CN107816336B - Sand prevention tool for filling thermal production well - Google Patents

Abstract

The invention discloses a thermal well filling and sand prevention tool, comprising a central tube, an outer flow cavity, a sealing sleeve, a slip mechanism, a leather cup, and a conversion mechanism. The outer flow cavity is sleeved on the outer side of the central tube, the outer wall of the outer flow cavity is sleeved with a slip mechanism, the outer side of the upper end of the slip mechanism is sleeved with a sealing sleeve, the outer side of the lower end of the slip mechanism is sleeved with a leather cup, the central tube and the lower end of the outer flow cavity are simultaneously connected to the conversion mechanism; when filling and sand prevention, the sealing sleeve is a rubber seal, and when subsequent steam injection is performed, the sealing sleeve is a lead seal. The invention has the characteristics of safety, environmental protection, simple construction, high pressure resistance, high temperature resistance, etc., and is an ideal tool for thermal well filling and sand prevention.

Description

Sand prevention tool for filling thermal production well

Technical Field

The invention relates to a tool for thick oil exploitation, in particular to a filling sand prevention tool for a thermal production well.

Background

At present, the domestic heavy oil exploitation proportion is about one fourth of the whole crude oil exploitation, and the exploitation trend is that the heavy oil exploitation is increased year by year, the heavy oil well exploitation requires sand prevention to be matched and adapted, so that the heavy oil well can resist the high temperature of about 360 ℃ after sand prevention, and more rounds of steam injection exploitation are maintained. The prior high-temperature sealing elements mostly adopt improved polytetrafluoroethylene or lead sealing, the temperature resistance of the sealing elements does not meet the requirement, the sealing elements are easy to break during filling, the function of filling sand prevention construction cannot be realized, and the problem of how to solve the problems of not only effectively gravel filling sand prevention, but also ensuring the high-temperature sealing effect is solved.

Through searching, application number is 200520087041.5, and patent application date is 2005-09-07 discloses a thermal recovery sand prevention filling tool, which comprises an extrusion conversion device, a suspension release device and a filling sealing device, wherein the extrusion conversion device comprises a conversion joint, a central pipe, a main body outer pipe, a conversion inner pipe, a conversion assembly, a reducer union, a check valve ball, a sealing sleeve, a locking plate, a baffle ring, a flushing pipe nipple and a lengthening sleeve, the suspension release device comprises a piston, a shear pin and a locking block, the filling sealing device comprises a pressure cap, a sealing cup and a spacer sleeve, and the filling sealing device further comprises a lead sealing device arranged between the filling sealing device and the extrusion conversion device, and the lead sealing device comprises a pressure transmitting joint, a locking sleeve, a steel ball, a lead sealing, a suspension sleeve, a suspension nipple and a pressure bearing joint which are connected and arranged in sequence. The utility model has the characteristics of few construction procedures, capability of completing the thermal recovery sand prevention by only one pipe column, tight closing of the filling hole, no error opening and the like, and is widely applied to the thermal recovery filling sand prevention process of petroleum exploitation.

The prior art is a standard technology which only adopts lead sealing for sealing, is easy to break during filling and can not realize the filling sand prevention construction function, and is different from the specific technical scheme of the invention.

Disclosure of Invention

The invention aims to provide a filling sand prevention tool for a thermal production well, which has the characteristics of safety, environment friendliness, simplicity in construction, high pressure resistance, high temperature resistance and the like, and is an ideal filling sand prevention tool for the thermal production well.

The invention adopts the following technical scheme that the thermal production well filling sand prevention tool comprises a central pipe, an overflow outer cavity, a sealing sleeve, a slip mechanism, a leather cup and a conversion mechanism, wherein the overflow outer cavity is sleeved outside the central pipe, the slip mechanism is sleeved on the outer wall of the overflow outer cavity, the sealing sleeve is sleeved on the outer side of the upper end of the slip mechanism, the leather cup is sleeved on the outer side of the lower end of the slip mechanism, the central pipe and the lower end of the overflow outer cavity are simultaneously connected with the conversion mechanism, when sand prevention is filled, the sealing sleeve is a rubber sealing piece, and when steam is subsequently injected, the sealing sleeve is a lead sealing piece.

The slip mechanism comprises an upper cone, a slip sleeve, slips and a lower cone, wherein the slips are positioned between the upper cone and the lower cone, and the slip sleeve is arranged at two ends of the slips and sleeved on the upper cone and the lower cone.

The sealing sleeve is sleeved on the outer wall of the upper cone, the upper end of the sealing sleeve is connected with a locking ring sleeve, the upper end of the locking ring sleeve is connected with an upper pressing ring, a locking ring is arranged between the upper pressing ring and the locking ring sleeve, the locking ring is connected with an overflow outer cavity in a threaded manner, the upper end of the central tube is connected with an upper joint, a piston cavity is formed between the locking ring and the upper joint, a piston is arranged in the piston cavity, the piston cavity is divided into an inner cavity and an outer cavity by the piston, through holes for communicating the inner cavity and the outer cavity are formed in the piston, the inner wall and the outer wall of the upper end of the piston are respectively sealed with the central tube and the upper joint, the piston cavity above the upper end of the piston is divided into an upper cavity, the central tube is provided with through holes for communicating the upper cavity, the overflow outer cavity is communicated with the inner cavity, the lower end of the piston is abutted to the upper pressing ring, and the locking ring sleeve is connected with the upper cone through pins.

The leather cup is sleeved on the outer wall of the lower cone, the upper end of the leather cup is provided with a leather cup support, the upper end of the leather cup support is simultaneously connected with an adjusting ring and an unsealing sleeve, and the unsealing sleeve is connected with the lower cone through a pin.

The switching mechanism comprises a switching body, an inner piston, a closing sleeve, a connector, a connecting cavity and an overcurrent cavity, wherein the lower end of the overcurrent outer cavity is connected with the switching body through a connecting sleeve, the lower end of the switching body is connected with the connecting cavity, the lower end of the connecting cavity is connected with a lower joint, the lower end of the inner part of the lower joint is connected with an inner pipe joint, the upper end of the inner pipe joint is connected with the overcurrent cavity, the upper end of the overcurrent cavity is connected with a central pipe, the inner wall of the lower end of the central pipe is provided with the inner piston, the closing sleeve is arranged between the switching body and the central pipe, the lower end of the closing sleeve is connected with the connector, the connector is connected onto the central pipe, the inner piston is connected onto the connector through a pin, the lower end of the overcurrent outer cavity is communicated with the upper end of the switching body, an inner conical surface is formed in the inner wall of the upper end of the inner piston, the inner wall of the inner pipe joint is also provided with an inner conical surface, and the inner conical surface is also formed by a steel ball.

The inner piston temporarily seals the radial through holes of the central tube, the inner part of the overflow cavity is communicated to the inner cavity of the central tube, the outer part of the overflow cavity is communicated to the inner part of the connecting cavity, and the closing sleeve temporarily seals between the connecting cavity and the inner cavity of the conversion body.

Compared with the prior art, the invention has the following beneficial effects:

The tool adopts a combined sealing structure, when sand prevention is carried out in filling, a conventional rubber material is adopted as a sealing element, the sealing element can ensure the tightness under high filling pressure, the construction effect can be ensured, and when steam is subsequently injected, a lead seal is adopted as the sealing element, and the lead seal has higher pressure resistance under static state and can ensure the effect under high temperature. The invention has the characteristics of safety, environmental protection, simple construction, high pressure resistance, high temperature resistance and the like, is an ideal tool for filling sand prevention of a thermal production well, and has high popularization and application value and strong applicability.

Drawings

FIG. 1 is a schematic diagram of a thermal production well packing sand control tool of the present invention.

The device comprises a 1-upper joint, 2,3, 13, 27, 28, 29, 35 and 36-sealing rings, 11-sealing sleeves, 4-central pipes, 5-pistons, 6-upper compression rings, 7-locking rings, 8-locking ring sleeves, 9-overflowing outer cavities, 10, 17, 31-pins, 12-upper cones, 14-slip sleeves, 15-slips, 16-lower cones, 18-deblocking sleeves, 19-adjusting rings, 20-cup holders, 21-cup holders, 22-cup holders, 23-top sleeves, 24-connecting sleeves, 25-conversion bodies, 26-inner pistons, 30-closing sleeves, 32-connecting heads, 33-connecting cavities, 34-overflowing cavities, 37-lower joints, 38-inner pipe joints and 39-steel balls.

Detailed Description

The detailed description and technical content of the present invention are described below with reference to the accompanying drawings, which are provided for reference and description only, and are not intended to limit the present invention.

According to fig. 1, the filling sand prevention tool for the thermal production well comprises a central tube 4, an overflow outer cavity 9, a sealing sleeve 11, a slip mechanism, a leather cup 22 and a conversion mechanism, wherein the overflow outer cavity 9 is sleeved outside the central tube 4, the slip mechanism is sleeved on the outer wall of the overflow outer cavity, the sealing sleeve is sleeved on the outer side of the upper end of the slip mechanism, the leather cup is sleeved on the outer side of the lower end of the slip mechanism, the central tube and the lower end of the overflow outer cavity are simultaneously connected with the conversion mechanism, when sand prevention is filled, the sealing sleeve is a rubber sealing element, and when steam is subsequently injected, the sealing sleeve is a lead sealing element. The slip mechanism comprises an upper cone 12, a slip sleeve 14, a slip 15 and a lower cone 16, wherein the slip is positioned between the upper cone and the lower cone, and the slip sleeve is arranged at two ends of the slip and sleeved on the upper cone and the lower cone.

The sealing sleeve 11 is sleeved on the outer wall of the upper cone, the upper end of the sealing sleeve is connected with the locking ring sleeve 8, the upper end of the locking ring sleeve is connected with the upper pressing ring 6, a locking ring 7 is arranged between the upper pressing ring and the locking ring sleeve, the upper end of the central tube is connected with the upper joint 1 in a threaded manner, a piston cavity is formed between the upper pressing ring and the upper joint, a piston 5 is arranged in the piston cavity, the piston divides the piston cavity into an inner cavity and an outer cavity, through holes for communicating the inner cavity and the outer cavity are formed in the piston, the inner wall and the outer wall of the upper end of the piston are respectively sealed with the central tube and the upper joint 1, the piston cavity above the upper end of the piston is divided into an upper cavity, the central tube is provided with through holes for communicating the upper cavity, the outer cavity is communicated with the inner cavity, the lower end of the piston is abutted on the upper pressing ring, and the locking ring sleeve is connected with the upper cone through the pin 10. The cup 22 is sleeved on the outer wall of the lower cone 16, the cup holder 21 is arranged at the upper end of the cup, the upper end of the cup holder is simultaneously connected with the adjusting ring 19 and the deblocking sleeve 18, and the deblocking sleeve is connected with the lower cone through the pin 17.

The switching mechanism comprises a switching body 25, an inner piston 26, a closing sleeve 30, a connector 32, a connecting cavity 33 and an overcurrent cavity 34, wherein the lower end of the overcurrent outer cavity is connected with the switching body 25 through a connecting sleeve, the lower end of the switching body is connected with the connecting cavity, the lower end of the connecting cavity is connected with a lower joint 37, the lower end of the inner part of the lower joint is connected with an inner pipe joint 38, the upper end of the inner pipe joint is connected with the overcurrent cavity, the upper end of the overcurrent cavity is connected with a central pipe, the inner wall of the lower end of the central pipe is provided with the inner piston 26, the closing sleeve 30 is arranged between the switching body and the central pipe, the lower end of the closing sleeve is connected with the connector 32, the connector is connected with the central pipe 4, the inner piston is connected with the connector through a pin 31, the lower end of the overcurrent outer cavity is communicated to the upper end of the switching body, the inner wall of the upper end of the inner piston is provided with an inner conical surface, the inner conical surface is located, and the inner wall of the inner pipe joint is also provided with an inner conical surface and a steel ball 39 is located. The central tube, the closing sleeve and the conversion body are simultaneously provided with radial through holes which are communicated, the inner piston temporarily seals the radial through holes of the central tube, the inner part of the overflow cavity 34 is communicated with the inner cavity of the central tube, the outer part of the overflow cavity is communicated with the inner part of the connecting cavity, and the closing sleeve 30 temporarily seals between the connecting cavity and the inner cavity of the conversion body.

The upper joint 1 is connected with the central tube 4 through screw threads, the piston 5 is placed in an inner cavity formed by the upper joint 1 and the central tube 4, the inner end surface and the outer end surface are in sealing fit with the contact surface of the upper joint 1 and the piston 5 through the sealing rings 2 and 3, and the central tube 4 is provided with a back-button 4-1 which is connected with the overcurrent outer cavity 9 through back-button. The upper compression ring 6 and the lock ring sleeve 8 are connected through threads, the lock ring 7 is placed in a space between the upper compression ring 6 and the lock ring sleeve 8, the lock ring 7 is connected with the overflow outer cavity 9 through a threaded fastener, the lock ring sleeve 8 and the upper cone 12 can be moved in and out, the lock ring sleeve 8 is connected with the upper cone 12 through a pin 10, the sealing sleeve 11 is sleeved on the upper cone 12, and the lock ring is placed between the lock ring sleeve 8 and the upper cone 12. The slips 15 are placed in the inner cavity of the slip sleeve 14, the upper end of the slip sleeve 14 is connected with the upper cone 12 through threads, the lower end of the slip sleeve 14 is connected with the lower cone 16 through threads, the upper end of the deblocking sleeve 18 is connected with the lower cone 16 through threads, the lower end of the outer sleeve is connected with the adjusting ring 19 through threads, the upper end of the inner sleeve is connected with the inner lower end of the overflow outer cavity 9 through pins 17, the leather cup holder 20, the leather cup 22 and the top sleeve 23 are sleeved on the leather cup sleeve 21 from top to bottom, the upper adjusting ring 19 is propped against the lower connecting sleeve 24, the connecting sleeve 24 is connected with the leather cup sleeve 21 through threads, tightness can be adjusted through threads of the adjusting ring 19, the upper end of the conversion body 25 is connected with the connecting sleeve 24 through threads, the lower end of the conversion body 33 is connected with threads, two symmetrical filling holes are formed in the conversion body 25 and placed on the central tube 4, the inner surface of the conversion body 25 is in sealing fit with the central tube 4, the lower end of the connecting cavity 33 is connected with the lower connector 37 through threads, the closing sleeve 30 is placed on the conversion body 25, the conversion body 25 is placed on the conversion body 33, the connecting cavity 33, the lower connector 37 is connected with the inner cavity 4 through the inner cavity 4 and the inner cavity 4 is in sealing fit, and the inner cavity 4 is in sealing fit. The connector 32 is screwed with the lower end of the central tube 4, the inner piston 26 is placed in the central tube 4, symmetrical holes formed in the central tube 4 are closed, contact surfaces with the central tube 4 are kept sealed, and the inner piston 26 is connected with the connector 32 by pins 31. The upper end of the overflow cavity 34 is connected with the inner piston 26 by screw threads, the lower end of the overflow cavity is connected with the inner pipe joint 38 by screw threads, the steel ball 39 is placed in the inner cavity of the inner pipe joint 38, the overflow cavity 34 controls the steel ball 39 to move upwards, and the screw threads are reserved at the lower end of the inner pipe joint 38 and connected with the flushing pipe to form a filling inner pipe.

When in construction, the tool is connected with the pipe column according to the design, an inner layer pipe column and an outer layer pipe column are formed at the lower part of the tool, the pipe column is put into the design position, and the wellhead and the pipeline are assembled and connected with the ground filling equipment. The steel ball is put into the oil pipe, after the steel ball is in place, the oil pipe is pressurized at 12-15MPa, the piston 5 pushes the upper compression ring 6, the lock ring 7, the lock ring sleeve 8, the overflow outer cavity 9, the pin 10, the sealing sleeve 11 and the upper cone 12 to move, the slips 15 are pressed out until the lower cone 16 is static, the pin 10 is sheared, the sealing sleeve 11 seals the inner wall of the sleeve, and the seat sealing is completed. Continuing to press to 18-20MPa, the pin 31 is sheared off, the inner piston 26 descends to the joint 32, at the moment, the filling hole on the central tube 4 is opened, the ground pump pressure drop is zero, and the filling channel is opened. When filling, mortar enters the inner cavity of the central tube 4 through an oil tube, and enters an annulus formed by a tubular column below a tool and a sleeve through a filling hole of the central tube 4 and a conversion body 25, the rubber cup 22 prevents high-pressure mortar from ascending, when a ground sleeve gate is closed, the mortar is extruded into a stratum to realize extrusion filling sand prevention, when the ground sleeve gate is opened, the mortar is separated in the annulus, the filling sand is left in the annulus, liquid enters a flushing tube from a downhole screen tube, and flows to the ground through a liquid flow channel formed by the central tube 4 and an overflow outer cavity 9, bypasses a sealing sleeve 11 and an oil sleeve annulus above the tool by a sealing element of the rubber cup 22, and the liquid is recycled to form circulation to realize circulation filling sand prevention. During well flushing, well flushing liquid is pumped into the inner cavity of the overflow cavity 34 through the sleeve, and the steel balls 39 block the inner pipe joint 38, so that the residual mortar in the oil pipe is carried to the ground until the inlet and outlet liquids are consistent, and well flushing is completed. During releasing, the tool is rotated in the forward direction, the back buckle between the back buckle 4-1 and the overflow outer cavity 9 is loosened, and the hanging weight of the ground pressure gauge drops suddenly, so that the upper part and the lower part of the tool are separated, and releasing is completed.

The foregoing description of the preferred embodiments of the present invention is not intended to limit the scope of the invention, but rather to limit the scope of the invention to the equivalents of the claims to which the invention pertains.

Claims (1)

1. A sand control method for filling sand control tools in thermal recovery wells, characterized in that: the sand control method uses a sand control tool for filling sand control tools in thermal recovery wells, the sand control tool comprises a central tube, an outer flow cavity, a sealing sleeve, a slip mechanism, a leather cup, and a conversion mechanism, the outer flow cavity is sleeved on the outer side of the central tube, the outer wall of the outer flow cavity is sleeved with a slip mechanism, the outer side of the upper end of the slip mechanism is sleeved with a sealing sleeve, the outer side of the lower end of the slip mechanism is sleeved with a leather cup, the central tube and the lower end of the outer flow cavity are simultaneously connected to the conversion mechanism; when filling for sand control, the sealing sleeve is a rubber seal, and when subsequent steam injection is performed, the sealing sleeve is a lead seal; The slip mechanism comprises an upper cone, a slip sleeve, a slip and a lower cone, wherein the slip is located between the upper cone and the lower cone, and the slip sleeve is arranged at both ends of the slip and sleeved on the upper cone and the lower cone; The sealing sleeve is sleeved on the outer wall of the upper cone, the upper end of the sealing sleeve is connected to the locking ring sleeve, the upper end of the locking ring sleeve is connected to the upper pressure ring, a locking ring is arranged between the upper pressure ring and the locking ring sleeve, the locking ring is threadedly connected to the flow-through outer cavity, the upper end of the center tube is connected to the upper joint, and a piston cavity is formed between the two, a piston is arranged in the piston cavity, the piston divides the piston cavity into an inner cavity and an outer cavity, wherein a through hole connecting the inner cavity and the outer cavity is arranged on the piston, the inner and outer walls of the upper end of the piston are respectively sealed with the center tube and the upper joint, the piston cavity above the upper end of the piston is divided into an upper cavity, the center tube is provided with a through hole connected to the upper cavity, the flow-through outer cavity is connected with the above-mentioned inner cavity, the lower end of the piston abuts on the upper pressure ring, and the locking ring sleeve is connected to the upper cone through a pin; The conversion mechanism comprises a conversion body, an inner piston, a closing sleeve, a connector, a connecting chamber, and a flow chamber. The lower end of the flow outer chamber is connected to the conversion body through a connecting sleeve, the lower end of the conversion body is connected to the connecting chamber, the lower end of the connecting chamber is connected to the lower joint, the lower end of the lower joint is connected to the inner pipe joint, the upper end of the inner pipe joint is connected to the flow chamber, the upper end of the flow chamber is connected to the center pipe, the inner piston is arranged on the inner wall of the lower end of the center pipe, a closing sleeve is arranged between the conversion body and the center pipe, the lower end of the closing sleeve is connected to the connecting head, the connecting head is connected to the center pipe, the inner piston is connected to the connecting head through a pin, the lower end of the flow outer chamber is connected to the upper end of the conversion body, the inner wall of the upper end of the inner piston is provided with an inner conical surface, a steel ball is seated on it, the inner wall of the inner pipe joint is also provided with an inner conical surface, and a steel ball is also seated on it; The leather cup is sleeved on the outer wall of the lower cone, a leather cup support is arranged on the upper end of the leather cup, the upper end of the leather cup support is connected to the adjusting ring and the unsealing sleeve at the same time, and the unsealing sleeve is connected to the lower cone through a pin; The central tube, the closing sleeve and the converter are provided with interconnected radial through holes at the same time, the inner piston temporarily blocks the above-mentioned radial through holes of the central tube, the inside of the flow chamber is connected to the inner cavity of the central tube, and the outside is connected to the inside of the connecting cavity, and the closing sleeve temporarily blocks between the connecting cavity and the inner cavity of the converter; Sand control methods include: During construction, the thermal well filling sand control tool is connected to the pipe string, and the lower part of the thermal well filling sand control tool forms an inner and outer layer of the pipe string, and the pipe string is lowered to the designed position, the wellhead and pipeline are installed, and the ground filling equipment is connected; a steel ball is put into the oil pipe, and after the steel ball is in place, the oil pipe is pressurized to 12-15MPa, and the piston moves downward to push the upper pressure ring, lock ring, lock ring sleeve, flow outer cavity, pin, sealing sleeve, and upper cone to move. Since the lower cone is stationary, the slip is pressed out until it bites the casing wall, and then the pin is cut off, and the sealing sleeve is compressed to seal the inner wall of the casing, and the seat seal is completed; continue to pressurize to 18-20MPa, the pin is cut off, and the inner piston moves downward to the connector. At this time, the filling hole on the central pipe is opened, the pressure drop of the ground pump is zero, and the filling channel is opened; During filling, the mortar enters the inner cavity of the center pipe through the oil pipe, and enters the annulus composed of the tubing and casing below the tool through the filling holes of the center pipe and the converter. The leather cup prevents the high-pressure mortar from going up. At this time, if the ground casing gate is closed, the mortar is squeezed into the formation to achieve extrusion filling and sand prevention. If the ground casing gate is opened, the mortar will be separated in the annulus, and the filling sand will remain in the annulus. The liquid enters the flushing pipe from the downhole screen pipe, and bypasses the sealing sleeve and the leather cup seal through the liquid flow channel formed by the center pipe and the flow outer cavity to enter the oil casing annulus above the tool and discharge to the ground. The liquid is reused to form a cycle, realizing cyclic filling and sand prevention. When washing the well, the washing fluid is pumped in through the casing, and enters the inner cavity of the flow chamber through the annular channel formed by the center pipe and the outer flow chamber. Since the steel ball blocks the inner pipe joint channel, the liquid flows upward into the inner cavity of the center pipe and the upper oil pipe, thereby carrying the residual mortar in the oil pipe to the ground until the inlet and outlet liquids are consistent, and the well washing is completed; When releasing the tool, rotate the tool forward, the back buckle between the back buckle and the flow-through outer chamber is loosened, and the suspended weight of the ground pressure gauge drops suddenly, indicating that the upper and lower parts of the tool are disengaged and the release is completed.