CN220434682U - Multifunctional underground flushing nipple - Google Patents

Abstract

The utility model discloses a multifunctional underground flushing pup joint, which comprises a barrel and a sand flushing pipe, wherein a switching barrel is further arranged in the barrel, the outer diameter of the switching barrel is matched with the inner diameter of the barrel, the top of the sand flushing pipe is provided with a connecting part which is matched with the inner diameter of the barrel, the side wall of the switching barrel is provided with a guiding-out window, the inside of the switching barrel is provided with a ball seat part, the guiding-out window is higher than the ball seat part, the sand flushing pipe is provided with a guiding-in window, the inner side wall of the barrel is provided with a ring groove A, the side wall of the barrel is provided with a back flushing hole above the ring groove A, and the back flushing hole is obliquely arranged towards the upper end of the barrel and penetrates through the inner side and the outer side of the barrel; the switching cylinder and the sand washing pipe are fixedly connected with the cylinder body through a shearing pin A and a shearing pin B respectively, the shearing force of the shearing pin B is larger than that of the shearing pin A, and the position of the leading-out window is higher than that of the back flushing hole. Fewer parts are adopted to meet the requirements of fracturing and flushing sand, the reliability is increased, the difficulty of processing and assembling is reduced, the flushing efficiency is improved, and the flushing time is shortened.

Description

Multifunctional underground flushing nipple

Technical Field

The utility model belongs to the field of special tools for oil and gas exploitation, and particularly relates to a multifunctional underground flushing nipple.

Background

After long-time exploitation, oil and gas wells are prone to oil layer blockage, so that yield is reduced, and particularly for some low permeability oil fields, the phenomenon is obvious, and therefore the reservoir needs to be artificially modified, namely the reservoir crack condition is improved, so that normal exploitation requirements are met.

At present, a fracturing mode is mainly adopted to reform a reservoir, a high-pressure pump truck is utilized to press fluid into a well at a high speed, planned expansion is carried out on a reservoir fracture by means of well bottom pressure holding, propping agents (such as sand grains or glass particles) are mixed into the pumped fluid under normal conditions, the propping agents are mainly used for keeping stability of the expanded fracture in the later stage, but at the same time, a lot of propping agents are deposited at the well bottom in the fracturing process, so that well flushing operation is usually carried out after the fracturing is finished, the deposited propping agents are prevented from influencing production, and a step operation mode is adopted, so that the operation cost is greatly increased when a pipe column is started, the operation is complicated, and the operation risk is increased.

In view of this situation, the present technology tends to combine fracturing and flushing operations, that is, to achieve that two operations can be simultaneously met through one tool, related tools appear on the market, and the applicant has also proposed a patent application with the application number of 202122364293.X, named as "integrated fracturing sand flushing head", in the early stage, which is mainly used for solving the problem of poor reliability of sand flushing pipes in the traditional tools, but in the later implementation process of the applicant, it is found that, because of the need of installing ball seats, force transmission sleeves and connecting sleeves in the outer cylinder, the processing and assembling costs of the tools are relatively increased, the processing precision of each component is also required to be higher, the number of components is too large, the corresponding possible problems also affect the reliability of the tools, and on the other hand, the applicant finds that after the traditional tools throw balls, the conventional tools are directly flushed down the bottom of the well, the flushing direction is opposite to the reverse drainage direction, which is unfavorable for rapidly discharging propping agents in the annular space.

Disclosure of Invention

In view of the above, the utility model provides a multifunctional downhole flushing nipple, which meets the double operation requirements of fracturing and flushing, and solves the problems of complex structure, high production, processing and assembly difficulty, high cost, long flushing time and the like of the existing tool.

The technical scheme is as follows:

the utility model provides a nipple joint is washed in multi-functional pit, includes the barrel and sets up in this barrel sand washing pipe, its key lies in: the upper end and the lower end of the cylinder body are respectively provided with an upper joint and a lower plug which are fixedly connected with the upper joint and the lower plug, a switching cylinder is also arranged in the cylinder body, and the switching cylinder is positioned above the sand washing pipe;

the outer diameter of the switching cylinder is matched with the inner diameter of the cylinder, the top of the sand washing pipe is provided with a connecting part matched with the inner diameter of the cylinder, the side wall of the switching cylinder is provided with a guiding-out window, the inside of the switching cylinder is provided with a ball seat part, the guiding-out window is higher than the ball seat part, the sand washing pipe is provided with a guiding-in window, the inner side wall of the cylinder is provided with a ring groove A, the side wall of the cylinder is provided with a back flushing hole above the ring groove A, and the back flushing hole is obliquely arranged towards the upper end of the cylinder and penetrates through the inner side and the outer side of the cylinder;

in the initial state, the switching cylinder and the sand washing pipe are fixedly connected with the cylinder body through a shearing pin A and a shearing pin B respectively, the shearing force of the shearing pin B is larger than that of the shearing pin A, and the position of the leading-out window is higher than that of the back flushing hole;

when the shear pin A is damaged, the switching cylinder descends, so that the leading-out window is opposite to the back flushing hole, and a back flushing flow channel is established;

when the lower end of the switching cylinder is propped against the sand washing pipe and the shearing pin B is damaged, the switching cylinder pushes the sand washing pipe part to the outside of the lower plug, the leading-in window and the leading-out window are simultaneously positioned in the height range of the annular groove A, and a sand washing bypass flow passage is established.

According to the scheme, in the fracturing process, the fracturing process can be completed through the middle runner, when the well flushing is needed, after the steel ball is thrown into, the shearing pin A is damaged by utilizing fluid pressure, the switching cylinder moves downwards to prop against the upper end of the sand flushing pipe, the control pressure is smaller than the shearing force of the shearing pin B, the leading-out window is opposite to the back flushing hole, the well flushing liquid enters the annular space in an obliquely upward direction through the back flushing hole to flush, the fracturing liquid in the annular space can be quickly brought out of the ground, after the well flushing liquid is basically discharged according to the ground back flushing condition, the pressure is increased to damage the shearing pin B, the switching cylinder and the sand flushing pipe synchronously descend, the sand flushing pipe is exposed to the outside of the lower plug, and a bypass runner is established by utilizing the leading-out window, the annular groove A and the leading-in window, so that bottom sand flushing is carried out, and at the moment, fracturing residual material liquid at the bottom of the well is more easily carried and discharged, compared with the traditional structure, the whole parts are fewer, the production processing difficulty and the cost are reduced, the whole service life is prolonged, the well flushing efficiency is improved, and the flushing operation time is shortened.

As preferable: the inner side wall of the cylinder body is provided with a ring groove B corresponding to the back flushing hole. By adopting the scheme, even if the back flushing hole is not right opposite to the leading-out window, the back flushing can be normally performed through the annular groove, and flushing dead zones are reduced or avoided.

As preferable: the sand washing pipe is provided with a limiting part protruding outwards along the radial direction of the sand washing pipe, the limiting part is positioned below the guide-in window, and when the sand washing pipe slides downwards to the lowest position, the limiting part is propped against the lower end of the annular groove A or/and the inner end of the lower plug. By adopting the scheme, the axial stability of the sand washing pipe in the sand washing process can be ensured, and the sand washing pipe is prevented from falling off.

As preferable: in the initial state, the sand washing pipe is at least partially positioned in the lower plug, guide keys which are axially arranged in parallel are arranged on the inner side wall of the lower plug, and guide grooves matched with the guide keys are formed in the sand washing pipe. By adopting the scheme, the circumferential stability of the sand washing pipe in the sand washing process can be better ensured, the rotation is prevented, and the sand washing operation towards the fixed direction can be ensured.

As preferable: sealing rings A are respectively sleeved on the upper side and the lower side of the guide-out window on the outer side wall of the switching cylinder. By adopting the scheme, the central runner fluid is prevented from penetrating into the gap between the switching cylinder and the cylinder body through the leading-out window in the fracturing process, and the fracturing pressure is prevented from being influenced.

As preferable: when the sand washing pipe slides downwards to the lowest position, the sealing ring A positioned above the guiding-out window is positioned above the annular groove A. By adopting the scheme, the upper part of the bypass flow passage is mainly sealed to a certain extent, and the fluid in the annular groove A is prevented from being dispersed upwards.

As preferable: the limiting part is annular, and a sealing ring B is embedded at the bottom or/and the outer side of the circumference of the limiting part. By adopting the sealing scheme, the fluid in the annular groove A can be prevented from entering a gap between the sand washing pipe and the lower plug, and the sand washing pressure is prevented from being influenced.

As preferable: the inner end of the lower plug is flush with the lower end of the annular groove A. By adopting the scheme, the sealing effect and the supporting stability can be further improved.

As preferable: the outer end of the lower plug is horn-shaped.

As preferable: the flow area of the export window is larger than or equal to the flow area of the import window. By adopting the scheme, the sand washing pressure can be better ensured, and the sand washing effect is improved.

Compared with the prior art, the utility model has the beneficial effects that:

the multifunctional downhole flushing nipple provided by the utility model adopts fewer parts to form the central runner, the back flushing runner and the bypass runner before and after ball throwing, so that the requirements of fracturing and sand flushing are met, the parts are reduced, the reliability is increased, the difficulty in processing and assembling and the production cost are reduced, the well flushing efficiency can be greatly improved through the back flushing runner, and the well flushing time is shortened.

Drawings

FIG. 1 is a schematic diagram of the structure of the present utility model;

FIG. 2 is an exploded view of the present utility model;

FIG. 3 is a cross-sectional view of a cartridge;

FIG. 4 is a cross-sectional view of a switch barrel;

FIG. 5 is a schematic view of a sand washing pipe structure;

FIG. 6 is a cross-sectional view of FIG. 5;

FIG. 7 is a schematic view of shear pin A being broken to form a back flush flow path;

FIG. 8 is a schematic view of shear pin B being broken to form a sand washing bypass flow passage;

fig. 9 is a schematic view of another embodiment of the stopper.

Detailed Description

The present utility model will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1 to 9, the multifunctional downhole flushing nipple mainly comprises a barrel 1 with a hollow revolution structure and a sand flushing pipe 2 positioned in the barrel 1, wherein the upper end and the lower end of the barrel 1 are respectively provided with an upper joint 10 and a lower plug 11 fixedly connected with the barrel 1, specifically, the upper end and the lower end of the barrel 1 are both provided with internal threads, the upper joint 10 and the lower plug 11 are connected with the barrel 1 through threaded fit, wherein the outer end of the upper joint 10 is provided with internal threads and mainly used for being connected with an upper drilling tool, and the outer end of the lower plug 11 is in a horn shape so as to facilitate fluid outflow and sand flushing pipe extension.

The outer diameter of the switching cylinder 3 is matched with the inner diameter of the cylinder body 1, the top of the sand washing pipe 2 is provided with a connecting part 24 matched with the inner diameter of the cylinder body 1, the side wall of the switching cylinder 3 is provided with a guiding-out window 30, the inside of the switching cylinder 3 is provided with a ball seat part 32, the ball seat part 32 is approximately conical and mainly used for receiving input steel balls and forming a seal on the lower end of the switching cylinder 3, the guiding-out window 30 is higher than the ball seat part 32, the sand washing pipe 2 is provided with a guiding-in window 20, the inner side wall of the cylinder body 1 is provided with a ring groove A12, the side wall of the cylinder body 1 is provided with a back flushing hole 16 above the ring groove A12, and the back flushing hole 16 is obliquely arranged towards the upper end of the cylinder body 1 and penetrates through the inner side and the outer side of the cylinder body 1.

In the initial state, the switching cylinder 3 is fixedly connected with the cylinder 1 through the shearing pin A13, the sand washing pipe 2 is fixedly connected with the cylinder 1 through the shearing pin B15, the shearing pin B15 corresponds to the position of the connecting part 24, at least two shearing pins A13 and B15 are uniformly distributed along the circumferential direction of the cylinder 1, the shearing force of the shearing pin B15 is larger than that of the shearing pin A13, in other words, the ball throwing impact force is F1, the F1 can damage the shearing pin A13, but when the steel ball drives the switching cylinder 3 to fall down to be in contact with the sand washing pipe 2, the impact force is F2, the F2 is insufficient to damage the shearing pin B15, and at the moment, the shearing pin B15 can be damaged only by holding down the well mouth or throwing the steel ball again by means of fluid.

In the initial state, the position of the leading-out window 30 is higher than that of the back flushing hole 16, when the shearing pin A13 is damaged, the switching cylinder 3 descends, when the leading-out window 30 is opposite to the back flushing hole 16, a back flushing flow channel is established, and at the moment, well flushing liquid pumped by a wellhead directly enters the annulus through the leading-out window 30 and the back flushing hole 16 and flushes the annulus upwards.

When the lower end of the switching cylinder 3 is propped against the sand washing pipe 2, after the shearing pin B15 is damaged in a mode of pressing or pitching again, the switching cylinder 3 pushes the sand washing pipe 2 to synchronously move downwards, part of the sand washing pipe 2 is exposed out of the lower plug 11, the leading-in window 20 and the leading-out window 30 are simultaneously positioned in the height range of the annular groove A12, a sand washing bypass flow passage is established, and well washing liquid pumped in by a wellhead flows out from the lower end of the sand washing pipe 2 after sequentially passing through the annular groove A12 of the leading-out window 30 and the leading-in window 20, so that the bottom of a well is washed.

The inner side wall of the cylinder 1 is provided with annular grooves B17 corresponding to the back flushing holes 16, the back flushing holes 16 are uniformly distributed along the circumferential direction of the cylinder 1, the annular grooves B17 can ensure that liquid entering the back flushing holes can flow out through the back flushing holes 16, and the lower end of the guide-out window 30 is higher than the upper end of the annular grooves B17 in the initial state.

The sand washing pipe 2 is provided with a limiting part 21 protruding outwards along the radial direction, the limiting part 21 is positioned below the leading-in window 20, and when the sand washing pipe 2 slides downwards to the lowest position (as shown in fig. 8), the limiting part 21 is propped against the lower end of the annular groove A12 or/and the inner end of the lower plug 11, so that the lower limit of the sand washing pipe 2 is realized, and the sand washing pipe is prevented from falling off.

In the initial state, the sand washing pipe 2 is at least partially positioned in the lower plug 11, the inner side wall of the lower plug 11 is provided with guide keys 14 which are axially arranged in parallel, the sand washing pipe 2 is provided with guide grooves 22 matched with the guide keys 14, and the guide grooves 22 extend to the lower end of the sand washing pipe 2 and are positioned at the lower side of the sand washing pipe, so that circumferential limitation of the sand washing pipe 2 is realized, rotation is prevented, and consistency of sand washing directions is ensured.

Sealing rings A31 are respectively sleeved on the upper side and the lower side of the guiding-out window 30 on the outer side wall of the switching cylinder 3, and when the sand washing pipe 2 slides downwards to the lowest position, the sealing rings A31 above the guiding-out window 30 are positioned above the annular grooves A12.

In addition, the limiting portion 21 is annular, and a sealing ring B23 is embedded at the bottom or/and the outer side of the circumference, referring to fig. 9, in this embodiment, the outer diameter of the limiting portion 21 is adapted to the inner diameter of the annular groove a12, and the sealing ring B23 is directly sleeved on the limiting portion 21.

Of course, in order to avoid the strength weakening caused by too small thickness of the lower end wall of the barrel 1, the lower end of the ring groove a12 generally does not extend to the end portion, so as to ensure that the lower end of the barrel 1 has better strength, in this case, the inner end of the lower plug 11 is generally flush with the lower end of the ring groove a12, and at this time, the sealing ring B23 is directly embedded in the lower surface of the limiting portion 21.

In this application, in order to sufficiently secure the sand washing pressure, the flow area of the outlet window 30 is larger than or equal to the flow area of the inlet window 20, and is also larger than or equal to the sum of the flow areas of the backflushing holes 16.

The working principle of the multifunctional downhole flushing nipple shown with reference to fig. 1 to 9 is as follows: in the fracturing operation, as shown in fig. 1, the steel ball 4 is not put into the fracturing operation, the central channel is smooth, and the shearing pin 13 and the shearing pin B are kept in a connected state.

Referring to fig. 7, after the fracturing operation is completed, the steel ball 4 is put into the ball seat 32 in the switching cylinder 3, the shearing pin a13 is destroyed by impact force or liquid pressure, the switching cylinder 3 descends to the lower end of the switching cylinder to be propped against the upper end of the sand washing pipe 2, the annular groove B17 is positioned in the range of the leading-out window 30, the lower part of the central channel is blocked to form a back flushing runner, upper fluid enters the annular groove B17 through the leading-out window 30 and then directly enters the annular space through the back flushing hole 16, and the purpose of quickly reversely discharging annular fracturing fluid is achieved.

According to the requirement, the wellhead is pressed or/and thrown again, the shear pin B15 is sheared by virtue of larger pressure and impact force, the switching cylinder 3 and the sand washing pipe 2 synchronously descend, the sand washing pipe 2 is pushed to the lowest position, the limiting part 21 is propped against the inner end surface of the lower plug 11, at the moment, the leading-out window 30 and the leading-in window 20 are both positioned in the range of the annular groove A12 to form a sand washing bypass flow passage bypassing the steel ball 4, fluid above the steel ball enters the annular groove A12 through the leading-out window 30, and fluid in the annular groove A12 enters the lower part of the sand washing pipe 2 through the leading-in window 20 to form a sand washing flow passage, so that sand washing operation can be performed as shown in fig. 8.

Finally, it should be noted that the above description is only a preferred embodiment of the present utility model, and that many similar changes can be made by those skilled in the art without departing from the spirit and scope of the utility model as defined in the appended claims.

Claims (8)

1. The utility model provides a nipple joint is washed in multi-functional pit, includes barrel (1) and sets up in this barrel (1) sand washing pipe (2), its characterized in that: the upper end and the lower end of the cylinder body (1) are respectively provided with an upper joint (10) and a lower plug (11) which are fixedly connected with the upper joint, a switching cylinder (3) is also arranged in the cylinder body (1), and the switching cylinder (3) is positioned above the sand washing pipe (2);

the outer diameter of the switching cylinder (3) is matched with the inner diameter of the cylinder body (1), a connecting part (24) matched with the inner diameter of the cylinder body (1) is arranged at the top of the sand washing pipe (2), a guiding-out window (30) is arranged on the side wall of the switching cylinder (3), a ball seat part (32) is arranged in the switching cylinder (3), the guiding-out window (30) is higher than the ball seat part (32), a guiding-in window (20) is arranged on the sand washing pipe (2), a ring groove A (12) is arranged on the inner side wall of the cylinder body (1), a back flushing hole (16) is arranged above the ring groove A (12) on the side wall of the cylinder body (1), and the back flushing hole (16) is obliquely arranged towards the upper end of the cylinder body (1) and penetrates through the inner side and the outer side of the cylinder body (1);

in an initial state, the switching cylinder (3) and the sand washing pipe (2) are fixedly connected with the cylinder body (1) through a shearing pin A (13) and a shearing pin B (15) respectively, the shearing force of the shearing pin B (15) is larger than that of the shearing pin A (13), and the position of the guiding-out window (30) is higher than that of the back flushing hole (16);

when the shear pin A (13) is damaged, the switching cylinder (3) descends, so that the leading-out window (30) is opposite to the back flushing hole (16), and a back flushing flow channel is established;

when the lower end of the switching cylinder (3) is propped against the sand washing pipe (2) and the shearing pin B (15) is damaged, the switching cylinder (3) pushes the sand washing pipe (2) to the outside of the lower plug (11), the leading-in window (20) and the leading-out window (30) are simultaneously positioned in the height range of the annular groove A (12), and a sand washing bypass flow passage is established.

2. The multi-functional downhole flushing sub of claim 1, wherein: the inner side wall of the cylinder body (1) is provided with a ring groove B (17) at a position corresponding to the back flushing hole (16).

3. The multi-functional downhole flushing sub of claim 1, wherein: the sand washing pipe (2) is provided with a limiting part (21) protruding outwards along the radial direction of the sand washing pipe, the limiting part (21) is positioned below the guide-in window (20), and when the sand washing pipe (2) slides downwards to the lowest position, the limiting part (21) is propped against the lower end of the annular groove A (12) or/and the inner end of the lower plug (11).

4. A multi-functional downhole flushing sub according to claim 3, wherein: in the initial state, the sand washing pipe (2) is at least partially positioned in the lower plug (11), guide keys (14) which are axially arranged in parallel are arranged on the inner side wall of the lower plug (11), and guide grooves (22) matched with the guide keys (14) are formed in the sand washing pipe (2).

5. The multi-function downhole flushing sub of claim 3 or 4, wherein: sealing rings A (31) are sleeved on the upper side and the lower side of the guide-out window (30) on the outer side wall of the switching cylinder (3).

6. The multi-functional downhole flushing sub of claim 5, wherein: when the sand washing pipe (2) slides downwards to the lowest position, a sealing ring A (31) above the guiding-out window (30) is positioned above the annular groove A (12).

7. The multi-function downhole flushing sub of claim 3 or 4, wherein: the limiting part (21) is annular, and a sealing ring B (23) is embedded at the bottom or/and the outer side of the circumference of the limiting part.

8. The multi-functional downhole flushing sub of claim 1 or 2, wherein: the flow area of the outlet window (30) is greater than or equal to the flow area of the inlet window (20).