middle of the middle working string 7, and the edge of both sides of the high-elastic rubber ring 5 is sealed with the middle working string 7, and the middle working string 7 corresponds to the high elastic The rubber ring 5 is provided with a through-hole 10 as a flow channel for the plugging agent 15, and the outer wall of the middle working string 7 is respectively provided with a T-shaped channel 3 near both ends, and the extension direction of the T-shaped channel 3 is the middle working direction. In the axial direction of the pipe string 7, the end of the T-shaped channel 3 extends to the middle of the middle working pipe string 7, the T-shaped member 8 is clamped in the T-shaped channel 3, and the T-shaped member 8 can be inserted into the T-shaped channel 3 Slide along the axial direction of the middle working string 7, the second spring 12 is placed in the T-shaped channel 3, and the two ends of the second spring 12 respectively abut against the end of the T-shaped channel 3 and the T-shaped member 8 Above, the second spring 12 is used to push the T-shaped member 8 away from the middle of the middle working column 7. The T-shaped members 8 on both sides of the high-elastic rubber ring 5 are respectively connected by the steel ring 2. The elastic steel sheet 6 has several One, the elastic steel sheet 6 is elongated, and the two ends of the elastic steel sheet 6 are connected with the steel ring 2 through the first spring 9 respectively.

The part of the T-shaped member 8 protrudes from the outer ring surface of the intermediate working string 7, and the steel ring 2 passes through the part of the T-shaped member 8 protruding from the outer ring surface of the intermediate working string 7; the T-shaped member 8 has a steel ring 2 passes through the through hole 10, and the diameter of the through hole 10 of the T-shaped member 8 is consistent with the diameter of the open steel ring 2, so as to ensure that the T-shaped member 8 will not slip around the steel ring 2.

The main body of the lower joint 13 is a conical structure, the maximum outer diameter of the lower joint 13 is larger than the diameter of the intermediate working string 7, and the conical surface of the lower joint 13 is provided with an external thread 14 structure protruding from the conical surface. The main body of the upper joint 1 is a tubular structure, and the inner ring surface of the upper joint 1 has internal threads.

There are a plurality of through holes 10 and they are evenly distributed at equal intervals around the circumference of the middle working string 7 . The outer ring surface of the middle working column 7 is provided with two inverted triangular grooves 4 opened in the circumferential direction. The contact part of the inverted triangular groove 4 is installed with an annular sealing ring 11 .

The inverted triangular grooves 4 are respectively arranged at the quarter length position and the three quarter length position of the intermediate working string 7 in the axial direction. There are several elastic steel sheets 6, and the several elastic steel sheets 6 are equally spaced; there are several sets of T-shaped channels 3 and T-shaped members 8, and the number of elastic steel sheets 6 is greater than the number of T-shaped members 8.

The upper joint 1, the middle working string 7 and the lower joint 13 are integrally welded. The length of the T-shaped channel 3 does not exceed one-third of the length of the middle working string 7 .

The specific structure and working process of the joint structure will be described in detail below through Example 1.

Example 1

As shown in Figure 1 and Figure 2, a downhole stable joint used for plugging operations in this embodiment, the upper joint 1 used to connect the tubing is a concave joint with an annular space inside and a thread inside it. Used to connect with the oil pipe joint, the size of the outer wall of the upper joint 1 is larger than the size of the outer wall of the middle working string 7 .

As shown in Figure 1, a through hole 10 is set in the middle of the middle working string 7, the size of the through hole 10 is kept consistent, and the through holes 10 are evenly distributed around the circumference of the middle working string 7 at equal intervals, the purpose is to ensure that the leakage stoppage agent 15 When the pressure difference passes through the through hole 10, the flow velocity flowing through the through hole 10 is equal, so that the leakage sealing agent 15 can enter the high elastic rubber ring 5 to expand evenly under the action of the pressure difference, and further fill the gap between the joint and the casing. gap.

Two annular closed inverted triangular grooves 4 surrounding the intermediate working string 7 are provided at the quarter length position and the three quarter length position in the axial direction of the intermediate working string 7 .

The high elastic rubber ring 5 is embedded in the inverted triangular groove 4. The high elastic rubber ring 5 is rubber made of vinyl silicone resin and has high elasticity. The annular sealing ring 11 prevents the leaking of the leak-stopping agent 15. The high-elastic rubber ring 5 tightly wraps the middle working string 7 and completely covers the through hole 10, and is used to wrap the leak-stopping agent 15 flowing out of the through hole 10. The elastic rubber ring 5 expands under the filling of the leakage stoppage agent 15, and the expanded size is larger than the diameter of the joint, and contacts with the casing, thereby playing a fixing role.

Wherein, the depth dimension of the annular inverted triangular groove 4 on the middle working string 7 is moderate, one is to ensure the stability of the middle working string 7; the other is to ensure that the high elastic rubber ring 5 will not fall off.

The middle working string 7 is provided with T-shaped channels 3 connected to the outside. The initial positions of the channels 3 start from both ends of the intermediate working string 7 and extend along the axial direction of the intermediate working string 7 , and the length of the T-shaped channel 3 does not exceed one-third of the intermediate working string 7 length.

The bottom end of the T-shaped member 8 is provided with a through hole 10, and then connected in series with the open steel ring 2, and the T-shaped member 8 is distributed around the circumference of the steel ring 2 at intervals, and the interval angle is consistent with the angle of the T-shaped channel 3.

As shown in Figure 4, the open steel ring 2 is welded to form a closed steel ring 2; the T-shaped member 8 is placed in the corresponding T-shaped channel 3, and the first spring 9 is placed in the T-shaped channel 3, located in the T-shaped The top of the channel 3 is welded to the middle of the T-shaped member 8, and the two ends are welded respectively; the upper and lower steel rings 2 are welded at equal intervals to the second spring 12, and the second springs 12 are distributed around the circumference of the steel ring 2 at intervals, and the second spring 12 There are multiple ones, the number of which is greater than the number of T-shaped members 8, and elastic steel sheets 6 are welded between the corresponding second springs 12 in pairs.

In this embodiment, the upper joint 1, the middle working string 7 and the lower joint 13 are integrally welded.

As shown in Figure 3, the leak-stopping agent 15 produces a pressure difference due to uneven flow velocity in the oil pipe, the leak-stopping agent 15 flows out through the through hole 10 under force, the high-elastic rubber ring 5 expands due to the filling of the leak-stopping agent 15, and the elastic steel sheet 6. As the high elastic rubber ring 5 expands and deforms accordingly, the second spring 12 stretches, driving the T-shaped member 8 to slide along the axial direction of the T-shaped channel 3, and the first spring 9 is compressed to form an annular spherical cage.

The ball cage will protect the high-elastic rubber ring 5 and also protect the casing from damage; the further ball cage will play a position-limiting role to prevent sliding between the high-elastic rubber ring 5 and the casing; further strengthen the stability of the joint performance, reducing the vibration of the tubing.

There will be cracks in the casing. The high-elastic rubber ring 5 will expand irregularly under the pressure of the plugging agent 15 and enter the crack. stability.

When the flow rate in the oil pipe is gradually uniform and the existing pressure gradually decreases, the first spring 9 stretches, and the T-shaped member 8 slides to the original position under the force of the second spring 12, driving the elastic steel sheet 6 to reset; until there is no pressure Poor, the first spring 9 and the second spring 12 return to their original state, and the leak-stopping agent 15 in the high elastic rubber ring 5 is completely removed under the action of the second spring 12 .

The above content is only a preferred embodiment of the present invention. For those of ordinary skill in the art, many changes can be made in the specific implementation and application scope according to the thought of the technical content, as long as these changes do not depart from the concept of the present invention, All belong to the scope of protection of this patent.

Claims (10)

1. The utility model provides a stable joint in pit for leaking stoppage operation which characterized in that: the high-elasticity rubber ring is of an annular structure with a certain width, the high-elasticity rubber ring is sleeved in the middle of the middle working pipe column, the edges of the two sides of the high-elasticity rubber ring are in sealing connection with the middle working pipe column, through holes serving as leaking stoppage agent flow channels are formed in the positions, corresponding to the high-elasticity rubber ring, of the middle working pipe column, T-shaped channels are formed in the positions, close to the two ends, of the outer wall of the middle working pipe column respectively, the extending direction of the T-shaped channels is the axial direction of the middle working pipe column, the tail ends of the T-shaped channels extend towards the middle of the middle working pipe column, the T-shaped components are clamped in the T-shaped channels, the T-shaped components can slide in the T-shaped channels along the axial direction of the middle working pipe column, the second springs are arranged in the T-shaped channels, the two ends of the second springs are respectively abutted to the tail ends of the T-shaped channels and the T-shaped components, the second springs are used for being connected with the two sides of the steel disc through the long steel rings, and the two sides of the second springs are respectively connected with the long steel rings.

2. A downhole stabilizing joint for lost circulation according to claim 1, wherein: the part of the T-shaped component protrudes out of the outer ring surface of the middle working string, and the steel ring penetrates through the part of the T-shaped component protruding out of the outer ring surface of the middle working string; the T-shaped component is provided with a through hole used for the steel ring to pass through, and the diameter of the through hole of the T-shaped component is consistent with that of the opening steel ring, so that the T-shaped component can not slide around the steel ring.

3. A downhole stabilizing joint for lost circulation according to claim 1, wherein: the main body of the lower joint is of a conical structure, the maximum outer diameter of the lower joint is larger than the diameter of the middle working string, and an external thread structure protruding out of the conical surface is arranged on the conical surface of the lower joint.

4. A downhole stabilizing joint for lost circulation according to claim 1, wherein: the main body of the upper joint is of a tubular structure, and the inner annular surface of the upper joint is provided with an internal thread.

5. A downhole stabilizing joint for lost circulation according to claim 1, wherein: the through holes are distributed uniformly at equal intervals around the circumference of the middle working string.

6. A downhole stabilizing joint for lost circulation according to claim 1, wherein: the outer ring surface of the middle working string is provided with two reverse triangular grooves formed in the circumferential direction, two side end parts of the high-elasticity rubber ring are respectively embedded into the two reverse triangular grooves, and an annular sealing ring is arranged at the contact part of the high-elasticity rubber and the reverse triangular grooves.

7. The downhole stabilizing joint for lost circulation according to claim 6, wherein: the inverted triangle grooves are respectively arranged at a quarter length position and a three-quarter length position in the axial direction of the middle working string.

8. A downhole stabilizing joint for lost circulation according to claim 1, wherein: the elastic steel sheets are distributed at equal intervals; the T-shaped channels and the T-shaped members have a number of sets, and the number of elastic steel sheets is greater than the number of T-shaped members.

9. A downhole stabilizing joint for lost circulation according to claim 1, wherein: and the upper joint, the middle working string and the lower joint are integrally welded.

10. A downhole stabilizing joint for lost circulation according to claim 1, wherein: the length of the T-shaped channel is not more than one third of the length of the middle working string.

Images