CN114482957A - Open hole full-bore infinite staged fracturing well completion device and fracturing well completion method thereof - Google Patents

Abstract

The invention discloses an open hole full-drift diameter infinite stage staged fracturing well completion device and a fracturing well completion method thereof, which are suitable for fracturing well completion processes of horizontal wells and vertical wells. The device comprises a casing string, a top suspension packer, an open hole fracturing packer, a fracturing well completion sliding sleeve, a differential pressure type fracturing well completion sliding sleeve, a shaft isolation valve and a bottom circulating valve, wherein the open hole fracturing packer and the fracturing well completion sliding sleeve are multiple and are matched with the casing string to form an open hole full-drift-diameter infinite-grade segmented fracturing well completion device; the staged fracturing series of the invention is not limited; the fracturing sleeve not only can realize one spoon one opening of the fracturing well completion sliding sleeve at any fixed point, but also can realize one spoon one opening of the one-level multi-cluster fracturing well completion sliding sleeve, and after the fracturing sleeve is pressed, the full drift diameter of a well completion pipe column is realized, the requirements of continuous, rapid, large-scale and multi-level multi-cluster fracturing construction are met, and the fracturing efficiency is improved.

Description

Open hole full-bore infinite staged fracturing well completion device and fracturing well completion method thereof

Technical Field

The invention relates to a fracturing well completion device of an oil-water well in the petroleum industry, in particular to a full-bore infinite-diameter staged fracturing well completion device for an open hole and a fracturing well completion method thereof.

Background

At present, fracturing well completion technologies for low-permeability and compact oil reservoirs at home and abroad are mainly divided into an open hole multistage staged fracturing well completion technology and a casing cementing multistage staged fracturing well completion technology. The mainstream technology covers modes such as ball-throwing sliding sleeve type multi-stage staged fracturing well completion, pumping bridge plug multi-stage staged fracturing well completion and the like.

The ball throwing sliding sleeve type multistage staged fracturing well completion technology is applied to open hole fracturing well completion or casing cementing fracturing well completion, balls and ball seats with different grade differences are combined, and staged fracturing is completed stage by throwing the balls with different grade differences and opening fracturing well completion sliding sleeves with corresponding grade differences. The technology is influenced by the size of the ball seats arranged in a grading way, the subsection quantity and the fracturing scale of the technology are greatly limited, the transformation effect is influenced, the ball seats are required to be drilled and ground in the later production to form a full drift diameter, and the operation cost is high. The pumping bridge plug multistage staged fracturing well completion technology is applied to casing cementing fracturing well completion, the technology has no limitation on staged stages, but the perforation fracturing combined process cannot keep fracturing continuity, the operation period is long, drilling plugs are needed after the operation is completed, the operation cost is high, and selective production or secondary fracturing cannot be performed in the later stage.

In recent years, various delivery type fracturing technologies for opening a fracturing sliding sleeve are developed successively by various large oil companies. For example, chinese patent CN103556971B entitled "full-bore layered fracturing sliding sleeve for oil-gas well operation" granted 3/2/2016 discloses a novel pitching sliding sleeve containing a step-type moving mechanism, which can realize the function of sequentially pitching balls with the same size to open the sliding sleeve step by step, and can realize unlimited number of numbers and maintain all the full-bore diameters of the sliding sleeve in principle, but the sliding sleeve has sand-blocking risk in actual use, which causes the sliding sleeve to be unable to be normally opened and lose the fracturing layer section; in addition, as the structure of the fracturing head does not relate to a sealing mechanism, the fracturing construction is easy to cause vertical leakage; the starting ball in the later process still needs to be discharged back, and the process is complex.

In addition, chinese patent application CN110905448A published in 24/3/2020, "an infinite graded full-bore fracturing sliding sleeve assembly system", discloses a fracturing system including a plurality of sub-fracturing sliding sleeves connected in series through a pipeline and corresponding to a plurality of opening mechanisms one by one, and the system can realize that after fracturing of all intervals is completed, the whole pipe column is a full bore without drilling operation, thereby facilitating later-stage production management, and the multistage sliding sleeves can realize infinite grading in series, but the positioning elastic member of the opening mechanism in the fracturing sliding sleeve system is easy to generate plastic deformation in the process of passing through the multistage fracturing sliding sleeves, causing opening failure and losing fracturing; meanwhile, the positioning groove is an annular gap between the upper joint and the inner sleeve, and selective switching cannot be performed at the later stage.

Therefore, a full-drift-diameter infinite-stage fracturing well completion device which can be rapidly implemented in an infinite-stage, multistage and multi-cluster, large-scale and continuous manner in a horizontal well, a straight inclined well and the like is urgently needed, and any sliding sleeve can be selectively opened or closed in the later period according to needs.

Disclosure of Invention

The invention aims to provide an open hole full-bore infinite-grade segmented fracturing well completion device aiming at the defects in the prior art. The fracturing well completion sliding sleeve can match the opening tool with the fracturing well completion sliding sleeve one by one, meets the requirements of full-drift-diameter, limitless, continuous, rapid and multistage multi-cluster fracturing well completion construction of open hole well completion, and improves construction scale, staged stage and fracturing efficiency.

The invention also provides a fracturing well completion method using the fracturing well completion device.

1. The technical scheme of the invention is as follows: the open hole full drift diameter infinite stage staged fracturing well completion device comprises a casing string, a top suspension packer, a plurality of open hole fracturing packers, a fracturing well completion sliding sleeve, a pressure differential type fracturing well completion sliding sleeve, a shaft isolation valve and a bottom circulating valve, wherein the top suspension packer is arranged at the upper end of the casing string, the plurality of open hole fracturing packers are arranged on the casing string at intervals, the fracturing well completion sliding sleeves are multiple and are arranged on the casing string to form the open hole full drift diameter infinite stage staged fracturing well completion device, the two ends of each stage of the fracturing well completion sliding sleeve are provided with the open hole fracturing packers, and the pressure differential type fracturing well completion sliding sleeve, the shaft isolation valve and the bottom circulating valve are sequentially arranged at the lower end of the casing string from top to bottom;

wherein, each fracturing completion sliding sleeve all includes:

the outer sleeve is provided with a plurality of sand blasting holes communicated with the inner cavity, and the outer sleeve is provided with a plurality of positioning grooves;

the inner sliding sleeve is arranged on the inner wall of the outer sleeve in a sliding mode and connected with the outer sleeve through a shearing pin, and the outer wall of the inner sliding sleeve is used for sealing the sand blasting hole; a positioning piece matched with the positioning groove is movably arranged on the outer surface of the inner sliding sleeve; a first sealing element is also arranged between the outer sleeve and the inner sliding sleeve; an opening groove and a closing groove are respectively arranged on the inner wall of the inner sliding sleeve, and the opening groove is matched with an opening tool; an inner sliding sleeve accommodating cavity used for opening the sand blasting hole when the inner sliding sleeve moves is arranged in the outer sleeve, and one positioning groove is positioned in the inner sliding sleeve accommodating cavity;

the sliding sleeve lower joint is in threaded connection with the lower end of the outer sleeve, and a guide slope surface is arranged at the upper end of the sliding sleeve lower joint.

Preferably, an opening tool for opening the inner sliding sleeve is movably arranged inside the fracturing completion sliding sleeve, and the opening tool comprises:

the outer surface of the tool upper joint is provided with a second sealing element used for sealing the inner wall of the inner sliding sleeve, and the upper end of the tool upper joint is provided with a soluble ball used for sealing the inner cavity;

the central tube is in threaded connection with the upper tool joint, an opening sliding block matched with the opening groove is movably mounted on the outer wall of the central tube, and a spring used for opening the radial expansion of the sliding block is further arranged between the central tube and the opening sliding block;

and the lower tool joint is arranged at the lower end of the central pipe.

Preferably, the opening grooves are spirally distributed at the lower part of the inner sliding sleeve in 360 degrees, the opening grooves and the axis of the inner sliding sleeve form an inclination angle alpha, and the inclination angle alpha is 0-60 degrees.

Preferably, the opening groove comprises a guide opening and a slider groove connected with the guide opening, and the opening slider is matched with the opening groove; an annular groove for radially limiting the opening slide block is formed between the lower tool joint and the upper tool joint and between the lower tool joint and the central tube; the upper end and the lower end of the opening sliding block are respectively provided with an inclined plane, and the inclined plane at the lower end of the opening sliding block is matched with the conical opening of the lower joint of the sliding sleeve.

Preferably, the opening groove comprises a guide opening, a slider groove connected with the guide opening and a guide groove connected with the lower end of the slider groove, the lower tool joint is connected with the central pipe through a connecting piece, and a limiting groove for radially limiting the opening slider is formed between the connecting piece and the upper tool joint as well as between the connecting piece and the central pipe; and a pressing cap is arranged between the connecting piece and the lower tool joint, a plurality of guide keys extending out of the outer surface of the pressing cap are mounted on the pressing cap, and the guide keys are matched with the guide grooves.

Preferably, the number of the fracturing completion sliding sleeves on each stage of fracturing completion device is one or more.

Preferably, the number of the springs between each opening slide block and the central pipe is 2-6, and a telescopic space for the opening slide blocks to stretch is arranged between each opening slide block and the central pipe.

Preferably, the positioning piece is an elastic positioning piece, and the opening tool is made of a soluble metal material.

The invention provides a fracturing well completion method of an open hole full-bore infinite-grade segmented fracturing well completion device, which comprises the following steps of:

1) after determining the staged fracturing stage number and the installation position of the fracturing completion sliding sleeve, matching the fracturing completion pipe string;

2) putting the matched fracturing completion pipe string into the well for positive circulation displacement, throwing balls to close a shaft isolation valve, completing setting of a plurality of open hole fracturing packers by means of pressure, continuing to complete setting releasing of the top suspension packer, and enabling the whole well to be qualified in pressure test;

3) after open hole well completion, installing a large-drift-diameter fracturing well mouth, firstly, opening the lowest-level differential fracturing well completion sliding sleeve by pumping and pressurizing so as to establish a communication channel between a casing and a stratum, then sequentially delivering opening tools matched with each-level fracturing well completion sliding sleeve one by one from bottom to top so that the opening tools enter the fracturing well completion sliding sleeve by pumping, and completing opening action on each-level fracturing well completion sliding sleeve step by step;

4) when the opening tool is not matched with the fracturing well completion sliding sleeve, namely the shape and the size of the opening sliding block are not matched with those of the opening groove, the opening action cannot be realized, and at the moment, the opening sliding block is always in a compressed state and passes through the unmatched sliding sleeve until entering the corresponding matched sliding sleeve;

5) when the opening tool is matched with the fracturing well completion sliding sleeve, the opening sliding block is in a compressed state when not entering the opening groove, when entering the opening groove, the shape and the size of the opening groove are completely matched with those of the opening sliding block of the opening tool, and the opening sliding block is in a free state and is locked with the opening groove; at the moment, the inner cavity of the tool is opened by the soluble ball seal, the second sealing element and the inner sliding sleeve are in an interference sealing state, and the channel in the inner sliding sleeve is completely sealed;

6) when the casing pipe is suppressed to a preset pressure under the hydraulic action, shearing pins on the fracturing completion sliding sleeve are sheared, an opening tool drives the inner sliding sleeve to move downwards, the positioning piece climbs out of the positioning groove and is in a compressed state, and the positioning piece and the inner sliding sleeve continue to move downwards to enter the next positioning groove and are in a free state; at this moment, the inner sliding sleeve is opened in place, the sand blasting hole is exposed, the fracturing well completion sliding sleeve is in a fully opened state, and a fracturing channel is established;

7) when the pressure in the sleeve continues to be increased, the opening tool drives the inner sliding sleeve to continue to move downwards, the lower tool joint slides to the left end part of the lower sliding sleeve joint of the fracturing well completion sliding sleeve and continues to move downwards to enter the lower sliding sleeve joint, at the moment, the inclined plane at the right end of the opening sliding block is contacted with the guide slope surface at the left end of the lower sliding sleeve joint and is extruded, the opening sliding block climbs out of the opening groove under the action of the pumping pressure of the sleeve, the opening tool is gradually separated from the inner sliding sleeve, the inner sliding sleeve is positioned in the accommodating cavity of the inner sliding sleeve in place and does not move downwards any more, a certain stroke allowance is reserved at the positioning groove at the lower part of the outer sleeve, and the positioning element cannot climb out of the positioning groove;

8) the opening tool continues to move downwards under the action of hydraulic pressure, enters the next cluster of fracturing well completion sliding sleeves matched with the opening tool, continues to perform the actions, completely opens the corresponding fracturing well completion sliding sleeves matched with the opening tool, establishes a fracturing channel, and is locked with the inner sliding sleeve and does not move downwards after the opening tool enters the last cluster of fracturing well completion sliding sleeves matched with the opening tool and finishes the action of opening the inner sliding sleeve, and at the moment, finishes the action of 'one key and more openings' of all the first-stage multi-cluster fracturing well completion sliding sleeves;

9) after pressing, the opening tools can be completely dissolved to form a full-drift-diameter fracturing well completion shaft, then, according to production requirements, a special hydraulic control closing tool can be selected for selectively closing the fracturing well completion sliding sleeve, if the fracturing well completion sliding sleeve needs to be opened again at a fixed point, the opening tool matched with the fixed-point fracturing well completion sliding sleeve can be selected, and hydraulic delivery is carried out and actions from 4) to 8) are repeated to complete opening.

The invention provides a fracturing well completion method of a second open hole full-bore infinite-grade segmented fracturing well completion device, which comprises the following steps of:

1) after determining the staged fracturing stage number and the installation position of the fracturing completion sliding sleeve, matching the fracturing completion pipe string;

2) putting the matched fracturing completion pipe string into the well for positive circulation displacement, throwing balls to close a shaft isolation valve, completing setting of a plurality of open hole fracturing packers by means of pressure, continuing to complete setting releasing of the top suspension packer, and enabling the whole well to be qualified in pressure test;

3) after open hole well completion, a large-drift-diameter fracturing well head is installed, firstly, the lowest-level differential pressure type fracturing well completion sliding sleeve is opened through pumping pressurization, so that a communication channel between a casing and a stratum is established, then opening tools matched with each level of fracturing well completion sliding sleeves are sequentially delivered one by one from bottom to top, so that the opening tools enter the fracturing well completion sliding sleeves through pumping, and the opening action of each level of fracturing well completion sliding sleeves is completed step by step;

4) when the opening tool is not matched with the fracturing well completion sliding sleeve, namely the shape and the size of the opening sliding block and the guide key are not matched with the shape and the size of the opening groove, the opening action cannot be realized, and at the moment, the opening sliding block and the guide key are always in a compressed state and pass through the unmatched sliding sleeve until entering the corresponding matched sliding sleeve;

5) when the shapes and the sizes of the opening slide block and the guide key are respectively matched with the shapes and the sizes of the slide block groove and the guide groove, the opening slide block and the guide key are in a compressed state when not entering the opening groove, and when respectively entering the slide block groove and the guide groove, the opening slide block and the guide key are in a free state and are locked with the opening groove, at the moment, the soluble ball seals an inner cavity of the tool, the second sealing element and the inner sliding sleeve are in an interference sealing state, and a channel in the inner sliding sleeve is completely sealed;

6) when the casing pipe is suppressed to preset pressure under the action of hydraulic pressure, shearing pins on the fracturing well completion sliding sleeve are sheared, an opening tool drives the inner sliding sleeve to move downwards, a positioning piece climbs out of a positioning groove and is in a compressed state, and the positioning piece and the inner sliding sleeve continue to move downwards to enter the next positioning groove and are in a free state, so that the inner sliding sleeve and the opening tool are locked and are positioned in an inner sliding sleeve accommodating cavity to be opened in place, the inner sliding sleeve does not move downwards any more, a sand blasting hole is exposed, the fracturing well completion sliding sleeve is in a completely opened state, a fracturing channel is established, and the 'one-spoon one-opening' action of opening the fracturing well completion sliding sleeve at any fixed point is completed;

7) after pressing, the opening tools can be completely dissolved to form a full-drift-diameter fracturing well completion shaft, then, according to production requirements, a special hydraulic control closing tool can be selected for selectively closing the fracturing well completion sliding sleeve, if the fracturing well completion sliding sleeve needs to be opened again at a fixed point, the opening tool matched with the fixed-point fracturing well completion sliding sleeve can be selected, and hydraulic delivery is carried out and actions from 4) -6) are repeated to complete opening.

Compared with the prior art, the invention has the following advantages:

(1) the matching of the fracturing well completion sliding sleeve and the sliding block and the groove of the opening tool in the open hole full-drift-diameter infinite-stage staged fracturing well completion device has uniqueness, and the opening at any fixed point can be realized;

(2) the matching of the fracturing completion sliding sleeve and the sliding block and the groove of the opening tool has various sequence combinations, so that the stage number of staged fracturing is not limited;

(3) a plurality of fracturing well completion sliding sleeves can be placed in the open hole staged fracturing well completion device according to needs, the fracturing well completion sliding sleeves are designed to be of equal drift diameter, no level difference exists, the number of fracturing stages is not limited, and the requirements of large-displacement and large-scale fracturing construction are met;

(4) the fracturing well completion sliding sleeves are matched with the opening tools one by one, so that not only can one spoon be opened, but also more spoons can be opened, the continuous, rapid, multistage and multi-cluster fracturing construction requirements are met, and the fracturing efficiency is improved;

(5) the opening tool in the fracturing well completion device can be dissolved after being pressed, the full drift diameter of the open hole full drift diameter infinite stage fracturing well completion device is ensured, drilling, plugging and fishing are not needed, and the process is simple, safe and reliable;

(6) after pressing, any fracturing well completion sliding sleeve can be selectively opened or closed through a special switch tool, and the requirements of selective water control production or secondary fracturing construction are met.

Drawings

FIG. 1 is a schematic diagram of a fracturing completion sliding sleeve structure of an open hole full bore infinite stage staged fracturing completion device;

FIG. 1a is a schematic view showing the expansion of the opening grooves of the second embodiment;

FIG. 1b is an enlarged partial schematic view of FIG. 1 a;

FIG. 1 a' is a schematic view showing the expansion of the opening groove in the first embodiment;

FIG. 1b 'is an enlarged partial schematic view of FIG. 1 a';

FIG. 2 is a schematic diagram of an open tool configuration corresponding to FIG. 1a in an open hole full bore infinite staged fracturing completion;

FIG. 2 'is a schematic view of an open tool configuration corresponding to FIG. 1 a' in an open hole full bore infinite staged fracturing completion;

FIG. 2a is a schematic top view of the opening slider of FIGS. 2 and 2';

FIG. 2b is a schematic top view of the guide key of FIG. 2;

FIG. 3 is a schematic diagram of the assembly of a first-grade cluster (one spoon and one key) of the open hole full-bore infinite staged fracturing completion device;

FIG. 3' is a schematic diagram of the assembly of a first-order multi-cluster (one spoon and more open) of an open hole full-bore infinite staged fracturing completion device;

FIG. 4 is a state diagram of an unopened sand blast hole with an opening tool engaged with a fracturing completion sliding sleeve;

FIG. 4a is a state diagram of the opening tool in cooperation with the fracturing completion sliding sleeve to open the sand blasting holes;

FIG. 5 is a schematic diagram of a dedicated shut-off string;

in the figure: 1. a casing string; 3. fracturing a well completion sliding sleeve; 7. a bottom circulation valve; 8. a top suspension packer; 9. fracturing the packer with open hole; 10. a wellbore isolation valve; 11. a coiled tubing; 12. a dedicated hydraulic control shut-off tool; 13. opening the tool; 14. a differential pressure type fracturing completion sliding sleeve; 3-1, coating; 3-2, closing the groove; 3-3, an inner sliding sleeve; 3-4, sand blasting; 3-5, shearing pins; 3-6, positioning parts; 3-7, opening the groove; 3-8, positioning grooves; 3-9, a first seal; 3-10 parts of sliding sleeve lower joint, 3-11 parts of sliding block groove; 3-12, a guide groove; 3-13, a guide opening; 13-1, soluble spheres; 13-2, connecting the tool; 13-3, a second seal; 13-4, a central tube; 13-5, a spring; 13-6, opening a sliding block; 13-7, connecting pieces; 13-8, a guide key; 13-9, a lower tool joint; 13-10, pressing the cap.

Detailed Description

The invention is further illustrated below with reference to the figures and examples.

Example one

Referring to fig. 1, 1a ', 1b ', 2a, 3 ', 4 and 4a, the open hole full-path infinite staged fracturing completion device comprises a casing string 1, a top hanging packer 8, a plurality of open hole fracturing packers 9 and a plurality of fracturing completion sliding sleeves 3 (determined according to staged fracturing stages), a differential fracturing completion sliding sleeve 14, a wellbore isolation valve 10 and a bottom circulating valve 7. The top hangs packer 8 and sets up in 1 upper end of casing string, and a plurality of bore hole fracturing packers 9 intervals set up on casing string 1, fracturing well completion sliding sleeve 3 is a plurality of and installs and form the unlimited grade segmentation fracturing well completion device of bore hole full-bore on casing string 1, and the both ends of every grade of fracturing well completion sliding sleeve all are provided with bore hole fracturing packer 9, and differential fracturing well completion sliding sleeve 14, pit shaft isolation valve 10 and bottom circulation valve 7 are installed in proper order from top to bottom at the lower extreme of casing string 1.

And each stage of fracturing well completion device is provided with a plurality of clusters of fracturing well completion sliding sleeves formed by a plurality of fracturing well completion sliding sleeves 3.

The fracturing well completion sliding sleeve 3 comprises a fixed outer sleeve 3-1 and an inner sliding sleeve 3-3 connected to the inner wall of the outer sleeve 3-1 through a shearing pin 3-5, and a positioning piece 3-6 is further arranged between the outer sleeve 3-1 and the inner sliding sleeve 3-3. Wherein, the outer sleeve 3-1 is provided with 3-4 (6-10 evenly distributed) sand blasting holes and 2 positioning grooves which are communicated with the inner cavity, the upper part of the inner sliding sleeve 3-3 is provided with a closing groove 3-2, the lower part is provided with an opening groove 3-7, and the middle part is provided with a plurality of sealing elements 3-9. The outer sleeve 3-1 is connected with the lower joint 3-10 of the sliding sleeve through threads. The positioning piece 3-6 is an elastic body (an elastic sheet or an elastic ring) embedded in the positioning groove 3-8.

When the outer sleeve 3-1 and the inner sliding sleeve 3-3 are connected together through the shearing pin 3-5, the outer wall of the inner sliding sleeve 3-3 is used for sealing the sand blasting hole 3-4, and the sand blasting hole 3-4 is in a sealing state at the moment.

A plurality of first sealing elements 3-9 are also arranged between the outer sleeve 3-1 and the inner sliding sleeve 3-3, and the inner sliding sleeve 3-3 can be in a sealing state when sliding relative to the outer sleeve 3-1 through the first sealing elements 3-9.

The upper end of the lower joint 3-10 of the sliding sleeve is provided with a guide slope surface, an inner sliding sleeve accommodating cavity used for opening the sand blasting hole 3-4 when the inner sliding sleeve 3-3 moves is arranged in the outer sleeve 3-1, and one positioning groove 3-8 is positioned in the inner sliding sleeve accommodating cavity. When the shearing pin 3-5 is sheared, the inner sliding sleeve 3-3 moves downwards to the inner sliding sleeve accommodating cavity and enters the positioning groove 3-8 in the inner sliding sleeve accommodating cavity through the positioning piece 3-6 for positioning, and at the moment, the sand blasting hole 3-4 is in an opening state.

The opening tool 13 includes: soluble ball 13-1, tool upper joint 13-2, second sealing element 13-3, central tube 13-4, spring 13-5, opening slide 13-6 and tool lower joint 13-9.

Wherein the second sealing element 13-3 is arranged on the outer surface of the tool upper joint 13-2, and the upper end of the tool upper joint 13-2 is provided with a soluble ball 13-1 for sealing the inner cavity.

The central tube 13-4 is in threaded connection with the tool upper joint 13-2, the outer wall of the central tube 13-4 is movably provided with an opening slide block 13-6 matched with the opening groove 3-7, and the outer wall of the central tube 13-4 is also provided with a spring 13-5 for radially expanding and contracting the opening slide block 13-6; the upper end of the lower tool joint 13-9 is connected with the lower end of the central tube 13-4 through threads, and the lower end of the upper tool joint 13-2, the lower tool joint 13-9 and the outer surface of the central tube 13-4 form a limiting groove for radially limiting the opening slide block 13-6. The opening grooves 3-7 comprise guide openings 3-13 and slider grooves 3-11 connected with the guide openings 3-13, the opening sliders 13-6 are matched with the slider grooves 3-11, and when the opening tool 13 is completely matched with the fracturing well completion sliding sleeve 3, the opening sliders 13-6 are guided into the slider grooves 3-11 through the guide openings 3-13; the upper end and the lower end of the opening sliding block 13-6 are respectively provided with an inclined plane, and the inclined plane at the lower end of the opening sliding block 13-6 is matched with the guide slope surface of the lower joint 3-10 of the sliding sleeve, so that the opening sliding block 13-6 can be separated from the groove 3-11 of the sliding block, the opening tool 13 enters the next cluster of fracturing completion sliding sleeve 3 which is completely matched, the step of opening the sliding sleeve as above is completed, and the one-spoon multi-opening action is realized.

The process method specifically comprises the following steps:

1) the open hole full-drift diameter infinite staged fracturing well completion device is used for adapting a fracturing well completion string after staged fracturing stages and the installation position of the fracturing well completion sliding sleeve 3 are determined, the adapted fracturing well completion string is put into a well for positive circulation replacement, a ball is thrown to close a shaft isolation valve 10, a plurality of open hole fracturing packers 9 are set after fracturing, setting release of the top hanging packer 13 is continued to be finished after fracturing, and the whole well is qualified in pressure testing.

2) And (4) after the open hole well completion, installing the large-drift-diameter fracturing wellhead. First, the lowermost stage of the differential pressure fracturing completion sleeve 14 is opened by pumping pressure, thereby establishing a communication path between the casing and the formation. And then, hydraulically delivering opening tools 13 matched with the fracturing well completion sliding sleeve 3 one by one from bottom to top in sequence, and opening the fracturing well completion sliding sleeve 3 of each stage and clusters step by step to complete one-key multi-opening action and perform multi-stage and multi-cluster staged fracturing well completion operation.

3) After staged fracturing is finished, the opening tool 13 is made of a soluble metal material and can be completely dissolved according to preset time to form a full-drift-diameter fracturing well completion shaft.

4) When selective production or secondary fracturing is needed at a later stage according to production requirements, referring to a special closing pipe column shown in the attached figure 5, a special closing pipe column which is matched and connected with a special hydraulic control closing tool 12 through a continuous oil pipe 11 (or an oil pipe) is put into a fracturing completion sliding sleeve 3 which needs to be closed, when the special hydraulic control closing tool 12 enters an inner sliding sleeve 3-3 of the fracturing completion sliding sleeve 3 which needs to be closed, the locking claw of the special hydraulic control closing tool 12 is extended out to be combined and locked with a closing groove 3-2 by pressurizing, the special closing pipe column is lifted up to drive the inner sliding sleeve 3-3 to move upwards, a sand spraying hole 3-4 on an outer sleeve 3-1 is closed, at the moment, the inner sliding sleeve 3-3 drives a positioning part 3-6 (an elastomer) to climb out from a positioning groove 3-8 at the lower part and to be embedded into a positioning groove 3-8 at the upper part, and after the closing action is completed, the special shut-off string is depressurized, the locking claw on the special hydraulic shut-off tool 12 is retracted, and the special shut-off string can be pulled out. The special closing pipe column can close the fracturing well completion sliding sleeve 3 at any fixed point; if the fracturing completion sliding sleeve 3 is opened again at a fixed point, an opening tool 13 matched with the fixed point fracturing completion sliding sleeve 3 can be selected to implement the opening action.

In the step 2), when fracturing construction is carried out, the opening tool 13 is delivered, and the fracturing completion sliding sleeve 3 in the initial state is entered through pumping (the initial state is a state that the inner sliding sleeve 3-3 closes the sand blasting holes 3-4).

Firstly, when the opening tool 13 is not matched with the fracturing well completion sliding sleeve 3, namely the shape and the size of the opening sliding block 13-6 are not matched with the shape and the size of the opening groove 3-7, the opening action can not be realized, and at the moment, the opening sliding block 13-6 is always in a compressed state and passes through the unmatched sliding sleeve until entering the corresponding matched sliding sleeve.

When the opening tool 13 is matched with the fracturing well completion sliding sleeve 3, the opening sliding block 13-6 is in a compressed state when not entering the opening groove 3-7, when entering the opening groove 3-7, the shape and the size of the opening groove 3-7 are completely matched with the shape and the size of the opening sliding block 13-6 of the opening tool 13, and the opening sliding block 13-6 is in a free state and locked with the sliding block groove 3-11. At the moment, the soluble ball 13-1 seals the inner cavity of the opening tool 13, the second sealing element 13-3 and the inner sliding sleeve 3-3 are in an interference sealing state, the inner channel of the inner sliding sleeve 3-3 is completely sealed, when the pressure in the sleeve is suppressed to a preset pressure under the action of hydraulic pressure, the shearing pin 3-5 on the fracturing completion sliding sleeve 3 is sheared, the opening tool 13 drives the inner sliding sleeve 3-3 to move downwards, the positioning element 3-6 climbs out of the positioning groove 3-8 and is in a compression state, and the inner sliding sleeve 3-3 continues to move downwards to enter the next positioning groove 3-8 and is in a free state. And then, the inner sliding sleeve 3-3 is opened in place, the sand blasting holes 3-4 are exposed, and the fracturing completion sliding sleeve 3 is in a fully opened state to establish a fracturing channel. At the moment, the sand blasting holes 3-4 are provided with flow limiting valves and are in a flow limiting state, enough pressure still exists in the sleeve under certain pumping displacement, the opening tool 13 can be pushed to enter the next cluster of fracturing completion sliding sleeve 3, when the cluster of fracturing completion sliding sleeves 3 at the section are all opened to prepare fracturing, the fracturing displacement is increased to a preset index, the flow limiting valves on the sand blasting holes 3-4 can be completely opened, and smooth liquid feeding of fracturing construction is guaranteed.

Thirdly, when the interior of the sleeve continues to be pressed, the opening tool 13 drives the inner sliding sleeve to continue to move downwards, the lower tool joint 13-9 slides to the left end part of the lower sliding sleeve joint 3-10 of the fracturing well completion sliding sleeve 3 and continues to move downwards to enter the lower sliding sleeve joint 3-10, at the moment, the inclined plane at the right end of the opening sliding block 13-6 is in contact with the guide slope surface at the left end of the lower sliding sleeve joint 3-10 and is extruded, under the action of the pumping pressure of the sleeve, the opening sliding block 13-6 climbs out of the sliding block groove 3-11, the opening tool 13 is gradually separated from the inner sliding sleeve 3-3, the inner sliding sleeve 3-3 is located in the inner sliding sleeve accommodating cavity and does not move downwards, a certain stroke allowance is formed at the positioning groove 3-8 at the lower part of the outer sleeve 3-1, and the positioning piece 3-6 cannot climb out of the positioning groove 3-8.

The opening tool 13 continues to move downwards under the hydraulic action, enters the next cluster of fracturing completion sliding sleeve 3 matched with the opening tool, continues to perform the actions II and III, completely opens the corresponding fracturing completion sliding sleeve 3 matched with the opening tool, establishes a fracturing channel, and does not move downwards after the opening tool 13 enters the last cluster of fracturing completion sliding sleeve 3 matched with the opening tool and finishes the action of opening the inner sliding sleeve 3-3, and is locked with the inner sliding sleeve 3-3, and at the moment, the action of one key and multiple openings of all the first-stage and multiple clusters of fracturing completion sliding sleeves is finished.

The parameters of C, D and alpha on the opening groove 3-7 on the fracturing completion sliding sleeve 3 of the invention and the matching parameters of C ', D' and alpha 'on the opening slide block 13-6 of the opening tool 13 need to be all in one-to-one correspondence to realize the opening action of the inner sliding sleeve 3-3, and the parameters of C', D 'and alpha' on the opening tool 13 can be matched with the parameters of C, D and alpha on a plurality of completely identical fracturing completion sliding sleeves 3.

The C, D, alpha parameters on multiple fracturing completion slips 3 that are identical in the present invention should be set so that all parameters of the slips can be identified as all parameters C ', D ', alpha ' on the corresponding opening tools 13 that are matched with the slips one by one. When the opening grooves 3-7 on the fracturing completion sliding sleeves 3 are completely matched with the opening tool 13, the opening sliding blocks 13-6 can be squeezed into the opening grooves 3-7 on the fracturing completion sliding sleeves 3 under the action of elasticity, so that two corresponding tools are combined together to complete the opening action, and the multi-cluster fracturing completion sliding sleeves 3 can be opened at any fixed point. Therefore, the operation action of one-key multi-opening of the first-stage multi-cluster fracturing well completion sliding sleeve is realized. Wherein, when the 'first-stage multi-cluster' is multi-stage staged fracturing, a section is provided with a plurality of fracturing completion sliding sleeves 3 with the same parameters.

The C, D and alpha parameters on the multiple identical fracturing completion sliding sleeves 3 and the C ', D ' and alpha ' parameters on the corresponding opening tools 13 can be correspondingly and randomly changed and combined, and as long as the parameters can be completely matched, the combination of a one-spoon multi-opening full-path infinite-grade fracturing completion sliding sleeve can be realized.

Example two

Referring to fig. 1, 1a, 1b, 2a, 2b and 3, as a preferred embodiment, the same as the first embodiment is provided, except that a fracturing completion sliding sleeve 3 is arranged on each stage of fracturing completion device, and the opening grooves 3-7 on the fracturing completion sliding sleeve 3 comprise guide openings 3-13, sliding block grooves 3-11 and guide grooves 3-12. Wherein, the guide opening 3-13 is conical and is connected with the slide block groove 3-11 and the guide groove 3-12, the slide block groove 3-11 is matched with the opening slide block 13-6, and the guide groove 3-12 is matched with the guide key 13-8. A connecting piece 13-7 is also arranged between the lower tool joint 13-9 and the central tube 13-4, and a limiting groove for radially limiting the opening slide block 13-6 is formed between the connecting piece 13-7 and the upper tool joint 13-2 and the central tube 13-4. A pressing cap 13-10 is arranged between the connecting piece 13-7 and the lower tool joint 13-9, a plurality of guide keys 13-8 extending out of the outer surface of the pressing cap 13-10 are arranged on the pressing cap 13-10, the guide keys 13-8 are elastic guide keys, and the guide keys 13-8 are matched with the guide grooves 3-12. In conclusion, the shape and size of the opening recess 3-7 exactly match the shape and size of the opening slider 13-6 and the guide key 13-8.

The specific process method comprises the following steps:

1) the open hole full-drift diameter infinite staged fracturing well completion device is used for adapting a fracturing well completion string after staged fracturing stages and the installation position of the fracturing well completion sliding sleeve 3 are determined, the adapted fracturing well completion string is put into a well for positive circulation replacement, a ball is thrown to close a shaft isolation valve 10, a plurality of open hole fracturing packers 9 are set after fracturing, setting release of the top hanging packer 13 is continued to be finished after fracturing, and the whole well is qualified in pressure testing.

2) And (4) after the open hole well completion, installing the large-drift-diameter fracturing wellhead. First, the lowermost stage of the differential pressure fracturing completion sleeve 14 is opened by pumping pressure, thereby establishing a communication path between the casing and the formation. Then, the opening tools 13 matched with the fracturing well completion sliding sleeves 3 are hydraulically delivered one by one from bottom to top in sequence, and the fracturing well completion sliding sleeves 3 at all levels are opened step by step to complete one-key one-opening action and carry out infinite-level segmented fracturing well completion operation.

3) After the staged fracturing is finished, the opening tool 13 is made of a soluble metal material and is completely dissolved according to preset time to form a full-bore fracturing well completion shaft.

4) When selective production or secondary fracturing is needed at a later stage according to production requirements, referring to a special closing pipe column shown in the attached figure 5, a special closing pipe column which is matched and connected with a special hydraulic control closing tool 12 through a continuous oil pipe 11 (or an oil pipe) is put into a fracturing completion sliding sleeve 3 which needs to be closed, when the special hydraulic control closing tool 12 enters an inner sliding sleeve 3-3 of the fracturing completion sliding sleeve 3 which needs to be closed, the locking claw of the special hydraulic control closing tool 12 is extended out to be combined and locked with a closing groove 3-2 by pressurizing, the special closing pipe column is lifted up to drive the inner sliding sleeve 3-3 to move upwards, a sand spraying hole 3-4 on an outer sleeve 3-1 is closed, at the moment, the inner sliding sleeve 3-3 drives a positioning part 3-6 (an elastomer) to climb out from a positioning groove 3-8 at the lower part and to be embedded into a positioning groove 3-8 at the upper part, and after the closing action is completed, the special shut-off string is depressurized, the locking claw on the special hydraulic shut-off tool 12 is retracted, and the special shut-off string can be pulled out. The special closing pipe column can close the fracturing well completion sliding sleeve 3 at any fixed point; if the fracturing completion sliding sleeve 3 is opened again at a fixed point, an opening tool 13 matched with the fixed point fracturing completion sliding sleeve 3 can be selected to implement the opening action.

In the step 2), when fracturing construction is carried out, the opening tool 13 is delivered, and the fracturing completion sliding sleeve 3 in the initial state is entered through pumping (the initial state is a state that the inner sliding sleeve 3-3 closes the sand blasting holes 3-4).

Firstly, when the opening tool 13 is not matched with the fracturing well completion sliding sleeve 3, namely the shape and the size of the opening sliding block 13-6 and the guide key 13-8 are not matched with the shape and the size of the sliding block groove 3-11 and the guide groove 3-12 respectively, the opening action can not be realized, and at the moment, the opening sliding block 13-6 and the guide key 13-8 are always in a compression state and pass through the mismatched sliding sleeve until entering the corresponding matched sliding sleeve.

Secondly, when the opening tool 13 is matched with the fracturing well completion sliding sleeve 3, the opening slide block 13-6 and the guide key 13-8 are in a compressed state when not entering the opening groove 3-7, when entering the opening groove 3-7, the shapes and the sizes of the slide block groove 3-11 and the guide groove 3-12 are completely matched with those of the opening slide block 13-6 and the guide key 13-8 of the opening tool 13, and the opening slide block 13-6 and the guide key 13-8 are in a free state and locked with the slide block groove 3-11 and the guide groove 3-12. At the moment, the soluble ball 13-1 seals the inner cavity of the opening tool 13, the second sealing element 13-3 and the inner sliding sleeve 3-3 are in an interference sealing state, the inner channel of the inner sliding sleeve 3-3 is completely sealed, when the casing is suppressed to a preset pressure under the action of hydraulic pressure, the shearing pin 3-5 on the fracturing completion sliding sleeve 3 is sheared, the opening tool 13 drives the inner sliding sleeve 3-3 to move downwards, the positioning element 3-6 climbs out of the positioning groove 3-8 and is in a compression state, and the positioning element and the inner sliding sleeve 3-3 continue to move downwards to enter the next positioning groove 3-8 and are in a free state. Therefore, the inner sliding sleeve 3-3 is locked with the opening tool 13 and is positioned in the inner sliding sleeve accommodating cavity to be opened in place, the inner sliding sleeve does not move downwards, the sand blasting hole 3-4 is exposed, the fracturing well completion sliding sleeve 3 is in a fully opened state, a fracturing channel is established, and the one-spoon one-opening action of opening the fracturing well completion sliding sleeve 3 at any fixed point is completed.

The matching parameters of A, B, C, D and alpha on the opening groove 3-7 on the fracturing completion sliding sleeve 3, the A ', B ', and alpha ' on the guide key 13-8 of the opening tool 13 and the C ', D ', and alpha ' on the opening sliding block 13-6 are all in one-to-one correspondence to realize the opening action of the inner sliding sleeve 3-3, and the A, B, C, D and alpha parameters on each fracturing completion sliding sleeve 3 can only be matched with one single parameter, namely the A ', B ', C ', D ', and alpha ' parameters on the opening tool 13.

The A, B, C, D, alpha parameters on the fracturing completion sleeve 3 of the present invention should be set so that all parameters of the sleeve identify all the parameters a ', B ', C ', D ', alpha ' on the corresponding opening tool 13 uniquely matching the sleeve. When the opening grooves 3-7 on one fracturing well completion sliding sleeve 3 are completely matched with the opening tool 13, the opening sliding blocks 13-6 and the guide keys 13-8 are squeezed into the opening grooves 3-7 under the action of elasticity, so that the two corresponding tools are combined together to complete the opening action, and the fracturing well completion sliding sleeve 3 is opened uniquely at any fixed point. Thereby realizing the operation of one key and one opening.

A, B, C, D and alpha parameters on the fracturing completion sliding sleeve 3 and corresponding A ', B ', C ', D ' and alpha ' parameters on the opening tool 13 can be combined in a one-to-one correspondence and random change mode, and as long as the parameters are completely matched, the combination of the full-drift-diameter infinite-stage fracturing completion sliding sleeve with one key and one opening can be realized.

EXAMPLE III

Basically the same as the first embodiment, except that the plurality of open grooves 3-7 are spirally distributed at 360 degrees at the lower part of the inner sliding sleeve 3-3, the open grooves 3-7 and the axis of the inner sliding sleeve 3-3 can have an inclination angle alpha, and the inclination angle alpha is 0-60 degrees.

Example four

Basically the same as the first embodiment, except that 2-6 springs 13-5 are arranged between each opening slider 13-6 and the central tube 13-4, and a telescopic space for the opening slider 13-6 to extend and retract is arranged between each opening slider 13-6 and the central tube 13-4. By setting the number of the springs 13-5 to 2-6, a better balance and stabilization effect can be achieved, and the expansion of the opening slide block 13-6 and the stability of the opening load are ensured.

EXAMPLE five

Basically the same as the first embodiment, except that the first sealing member 3-9 is provided in plurality, the first sealing member 3-9 and the second sealing member 13-3 are rubber seal rings, and the first sealing member 3-9 is respectively arranged between the sand blasting hole 3-4, the shear pin 3-5 and the positioning member 3-6. The positioning elements 3-6 in the various embodiments are elastic positioning elements.

The present invention is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention, and the contents of the changes still fall within the scope of the present invention.

Claims (10)

1. The open hole full-drift diameter infinite stage staged fracturing well completion device is characterized by comprising a casing string, a top suspension packer, a plurality of open hole fracturing packers, a fracturing well completion sliding sleeve, a pressure differential type fracturing well completion sliding sleeve, a shaft isolation valve and a bottom circulating valve, wherein the top suspension packer is arranged at the upper end of the casing string, the plurality of open hole fracturing packers are arranged on the casing string at intervals, the fracturing well completion sliding sleeves are arranged on the casing string in parallel to form the open hole full-drift diameter infinite stage staged fracturing well completion device, the two ends of each stage of the fracturing well completion sliding sleeve are provided with the open hole fracturing packers, and the pressure differential type fracturing well completion sliding sleeve, the shaft isolation valve and the bottom circulating valve are sequentially arranged at the lower end of the casing string from top to bottom;

wherein, each fracturing completion sliding sleeve all includes:

the outer sleeve is provided with a plurality of sand blasting holes communicated with the inner cavity, and the outer sleeve is provided with a plurality of positioning grooves;

the inner sliding sleeve is arranged on the inner wall of the outer sleeve in a sliding mode and connected with the outer sleeve through a shearing pin, and the outer wall of the inner sliding sleeve is used for sealing the sand blasting hole; a positioning piece matched with the positioning groove is movably arranged on the outer surface of the inner sliding sleeve; a first sealing element is also arranged between the outer sleeve and the inner sliding sleeve; an opening groove and a closing groove are respectively arranged on the inner wall of the inner sliding sleeve, and the opening groove is matched with an opening tool; an inner sliding sleeve accommodating cavity used for opening the sand blasting hole when the inner sliding sleeve moves is arranged in the outer sleeve, and one positioning groove is positioned in the inner sliding sleeve accommodating cavity;

the sliding sleeve lower joint is in threaded connection with the lower end of the outer sleeve, and a guide slope surface is arranged at the upper end of the sliding sleeve lower joint.

2. The open-hole full-bore infinite-grade segmented fracturing completion device according to claim 1, wherein an opening tool for opening the inner sliding sleeve is movably arranged inside the fracturing completion sliding sleeve, and the opening tool comprises:

the outer surface of the tool upper connector is provided with a second sealing element for sealing with the inner wall of the inner sliding sleeve, and the upper end of the tool upper connector is provided with a soluble ball for sealing the inner cavity;

the central tube is in threaded connection with the upper tool joint, an opening sliding block matched with the opening groove is movably mounted on the outer wall of the central tube, and a spring used for opening the radial expansion of the sliding block is further arranged between the central tube and the opening sliding block;

and the lower tool joint is arranged at the lower end of the central pipe.

3. The open-hole full-bore infinite-grade staged fracturing completion device of claim 2, wherein: the opening grooves are spirally distributed on the lower part of the inner sliding sleeve in 360 degrees, and an inclination angle alpha is formed between the opening grooves and the axis of the inner sliding sleeve and is 0-60 degrees.

4. The open-hole full-bore infinite-grade staged fracturing completion device of claim 3, wherein: the opening groove comprises a guide opening and a sliding block groove connected with the guide opening, and the opening sliding block is matched with the opening groove; an annular groove for radially limiting the opening slide block is formed between the lower tool joint and the upper tool joint and between the lower tool joint and the central tube; the upper end and the lower end of the opening sliding block are respectively provided with an inclined plane, and the inclined plane at the lower end of the opening sliding block is matched with the conical opening of the lower joint of the sliding sleeve.

5. The open-hole full-bore infinite-grade staged fracturing completion device of claim 3, wherein: the opening groove comprises a guide opening, a sliding block groove connected with the guide opening and a guide groove connected with the lower end of the sliding block groove, the lower tool joint is connected with the central pipe through a connecting piece, and a limiting groove used for radially limiting the opening sliding block is formed among the connecting piece, the upper tool joint and the central pipe; and a pressing cap is arranged between the connecting piece and the lower tool joint, a plurality of guide keys extending out of the outer surface of the pressing cap are mounted on the pressing cap, and the guide keys are matched with the guide grooves.

6. The open-hole full-bore infinite-grade staged fracturing completion device of claim 1, wherein: the fracturing completion sliding sleeves on each stage of fracturing completion device are one or more.

7. The open-hole full-bore infinite-grade staged fracturing completion device of claim 2, wherein: the number of the springs between each opening sliding block and the central pipe is 2-6, and a telescopic space for opening the sliding blocks to stretch is arranged between each opening sliding block and the central pipe.

8. The open-hole full-bore infinite-grade staged fracturing completion device of claim 2, wherein: the locating piece is an elastic locating piece, and the opening tool is made of a soluble metal material.

9. The fracturing completion method of the open hole full bore infinite staged fracturing completion device according to any of claims 1 to 8, comprising the steps of:

1) after determining the staged fracturing stage number and the installation position of the fracturing completion sliding sleeve, matching the fracturing completion pipe string;

2) putting the matched fracturing completion pipe string into the well for positive circulation displacement, throwing balls to close a shaft isolation valve, completing setting of a plurality of open hole fracturing packers by means of pressure, continuing to complete setting releasing of the top suspension packer, and enabling the whole well to be qualified in pressure test;

3) after open hole well completion, a large-drift-diameter fracturing well head is installed, firstly, the lowest-level differential pressure type fracturing well completion sliding sleeve is opened through pumping pressurization, so that a communication channel between a casing and a stratum is established, then opening tools matched with each level of fracturing well completion sliding sleeves are sequentially delivered one by one from bottom to top, so that the opening tools enter the fracturing well completion sliding sleeves through pumping, and the opening action of each level of fracturing well completion sliding sleeves is completed step by step;

4) when the opening tool is not matched with the fracturing well completion sliding sleeve, namely the shape and the size of the opening sliding block are not matched with those of the opening groove, the opening action cannot be realized, and at the moment, the opening sliding block is always in a compressed state and passes through the unmatched sliding sleeve until entering the corresponding matched sliding sleeve;

5) when the opening tool is matched with the fracturing well completion sliding sleeve, the opening sliding block is in a compressed state when not entering the opening groove, when entering the opening groove, the shape and the size of the opening groove are completely matched with those of the opening sliding block of the opening tool, and the opening sliding block is in a free state and is locked with the opening groove; at the moment, the inner cavity of the tool is opened by the soluble ball seal, the second sealing element and the inner sliding sleeve are in an interference sealing state, and the channel in the inner sliding sleeve is completely sealed;

6) when the casing pipe is suppressed to a preset pressure under the hydraulic action, shearing pins on the fracturing completion sliding sleeve are sheared, an opening tool drives the inner sliding sleeve to move downwards, the positioning piece climbs out of the positioning groove and is in a compressed state, and the positioning piece and the inner sliding sleeve continue to move downwards to enter the next positioning groove and are in a free state; at this moment, the inner sliding sleeve is opened in place, the sand blasting hole is exposed, the fracturing well completion sliding sleeve is in a fully opened state, and a fracturing channel is established;

7) when the pressure in the sleeve continues to be increased, the opening tool drives the inner sliding sleeve to continue to move downwards, the lower tool joint slides to the left end part of the lower sliding sleeve joint of the fracturing well completion sliding sleeve and continues to move downwards to enter the lower sliding sleeve joint, at the moment, the inclined plane at the right end of the opening sliding block is contacted with the guide slope surface at the left end of the lower sliding sleeve joint and is extruded, the opening sliding block climbs out of the opening groove under the action of the pumping pressure of the sleeve, the opening tool is gradually separated from the inner sliding sleeve, the inner sliding sleeve is positioned in the accommodating cavity of the inner sliding sleeve in place and does not move downwards any more, a certain stroke allowance is reserved at the positioning groove at the lower part of the outer sleeve, and the positioning element cannot climb out of the positioning groove;

8) the opening tool continuously descends under the hydraulic action, enters the next cluster of fracturing well completion sliding sleeves matched with the opening tool, continues to perform the actions, completely opens the corresponding fracturing well completion sliding sleeves matched with the opening tool, establishes a fracturing channel, and is locked with the inner sliding sleeve and does not descend until the opening tool enters the last cluster of fracturing well completion sliding sleeves matched with the opening tool and finishes the action of opening the inner sliding sleeve, and at the moment, finishes the action of one spoon and more openings of all the first-stage and multi-cluster fracturing well completion sliding sleeves;

9) after pressing, the opening tools can be completely dissolved to form a full-drift-diameter fracturing well completion shaft, then, according to production requirements, a special hydraulic control closing tool can be selected for selectively closing the fracturing well completion sliding sleeve, if the fracturing well completion sliding sleeve needs to be opened again at a fixed point, the opening tool matched with the fixed-point fracturing well completion sliding sleeve can be selected, and hydraulic delivery is carried out and actions from 4) to 8) are repeated to complete opening.

10. The fracturing completion method of the open hole full bore infinite staged fracturing completion device according to any of claims 1 to 8, comprising the steps of:

1) after determining the staged fracturing stage number and the installation position of the fracturing completion sliding sleeve, matching and connecting fracturing completion pipe strings;

2) putting the matched fracturing completion pipe string into the well for positive circulation displacement, throwing balls to close a shaft isolation valve, completing setting of a plurality of open hole fracturing packers by means of pressure, continuing to complete setting releasing of the top suspension packer, and enabling the whole well to be qualified in pressure test;

3) after open hole well completion, a large-drift-diameter fracturing well head is installed, firstly, the lowest-level differential pressure type fracturing well completion sliding sleeve is opened through pumping pressurization, so that a communication channel between a casing and a stratum is established, then opening tools matched with each level of fracturing well completion sliding sleeves are sequentially delivered one by one from bottom to top, so that the opening tools enter the fracturing well completion sliding sleeves through pumping, and the opening action of each level of fracturing well completion sliding sleeves is completed step by step;

4) when the opening tool is not matched with the fracturing well completion sliding sleeve, namely the shape and the size of the opening sliding block and the guide key are not matched with the shape and the size of the opening groove, the opening action cannot be realized, and at the moment, the opening sliding block and the guide key are always in a compressed state and pass through the unmatched sliding sleeve until entering the corresponding matched sliding sleeve;

5) when the shapes and the sizes of the opening slide block and the guide key are respectively matched with the shapes and the sizes of the slide block groove and the guide groove, the opening slide block and the guide key are in a compressed state when not entering the opening groove, and when respectively entering the slide block groove and the guide groove, the opening slide block and the guide key are in a free state and are locked with the opening groove, at the moment, the soluble ball seals an inner cavity of the tool, the second sealing element and the inner sliding sleeve are in an interference sealing state, and a channel in the inner sliding sleeve is completely sealed;

6) when the casing pipe is suppressed to preset pressure under the action of hydraulic pressure, shearing pins on the fracturing well completion sliding sleeve are sheared, an opening tool drives the inner sliding sleeve to move downwards, a positioning piece climbs out of a positioning groove and is in a compressed state, and the positioning piece and the inner sliding sleeve continue to move downwards to enter the next positioning groove and are in a free state, so that the inner sliding sleeve and the opening tool are locked and are positioned in an inner sliding sleeve accommodating cavity to be opened in place, the inner sliding sleeve does not move downwards any more, a sand blasting hole is exposed, the fracturing well completion sliding sleeve is in a completely opened state, a fracturing channel is established, and the 'one-spoon one-opening' action of opening the fracturing well completion sliding sleeve at any fixed point is completed;

7) after pressing, the opening tools can be completely dissolved to form a full-drift-diameter fracturing well completion shaft, then, according to production requirements, a special hydraulic control closing tool can be selected for selectively closing the fracturing well completion sliding sleeve, if the fracturing well completion sliding sleeve needs to be opened again at a fixed point, the opening tool matched with the fixed-point fracturing well completion sliding sleeve can be selected, and hydraulic delivery is carried out and actions from 4) -6) are repeated to complete opening.

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