Disclosure of Invention
The invention aims to provide a coiled tubing fracturing packer which does not need ball-throwing setting, and realizes the setting of the packer by sliding a sealing assembly through rail replacement sliding of a rail pin in an L-shaped track groove.
The above object of the present invention can be achieved by the following technical solutions:
a coiled tubing fracture packer, the packer comprising: the central tube is provided with an L-shaped track groove, and the lower end of the central tube is connected with a lower joint; the backwashing valve assembly is connected to the upper end of the central pipe, the upper end of the backwashing valve assembly is connected with the upper connector, the backwashing valve assembly comprises a backwashing valve seat and a valve body, the backwashing valve seat is sleeved outside the valve body, a shear pin is connected between the backwashing valve seat and the valve body, a backwashing channel is arranged on the backwashing valve seat, the backwashing channel is blocked by the valve body when the shear pin is not sheared, and the valve body moves upwards to leave the backwashing channel when the shear pin is sheared; and the sealing assembly is sleeved outside the central pipe, an interlayer flow channel is arranged between the sealing assembly and the central pipe, the sealing assembly is movably connected with or far away from the backwashing valve assembly, a track pin is arranged on the sealing assembly, and the track pin can change tracks and slide in the L-shaped track groove along with the movement of the sealing assembly.
The coiled tubing fracturing packer comprises a coiled tubing fracturing packer, wherein the backwashing valve assembly further comprises a sealing rubber piece and a pressing cap, the sealing rubber piece is sleeved outside the central pipe in a sealing mode and connected to the lower end of the backwashing valve seat, an annular supporting portion is arranged on the lower portion of the pressing cap and connected to the lower portion of the sealing rubber piece, and the upper portion of the pressing cap is in threaded connection with the backwashing valve seat.
The coiled tubing frac packer as described above, said L-shaped track groove comprising: the long groove is arranged along the direction parallel to the axis of the central tube, and the upper end of the long groove is a long groove top dead center; the short hook groove is provided with a short groove and a hook groove, the hook groove is communicated with the long groove through the short groove, the short groove is arranged along the direction inclined to the axis of the central pipe, the hook groove is arranged along the direction parallel to the axis of the central pipe, the upper end of the hook groove is a short hook groove top dead center, the lower end of the short groove is a short hook groove bottom dead center, and the long groove top dead center is located above the short hook groove top dead center.
The packer for fracturing the continuous oil pipe comprises a lining sleeve, a rubber cylinder group, a leather cup seat and a centering leather cup, wherein the lining sleeve is sleeved outside a central pipe, the top of the lining sleeve is connected to a sealing assembly to seal an interlayer flow passage under the condition that the sealing assembly is connected with a backwashing valve assembly, and a lining convex block is arranged at the upper end of the lining sleeve; the rubber cylinder group, the rubber cup seat and the righting rubber cup are all sleeved on the outer portion of the bushing, the rubber cylinder group is connected between the bushing convex block and the rubber cup seat, the righting rubber cup is connected to the lower end of the rubber cup seat, and the rail pin is fixed to the bushing.
According to the coiled tubing fracturing packer, the top of the bushing is provided with the ejector block which can be used for ejecting the sealing assembly, and the bushing convex block is located below the ejector block.
According to the coiled tubing fracturing packer, the rubber sleeve group is provided with a plurality of rubber sleeves, and a spacer ring is connected between every two adjacent rubber sleeves.
According to the coiled tubing fracturing packer, the bottom end of the bushing is provided with the claw spring.
The fracturing packer of the embodiment of the invention has the characteristics and advantages that: the central pipe is provided with an L-shaped track groove, the sealing assembly and the central pipe are provided with interlayer flow passages, so that the packer can be smoothly put into a design position in the well, the seat seal does not need to throw balls during fracturing construction, normal fracturing construction can be carried out only by lifting the pipe column, a backwashing valve is adopted during backwashing, the sealing assembly is downwards supported and opened by a double-safety design, and the possibility of sand blocking of the pipe column is extremely low.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The up and down positions described herein are for the use of the frac packer after it has been run downhole, specifically the frac packer has an up joint position and a down joint position.
As shown in fig. 1, when the fracturing packer a is used, a hydraulic anchor B and a coiled tubing C are sequentially connected above the fracturing packer a, the hydraulic anchor B and the coiled tubing C are referred to as a tubular column, and a casing D is arranged outside the tubular column.
As shown in fig. 2 to 4, the coiled tubing fracture packer provided by the embodiment of the invention comprises a central pipe 1, a backwash valve assembly 2 and a sealing assembly 3. The L-shaped track groove 1a is formed in the central tube 1, and the lower end of the central tube 1 is connected with the lower connector 4. The backwash valve assembly 2 is connected to the upper end of the central pipe 1, and the upper end of the backwash valve assembly 2 is connected with the upper connector 5. The sealing assembly 3 is sleeved outside the central pipe 1, an interlayer flow channel 6 is arranged between the sealing assembly 3 and the central pipe 1, the sealing assembly 3 is movably connected with or far away from the backwashing valve assembly 2, a track pin 7 is arranged on the sealing assembly 3, and the track pin 7 can slide in the L-shaped track groove 1a in a rail changing manner along with the movement of the sealing assembly 3.
In the embodiment of the invention, the interlayer flow channel 6 is arranged between the sealing assembly 3 and the central pipe 1, so that the fracturing packer can be smoothly and underground arranged at a designed position underground, and the L-shaped track groove 1a on the central pipe 1 can be used for rail replacement sliding of the track pin 7 so as to perform setting and unsetting according to the requirement of fracturing construction. That is, the embodiment of the present invention does not need to perform ball setting, and the central pipe 1 can force the seal assembly 3 to slide through the track pin 7 to perform setting of the packer, so that the coiled tubing fracture packer can be used in a complex trajectory well. In addition, the packer of the embodiment of the invention is also provided with a backwashing valve assembly 2, so that backwashing construction is easy to carry out in a complex trace well.
The backwash valve assembly 2 comprises a backwash valve seat 2a and a valve body 2b, the backwash valve seat 2a is sleeved outside the valve body 2b, a shear pin 2c is connected between the backwash valve seat 2a and the valve body 2b, a backwash channel 2d is arranged on the backwash valve seat 2a, when the shear pin 2c is not sheared, the backwash channel 2d is blocked by the valve body 2b, and when the shear pin 2c is sheared, the valve body 2b moves upwards to leave the backwash channel 2 d.
Wherein, the backwashing channel 2d can be provided with a plurality of channels which are evenly distributed on the backwashing valve seat 2a along the circumferential direction.
In this embodiment, when the backwashing operation is performed, there are two passages. The first is a backwashing channel 2D, namely, when the coiled tubing C is reversely pressurized, the shear pin 2C is sheared by pressure, the valve body 2b moves upwards, so that the backwashing channel 2D is opened, and the sleeve D and the packer flow channel are opened. The second is an interlayer runner 6, namely, the pressure reversely pushes the sealing assembly 3 to descend during backwashing, the interlayer runner 6 is opened, and fluid returns to the root of the packer through the interlayer runner 6 and then returns to the ground along the continuous oil pipe C to realize the sand backwashing function.
Further, the backwash valve assembly 2 further comprises a sealing rubber member 2e and a pressing cap 2f, the sealing rubber member 2e is hermetically sleeved outside the central pipe 1 and connected to the lower end of the backwash valve seat 2a, the lower portion of the pressing cap 2f is provided with an annular support portion 2g, the annular support portion 2g is connected below the sealing rubber member 2e, and the upper portion of the pressing cap 2f is in threaded connection with the backwash valve seat 2 a.
In this embodiment, the sealant 2e is fixedly connected to the lower end of the backwash valve assembly 2 by the pressing cap 2f, the lower portion of the pressing cap 2f is an annular support portion 2g, and the annular support portion 2g supports the sealant 2e, so that the part of the sealant 2e is exposed to facilitate the upward movement of the seal assembly 3, and can be connected with the sealant 2e, thereby better sealing the interlayer flow channel 6.
As an embodiment of the present invention, as shown in fig. 2 and 2B, fig. 3 and 3A, and fig. 4, the L-shaped track groove 1a includes a long groove 1B and a short hook groove. The long groove 1b is arranged along the direction parallel to the axis of the central tube 1, and the upper end of the long groove 1b is a long groove top dead center 1 c. The short hook groove is provided with a short groove 1d and a hook groove 1e, the hook groove 1e is communicated with the long groove 1b through the short groove 1d, the short groove 1d is arranged along the direction inclined to the axis of the central tube 1, namely, an included angle is formed between the short groove 1d and the axis of the central tube 1, the hook groove 1e is arranged along the direction parallel to the axis of the central tube 1, the upper end of the hook groove 1e is a short hook groove top dead center 1f, the lower end of the short groove 1d is a short hook groove bottom dead center 1g, and the long groove top dead center 1c is positioned above the short hook groove top dead center 1 f.
The L-shaped track groove 1a can be arranged in a circle on the outer surface of the central tube 1, so that the track pin 7 can conveniently slide in the L-shaped track groove 1a in a track changing manner.
As an embodiment of the present invention, the sealing assembly 3 includes a bushing 3a, a rubber cylinder set, a cup holder 3b and a centering cup 3 c. The bushing 3a is sleeved outside the central tube 1, when the sealing assembly 3 is connected with the backwash valve assembly 1, the top of the bushing 3a is connected to the sealing assembly 3 to close the interlayer flow channel 6, and the upper end of the bushing 3a is provided with a bushing convex block 3 d. The rubber cylinder group, leather cup seat 3b and the rubber cup 3c of righting all establish the outside of bush 3a, and rubber cylinder group link is between bush lug 3d and leather cup seat 3b, and the lower extreme at leather cup seat 3b is connected to the leather cup 3c of righting, track pin 7 is fixed on the bush 3 a.
The top of the bushing 3a may be provided with a top block 3e for supporting the sealing assembly 3, and the bushing protrusion 3d is located below the top block 3 e. Further, the top block 3e can be directly abutted on the sealant 2e, so that the interlayer flow channel 6 can be better closed.
The rubber cylinder group can be provided with a plurality of rubber cylinders 3f, and a spacing ring 3g is connected between two adjacent rubber cylinders 3 f. Here, there are two glue cartridges 3f and one spacer ring 3 g.
The bottom end of the bushing 3a may be provided with a pawl spring 3 h. Specifically, the connecting member 3i such as a press cap holds the pawl spring 3h and is connected to the centering cup 3c, thereby positioning the pawl spring 3h and the centering cup 3c better.
In addition, as shown in fig. 2A, the two sides of the center tube 1 are symmetrically cut off to form a flat surface, so that the cut-off portion of the center tube 1 forms the sandwich flow channel 6 when the center tube 1 is fitted with the seal assembly 3. Of course, in addition, the inner side of the bushing 3a of the sealing assembly 3 can be cut out, so that the bushing 3a and the central tube 1 can cooperate to form a sandwich flow channel.
When the packer provided by the embodiment of the invention is used, three processes of setting, unsetting and backwashing are carried out.
The method comprises the following steps of putting a pipe column into a well to a designed position, namely before setting, positioning the track pin 7 at the top dead center 1f of a short hook groove (shown in figure 2B), and then setting the packer, wherein specifically, the pipe column is lifted up firstly, because the righting leather cup 3c of the sealing assembly 3 is in interference fit with a casing D, when the pipe column is lifted up, under the action of friction force between the righting leather cup 3c and the casing D, the track pin 7 enters the bottom dead center 1g of the short hook groove from the top dead center 1f of the L-shaped track groove 1a of the central pipe 1 (shown in figure 4), then the pipe column is lowered, and the track pin 7 enters the top dead center 1c of the long groove 1B (shown in figure 3A), so that setting is completed.
After the well mouth is connected to the tubular column, the pressure is positively pressed from the interior of the continuous oil pipe C, the pressure acts on the righting leather cup 3C, the sealing assembly 3 is pushed to go upwards and is butted with the sealing rubber piece 2e in the backwashing valve assembly 2, the interlayer flow channel 6 is sealed, the pressure is continuously pressed, the righting leather cup 3C is pushed by the pressure to extrude the rubber barrel 3f, the rubber barrel 3f is sealed in an expanding manner, at the moment, the hydraulic anchor B is anchored under the action of the internal pressure, the tubular column creep is prevented, and then normal fracturing construction can be carried out. And when the fracturing construction is finished, the rubber cylinder 3f of the sealing assembly 3 is recovered and deblocked after pressure relief.
The backwash process is described above and will not be described in detail.
The above description is only a few embodiments of the present invention, and those skilled in the art can make various changes or modifications to the embodiments of the present invention according to the disclosure of the application document without departing from the spirit and scope of the present invention.