A horizontal well sand bailing device

Abstract

The present invention discloses a horizontal well sand bailing device, comprising a rotor assembly installed at the end of a screw drill output shaft, a sand pipe assembly mounted on the rotor assembly, so as to form an annular sand settling space between the sand pipe assembly and the rotor assembly, the horizontal well sand bailing device also comprises a water sand flushing system for injecting water flow pumped out of the screw drill output shaft into the oil casing annulus, entering the annular sand settling space from the front end of the sand pipe assembly, and then discharging into the oil casing annulus from the rear end of the annular sand settling space, a spiral auger is installed at the front end of the rotor assembly, which can mix the accumulated sand in the casing with water and send it into the annular sand settling space, and a one-way sand blocking valve is installed on the sand pipe assembly behind the spiral auger to prevent the accumulated sand in the annular sand settling space from flowing out in the reverse direction. When the horizontal well sand bailing device is in operation, the accumulated sand will not accumulate and clog at the sand inlet of the sand pipe after entering the sand pipe, the accumulated sand moves a long distance in the sand pipe, the sedimentation distribution area is long, the sand pipe has a strong sand carrying capacity, and the sand carrying amount of a single sand bailing operation is large.

Description

Technical Field

[0001] The invention relates to a sand bailing device for bailing sand accumulated in a casing downhole in an oil field, in particular to a horizontal well sand bailing device for bailing sand from a horizontal section casing of an oil well. Background Art

[0002] After a period of oil well exploitation, sand accumulation will occur in the horizontal section casing. When the sand accumulates to a certain extent in the casing, it will not only affect the production, but also increase the risk of equipment damage. Therefore, it is necessary to regularly remove the sand in the horizontal section casing of the oil well. The horizontal well sand removal device in the prior art does not have the ability to rotate. It mostly relies on the horizontal thrust of the sand shovel to make the sand in the casing enter the sand pipe, and then the sand pipe takes the sand out of the oil well. When the sand removal device with this structure is used, the sand will gradually accumulate in the sand pipe after entering the sand pipe. When it accumulates to a certain extent, the sand in the sand pipe will block the sand inlet of the sand pipe, so that the sand in the casing can no longer enter the sand pipe. At this time, the sand shovel will only push the sand in the casing forward, causing the sand to accumulate in the casing, and even completely block the casing. It is necessary to take the sand removal device out of the oil well, remove the sand in the sand pipe, and then put the sand removal device back into the oil well for sand removal. Therefore, the sand carrying capacity of the sand bailing device in the prior art is limited in a single operation, and the accumulated sand in the casing can be bailed out cleanly only after repeated operations, which results in a long construction time and high sand bailing cost. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, a horizontal well sand bailing device is provided. When the horizontal well sand bailing device is in operation, the accumulated sand will not accumulate and clog at the sand inlet of the sand pipe after entering the sand pipe. The accumulated sand moves a long distance in the sand pipe, the sedimentation distribution area is long, the sand pipe has a strong sand carrying capacity, and a large amount of sand can be carried in a single sand bailing operation.

[0004] The technical solution adopted to solve the technical problem: a horizontal well sand bailing device, including a rotor assembly installed at the end of a screw drill output shaft and driven to rotate by the screw drill, a sand pipe assembly is mounted on the rotor assembly and can rotate relative to the rotor assembly in a circumferential direction, thereby forming an annular sand settling space between the sand pipe assembly and the rotor assembly, the horizontal well sand bailing device also includes a water flushing system for injecting water pumped out by the screw drill output shaft into the annular space of the oil casing, entering the annular sand settling space from the front end of the sand pipe assembly, and then discharging the water into the annular space of the oil casing from the rear end of the annular sand settling space, a spiral auger is installed at the front end of the rotor assembly, and can mix the accumulated sand in the casing with water and send it into the annular sand settling space, and a one-way sand blocking valve is installed on the sand pipe assembly behind the spiral auger to prevent the accumulated sand in the annular sand settling space from flowing out in the opposite direction.

[0005] As a further improvement of the present invention: the water sand flushing system includes a water flushing shaft pipe and a rotary water distributor connected to the water outlet of the screw drill output shaft, the rotary water distributor includes a columnar body slidingly sealed with the inner wall of the sand pipe, a water flushing shaft hole connected to the water flushing shaft pipe and a radial water distribution port connected to the water flushing shaft hole are provided in the columnar body, an annular water distribution groove is opened on the outer wall of the columnar body corresponding to the radial water distribution port, a water injection hole is opened on the sand pipe wall corresponding to the annular water distribution groove to allow the water flow in the annular water distribution groove to be injected into the annulus of the oil casing, and an axial guide hole is also provided in the columnar body to conduct the annular sand settling space at both ends of the columnar body.

[0006] As a further improvement of the present invention: a drainage hole is provided on the wall of the sand pipe behind the rotary water distributor to discharge the water in the annular sand settling space into the annulus of the oil casing.

[0007] As a further improvement of the present invention: the one-way sand blocking valve includes a valve body connected to sand pipes at both ends, a rotor shaft hole is provided in the center of the valve body, and a plurality of valve holes connecting the annular sand settling spaces at both ends of the valve body are provided around the rotor shaft hole. An annular one-way sand blocking valve plate is installed in the valve body away from the spiral auger side, which can move axially by gravity and close the valve hole.

[0008] As a further improvement of the present invention: a plurality of sliding rings and / or sliding sleeves for reducing the friction between the rotor assembly and the sand tube assembly are arranged in the sand tube assembly.

[0009] As a further improvement of the present invention: the rotor assembly includes a hollow shaft section connecting the screw drill output shaft and the flushing shaft tube, as well as a plurality of shafts connected to the rotary water distributor and a connecting rod connecting adjacent shafts. The hollow shaft section is connected to the flushing shaft tube by a threaded connection, and a limiting ring protruding from the outer wall of the hollow shaft section is provided on the outer wall of the hollow shaft section.

[0010] As a further improvement of the present invention: the sand pipe assembly comprises a plurality of sand pipes connected end to end in sequence by threads, and a sand shovel for shoveling the accumulated sand in the casing is provided at the front end of the sand pipe in front of the one-way sand blocking valve.

[0011] As a further improvement of the present invention: a stirring blade is provided on at least one shaft in the annular sand settling space to make the sand-water mixture in the annular sand settling space perform a spiral motion.

[0012] Beneficial effects: The horizontal well sand bailing device of the present invention adopts a water sand flushing system and a spiral auger driven to rotate by a screw pump in the horizontal well sand bailing device, so that during operation, the accumulated sand in the casing forms a sand-water mixture under the action of water flow and the spiral auger and enters the annular sand settling space of the sand pipe, and less accumulated sand remains in the casing. Moreover, the accumulated sand moves along the annular sand settling space into the deep of the sand pipe under the drive of water, which can effectively prevent the accumulated sand from accumulating and clogging at the sand inlet of the sand pipe after entering the sand pipe, prolonging the length of the sedimentation distribution area of ​​the accumulated sand in the annular sand settling space, thereby improving the sand carrying capacity of the sand pipe. When the horizontal well sand bailing device is in operation, the sand carrying amount of a single sand bailing operation is large, which can reduce the number of times the sand bailing device is lifted and lowered, shorten the sand bailing operation time, and reduce the sand bailing operation cost. The water sand flushing system includes a water flushing shaft pipe and a rotary water distributor connected to the water outlet of the screw drill output shaft, and an annular water distribution groove is opened on the outer wall of the columnar body, and a water injection hole is opened on the wall of the sand pipe to allow the water flow in the annular water distribution groove to be injected into the oil casing annulus. The columnar body is also provided with an axial guide hole to conduct the annular sand settling space at both ends of the columnar body. Under the condition of normal rotation of the rotor assembly, the water flow output from the screw drill and entering the oil casing annulus and the water flow flowing out of the annular sand settling space and entering the oil casing annulus do not interfere with each other. The technical feature of opening a drainage hole on the wall of the sand pipe behind the rotary water distributor to discharge the water flow entering the annular sand settling space from the front end of the sand pipe to the oil casing annulus allows the water separated from the sand-water mixture to be smoothly discharged into the oil casing annulus, creating conditions for the sand-water mixture to continuously enter the annular sand settling space. Due to the technical features of the one-way sand blocking valve including a valve body connected to the sand pipe at both ends, a rotor shaft hole is provided in the center of the valve body, multiple valve holes are provided around the rotor shaft hole to connect the annular sand settling spaces at both ends of the valve body, and an annular one-way sand blocking valve plate that can close the valve hole by gravity is installed in the valve body away from the spiral auger side. While ensuring that the accumulated sand is sealed in the annular sand settling space when the pipe column is lifted, the one-way sand blocking valve will not interfere with the normal rotation of the rotor assembly. Due to the technical features of multiple slip rings and / or sleeves used to reduce the friction between the rotor assembly and the sand pipe assembly in the sand pipe assembly, not only can the working resistance of the rotor assembly be reduced, but also the eccentric operation of the rotor assembly can be prevented, thereby extending the service life of the equipment.The rotor assembly includes a hollow shaft section connecting the output shaft of the screw drill and the flushing shaft pipe, a plurality of shaft rods connected to the rotary water distributor, and a connecting rod connecting adjacent shaft rods. The hollow shaft section is connected to the flushing shaft pipe by threads, and a limiting ring protruding from the outer wall of the hollow shaft section is provided on the outer wall of the hollow shaft section. The sand pipe assembly includes a plurality of sand pipes connected end to end by threads, and a sand shovel for shoveling the accumulated sand in the casing is provided at the front end of the sand pipe in front of the one-way sand blocking valve. The technical features make it possible to conveniently determine the number of sections of the sand pipe and the shaft rod according to the length of the horizontal section casing and the sand accumulation situation, and conveniently assemble them into a horizontal well sand bailing tool of appropriate length, thereby making the length adjustment of the horizontal well sand bailing device of the present invention more convenient and more versatile. Due to the technical feature that at least one shaft in the annular sand settling space is provided with a stirring blade that causes the sand-water mixture in the annular sand settling space to perform a spiral motion, it can effectively prevent the accumulated sand from settling prematurely in the annular sand settling space, and make the accumulated sand settle evenly in the annular sand settling space, further improving the sand carrying capacity of the sand pipe and making the effective distance of a single sand dredging operation longer. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The horizontal well sand bailing device of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0014] Figure 1 It is an axial cross-sectional structural diagram of a horizontal well sand bailing device of the present invention;

[0015] Figure 2 It is an axial cross-sectional structural diagram of a rotor assembly in a horizontal well sand bailing device of the present invention;

[0016] Figure 3 It is an axial cross-sectional structural diagram of a sand pipe assembly in a horizontal well sand bailing device of the present invention. DETAILED DESCRIPTION

[0017] like Figure 1 , Figure 2 , Figure 3 As shown, the horizontal well sand bailing device of the present invention includes a rotor assembly 4 installed at the end of the output shaft of the screw drill 1 and driven to rotate by the screw drill, and a sand pipe assembly 2 is mounted on the rotor assembly and can rotate relative to the rotor assembly in a circumferential direction, so as to form an annular sand settling space 3 between the sand pipe assembly and the rotor assembly. The horizontal well sand bailing device also includes a water flushing system for injecting water pumped out by the output shaft of the screw drill into the annular space of the oil casing, entering the annular sand settling space from the front end of the sand pipe, and then discharging the water into the annular space of the oil casing from the rear end of the annular sand settling space. A spiral auger 20 is installed at the front end of the rotor assembly, which can mix and stir the accumulated sand in the well with water and then send it into the annular sand settling space, and a one-way sand blocking valve is installed on the sand pipe assembly behind the spiral auger to prevent the accumulated sand in the annular sand settling space from flowing out in the opposite direction.

[0018] The water sand flushing system includes a water flushing shaft pipe 9 connected to the water outlet of the screw drill output shaft 5 and a rotary water distributor. The rotary water distributor includes a columnar body 14 that is slidably sealed with the inner wall of the sand pipe 13. A water flushing shaft hole 12 connected to the water flushing shaft pipe and a plurality of radial water distribution ports 16 connected to the water flushing shaft hole are provided in the columnar body. An annular water distribution groove 15 is opened on the outer wall of the columnar body corresponding to the radial water distribution ports. A plurality of water injection holes 23 are opened on the wall of the sand pipe corresponding to the annular water distribution groove so that the water flow in the annular water distribution groove is injected into the annular space of the oil casing. A plurality of axial guide holes 11 are also provided in the columnar body so that the annular sand settling spaces at both ends of the columnar body are conducted. A plurality of drainage holes 21 are opened on the wall of the sand pipe 22 behind the rotary water distributor so that the water flow entering the annular sand settling space from the front end of the sand pipe is discharged into the annular space of the oil casing.

[0019] The one-way sand blocking valve comprises a valve body 26 with both ends being threadedly connected to the sand pipe, a rotor shaft hole 29 being provided at the center of the valve body, a plurality of valve holes 28 being parallel to the rotor shaft hole and connected to the annular sand settling spaces at both ends of the valve body being provided around the rotor shaft hole, and an annular one-way sand blocking valve plate 25 being installed in the valve body away from the spiral auger side and being able to move axially by gravity to close the valve hole.

[0020] like Figure 2 As shown, the rotor assembly includes a hollow shaft section 7 connecting the output shaft of the screw drill and the flushing shaft pipe, a plurality of shafts 17 connected to the rotary water distributor, and a connecting rod 18 connecting adjacent shafts. The hollow shaft section is connected to the flushing shaft pipe by threads, and a limiting ring 10 protruding from the outer wall of the hollow shaft section is provided on the outer wall of the hollow shaft section. A stirring blade 19 is provided on at least one shaft in the annular sand settling space to make the sand and water mixture in the annular sand settling space perform a spiral motion.

[0021] Preferably, a sand drilling cone tip 31 is provided at the front end of the rotor assembly, and the sand drilling cone tip protrudes from the front end of the sand pipe assembly. When the horizontal well sand bailing device with such a structure encounters a casing that is completely blocked by sand accumulation, the sand drilling cone tip can break up and disintegrate the compacted sand accumulation with a relatively small torque, so that the disintegrated sand accumulation can flow with the water flow, thereby improving the ability of the horizontal well sand bailing device to handle the casing that is completely blocked by sand accumulation.

[0022] like Figure 3As shown, the sand pipe assembly includes a plurality of sand pipes with male joints at both ends and sand pipes with female joints at both ends. Each sand pipe is connected in sequence by threads end to end to form a sand pipe assembly. A sand shovel 30 for shoveling the accumulated sand in the casing is provided at the front end of the sand pipe in front of the one-way sand blocking valve. An end cap 6 and a stepped connecting short pipe 8 matching with the limit ring are installed on the sand pipe near the screw drill, so that the rotor assembly can only rotate relative to the rotor assembly in the circumferential direction but cannot move in the axial direction. A plurality of sliding rings 24 and / or sliding sleeves 27 are provided in the sand pipe assembly to reduce the friction between the rotor assembly and the sand pipe assembly. Preferably, the sand pipe constituting the sand pipe assembly includes at least two sections of lifting sand pipes with lifting annular grooves 32 contracted inwardly on the outer wall. When lifting the pipe column, the sand pipe is lifted by clamping it at the lifting annular groove by a special tool, which can effectively reduce the load on the screw drill and prevent the screw drill from being damaged during the lifting process.

[0023] When the horizontal well sand bailing device of the present invention is in operation, the screw drill drives the drill assembly to rotate, and at the same time, the sand flushing water is pumped into the hollow shaft section, the water flushing shaft pipe and the rotating water distributor through the output shaft. The sand flushing water is injected into the oil casing annulus through the water injection hole, and reaches the front end of the sand pipe along the oil casing annulus. The accumulated sand in the casing is mixed with the sand flushing water to form a sand-water mixture under the action of the sand shovel and the spiral auger, and then enters the annular sand settling space in the sand pipe through the one-way sand blocking valve, and flows in the annular sand settling space toward the drainage hole of the sand pipe. During the flow process, the stirring blades rotating synchronously with the spiral auger continue to stir the sand-water mixture. Stirring prevents the accumulated sand from settling prematurely during the movement in the annular sand settling space, thereby causing the accumulated sand settling distribution area to move backward, and the accumulated sand is evenly settled in the annular sand settling space. When the accumulated sand in the annular sand settling space reaches the storage upper limit or there is no more accumulated sand in the horizontal casing, the screw drill is turned off, the water supply to the rotary water distributor is stopped, the pipe column is lifted, and the annular one-way sand retaining valve plate closes the valve hole under the action of its own gravity and the impact of water flow to prevent the accumulated sand in the annular sand settling space from reversely entering the casing, until the horizontal well sand bailing device is lifted out of the oil well, the accumulated sand in the sand pipe is cleaned up, and a single sand bailing operation is completed.

Claims

1. A horizontal well sand bailing device, comprising a rotor assembly mounted at the end of a screw drill output shaft and driven to rotate by the screw drill, a sand pipe assembly being mounted on the rotor assembly and being able to rotate relative to the rotor assembly in a circumferential direction, thereby forming an annular sand settling space between the sand pipe assembly and the rotor assembly, the horizontal well sand bailing device also comprising a water sand flushing system for injecting water flow pumped out of the screw drill output shaft into the annular space of the oil casing, entering the annular sand settling space from the front end of the sand pipe assembly, and then being discharged into the annular space of the oil casing from the rear end of the annular sand settling space, a spiral auger being mounted at the front end of the rotor assembly and being able to mix the accumulated sand in the casing with water and send it into the annular sand settling space, a one-way sand blocking valve being mounted on the sand pipe assembly behind the spiral auger to prevent the accumulated sand in the annular sand settling space from flowing out in the reverse direction, and the characteristics are as follows: The water sand flushing system comprises a water flushing shaft pipe connected to the water outlet of the screw drill output shaft and a rotary water distributor, wherein the rotary water distributor comprises a columnar body which is matched with the inner wall of the sand pipe in a sliding seal, a water flushing shaft hole connected to the water flushing shaft pipe and a radial water distribution port connected to the water flushing shaft hole are arranged in the columnar body, an annular water distribution groove is opened on the outer wall of the columnar body corresponding to the radial water distribution port, a water injection hole is opened on the sand pipe wall corresponding to the annular water distribution groove so that the water flow in the annular water distribution groove is injected into the annular space of the oil casing, and a water injection hole is also arranged in the columnar body so that the columnar body can be The annular sand settling space at both ends of the body is connected to the axial guide hole, the rotor assembly includes a hollow shaft section connecting the output shaft of the screw drill and the flushing shaft pipe, and a plurality of shafts connected to the rotary water distributor, and a connecting rod connecting adjacent shafts. The hollow shaft section is connected to the flushing shaft pipe by a threaded connection, and a limiting ring protruding from the outer wall of the hollow shaft section is provided on the outer wall of the hollow shaft section. At least one shaft in the annular sand settling space is provided with a stirring blade that causes the sand-water mixture in the annular sand settling space to perform a spiral motion.

2. The horizontal well sand bailing device according to claim 1 is characterized in that: A drainage hole is provided on the wall of the sand pipe behind the rotary water distributor to discharge the water in the annular sand settling space into the annulus of the oil casing.

3. The horizontal well sand bailing device according to claim 1 or 2, characterized in that: The one-way sand blocking valve comprises a valve body connected to sand pipes at both ends, a rotor shaft hole is arranged at the center of the valve body, a plurality of valve holes communicating with annular sand settling spaces at both ends of the valve body are arranged around the rotor shaft hole, and an annular one-way sand blocking valve plate which can move axially by gravity and close the valve hole is installed in the valve body away from the spiral auger side.

4. The horizontal well sand bailing device according to claim 3 is characterized in that: A plurality of slip rings and / or sliding sleeves are arranged in the sand tube assembly for reducing the friction between the rotor assembly and the sand tube assembly.

5. The horizontal well sand bailing device according to claim 4 is characterized in that: The sand pipe assembly comprises a plurality of sand pipes which are connected end to end in sequence through threads. A sand shovel for shoveling the accumulated sand in the casing is arranged at the front end of the sand pipe in front of the one-way sand blocking valve.

Images