CN111706303B

CN111706303B - One-time multilayer gravel filling sand prevention process and filling sand prevention tool pipe column

Info

Publication number: CN111706303B
Application number: CN202010617063.7A
Authority: CN
Inventors: 杨国
Original assignee: Sunrise Energy Technology Co ltd
Current assignee: Tianjin Sairui Energy Technology Co ltd
Priority date: 2020-07-01
Filing date: 2020-07-01
Publication date: 2022-03-25
Anticipated expiration: 2040-07-01
Also published as: CN111706303A

Abstract

The invention relates to a once multilayer gravel packing sand prevention process and a packing sand prevention tool pipe column, belonging to the field of downhole operation tools of oil and gas wells. The invention fills the oil layer from bottom to top layer by layer through the filling and reverse circulation method, wherein, the inner pipe column only needs to be lifted and lowered and is positioned through the display of the load indicator, thus realizing one-time multilayer gravel filling operation without needing to put in and take out the pipe column for many times, and the invention has the characteristics of simple operation and short time consumption. The problems that when the existing mechanical sand prevention single-layer sand prevention mode is used for carrying out multi-layer gravel packing operation, a tool pipe column needs to be put in for many times, so that the operation is long in time consumption, the operation is complex and the operation cost is high are solved; the invention can realize 3.88 'large inner diameter in 7' tubular column, provides large drift diameter for production operation to the greatest extent, meets the requirement of large discharge, improves the yield, and has positive popularization significance for sand control operation of oil and gas wells.

Description

One-time multilayer gravel filling sand prevention process and filling sand prevention tool pipe column

Technical Field

The invention relates to a once multilayer gravel packing sand prevention process and a packing sand prevention tool pipe column, belonging to the field of downhole operation tools of oil and gas wells.

Background

The loose sandstone reservoir in China has wide distribution range and large reserves, and sand production of oil and gas wells is a main contradiction in the development of the reservoir. The sand production often leads to sand-buried oil layers or shaft sand blocking or oil-gas well production stopping operation, causes serious abrasion of ground or underground equipment, sand blocking, frequent sand flushing, pump detection, ground tank cleaning and other maintenance to greatly increase the workload, not only improves the crude oil production cost, but also increases the oil field management difficulty. Therefore, the sand control is one of essential process measures for developing the oil and gas reservoir easy to generate sand, and plays an important role in stable production of crude oil and improvement of development benefits.

The prior sand control mode mainly comprises mechanical sand control and chemical sand control; the chemical sand control adopts a chemical agent formula, is influenced by squeeze conditions and construction parameters during squeeze, influences the permeability of an oil reservoir, is easy to cause yield reduction after sand control, and has a short validity period relative to mechanical sand control. The mechanical sand control adopts gravel filling sand control, compared with chemical sand control, the gravel filling sand control effect is better, the effective period is long, no pollution is caused, and the application to well mines is common.

However, the existing mechanical sand control adopts a one-layer and one-layer sand control mode to carry out multi-layer gravel packing, and a tool pipe column needs to be put down for many times during operation, so that the operation is long in time consumption, complex in operation and high in operation cost; on the other hand, in the 7 'oil well, the inner diameter can only be 3.25' during production operation, so that the requirement of large discharge capacity of an oil pipe cannot be met, and further, the yield is reduced, and therefore, improvement is needed.

Disclosure of Invention

The invention aims to: the once multilayer gravel packing sand prevention process and the packing sand prevention tool string have the advantages that the tool string does not need to be repeatedly put into the 7 'string, the 3.88' large inner diameter can be realized, the large drift diameter is provided for production operation to the greatest extent, the large discharge capacity is met, the yield is improved, and meanwhile, sufficient channels are provided for the packing operation.

The technical scheme of the invention is as follows:

a sand control process for once multi-layer gravel packing is characterized in that: it comprises the following steps:

1) connecting and assembling an outer pipe column (sand control tool string) and an inner pipe column (service tool string); the outer pipe column consists of a top packer, an upper extension barrel, an upper filling sliding sleeve, an upper load display coupling, an upper blind pipe, an upper sieve pipe, an isolation packer, a lower filling sliding sleeve, a lower load display coupling, a lower blind pipe, a lower sieve pipe, a sealing assembly and a sand setting packer; the inner pipe column is sequentially connected with a setting tool, an inner punching sleeve, an inner punching pipe short section, a sealing mandrel, a lower short section, a filling tool, a reverse circulation check valve, a load indicator, a one-way switching tool, a two-way switching tool, a perforated pipe and a bottom seal;

2) firstly, putting a sand setting packer of the sand prevention tool string into the bottom of a well through an oil pipe, and then setting the sand setting packer to finish bottom sealing of a shaft;

3) after the sand setting packer finishes bottom sealing and setting of the shaft, an outer pipe column which is connected except for the top packer is put into the shaft, and after the outer pipe column is put in, the top of the outer pipe column is hung on a well mouth through an upper extending cylinder; connecting the top packer with a setting tool on the inner string, and then lowering the inner string into the outer string through the top packer;

4) after the inner pipe column is lowered, the inner pipe column is in threaded connection with an upper extension cylinder of an outer pipe column through a top packer to fix the inner pipe column and the outer pipe column together, and then the inner pipe column and the outer pipe column are integrally lowered into a well bottom until the bottom of the outer pipe column is inserted into a sand setting packer through a sealing assembly; the whole pipe column is put in place, and then the operation can be started;

5) when the operation is operated, firstly, the ball is thrown into the setting tool for sealing, then the oil pipe is used for pressing the setting top packer, after the setting of the top packer is finished, the top packer is pressed from the sleeve pipe again to test whether the setting of the setting top packer is qualified or not, after the setting is qualified, the oil pipe is continued to be pressed, so that the setting tool and the top packer are separated from each other, and the connection relation between the inner pipe and the outer pipe is relieved. If the setting tool is not successfully released from the top packer, releasing can be realized in a mode of forward-rotation mechanical releasing;

6) after the setting tool and the top packer are separated from each other; closing the upper filling sliding sleeve through a one-way switch tool, then lifting the inner tubular column to an upper oil layer reverse circulation position, and washing the setting ball out of the shaft from the oil pipe in an upper oil layer reverse circulation mode;

7) after the setting ball is washed out of the oil pipe, setting an isolation packer between an upper oil layer and a lower oil layer, lifting the inner pipe column after setting is finished, lifting a filling hole of a filling tool out of an upper joint of the isolation packer, and testing whether the isolation packer is qualified or not through pressing of the oil pipe;

8) and after the isolation packer is qualified in setting, starting filling operation from bottom to top, lifting the pipe column to enable the two-way switch tool to reach the upper end of the lower filling sliding sleeve during the filling operation, opening the lower filling sliding sleeve by pressing the pipe column through the two-way switch tool, then pressing the pipe column, and determining the filling position of the tool through the load indicator and the lower load display coupling. Pumping filling sand into the oil pipe, filling the sand into the flow channel on the sliding sleeve from the lower part through the filling hole, and entering the annulus to start gravel filling operation on the lower oil layer;

9) after filling, reverse circulation is needed to wash gravel retained in the oil pipe out of the shaft, the inner pipe column is lifted up to close the lower filling sliding sleeve through a one-way switch tool, then the pipe column is pressed down to determine the reverse circulation position, liquid is pumped from the annular space, the liquid enters the small annular space through a hole in a setting tool and then reaches the ball valve body of the reverse circulation hole through a side bypass, the ball valve body is opened, the liquid enters the oil pipe through the reverse circulation hole and the filling hole to form a reverse circulation channel, and the purpose of washing redundant gravel in the oil pipe out of the shaft is achieved;

10) and after the filling operation of the lower oil layer is finished, filling the oil layer by layer from bottom to top by a filling and reverse circulation method according to the steps, wherein the inner pipe column only needs to be lifted and lowered and is positioned by the display of a load indicator, and the multi-layer gravel filling operation can be realized once.

The setting tool in the step 4) comprises a mandrel, a setting short section, an upper joint and a ball seat short section; one end of the upper joint is provided with a setting nipple, the setting nipple is provided with a piston outer cylinder, an outer cylinder pressing cap is arranged on the setting nipple at the end of the piston outer cylinder, a protective sleeve is arranged in the upper joint through internal threads, and one end with the protective sleeve extends into the setting nipple; a mandrel is installed in the internal thread of the setting short section on one side of the end of the protective sleeve, a locking block is installed between the mandrel and the setting short section, a piston is installed on the mandrel on one side of the locking block and the end of the setting short section, and a piston extension cylinder is installed on the mandrel on one side of the piston; one end of the piston extension cylinder and one end of the mandrel extend to the outer end of the piston outer cylinder, a setting sliding sleeve is arranged on the circumference of the end head of the piston extension cylinder extending to the outer end of the piston outer cylinder through a releasing pin, a bearing lug and an elastic chuck are arranged on the mandrel at the end head of the setting sliding sleeve through a skin rolling pin and a spring, and a shearing outer sleeve is arranged on the mandrel at one side of the skin rolling pin; the slips are installed on the mandrel on one side of the shearing outer sleeve through the slip support ring and the clip spring, the shearing release sleeve and the release pawl are installed on the mandrel on one side of the slips, the positioning short section is installed on the mandrel port thread extending to the outer end of the piston extension cylinder, and the ball seat short section is installed on the positioning short section end thread.

The filling tool in the step 7) comprises a central pipe, an upper tool joint, a long outer pipe, a filling short section, a three-way short section and a lower mandrel; one end of the filling short section is provided with a long sealing mandrel through a double short section; the end head of the long sealing mandrel is provided with an upper tool joint through the long outer pipe; install the intermediate layer pipe in the long outer tube, the center tube is installed through the intermediate head to the intermediate layer pipe end, fills the other end of nipple joint and installs double containment ring dabber through lower dabber and short sealed dabber, and double containment ring dabber one end is installed the sealed dabber of reducing through the tee bend nipple joint, and sealed dabber F is installed to the sealed dabber end of reducing. The interlayer pipe is internally provided with an insertion pipe in a sliding way, one end of the insertion pipe extends into the upper joint, and a sealing ring is arranged between the interlayer pipe and the insertion pipe. The double-meter short section is in threaded connection with the filling short section; the long sealing mandrel is composed of a sealing mandrel A, a sealing mandrel B, a sealing mandrel C, a sealing mandrel D and a sealing mandrel E, and the sealing mandrel A, the sealing mandrel B, the sealing mandrel C, the sealing mandrel D and the sealing mandrel E are in threaded connection with each other; the sealing mandrel A is in threaded connection with the double-mu short section; the sealing mandrel E is in threaded connection with the long outer pipe; the upper joint is in threaded connection with the long outer pipe; fill nipple joint and lower mandrel threaded connection, lower dabber, short sealed dabber, double seal ring dabber, tee bend nipple joint, reducing sealed dabber, sealed dabber F between threaded connection in proper order, lower dabber, short sealed dabber, double seal ring dabber, tee bend nipple joint, reducing sealed dabber, sealed dabber F on be provided with the external seal assembly respectively. The filling short section is a diameter-variable body, and filling holes are uniformly distributed on the circumference of the middle part of the filling short section in the radial direction; the filling hole is communicated with the central hole; a pipe wall of the filling nipple is symmetrically and axially provided with a nipple bypass hole; a protective pipe is arranged in a center hole of the filling nipple corresponding to the filling hole, and a protective pipe through hole is formed in the circumference of the protective pipe and corresponds to the filling hole; the protective pipe is connected with the plug and the filling short section through a set screw.

The reverse circulation check valve in the step 9) is composed of a check valve sealing sleeve, a check valve upper joint, a check valve lower joint, a valve core, a check valve suspension joint and a check valve suspension sleeve, wherein the check valve sealing sleeve is installed at one end of the check valve upper joint; a nut is installed on the end head of the sealing sleeve of the check valve in a threaded manner, and a lower joint of the check valve is arranged at one end of the sealing sleeve of the check valve; a check valve outer sealing assembly A is arranged on the circumference of one end of the check valve lower joint, and a check valve suspension joint is arranged on the check valve lower joint through a check valve suspension sleeve. The check valve sealing sleeve is provided with a reducing center hole; a flow guide disc is clamped between the check valve sealing sleeve and the check valve upper joint, a mounting hole is formed in the center of the flow guide disc, and liquid flow holes are uniformly distributed in the flow guide disc on the periphery of the mounting hole. A valve core is movably arranged on the flow guide disc through a check valve spring, and one end of the valve core is in sealing contact connection with the port of the lower joint of the check valve.

The invention has the beneficial effects that:

the once multilayer gravel packing sand control process can realize multilayer packing sand control operation by once putting the tubular column, does not need to put the tubular column in and take the tubular column out for many times, and has the characteristics of simple operation and short consumed time. The problems that when the existing mechanical sand prevention single-layer sand prevention mode is used for carrying out multi-layer gravel packing operation, a tool pipe column needs to be put in for many times, so that the operation is long in time consumption, the operation is complex and the operation cost is high are solved; the invention can realize 3.88 'large inner diameter in 7' tubular column, provides large drift diameter for production operation to the greatest extent, meets the requirement of large discharge, improves the yield, and has positive popularization significance for sand control operation of oil and gas wells.

Drawings

FIG. 1 is a schematic structural view of an inventive outer tubing string;

FIG. 2 is a schematic structural view of the inner tubular string of the present invention;

FIG. 3 is a schematic representation of the outer and inner tubular strings of the invention after being run downhole;

FIG. 4 is a schematic structural view of the setting tool of the present invention;

FIG. 5 is an enlarged view of the structure at A in FIG. 4;

FIG. 6 is an enlarged view of the structure at B in FIG. 4;

FIG. 7 is an enlarged view of the structure at C in FIG. 4;

FIG. 8 is an enlarged view of the structure at D in FIG. 4;

FIG. 9 is a schematic cross-sectional view taken along line A-A of FIG. 4;

FIG. 10 is a schematic cross-sectional view taken along line B-B of FIG. 4;

FIG. 11 is a schematic cross-sectional view taken along line C-C of FIG. 4;

FIG. 12 is a schematic cross-sectional view taken along line D-D of FIG. 4;

FIG. 13 is a schematic representation of a setting tool downhole of the present invention;

FIG. 14 is a schematic view of setting a top packer;

FIG. 15 is a schematic view of a setting tool hydraulic release;

FIG. 16 is a schematic view of a setting tool mechanical release;

FIG. 17 is a schematic view of the filling tool of the present invention;

FIG. 18 is an enlarged view of the structure at A in FIG. 17;

FIG. 19 is an enlarged view of the structure at B in FIG. 17;

FIG. 20 is an enlarged view of the structure at C in FIG. 17;

FIG. 21 is an enlarged view of the structure of FIG. 17 at D;

FIG. 22 is a schematic view of the cross-sectional structure taken along line A-A in FIG. 17 or FIG. 4;

FIG. 23 is a schematic view of a cross-sectional view taken along line B-B in FIG. 17 or FIG. 21;

FIG. 24 is a schematic view of a filling tool of the present invention in a filling cycle;

FIG. 25 is a schematic view of the reverse cycle operation of the filling tool of the present invention;

FIG. 26 is a schematic view of an open configuration of a reverse circulation check valve in accordance with the present invention;

fig. 27 is a schematic view of a closed state of a reverse circulation check valve of the present invention.

In the figure: 1. wellbore, 2, top packer, 3, upper extension casing, 4, upper filling sliding sleeve, 5, upper load display collar, 6, upper blind pipe, 7, upper screen pipe, 8, isolation packer, 9, lower filling sliding sleeve, 10, lower load display collar, 11, lower blind pipe, 12, lower screen pipe, 13, seal assembly, 14, sand setting packer, 15, setting tool, 16, inner flushing sleeve, 17, inner flushing pipe nipple, 18, sealing mandrel, 19, lower nipple, 20, filling tool, 21, reverse circulation check valve, 22, load indicator, 23, one-way switch tool, 24, two-way switch tool, 25, perforated pipe, 26, bottom seal, 27, oil pipe, 28, setting upper joint, 29, protective sleeve, 30, setting nipple, 31, outer barrel press cap, 32, separation ring, 33, piston outer barrel, 34, lock block, 35, piston, 36. piston extension cylinder, 37, sliding sleeve press cap, 38, setting sliding sleeve, 39, collet chuck, 40, shear pin B, 41, bearing lug, 42, spring, 43, mandrel, 44, shear outer sleeve, 45, shear release sleeve, 46, release pawl, 47, shear pawl, 48, card spring, 49, slip, 50, slip support ring, 51, positioning short section, 52, ball joint, 53, limit protrusion, 54, set pin, 55, set screw a, 56, set screw B, 57, shear pin a, 58, release pin, 59, shear pin C, 60, hold-down ball, 61, pressure transfer hole, 62, press hole, 63, wrapping pin, 64, set screw C, 65, set screw D, 66, setting joint, 67, setting envelope, 68, upper joint, 69, shear pin D, 70, filling hole; 71. central tube, 72, tool upper joint, 73, long outer tube, 74, filling short section, 75, tee short section, 76, lower mandrel, 77, double short section, 78, sealing mandrels a, 79, sealing mandrels B, 80, sealing mandrels C, 81, sealing mandrels D, 82, sealing mandrels E, 83, sandwich tube, 84, middle joint, 85, overflowing hole, 86, cannula, 87, short sealing mandrel, 88, double sealing ring mandrel; 89. the variable diameter sealing device comprises a variable diameter sealing mandrel 90, sealing mandrels F and 91, an outer sealing assembly 92, a tool filling hole 93, a short section bypass hole 94, a protective pipe 95, a set screw 96, a plug 97, an upper annular space 98, a valve seat 99, a ball valve body 100, a spring seat 101, a return spring 102, a liquid flow hole 103, a short section through hole 104, a three-way short section bypass hole 105, a lower annular space 106, a filling sliding sleeve 107 and a switching tool; 108. the device comprises a perforation 109, a check valve sealing sleeve 110, a check valve upper joint 111, a check valve lower joint 112, a check valve suspension joint 113, a check valve suspension sleeve 114, a valve core 115, check valve fastening screws A and 116, check valve outer sealing assemblies A and 117, check valve fastening screws C and 118, nuts and 119, check valve fastening screws B and 120, check valve outer sealing assemblies B and 121, a flow guide disc 122, check valve springs and 123 and a check valve liquid inlet hole.

Detailed Description

The once multilayer gravel pack sand control process comprises the following steps:

connecting and assembling an outer pipe column (sand control tool string) and an inner pipe column (service tool string); the outer string is composed of a top packer 2, an upper extension barrel 3, an upper filling sliding sleeve 4, an upper load display coupling 5, an upper blind pipe 6, an upper sieve pipe 7, an isolation packer 8, a lower filling sliding sleeve 9, a lower load display coupling 10, a lower blind pipe 11, a lower sieve pipe 12, a sealing assembly 13 and a sand setting packer 14. When the outer pipe column is assembled, an upper extension barrel 3, an upper filling sliding sleeve 4, an upper load display coupling 5, an upper blind pipe 6, an upper sieve pipe 7, an isolation packer 8, a lower filling sliding sleeve 9, a lower load display coupling 10, a lower blind pipe 11, a lower sieve pipe 12 and a sealing assembly 13 are sequentially connected.

The inner pipe column consists of a setting tool 15, an inner flushing sleeve 16, an inner flushing pipe short section 17, a sealing mandrel 18, a lower short section 19, a filling tool 20, a reverse circulation check valve 21, a load indicator 22, a one-way switching tool 23, a two-way switching tool 24, a perforated pipe 25 and a bottom seal 26 which are connected in sequence. After the connection and assembly of the outer pipe string and the inner pipe string are completed, the sand setting packer 14 is lowered into the shaft 1 at the bottom of the shaft through the oil pipe 27, and then the sand setting packer 14 is set to complete bottom sealing of the shaft 1. After completing bottom sealing and setting of the shaft 1, the sand setting packer 14 lowers the connected outer pipe column except the top packer 2 into the shaft 1 (wellhead), wherein the top of the outer pipe column is fixed on the wellhead through the upper extension barrel 3; namely, the top of the outer pipe column is hung on a wellhead through an upper extension cylinder 3; connecting a top packer 2 with a setting tool 15 on the inner tubular column, then lowering the inner tubular column into the outer tubular column through the top packer 2, after the inner tubular column is lowered, connecting the inner tubular column with an upper extension barrel 3 of the outer tubular column through the top packer 2 in a threaded manner to fix the inner tubular column and the outer tubular column together, and then lowering the inner tubular column and the outer tubular column into the bottom of the well integrally until the bottom of the outer tubular column is inserted into a sand setting packer 14 through a sealing assembly 13; after the whole filling sand control tool pipe column is completely put in, the operation can be started (see attached figures 1-3).

In operation, a pressure-building ball 60 (ball seal) is first introduced into the setting tool 15 through the tubing, and the setting top packer 2 is then pressed through the tubing 27. And after the top packer 2 is sealed, pressing the top packer 2 from the casing to test whether the set of the top packer 2 is qualified or not, and after the set is tested to be qualified, continuing pressing the oil pipe to enable the setting tool 15 to be separated from the top packer 2 so as to remove the connection relation between the inner pipe column and the outer pipe column. If the setting tool 15 is not successfully released from the top packer 2, releasing can be realized by a forward-rotation mechanical releasing mode. The specific structure and principle of the setting tool 15 are as follows: the setting tool 15 comprises a mandrel 43, a setting sub 30, a setting top sub 28 and a ball seat sub. One end of the setting upper joint 28 is provided with a setting short section 30, the setting upper joint 28 is in threaded connection with the setting short section 30, and the setting upper joint 28 is fixedly connected with the setting short section 30 through a set screw A55 so as to carry out circumferential limiting; meanwhile, a sealing ring is arranged between the setting upper joint 28 and the setting short section 30 to ensure the sealing between the setting upper joint 28 and the setting short section 30. A piston outer cylinder 33 is arranged on the setting nipple 30, and one end of the piston outer cylinder 33 is open so as to be convenient for assembly; the other end of the piston outer cylinder 33 is closed. An outer cylinder pressing cap 31 is installed on the setting nipple 30 at the end of the piston outer cylinder 33, and the outer cylinder pressing cap 31 is connected with the piston outer cylinder 33 through a fastening pin 54.

The circumference of the end of the setting short section 30 is provided with a limiting bulge 53, and the setting short section 30 and the piston outer cylinder 33 are matched and mutually clamped and connected through the limiting bulge 53 and the closing end face of the piston outer cylinder 33. A separating ring 32 is clamped on the setting nipple 30 at the end of the piston outer cylinder 33 in the outer cylinder pressing cap 31, two ends of the separating ring 32 are respectively in contact connection with the outer cylinder pressing cap 31 and the piston outer cylinder 33, and the separating ring 32 is matched with the limiting protrusion 53 to axially limit the piston outer cylinder 33. And a sealing ring is arranged between the setting nipple 30 and the piston outer cylinder 33 to ensure the sealing property between the setting nipple 30 and the piston outer cylinder 33.

A protective sleeve 29 is arranged in the setting upper joint 28 through threads, and a sealing ring is arranged between the setting upper joint 28 and the protective sleeve 29 to ensure the sealing property between the setting upper joint 28 and the protective sleeve 29. In operation, the protective sleeve 29 protects the setting top sub 28 by preventing the setting top sub 28 from directly contacting the well fluid to create an erosive effect. One end of the sheath 29 extends into the setting nipple 30; a mandrel 43 is mounted on an internal thread of the setting nipple 30 at the end of the protective sleeve 29, and the mandrel 43 is a stepped reducing tubular body; a plurality of protrusions formed by the change in diameter are provided on the outer circumference of the mandrel 43. And a locking block 34 is inserted between the mandrel 43 and the setting short section 30 so as to limit the mutual circumferential limit between the mandrel 43 and the setting short section 30.

And a piston 35 is arranged on the mandrel 43 on one side of the locking block 34, and sealing rings are respectively arranged between the piston 35 and the mandrel 43 as well as between the piston 35 and the piston outer cylinder 33 so as to ensure the sealing performance between the piston 35 and the mandrel 43 as well as between the piston outer cylinder 33. A piston extension cylinder 36 is arranged on a mandrel 43 at one side of the piston 35; one end of the piston extension cylinder 36 extends to the outer end of the piston outer cylinder 33, and one end of the mandrel 43 extends to the outer end of the piston extension cylinder 36. The setting nipple 30 inner wall boss of locking piece 34 opposite side is provided with and passes pressure hole 61, is provided with between the terminal surface of setting top connection 28 and the inner wall boss terminal surface of setting nipple 30 and overflows the clearance, radially is provided with on the protective sheath 29 and beats pressure hole 62, passes pressure hole 61 and beats pressure hole 62 intercommunication through flowing the clearance. The piston 35 is connected in contact with one end port of the pressure transmission hole 61.

A setting sliding sleeve 38 is arranged on the circumference of the end of the piston extension cylinder 36 extending to the outer end of the piston outer cylinder 33 through a releasing pin 58, a sliding sleeve pressing cap 37 is arranged at one end of the setting sliding sleeve 38 through a set screw B56, and the end of the piston extension cylinder 36 is connected with the mandrel 43 through a shearing pin A57. The mandrel 43 at the end of the setting sliding sleeve 38 and the piston extension cylinder 36 is provided with a bearing lug 41 and an elastic chuck 39 through a rolling leather pin 63 and a spring 42, the end of the elastic chuck 39 is provided with a convex block, the mandrel 43 corresponding to the convex block is provided with a clamping groove, and the elastic chuck 39 is mutually clamped with the clamping groove through the matching of the piston extension cylinder 36.

A cutting outer sleeve 44 is arranged on the mandrel 43 at one side of the skin rolling pin 36; slips 49 are arranged on the mandrel 43 on one side of the shearing outer sleeve 44 through slip support rings 50 and a card spring 48, a shearing release sleeve 45 and a release pawl 46 are arranged on the mandrel 43 on one side of the slips 49, a shearing pawl 47 is arranged on the release pawl 46, and the release pawl 46 is axially connected with the mandrel 43 in a sliding mode through a connecting key. One end of the shear release sleeve 45 is connected in contact with the release pawl 46 and the other end of the shear release sleeve 45 is connected to the shear housing 44 by a shear pin C59. A shear pin D69 is provided between the release pawl 46 and the mandrel 43 to prevent premature compression of the slip collars 50 causing the slips 49 to retract.

The end of the mandrel 43 extending to the outer end of the piston extension cylinder 36 is provided with a positioning short section 51, the end of the positioning short section 51 is provided with a ball seat short section in a threaded manner, one end of the positioning short section 51 is connected with the mandrel 43 through a set screw C64, and the other end of the positioning short section 51 is connected with the ball seat short section through a set screw D65; the locating sub 51 is connected to the slip collars 50 by shear pin B40. The ball seat short section comprises a ball seat short section joint 52, an inner punching sleeve 16, an inner punching pipe short section 17, a sealing mandrel 18 and a lower short section 19, the inner punching sleeve 16 is installed on the ball seat short section joint 52 in a threaded mode, the inner punching pipe short section 17 is movably installed in the inner punching sleeve 16, the sealing mandrel 18 and the lower short section 19 are arranged on the inner punching pipe short section 17, one end of the sealing mandrel 18 is in threaded connection with the inner punching sleeve 16, and the other end of the sealing mandrel 18 is in threaded connection with the lower short section 19; and a filling hole 70 is formed in the circumference of the sealing mandrel 18, and the filling hole 70 is communicated with an annulus between the inner washing pipe nipple 17 and the sealing mandrel 18 and between the inner washing pipe nipple 19 and the lower nipple 19. When the setting tool works, a tool pipe string is formed by matching the top packer 2 with the ball seat short section joint 52, the inner flushing sleeve 16, the inner flushing pipe short section 17, the sealing mandrel 18, the lower short section 19 and the like; and is lowered to a predetermined position of the oil and gas well through an oil pipe 27 (drill string), and during the lowering process, the top packer 2 is sleeved on the setting tool 15; wherein; the load-bearing lugs 41 of the setting tool 15 are located in the pockets between the setting sub 66 of the top packer 2 and the setting sleeve 67 of the top packer, and the slips 49 of the setting tool 15 are engaged with the upper connector 68 of the top packer (both formed when the top packer is set down the well) to secure the setting tool 15 to the top packer 2 and prevent slippage therebetween. The setting tool 15 can be divided into four parts of an advance setting prevention mechanism, a torque transmission mechanism, a setting mechanism and a releasing mechanism according to the working performance.

Prevent the mechanism of setting in advance:

consists of an elastic chuck 39, a bearing lug 41, a spring 42 and a leather rolling pin 63; the spring 42 and the bearing lug 41 are embedded into a window of the elastic chuck 39, the leather rolling pin 63 presses the spring 42 and limits the bearing lug 41, the elastic chuck 39 is positioned on the excircle of the mandrel 43, and the inner hole inclined planes at the front end and the rear end are fixedly attached to the outer inclined plane of the mandrel 43, so that the bearing lug 41 fixes the setting sleeve 67, the setting sleeve cannot move when being subjected to external force, and the purpose of preventing the top packer from being set in advance is achieved.

The torque transmission mechanism:

the device comprises a setting upper joint 28, a setting short joint 30, a locking block 34, a mandrel 43, a release pawl 46, a shearing pawl 47 and a set screw A55; the setting nipple 30 is connected with the setting upper connector 28 through threads and is fixed through a set screw A55, the setting nipple 30 is connected with the mandrel 43 through threads and is fixed through a locking block 34, and when torque is applied to the upper end, the situation that the threads between the mandrel 43 and the setting nipple 30 are screwed more and more tightly is prevented, and the difficulty in dismounting during maintenance is avoided. The release pawl 46 is fixed with the mandrel 43 and the shearing pawl 47 in a key and key groove clamping manner, and the key on the shearing pawl 19 is limited with the clamping groove of the mandrel 43, so that the purpose of torque transmission is achieved.

A setting mechanism:

the device comprises a setting upper joint 28, a protective sleeve 29, a setting short joint 30, a piston outer cylinder 33, a piston 35, a piston extension cylinder 36, a setting sliding sleeve 38, an elastic chuck 39, a bearing lug 41, a spring 42, a mandrel 43, a shearing outer sleeve 44, a positioning short joint 51, a ball seat short joint, a pressure holding ball 60, a shearing pin C59, a shearing pin B40, a releasing pin 58 and a set screw B56. The setting upper joint 28 is fixedly connected with the setting short joint 30 through threads and a set screw A55, and the setting upper joint 28 is in threaded connection with the protective sleeve 29. During sand control, the reducing part of the setting upper joint 28 can be prevented from directly contacting with the fluid in the well to generate erosion effect through the protective sleeve 29, and the setting upper joint 28 is protected.

The releasing mechanism comprises:

the shear release sleeve 45, the release pawl 46, the shear pawl 47, the card spring 48, the slip 49, the slip counter ring 50, the shear pin A57, and the releasing pin 58 (shear pin).

When the top packer 2 on the outer string finishes setting, pressure pumping is continued, the setting sliding sleeve 38 does not displace any more, the setting sliding sleeve 38 and the piston extension cylinder 36 are fixed through the releasing pin 58, the pressure pumping is continued, the releasing pin 58 is sheared, the setting sliding sleeve 38 is disconnected from the setting extension cylinder 9, and hydraulic tool releasing is achieved. Namely: when the inner pipe column and the top packer 2 sleeved on the setting tool 15 are lowered to a preset position to set the top packer 2; and (3) putting a pressure-holding ball 60 made of resin into the ball seat short joint to enable the oil pipe 27 at the upper part of the inner pipe column to form pressure holding, and continuously pumping pressure, wherein in the process, high-pressure drilling fluid enters a pressure transmission hole 61 through a pressure holding hole 62, a gap between a protective sleeve 29 and the setting short joint 30 and acts on the end surface of the piston 35 to further act on the piston extension cylinder 36, when the pressure reaches a tool starting value, the shearing pin A57 is sheared, the piston 35 pushes the piston extension cylinder 36 to move downwards, at the moment, the end of the piston extension cylinder 36 slides on the elastic chuck 39, and the pressing state of the end of the piston extension cylinder 36 on a lug of the elastic chuck 39 is relieved. The projection at the end of the elastic chuck 39 is withdrawn from the clamping groove arranged on the mandrel 43, the clamping state of the elastic chuck 39 and the clamping groove is released, the advance setting mechanism is prevented from being released, and when the end of the piston extension cylinder 36 is contacted with one side end face of the elastic chuck 39, the elastic chuck 39 is integrally pushed to move downwards. In this process, the load lugs 41 are withdrawn from the pockets between the setting sub 66 of the top packer and the setting sleeve 67 of the top packer. Since the piston extension cylinder 36 is fixed with the setting sliding sleeve 38 through the releasing pin 58, while the piston extension cylinder 36 pushes the elastic collet 39 to move downwards, the setting sliding sleeve 38 is contacted with the setting joint 66 of the top packer, so that the setting sleeve 67 of the top packer is pushed to move downwards through the setting joint 66, in the process, the piston extension cylinder 36 pushes the shearing outer sleeve 44 to move downwards through the elastic collet 39, at the moment, the shearing pin C59 connecting the shearing outer sleeve 44 with the shearing release sleeve 45 is sheared, and the shearing outer sleeve 44 moves downwards along the shearing release sleeve 45; the setting sleeve 67 squeezes the packing element on the top packer; the top packer is set and the top packer 2 is set when the shear outer sleeve 44 presses the slips 49 through the shear pawls 47 and the glue barrel of the top packer 2 is fully squeezed by the setting sleeve 67.

After the top packer 2 completes setting, pumping pressure continues, when the pressure rises to the release pressure. The release pin 58 between the piston extension 36 and the setting sleeve 38 is sheared off, at which time the setting sleeve 38 is not traveling downward. The plunger extension 36 continues to push against the resilient cartridge 39, the shear housing 44, the shear release sleeve 45, and the release pawl 46 moves downward. When the key on the shear pawl 47 slides out of the key slot of the release pawl 46, the shear pin D69 shears; the torque transmitting mechanism is released. As the release pawl 46 continues to descend, the shear pin B40 is sheared by the release pawl 46 pushing the slip collar 50 to move, the support lugs between the slip collar 50 and the slips 49 displace relative to each other, thereby allowing the slip 49 to fall through, the compressed catch spring 48 is released, causing the slips 49 to retract radially and fall into the grooves between the support lugs of the slip collar 50, the slip teeth of the slips 49 disengage from the engagement of the teeth of the upper connector 68 of the top packer, and the setting tool 15 is lifted up, thereby achieving hydraulic release (lost).

The engaging state (connecting thread) between the slips 49 of the setting tool 15 and the upper connector 68 of the top packer 2 adopts left-handed threads, if the hydraulic pressure is disengaged due to some factors, the threads between the slips 49 and the upper connector 68 are not smoothly disengaged, the setting tool 15 can be directly and positively rotated, so that the engaging state of the slip teeth of the slips 49 and the latch teeth of the upper connector 68 of the top packer 2 is separated, and the mechanical disengagement is realized.

This setting instrument 15 is as one of downhole tool, can repeat repetitious usage, and piston urceolus 33 is fixed through the step of separating ring 32 with setting nipple joint 30, when the maintenance, directly detaches the holding screw 27 of fixing between the cap 31 is pressed to the urceolus, can realize overhauing the maintenance operation. Compared with the traditional method of fixing the piston outer cylinder 33 through threaded connection, the problem that repeated disassembly causes abrasion to the connecting thread and parts cannot be used when the tool is maintained can be prevented, the operation is simple, and the reliability of the setting tool is improved (see figures 4-16).

After the setting tool 15 is separated from the top packer 2; the upper filling slide 4 is closed by the one-way switch tool 23, and then the inner string is lifted to the upper reservoir reverse circulation position, so that the pressure-building ball 60 is washed out of the shaft from the oil pipe 27 by the upper reservoir reverse circulation mode. After the pressure-building ball 60 is washed out from the oil pipe 27, the isolation packer 8 between the upper oil layer and the lower oil layer is set, after the setting is finished, the inner pipe column is lifted up, the filling hole of the filling tool 20 is lifted out of the upper joint of the isolation packer 8, and whether the setting of the isolation packer 8 is qualified is tested through the pressing of the oil pipe 27. After the isolation packer 8 is qualified in setting, the filling operation is started from bottom to top, when the filling operation is performed, the inner pipe column is lifted up firstly to enable the two-way switch tool 24 to reach the upper end of the lower filling sliding sleeve 9, the inner pipe column is pressed down to open the lower filling sliding sleeve 9 through the two-way switch tool 24, then the inner pipe column is pressed down, and the position of the filling tool 20 is determined through the load indicator 22 and the lower load display coupling 10. Then pumping filling sand through the oil pipe 27, and entering the annular space from the filling hole to the upper runner groove of the lower filling sliding sleeve 9 to start gravel filling operation on the lower oil layer. The specific structure and operation principle of the filling tool 20 are as follows: the packing tool 20 includes a center tube 71, an upper tool joint 72, an elongated outer tube 73, a packing nipple 74, a tee nipple 75, and a lower mandrel 76. One end of the filling short joint 74 is provided with a long sealing mandrel through a double short joint 77; the long seal mandrel tip is fitted with an upper tool adapter 72 through a long outer tube 73. The long sealing mandrel is composed of a sealing mandrel A78, a sealing mandrel B79, a sealing mandrel C80, a sealing mandrel D81 and a sealing mandrel E82, and the sealing mandrel A78, the sealing mandrel B79, the sealing mandrel C80, the sealing mandrel D81 and the sealing mandrel E82 are in threaded connection with one another; one end of the sealing mandrel A78 is in threaded connection with the double-nipple 77; the double nipple 77 is in threaded connection with the filling nipple 74;

one end of the sealing mandrel E82 is in threaded connection with the long outer tube 73; the tool upper joint 72 is in threaded connection with the long outer pipe 73; the long outer pipe 73 is internally provided with an interlayer pipe 83, the end of the interlayer pipe 83 is provided with a central pipe 71 through an intermediate joint 84, and the intermediate joint 84 is respectively in threaded connection with the interlayer pipe 83 and the central pipe 71; one end of the central tube 71 is threadedly connected to the packing sub 74 to axially retain the sandwich tube 83, the intermediate joint 84 and the central tube 71. An upper annular space 97 is arranged between the interlayer pipe 83 and the long outer pipe 73, between the middle joint 84 and the central pipe 71 and the long outer pipe 73, and between the interlayer pipe 83 and the long outer pipe 73, and the long sealing mandrel, an overflowing hole 85 is arranged on the circumference of the end head of the interlayer pipe 83, and the overflowing hole 85 is communicated with the annular space; an insertion pipe 86 is slidably installed in the interlayer pipe 83, one end of the insertion pipe 86 extends into the tool upper joint 72, and a sealing ring is arranged between the interlayer pipe 83 and the insertion pipe 86. Limiting bosses are respectively arranged between contact surfaces of the interlayer pipe 83 and the insertion pipe 86, and the insertion pipe 86 cannot slide downwards (rightwards) through the mutual matching of the limiting bosses on the interlayer pipe 83 and the insertion pipe 86, so that the insertion pipe 86 is axially limited.

The other end of the filling short section 74 is provided with a double-sealing ring mandrel 88 through a lower mandrel 76 and a short sealing mandrel 87, one end of the double-sealing ring mandrel 88 is provided with a reducing sealing mandrel 89 through a three-way short section 75, the end of the reducing sealing mandrel 89 is provided with a sealing mandrel F90, the filling short section 74 is in threaded connection with the lower mandrel 76, and the lower mandrel 76, the short sealing mandrel 87, the double-sealing ring mandrel 88, the three-way short section 75, the reducing sealing mandrel 89 and the sealing mandrel F90 are sequentially in threaded connection.

The filling short section 74, the double-diameter short section 77, the long outer tube 73, the sealing mandrel A78, the sealing mandrel B79, the sealing mandrel C80, the sealing mandrel D81 and the sealing mandrel E82 are respectively provided with an outer sealing assembly 91 on the lower mandrel 76, the short sealing mandrel 87, the double-sealing ring mandrel 88, the three-way short section 75, the reducing sealing mandrel 89 and the sealing mandrel F90; the outer seal assembly 91 is composed of an assembly ring and seal rings uniformly distributed on the circumference of the assembly ring. To form multiple seals on the filling tool.

The filling short section 74 is a diameter-variable body, and tool filling holes 92 are uniformly distributed on the circumference of the middle part of the filling short section 74 in the radial direction; tool fill bore 92 communicates with the central bore of the fill sub 74; pipe walls of the filling nipples 74 on two sides of the central hole are symmetrically and axially provided with nipple bypass holes 93; nipple bypass orifice 93 communicates with upper annulus 97.

A protective pipe 94 is arranged in the center hole of the filling short section 74 corresponding to the tool filling hole 92, and a protective pipe through hole is formed in the circumference of the protective pipe 94 corresponding to the tool filling hole 92; a plug 96 is arranged in the internal thread of the filling nipple 74 at one side of the tool filling hole 92, and the plug 96 is a reducing cup-shaped body; one end of plug 96 extends into lower mandrel 76; the plug 96 cooperates with the filling nipple 74 to clamp the protective pipe 94; the protective tube 94 is fixedly connected with the plug 96 and the filling nipple 74 through a set screw 95.

A ball valve body 99 is arranged in the central holes of the three-way nipple 75 and the double-sealing ring mandrel 88 through a valve seat 98, and a return spring 101 is arranged on the ball valve body 99 through a spring seat 100. One end of the spring seat 100 is in threaded connection with the valve seat 98, and the other end of the spring seat 100 is in threaded connection with the double seal ring mandrel 88. The ball valve 99 is cylindrical, a ball head is arranged at the end of the ball valve 99, and a liquid flow hole 102 is radially arranged on the circumference of the ball valve 99. The ball head is connected with the valve seat 98 in a sliding and sealing way. The circumference of the three-way nipple 75 is symmetrically provided with nipple through holes 103, and the nipple through holes 103 are communicated with a central hole of the three-way nipple 75; one end of a central hole of the three-way nipple 75 is in a plugging shape; and the pipe walls of the three-way nipple 75 at two sides of the central hole are axially provided with three-way nipple bypass holes 104 so as to communicate two sides of the three-way nipple 75. A lower annulus 105 is disposed between the spring seat 100 and the valve seat 98 and the dual seal ring mandrel 88, the lower annulus 105 communicating with a through nipple bypass hole 104.

The filling tool 20 can be divided into a filling mechanism, a reverse circulation mechanism and a sealing mechanism according to functions;

a filling mechanism: the device comprises a protective pipe 94, a filling short joint 74, a plug 96, a lower mandrel 76 and a three-way short joint 75. When the filling tool works, when filling liquid enters the filling tool from the inside of an oil pipe, the filling liquid is blocked at the plug 96 and flows out through the protective pipe through hole of the protective pipe 94 and the tool filling hole 92 of the filling short section 74, the protective pipe 94 plays a role in protecting the filling short section 74 when the filling liquid flows out, the protective pipe through hole of the protective pipe 94 is designed to be a certain oblique angle so as to facilitate the liquid to pass through the protective pipe through hole along the pipe wall, the large impact force on the filling short section 74 caused by sudden large-angle turning of the liquid flow is reduced, the protective pipe 94 is made of alloy materials so as to increase the erosion resistance of the protective pipe 94, the filling tool is prevented from being broken by the liquid during long-time filling operation, and the subsequent maintenance risk is increased;

reverse circulation mechanism: the device comprises a protective pipe 94, a filling nipple 74, a plug 96, a valve seat 98, a ball valve body 99, a return spring 101, a spring seat 100 and a three-way nipple 75; during reverse circulation, liquid is upwards discharged through the nipple through hole 103 of the three-way nipple 75, and reverse circulation of the liquid is realized.

A sealing mechanism: the sealing device is composed of a filling short section 74, a double-mu short section 77, a long outer tube 73, a sealing mandrel A78, a sealing mandrel B79, a sealing mandrel C80, a sealing mandrel D81, an upper sealing mandrel E82, a lower sealing mandrel 76, a short sealing mandrel 87, a double-sealing ring mandrel 88, a three-way short section 75, a reducing sealing mandrel 89, a sealing mandrel F90 and sealing rings arranged among the components, wherein the outer sealing assemblies 91 are respectively arranged on the upper sealing mandrel, the lower sealing mandrel and the sealing mandrel E82; the provision of outer seal assemblies 91, each forming a multi-seal of the filling tool; not only provides the filling channel to the greatest extent to through many times closely, can prevent effectively that when carrying the tubular column from top to bottom, avoid certain sealed inefficacy, make the condition of different layers of oil reservoir intercommunication.

The filling tool 20 is operatively connected to the pipe string via the tool top connection 72, wherein the insert 86 is inserted into the pipe string to ensure the leak-tightness of the connection; the filling tool is connected with a reverse circulation valve, a flushing pipe and the like (not shown) through a sealing mandrel F90 to form a tool string, and then the tool string is lowered to a preset downhole position (filling operation position) together with an isolation packer 8; during filling operation (positive cycle); the filling tool 20 cooperates with the load indicator 22, and by the load indicator 22 being accurately positioned, to a predetermined position, the filling tool 20 is adapted to a seal size of 3.88 ", providing maximum possible access for filling operations. The method specifically comprises the following steps:

pumping glue solution carrying gravel with a certain concentration into the filling nipple 74 through a central hole of the tubular column, the insertion tube 86, the interlayer tube 83, the middle joint 84 and the central tube 71; one end of the central hole of the filling nipple 74 is provided with a plug 96; under the blocking action of the plug 96, the glue solution entering the filling nipple 74 flows out from the protective tube through hole of the protective tube 94 and the tool filling hole 92 of the filling nipple 74 and enters an annulus between the filling tool and the isolation packer to continuously descend. At this time, the perforation 108 on the packing sliding sleeve 106 of the isolation packer 8 is in an open state (the opening and closing of the perforation 108 is realized by pressing and lifting the pipe column, that is, the inner pipe column is pressed down to realize the sliding of the switch tool 107 by hooking the packing tool 20, so that the switch tool 107 releases the blocking state of the perforation 108 to realize the opening of the perforation 108, and the pipe column is lifted to realize the blocking of the perforation 108 by the switch tool 107 by hooking the packing tool to close the perforation 108).

Because the filling nipple 74 is provided with the outer sealing assembly 91, the outer sealing assembly 91 is matched with the inner wall of the isolation packer 8 to form sealing; the glue solution entering the annulus between the filling tool 20 and the filling sliding sleeve 106 of the isolation packer 8 is blocked by the outer sealing assembly 91 and cannot go down continuously; thus, a pressure build-up is formed in the annular space, and when the pressure build-up reaches a certain value, the pressure build-up flows out from the perforation 108 and enters the annular space (operation section) between the isolation packer 8 and the borehole; and (3) glue solution entering an annulus between the isolation packer 8 and the borehole, wherein gravel in the glue solution is deposited in the annulus to form an artificial sand blocking barrier until the whole sand prevention section is covered. The cement (containing very little small-diameter gravel) that has completed the gravel deposition re-enters the central bore of the packing tool through the screen and the perforated pipe 25 and reverse circulation valve at the bottom of the packing tool.

The glue solution entering the central hole of the filling tool 20 passes through the central holes of the sealing mandrel F90 and the reducing sealing mandrel 89, then passes through the tee joint sub bypass hole 104 of the tee joint sub 75 and the lower annulus 105 to enter the central holes of the short sealing mandrel 17 and the lower mandrel 76, and then returns to the ground through the sub bypass hole 93 and the upper annulus 97 of the filling sub 74, so that a positive circulation channel is established, and the aim of gravel filling sand control operation is fulfilled (see the attached figures 17-25).

After the filling operation is finished, the inner pipe column is lifted to the reverse circulation position, and then the reverse circulation sand washing operation can be carried out through the reverse circulation check valve 21, and the purpose of the reverse circulation sand washing operation is to return redundant gravel retained in the oil pipe to the ground through a single reverse circulation channel provided by the filling tool. During reverse circulation sand washing operation; the perforation 108 is in a closed state; the sand washing liquid is pumped into the upper annular space 97 of the filling tool from the ground, and the sand washing liquid entering the upper annular space 97 enters the central hole of the short sealing mandrel 17 through the nipple bypass hole 93 of the filling nipple 74 and the lower mandrel 76. In the process, as the reverse circulation valve at the bottom of the filling tool is in a closed state, the sand washing liquid entering the short sealing mandrel 87 forms a pressure-building effect; when the sand washing hydraulic pressure reaches a certain value, the ball valve body 99 is pushed to move downwards (to the right) and the return spring 101 is compressed, so that the sealing connection state between the ball head and the valve seat 98 is released. After the sealing connection state is released, the sand washing liquid enters the ball valve body 99 from a gap between the ball valve body 99 and the valve seat 98 and the liquid flow hole 102 and then enters the three-way nipple 75, and in the process, one end of a central hole of the three-way nipple 75 is in a blocking shape; under the action of pressure, the sand washing liquid entering the three-way nipple 75 enters an annular space between the filling tool and the isolation packer through the nipple through hole 103, and one end of the three-way nipple 75 is in a sealing state with the isolation packer under the action of the external sealing assembly; the sand washing liquid entering the filling tool and the isolated packer annular space moves upwards along the annular space under the action of pressure, the upward sand washing liquid enters the central hole of the filling short section 74 through the tool filling hole 92 of the filling short section 74 and then returns to the ground through the central pipe 1, the middle joint 84, the inserting pipe 86 and the pipe, and therefore reverse circulation sand washing operation is achieved. The filling tool 20 can perform filling and sand washing actions and realize the setting of the isolation packer 8 only by lifting and lowering the inner pipe column, and when the isolation packer 8 is set in the current period, the filling sliding sleeve of the packer is in a closed state, so that high-pressure liquid flows upwards from the tool filling hole 92 to the hydraulic setting hole of the isolation packer, and the setting of the isolation packer 8 can be realized. The insert pipe 86 is slidably arranged in the interlayer pipe 83 of the filling tool 20, and when the upper end pipe column is connected with the filling tool 20, the upper end pipe column can be directly inserted through the insert pipe 86, so that the effect of inserting and sealing is achieved, and the pipe column sealing is simply and quickly achieved. During filling operation, the protective tube 94 in the filling nipple 74 can effectively reduce the hidden danger that the tool is broken, the service life of the tool is prolonged, and the protective tube through hole in the protective tube 94 and the specific inclined angle of 45 degrees in the liquid flow direction are designed, so that liquid flow can pass through the protective tube through hole along the tube wall, and the impulsive force caused by sudden large-angle turning of the liquid flow to parts is reduced. The unique bypass flow channel is designed to provide a separate channel for filling and reverse circulation, so that the filling safety is ensured.

After filling, reverse circulation is needed to wash gravel retained in the oil pipe out of the shaft, the inner pipe column is lifted up to close the lower filling sliding sleeve 9 through the one-way switch tool 23, then the pipe column is pressed down to determine the position of the reverse circulation check valve 21, liquid is pumped into the annulus, the liquid enters the small annulus through the hole in the setting tool 5 and then reaches the ball valve body 99 of the reverse circulation hole through a side bypass, the ball valve body 99 is opened, and the liquid enters the oil pipe 27 through the reverse circulation hole and the filling hole to form a reverse circulation channel, so that the aim of washing redundant gravel in the oil pipe out of the shaft is fulfilled. The specific structure and the working principle of the reverse circulation check valve 21 are as follows: the reverse circulation check valve 21 is composed of a check valve sealing sleeve 109, a check valve upper joint 110, a check valve lower joint 111, a check valve spool 114, a check valve suspension joint 112 and a check valve suspension sleeve 113. One end of the check valve upper joint 110 is provided with a check valve sealing sleeve 109; the check valve sealing sleeve 109 is in threaded connection with the check valve upper joint 110, and the check valve sealing sleeve 109 and the check valve upper joint 110 are fixed with each other through a check valve fastening screw A115; an O-ring seal is provided between the check valve sealing sleeve 109 and the check valve upper fitting 110 to ensure the sealing between the check valve sealing sleeve 109 and the check valve upper fitting 110.

One end of the check valve sealing sleeve 109 is provided with a check valve lower joint 111; a check valve suspension joint 112 is arranged on the check valve lower joint 111 through a check valve suspension sleeve 113; liquid discharge through holes are axially and uniformly distributed on the circumference of the single-flow valve hanging sleeve 113. The lower joint 111 of the check valve is connected with the sealing sleeve 109 of the check valve and the suspension joint 112 of the check valve in a sliding and sealing way; the check valve suspension joint 112 and the check valve suspension sleeve 113 are slidably connected. The check valve suspension adapter 112 and the check valve suspension sleeve 113 are axially rotatable with respect to each other. The check valve lower joint 111 and the check valve suspension sleeve 113 are in threaded connection with each other, and the check valve lower joint 111 and the check valve suspension sleeve 113 are fixed with each other through a check valve fastening screw C117; the check valve lower joint 111 is a step-shaped reducing tubular body, and a check valve outer sealing assembly A116 is arranged on the circumference of one end of the check valve lower joint 111.

The check valve gland 109 is threaded with a nut 118 at the end, and the nut 118 is connected to the check valve suspension fitting 112 by a check valve fastening screw B11. A check valve and check valve outer sealing assembly B1200 is arranged on the circumference of the check valve sealing sleeve 109 on one side of the screw cap 118; the check valve outer sealing assembly B120 and the check valve outer sealing assembly A116 are respectively composed of an assembly ring and sealing rings arranged on the assembly ring at intervals. A clearance is provided between the nut 118 and the check valve suspension sleeve 113 to allow for travel for relative movement between the check valve suspension sleeve 113 and the check valve suspension adapter 112 during operation.

The central hole of the check valve sealing sleeve 109 is a step-shaped variable diameter hole; a flow guide disc 121 is fixedly clamped between the check valve sealing sleeve 109 and the check valve upper joint 110 through a step end face of the check valve sealing sleeve 109 and an end face of the check valve upper joint 110, the flow guide disc 121 is disc-shaped, a mounting hole is formed in the center of the flow guide disc 121, and liquid flow holes are uniformly distributed in the flow guide disc on the periphery of the mounting hole. The flow guiding disc 121 is movably provided with a check valve core 114 through a mounting hole and a check valve spring 122, and the check valve core 114 is in a T shape. One end of the check valve core 114 is in clearance-sealing contact connection with the port of the check valve lower joint 111 and the small port of the central hole of the check valve sealing sleeve 109, and check valve liquid inlet holes 123 are uniformly distributed on the circumference of the port of the check valve lower joint 111 adjacent to the check valve core 114 so as to communicate liquid flow channels at two ends of the check valve core 114. The flow guide disc 121 can limit the upward movement of the check valve core 114, and the check valve core 114 is inserted into the mounting hole of the flow guide disc 121 to play a role in righting the check valve core 114, so that the problem that the check valve core 114 in a highly deviated well is in an eccentric tubular column and cannot be seated well and sealed with the check valve sealing sleeve 109 is avoided.

The reverse circulation check valve 21 is mounted on the filling tool 20 through the check valve upper fitting 110 and cooperates with the load indicator 22; when filling at the sand control operation in-process, pushing down interior tubular column, guaranteeing that circulation channel is unblocked, during the reverse circulation, lifting interior tubular column, closing upper and lower passageway, realize the switch of artificial control reverse circulation check valve 21 to this improvement stability in use specifically is:

during filling operation, the pipe string is firstly pressed downwards, in the process, the check valve upper joint 110, the check valve sealing sleeve 109 and the check valve suspension joint 112 move downwards relative to the check valve lower joint 111, and the check valve lower joint 111 moves upwards; the check valve hanging joint 112 and the check valve hanging sleeve 113 axially slide relatively; when the check valve upper connector 110, the check valve sealing sleeve 109 and the check valve suspension connector 112 move downwards relative to the check valve lower connector 111 to a dead center, the check valve liquid inlet 123 on the check valve lower connector 111 is exposed from the check valve sealing sleeve 109, the sealing contact state of the check valve core 114 and the small port of the central hole of the check valve sealing sleeve 109 is released, and the reverse circulation check valve 21 is opened, thereby providing a circulation channel for the filling operation. At the moment, filling liquid which is not squeezed into the stratum and is deposited in the sand prevention section enters a lower oil pipe from the sieve pipe during filling, flows upwards to the reverse circulation check valve 21, then flows upwards through the check valve lower joint 111, the check valve liquid inlet hole 123, the check valve sealing sleeve 109, the liquid flow hole of the flow guide disc 121 and the check valve upper joint 110 until returning to a wellhead, so that the circulation channel is smooth during filling, and filling operation is realized.

After the filling operation is finished, excess gravel in the oil pipe needs to be washed out of the shaft through reverse circulation, namely when the reverse circulation is carried out, the inner pipe column is lifted up, in the process, the check valve upper joint 110, the check valve sealing sleeve 109, the check valve suspension joint 112 and the check valve lower joint 111 move back to back, and the check valve lower joint 111 moves downwards; the contact state of the end of the check valve lower joint 111 and the check valve core 114 is released; the check valve liquid inlet 123 on the check valve lower joint 111 enters the small hole in the check valve sealing sleeve 109 to be blocked, meanwhile, the check valve spring 122 rebounds to press the check valve core 114 on the small port of the central hole of the check valve sealing sleeve 109 to be in a sealing contact state, at the moment, the central hole of the check valve lower joint 111 is in a closed state, and the flow passage channel is closed, so that the purpose of isolating the upper flow passage and the lower flow passage is achieved, at the moment, the reverse circulation liquid is blocked when flowing to the reverse circulation valve in the oil pipe 27 and then flows to the upper annular space to take gravel remained in the oil pipe out of the well head, and the reverse circulation operation is achieved (see the attached figures 26-27).

The check valve core 114 of the reverse circulation check valve adopts a T-shaped design, and the end head of one end of the check valve core is hemispherical, so that the sealing state of the check valve core and a small-diameter hole port of a check valve sealing sleeve 109 can be ensured; and is inserted on the deflector 121 through the mounting hole of the deflector 121; the purpose of righting the check valve core 114 can be achieved through the mounting hole of the flow guide disc 121, and therefore the purpose that in a well with a large inclination, the check valve core 114 is deviated from a sealing position due to the influence of self gravity and the effect of closing and isolating an upper flow channel and a lower flow channel is influenced is avoided. The check valve suspension joint 112 and the check valve suspension sleeve 113 of the reverse circulation check valve can rotate circumferentially relative to each other, so that an upper pipe column can rotate independently without influencing a lower pipe column, and load limiting transmission is performed through limiting bosses at the ends of the check valve suspension joint 112 and the check valve suspension sleeve 113. The transmission of tubular column load has been guaranteed promptly, lower part tubular column is not influenced when can making upper portion tubular column free rotation again, only need during the operation through lift, push down the action of upper portion tubular column just can control opening, closing of this reverse circulation check valve, has guaranteed the stable form and the controllability that use from this.

After the filling operation of the lower oil layer is finished, the oil layer is filled layer by layer from bottom to top by a filling and reverse circulation method according to the steps, wherein the inner pipe column only needs to be lifted and lowered and is displayed and positioned by the load indicator 22, and the multi-layer gravel filling operation can be realized once. According to the invention, the multi-layer packing sand prevention operation can be realized by once putting the pipe column, the pipe column does not need to be put in and taken out for many times, and the problems of long operation time consumption, complex operation and high operation cost caused by the fact that tool pipe columns need to be put in for many times when the multi-layer gravel packing operation is carried out in the single-layer sand prevention mode of one layer of sand prevention of the existing machinery; the invention can realize 3.88 'large inner diameter in 7' tubular column, provides large drift diameter for production operation to the greatest extent, meets the requirement of large discharge, improves the yield, and has positive popularization significance for sand control operation of oil and gas wells.

Claims

1. A sand control process for once multi-layer gravel packing is characterized in that: it comprises the following steps:

1) connecting and assembling the outer pipe column and the inner pipe column; the outer pipe column consists of a top packer (2), an upper extension barrel (3), an upper filling sliding sleeve (4), an upper load display coupling (5), an upper blind pipe (6), an upper sieve pipe (7), an isolation packer (8), a lower filling sliding sleeve (9), a lower load display coupling (10), a lower blind pipe (11), a lower sieve pipe (12), a sealing assembly (13) and a sand setting packer (14); the inner pipe column consists of a setting tool (15), an inner flushing sleeve (16), an inner flushing pipe short section (17), a sealing mandrel (18), a lower short section (19), a filling tool (20), a reverse circulation check valve (21), a load indicator (22), a one-way switching tool (23), a two-way switching tool (24), a perforated pipe (25) and a bottom seal (26) which are connected in sequence;

2) setting the sand setting packer (14) into the bottom of the well, and setting the sand setting packer (14) to complete bottom sealing of the shaft (1);

3) after the sand setting packer (14) completes bottom sealing and setting of the shaft (1), an outer pipe column which is connected except for the top packer (2) is lowered into the shaft (1), and the top of the outer pipe column is fixed at a well mouth through an upper extension barrel (3); the bottom of the outer pipe column is inserted into a sand setting packer (14) through a sealing assembly (13);

4) connecting the top packer (2) with a setting tool (15) at the top of the inner tubular column, and then putting the inner tubular column into the outer tubular column; after the whole pipe column is completely put in, the operation can be started;

5) when in operation, firstly, a pressure-holding ball (60) is thrown into the setting tool (15) for sealing, then the setting top packer (2) is pressed through the oil pipe (27), after the top packer (2) is set, then the sleeve pipe is pressed to test whether the setting of the top packer (2) is qualified, after the setting is qualified, the oil pipe (27) is continuously pressed, so that the setting tool (15) and the top packer (2) are separated from each other, and the connection relation between the inner pipe and the outer pipe is released; if the setting tool (15) is not smoothly released from the top packer (2), releasing can be realized in a forward-rotation mechanical releasing mode;

6) after the setting tool (15) and the top packer (2) are separated from each other; closing the upper filling sliding sleeve (4) through a one-way switch tool (23), then lifting the inner pipe column to an upper oil layer reverse circulation position, and washing the pressure-building ball (60) out of the shaft in an upper oil layer reverse circulation mode;

7) after the pressure-building ball (60) is washed out, an isolation packer (8) between an upper oil layer and a lower oil layer is set, after the setting is finished, the inner pipe column is lifted up, a filling hole of the filling tool (20) is lifted out of an upper joint of the isolation packer (8), and whether the isolation packer (8) is qualified is tested by pressing through an oil pipe (27); the filling tool (20) comprises a central pipe (71), an upper tool joint (72), a long outer pipe (73), a filling short section (74), a three-way short section (75) and a lower mandrel (76); the filling short section (74) is a diameter-variable body, and tool filling holes (92) are radially and uniformly distributed on the circumference of the middle part of the filling short section (74); a tool fill hole (92) in communication with the central bore; a pipe wall of the filling nipple (74) is symmetrically and axially provided with a nipple bypass hole (93); a protective pipe (94) is arranged in a center hole of the filling short section (74) corresponding to the tool filling hole (92), and a protective pipe through hole is formed in the circumference of the protective pipe (94) and corresponds to the tool filling hole (92); the protective pipe (94) is connected with the plug (96) and the filling short section (74) through a set screw; one end of the filling short section (74) is provided with a long sealing mandrel through a double short section (77); the end head of the long sealing mandrel is provided with an upper tool joint (72) through a long outer tube (73); a sandwich pipe (83) is installed in the long outer pipe (73), the end of the sandwich pipe (83) is provided with a central pipe (71) through an intermediate joint (84), the other end of the filling short section (74) is provided with a double-sealing ring mandrel (88) through a lower mandrel (76) and a short sealing mandrel (87), one end of the double-sealing ring mandrel (88) is provided with a reducing sealing mandrel (89) through a tee short section (75), and the end of the reducing sealing mandrel (89) is provided with a sealing mandrel F (90);

8) after the isolation packer (8) is qualified in setting, the filling operation is started from bottom to top, during the filling operation, the inner pipe column is lifted up to enable the two-way switch tool (24) to reach the upper end of the lower filling sliding sleeve (9), the lower filling sliding sleeve (9) is opened by the lower pressing pipe column through the two-way switch tool (24), then the pipe column is pressed down, the position of the filling tool (20) is determined through the load indicator (22) and the lower load display coupling (10), filling sand is pumped in through the oil pipe (27), and the filling sand enters the annular space through the filling hole (70) to the upper runner groove of the lower filling sliding sleeve (9), so that the gravel filling operation is started for the lower oil layer;

9) after filling, gravel retained in the oil pipe (27) and the filling tool (20) needs to be washed out of the well bore (1) by reverse circulation, an inner pipe column is lifted up to close a lower filling sliding sleeve (9) through a one-way switch tool (23), then the pipe column is pressed down to determine the position of a reverse circulation check valve (21), liquid is pumped from the annulus, the liquid enters the small annulus through a hole in a setting tool (15), and then reaches the ball valve body (99) of a reverse circulation hole through a side bypass, the ball valve body (99) is opened, the liquid enters the oil pipe (27) through the reverse circulation hole and the filling hole (70) to form a reverse circulation channel, and the purpose of washing out redundant gravel in the well bore (1) in the oil pipe (27) and the filling tool (20) is achieved; the reverse circulation check valve (21) is composed of a check valve sealing sleeve (109), a check valve upper joint (110), a check valve lower joint (111), a valve core (114), a check valve suspension joint (112) and a check valve suspension sleeve (113), wherein the check valve sealing sleeve (109) is installed at one end of the check valve upper joint (110); a nut (118) is installed at the end of the check valve sealing sleeve (109) in a threaded manner, and a check valve lower joint (111) is arranged at one end of the check valve sealing sleeve (109); a check valve outer sealing assembly A (116) is arranged on the circumference of one end of the check valve lower joint (111), and a check valve suspension joint (112) is arranged on the check valve lower joint (111) through a check valve suspension sleeve (113); the check valve suspension joint (112) and the check valve suspension sleeve (113) can rotate circumferentially, so that the upper pipe column can rotate independently without influencing the lower pipe column, and load is transmitted in a limiting manner through limiting bosses at the ends of the check valve suspension joint (112) and the check valve suspension sleeve (113);

10) and after the filling operation of the lower oil layer is finished, filling the oil layer by layer from bottom to top by a filling and reverse circulation method according to the steps, wherein the inner pipe column only needs to be lifted and lowered and is displayed and positioned by a load indicator (22), and the multi-layer gravel filling operation can be realized once.

2. The sand control process of one-time multi-layer gravel packing as claimed in claim 1, wherein: the setting tool (15) comprises a mandrel (43), a setting short section (30), a setting upper joint (28) and a ball seat short section; a setting nipple (30) is installed at one end of the setting upper joint (28), a piston outer cylinder (33) is installed on the setting nipple (30), an outer cylinder pressing cap (31) is installed on the setting nipple (30) at the end of the piston outer cylinder (33), a protective sleeve (29) is installed on an internal thread of the setting upper joint (28), and one end of the protective sleeve (29) extends into the setting nipple (30); a mandrel (43) is installed in an internal thread of the setting short section (30) on one side of the end of the protective sleeve (29), a locking block (34) is installed between the mandrel (43) and the setting short section (30), a piston (35) is installed on one side of the locking block (34) and the mandrel (43) on the end of the setting short section (30), and a piston extension cylinder (36) is installed on the mandrel (43) on one side of the piston (35); one end of the piston extension cylinder (36) and one end of the mandrel (43) extend to the outer end of the piston outer cylinder (33), a setting sliding sleeve (38) is installed on the circumference of the end head of the piston extension cylinder (36) extending to the outer end of the piston outer cylinder (33) through a releasing pin (58), a bearing lug (41) and an elastic chuck (39) are installed on the mandrel (43) at the end head of the setting sliding sleeve (38) through a skin rolling pin (63) and a spring (42), and a shearing outer sleeve (44) is installed on the mandrel (43) on one side of the skin rolling pin (63); the slip (49) is installed through slip braced ring (50) and card spring (48) on cutting dabber (43) of overcoat (44) one side, is equipped with on dabber (43) of slip (49) one side and cuts release cover (45) and release pawl (46), and dabber (43) port screw thread that extends to piston extension section of thick bamboo (36) outer end installs location nipple joint (51), and ball seat nipple joint is installed to location nipple joint (51) end screw thread.

3. The sand control process of one-time multi-layer gravel packing as claimed in claim 1, wherein: an insertion pipe (86) is arranged in the interlayer pipe (83) in a sliding mode, one end of the insertion pipe (86) extends into the upper tool joint (72), and a sealing ring is arranged between the interlayer pipe (83) and the insertion pipe.

4. The sand control process of one-time multi-layer gravel packing as claimed in claim 1, wherein: the double-meter short section (77) is in threaded connection with the filling short section (74); the long sealing mandrel is composed of a sealing mandrel A (78), a sealing mandrel B (79), a sealing mandrel C (80), a sealing mandrel D (81) and a sealing mandrel E (82), and the sealing mandrel A (78), the sealing mandrel B (79), the sealing mandrel C (80), the sealing mandrel D (81) and the sealing mandrel E (82) are in threaded connection with each other; the sealing mandrel A (78) is in threaded connection with the double-mu short joint (77); the sealing mandrel E (82) is in threaded connection with the long outer tube (73); the upper tool joint (72) is in threaded connection with the long outer pipe (73); fill nipple joint (74) and dabber (76) threaded connection down, dabber (76), short sealed dabber (87), double seal ring dabber (88), tee bend nipple joint (75), reducing sealed dabber (89), sealed dabber F (90) between threaded connection in proper order, lower dabber (76), short sealed dabber (87), double seal ring dabber (88), tee bend nipple joint (75), reducing sealed dabber (89), sealed dabber F (90) on be provided with external seal assembly (91) respectively.

5. The sand control process of one-time multi-layer gravel packing as claimed in claim 1, wherein: the check valve sealing sleeve (109) is provided with a reducing central hole; a flow guide disc (121) is clamped between the check valve sealing sleeve (109) and the check valve upper joint (110), a mounting hole is formed in the center of the flow guide disc (121), and liquid flow holes are uniformly distributed in the flow guide disc (121) on the periphery of the mounting hole; a valve core (114) is movably mounted on the flow guide disc (121) through a check valve spring (122), and one end of the valve core (114) is in sealing contact connection with a port of a check valve lower connector (111).