CN105863594B

CN105863594B - A kind of high temperature and pressure stepped setting deblocking multistage fracturing tubing string and its application method

Info

Publication number: CN105863594B
Application number: CN201610292989.7A
Authority: CN
Inventors: 程智远; 詹鸿运; 刘志斌; 张鹏; 王学正; 宗庆伟; 秦诗涛; 骆劲羽; 崔振锚; 韩永亮
Original assignee: CNPC Bohai Drilling Engineering Co Ltd
Current assignee: China National Petroleum Corp; CNPC Bohai Drilling Engineering Co Ltd
Priority date: 2016-05-05
Filing date: 2016-05-05
Publication date: 2019-01-08
Anticipated expiration: 2036-05-05
Also published as: CN105863594A

Abstract

The present invention provides a kind of high temperature and pressure stepped setting deblocking multistage fracturing tubing string and its application methods, fracturing string of the invention, which throws a ball just in pressing crack construction, can open the corresponding matching used controllable confining in target construction layer position and sanding machine, keep pressing crack construction technique simpler, conveniently；It can be realized pressing crack construction zonal isolation device stepped setting, non-construction layer position packer is not set, construction layer position packer gradually deblocking, the leakproofness of every level-one packer can effectively be examined, reduce the number that packer sets deblocking repeatedly, the leakage efficiency of all packers of tubing string is improved, tubing string easily rises out after pressing crack construction.

Description

A kind of high temperature and pressure stepped setting deblocking multistage fracturing tubing string and its application method

Technical field

The present invention relates to a kind of high temperature and pressure stepped setting deblocking multistage fracturing tubing string and its application methods, are mainly used for height Warm high-pressure oil-gas well staged fracturing construction, belongs to completion practice construction tool.

Background technique

In recent years, oil-gas field fracturing technology has reached its maturity, and packer mechanical delamination fracturing technique has become raising The agent technology of oil gas field well yield, however in a large amount of live pressing crack construction process, there are some problems；

1. conventional multilayer partial pressure tubular column is matched using multiple packers with multiple sand blast sliding sleeves, in a certain layer of pressing crack construction When, all packers are set, and can not effectively be verified the sealing performance of every level-one packer, are easy to cause and alter layer, are influenced Pressing crack construction effect；

2. high temperature, high-pressure well, packer sets repeatedly, unseals, and packing element sealing performance reduces, and leads to packer sealing not Sternly, packer service life is reduced；

3. after pressing crack construction the easy sand of tool bury, sand card, whole tubing string acts difficulty, causes later period measure can not be into Row,

These problems constrain the further development of this technology；Therefore be badly in need of provide a kind of performance it is stable, it is structurally reasonable, It can adapt to high temperature and high pressure environment, set the oil/gas well multistage fracturing tubing string that deblocking is reliable, probability of recycling success is high.

Summary of the invention

In view of this, being directed to high temperature and pressure well fracturing construction characteristic, the purpose of the present invention is to provide a kind of high temperature High pressure stepped setting unseals multistage fracturing tubing string and its application method, wherein the special construction design of controllable confining, so that should Controllable confining to set state controllable, it is controllable to realize fracturing string controllable confining stepped setting at different levels, non-construction layer position Packer do not set, construction layer position controllable confining gradually deblocking, can effectively examine the close of every level-one controllable confining Feng Xing reduces the number that controllable confining sets deblocking repeatedly, improves the leakage efficiency of all controllable confinings of tubing string.

In order to achieve the above objectives, the technical scheme of the present invention is realized as follows:

A kind of high temperature and pressure stepped setting unseals multistage fracturing tubing string, the fracturing string include it is several to it is setting up and down simultaneously Matching used controllable confining and sanding machine, the fracturing string have been sequentially connected with bottom valve, packer, several right from the bottom to top The matching used controllable confining and sanding machine, sand-proof hydraulic anchor, hydraulic safety connector pass through oil between above-mentioned each tool Pipe connection；

The inner sliding sleeve component that can be glided with respect to controllable confining main body, the inner sliding sleeve group are equipped in the controllable confining It is fixedly connected between part and the controllable confining main body by shear pin, between the inner sliding sleeve component and the controllable confining main body Equipped with the inlet that can be opened, the inlet sets space with the intracorporal liquid of controllable confining master and is connected to, described interior Variable diameter ball seat is equipped in slide bushing assembly, the variable diameter ball seat becomes larger with the downslide internal diameter of the inner sliding sleeve component；

The sliding sleeve tee that can be glided with respect to sanding machine main body, the sliding sleeve tee and the sandblasting are equipped in the sanding machine It is fixedly connected between device main body by shear pin, the sanding machine main body is equipped with the open spray that can glide by the sliding sleeve tee Sand mouth；

The internal diameter of the sliding sleeve tee of variable diameter ball seat and the matched sanding machine used before the controllable confining variable diameter It is identical.

In the prior art, with several packers are usually disposable complete in fracturing string in oil pipe tripping in casing/naked eye Portion is set, and when needing to carry out fracturing operation to certain construction layer position, then opens with steel ball the sanding machine of equivalent layer position, but above-mentioned Packer sets that the time is longer, or even needs to set repeatedly to improve the leakproofness of packer, which is bound to shadow Ring the service life of packer；

The fracturing process of the fracturing string of above-mentioned technical proposal of the invention is as follows: putting into oil/gas well of corresponding size Low-density ball falls on the variable diameter ball seat of corresponding controllable confining, then suppresses into oil pipe, then builds the pressure and cut shear pin, The relatively described controllable confining main body of the inner sliding sleeve component glides, variable diameter ball seat during controllable confining main body glides It glides therewith, and variable diameter ball seat internal diameter expands, at the same time, inner sliding sleeve component and the intersubjective inlet of controllable confining are beaten It opens, suppresses liquid and set in space by the liquid that inlet enters controllable confining main body, packing element then expands, and realizes and sits Envelope, and can the leakproofness to the controllable confining targetedly detected；

Low-density ball is continued traveling downwardly to the sliding sleeve tee of matching used sanding machine after variable diameter ball seat internal diameter expands, and is suppressed Compression shear is broken shear pin, and sliding sleeve tee glides, and the sand jet outlet in sanding machine main body is opened, and downlink is simultaneously together for low-density ball and sliding sleeve tee It is located at the lower contact of lower packer/controllable confining, to block following channel, fracturing fluid enters correspondence from sand jet outlet Interval carries out pressing crack construction, and after corresponding to interval pressure break, larger-size another low-density is put into the case where not termination of pumping Ball so repeats the above steps, so that fracturing string is while completing target interval pressing crack construction, pressing crack construction layer position is controllable Packer stepped setting, non-construction layer position packer do not set, construction layer position packer gradually deblocking, effectively reduces controllable Packer sets the time, avoids because the problem of packing element damage and leakproofness decline caused by setting overlong time, favorably In the service life for extending controllable confining；

In addition, the controllable confining is used cooperatively with sanding machine, when pressing crack construction, which throws a ball, just can open a certain construction The corresponding controllable confining in layer position and sanding machine keep fracturing technology simpler, conveniently；

The equal yield density for the low-density ball that the present invention uses is 1.5-1.6g/cm³, anti-impact high compared with the voltage endurance capability of steel ball Hit intensity is high, and with its low-density, light weight can be improved a little its ability moved forward under horizontality, in pressure break After construction, it is also easy to the row of returning because its density is low, also reduces construction risk while reducing time cost.

When pressing crack construction, the anchor fluke opening of sand-proof hydraulic anchor is stuck on internal surface of sleeve pipe, plays fixed tubing string；Sand control water Power anchor upper end is provided with hydraulic safety connector, when the cases of emergency tubing strings such as sand plug occurs in construction, sand buries can not rise out safely, pitching Hydraulic safety connector is opened, tubing string disengages from hydraulic safety connector, acts top tubing string and implements countermeasure again.

In some embodiments, the inner sliding sleeve component includes sleeve, variable diameter ball seat, guide cylinder, spring and end cap；

It is fixedly connected between the sleeve and the controllable confining main body by shear pin；If circumferential in the middle part of the sleeve be equipped with Dry windowing, the variable diameter ball seat are several wedge blocks, and the wedge block is inserted by the windowing, the periphery of the wedge block and institute Controllable confining main body inner wall face contact is stated, a part of the wedge block is located in the windowing, and another part is located at described In sleeve, the wedge block is located at the section lower in the sleeve equipped with inclined-plane；

The guide cylinder is located at the sleeve inner, and is bonded with the sleeve lining, and spring is equipped in the guide cylinder, The upper surface of the guide cylinder abuts limit by the inclined-plane of the wedge block, and the end cap and sleeve lower end inner wall are spiral shell Line connection, the lower end surface of the guide cylinder are abutted with the interior shoulder of the end cap, the lower end of the sleeve and the end cap Outer shoulder abuts, compression of the spring by the end cap top surface.

In some embodiments, the controllable confining main body include top connection, packing element component, contact control set component and Lower contact；

The top connection sealing is fixedly arranged on the upper end of central tube；

The packing element component sealing shroud is set to the periphery of central tube, forms liquid between the packing element component and the central tube Set space；

Contact control set component is fixedly arranged on central tube periphery lower end, the contact control set component internal equipped with into Liquid channel；

The inner sliding sleeve component is fixedly arranged on contact control set component by the way that shear pin is opposite, the inner sliding sleeve component with it is described Contact control set inter-module is equipped with the inlet that can be opened, the inlet and the feed pathway and the liquid sets space Connection；

The lower contact sealing is fixedly arranged on the lower end of the contact control set component.

In some embodiments, the packing element component includes being vulcanized the upper rubber tube seat being connected as one, packing element and lower glue Cylinder base.Packing element uses high temperature high voltage resistant rubber material, and is cast with lower rubber cylinder seat by vulcanization with the upper rubber tube seat of irony It is integrated, is able to bear 90MPa pressure difference and 150 DEG C of high temperature；

In some embodiments, the contact control set component includes crossover sub, lock ring, contact sleeve and connecting cylinder；

The crossover sub upper end is connect with central tube lower end outer periphery threads；

The contact sleeve is sheathed on the periphery of inner sliding sleeve component upper end, and the contact sleeve periphery is equipped with first lap Slot, the crossover sub inner wall are equipped with the second ring recess, and the lock ring is located at what first ring recess was formed with second ring recess In lock space, the lock ring is the contact sleeve to be locked on the crossover sub；Be equipped in the contact sleeve first into Liquid channel, is equipped with the second feed pathway in the crossover sub, and the lock space is located at first feed pathway and described Between second feed pathway, and it is connected with the two；I.e. feed pathway is by the first feed pathway and crossover sub in contact sleeve The second interior feed pathway is constituted；

The upper end of the connecting cylinder is adjacent with the lower end of the lower rubber cylinder seat, the upper end of the connecting cylinder with it is described The outer periphery threads of crossover sub connect, and the lower end of the connecting cylinder is threadedly coupled with the upper end of the lower contact.The connection Cylinder is to connect contact control set component and lower contact, and the position to limit each accessory in inner sliding sleeve component, the setting make The position that control set component, lower contact and inner sliding sleeve component must be contacted is more reliable and more stable, is also convenient for assembling.

Wherein, the contact sleeve is slot pipe structure, and the slot is wire cutting, and first feed pathway is several institutes State the liquid-retaining volume of slot formation；I.e. the feed pathway is stitched using the wire cutting of 0.1~0.2mm, prevents fracturing sand from entering Packing element reduces controllable confining sand card risk, in addition, the contact sleeve periphery is equipped with a plurality of slot, packing element can be made quickly swollen Swollen or fast retractile quickly sets or unseals to realize.

The inner sliding sleeve component includes sleeve, variable diameter ball seat, guide cylinder, spring and end cap；

It is fixedly connected between the sleeve and the connecting cylinder by shear pin, the upper end periphery of the sleeve and crossover sub Inner wall is tightly connected；Circumferential in the middle part of the sleeve to be equipped with several windowings, the variable diameter ball seat is several wedge blocks, the wedge block It is inserted by the windowing, a part of the wedge block is located in the windowing, and another part is located in the sleeve, the wedge Periphery and the connecting cylinder inner wall face contact of shape block, the wedge block are located at the section lower in the sleeve equipped with inclined-plane；

The guide cylinder is located at the sleeve inner, and is bonded with the sleeve lining, and spring is equipped in the guide cylinder, The upper surface of the guide cylinder abuts limit by the inclined-plane of the wedge block, and the end cap and sleeve lower end inner wall are spiral shell Line connection, the lower end surface of the guide cylinder are abutted with the interior shoulder of the end cap, the lower end of the sleeve and the end cap Outer shoulder abuts, during end cap is screwed into sleeve, the spring by the end cap top surface pressure and gradually reduce, The elastic force of the spring passes to the inclined-plane of wedge block lower part by guide cylinder, i.e., wedge block is by the upward outside elastic force of guide cylinder It squeezes, in addition, wedge block is also by the extruding inside from connecting cylinder inner wall.

As a result, controllable confining in the initial state, inner sliding sleeve component by shear pin be fixed on contact control set component On, several wedge blocks in inner sliding sleeve component form fixed variable diameter ball seat under the collective effect of guide cylinder and connecting cylinder, and become Cooperate between diameter ball seat and sleeve for Elastic Sliding formula, effectively reduce low-density ball investment process to the impact force of variable diameter ball seat, Reduce damage of the pitching process to variable diameter ball seat；In addition, the shear pin is set between connecting cylinder and sleeve, belong to interior shear pin, Fixed form compared with outer shear pin is more reliable, prevents controllable confining shear pin during transport or lower tubular column from going out under external force Existing loose or dislocation or cutting and the case where premature setting.

In some embodiments, the upper end of the lower contact is connect with the connecting cylinder lower periphery thread seal, institute It states and is equipped with gap between lower contact inner wall and the connecting cylinder, the gap is to accommodate the variable diameter ball after gliding with inner sliding sleeve component Seat, i.e., when variable diameter ball seat is snapped down to the gap, variable diameter ball seat is entered in the gap by windowing, and the internal diameter of variable diameter ball seat becomes larger, To which steel ball can continue traveling downwardly the sand jet outlet to open the matching used sanding machine in lower part.

In some embodiments, adjusting ring, the adjusting ring lower end and the packing element group are additionally provided in the top connection The upper end of part is adjacent, and the adjusting ring inner wall is to be threadedly coupled with the top connection periphery.

In some embodiments, the sliding to prevent the packing element component circumferential direction sliding is additionally provided on the packing element component Baffle ring, the sliding baffle ring are connect with lower rubber cylinder seat lower end inner thread, and the sliding baffle ring is located at the lower rubber cylinder Between seat and the crossover sub.

In some embodiments, the lock ring surface is equipped with elastic rubber layer, facilitates in contact sleeve insertion crossover sub, and Be conducive to the relatively fixed of contact sleeve and crossover sub.

In some embodiments, the edge that the controllable confining may be contacted with the borehole wall is that fillet protection is set Meter, in addition the threaded connection place is equipped with jackscrew and is fixed, to ensure that controllable confining tripping in the process will not be due to knocking Borehole wall abrasion rigid body and packing element structure are touched, and prevents the premature setting phenomenon occurred during going into the well.

In addition, the present invention also aims to protect a kind of use of high temperature and pressure stepped setting deblocking multistage fracturing tubing string Method, including following order step:

(1) according to the reservoir situation of oil/gas well, prepare the controllable confining and sanding machine of corresponding number, by bottom valve, packing Device, the matching used controllable confining of corresponding number and sanding machine, sand-proof hydraulic anchor, hydraulic safety connector are on oil pipe It is assembled, forms it into fracturing string；

(2) by the pit shaft of assembled fracturing string tripping in oil/gas well, make the spray of the sanding machine of every level-one fracturing string Sand mouth is corresponding with the reservoir fragment position in oil/gas well；

(3) hydraulic, packer setting is beaten into oil pipe, each controllable confining on packer top is not set, can pass through bottom Valve carries out pressing crack construction to No. zero interval of the bottommost of reservoir, and after No. zero interval pressing crack construction, the liquid in oil pipe is still State is suppressed in not termination of pumping, so that the packer is still in setting state；

(4) first order low-density ball is put into oil/gas well by the pitching plug valve of well head, falls in the first order and controllably seals Every on the variable diameter ball seat of device, because fluid pressure effect then builds the pressure and cuts shear pin in oil pipe, the inner sliding sleeve component is relatively described Contact control set component glides, and the end cap of lower cartridge, which is run to recess in lower contact, to be stopped, and variable diameter ball seat comes downwards to down at this time In gap between connector and connecting cylinder, several wedge blocks are flared out by windowing, and variable diameter ball seat internal diameter expands, same with this When, the inlet of sleeve and contact inner room is opened, and it suppresses liquid and is entered in the first feed pathway of contact sleeve by inlet, and Enter in the second feed pathway of crossover sub via lock space, the liquid then eventually entered between packing element and central tube is set In space, packing element expansion, realization is set；

First order low-density ball is continued traveling downwardly to the sliding sleeve tee of matching used sanding machine after variable diameter ball seat internal diameter expands On, and build the pressure and cut shear pin, first order low-density ball glides together with sliding sleeve tee, and the sand jet outlet in sanding machine main body is opened, First order low-density ball continues to be snapped down in lower packer together with sliding sleeve tee, and is located at the lower contact of lower packer Place, to block following channel, bottom packer and first order controllable confining are in the state of setting at this time, and fracturing fluid is from spray Sand mouth enters No.1 interval, carries out pressing crack construction, and after No.1 interval pressing crack construction, the liquid in oil pipe is still in not termination of pumping Suppress state so that the bottom packer and first order controllable confining are still in setting state；

(5) second level low-density ball being relatively large in diameter is put into oil/gas well by the pitching plug valve of well head, repeats to walk Suddenly (4), second level low-density ball can be such that second level controllable confining sets in succession and open the sandblasting of second level sanding machine in turn Mouthful, second level low-density ball continues to be snapped down in the first order controllable confining of lower part together with sliding sleeve tee, and is located at At the end cap of first order controllable confining sleeve, to block following channel, bottom packer is then unsealed, and the first order is controllably sealed Setting state is in every device and second level controllable confining, fracturing fluid enters No. two intervals from sand jet outlet, carry out pressing crack construction, two After number interval pressing crack construction, the liquid in oil pipe suppresses state still in not termination of pumping so that the first order packer and Second level controllable confining is still in setting state；

(6) step (5) can be repeated to more intervals and pressing crack construction operation is carried out to it, thus completing fracturing string step by step While pressing crack construction, the stepped setting and gradually deblocking of packer and each controllable confining are realized；For example, the investment third level is low After density ball, first order controllable confining can be unsealed, and second level controllable confining and third level controllable confining are in and set State, so that convenient carry out pressing crack construction to No. three intervals.

Preferably, the packer is K344 packer.

Fracturing string of the invention is at most able to achieve point 7 grades of pressure breaks in 5 1/2in casings.

Compared with the existing technology, present invention has the advantage that fracturing string of the invention is thrown once in pressing crack construction Ball just can open the corresponding matching used controllable confining in target construction layer position and sanding machine, keep pressing crack construction technique simpler Singly, conveniently；It can be realized pressing crack construction zonal isolation device stepped setting, non-construction layer position packer is not set, construction layer position Packer gradually deblocking can effectively examine the leakproofness of every level-one packer, reduce time that packer sets deblocking repeatedly Number, improves the leakage efficiency of all packers of tubing string.

Detailed description of the invention

The attached drawing for constituting a part of the invention is used to provide further understanding of the present invention, schematic reality of the invention It applies example and its explanation is used to explain the present invention, do not constitute improper limitations of the present invention.In the accompanying drawings:

Fig. 1 is the attachment structure schematic diagram of fracturing string described in the embodiment of the present invention；

Fig. 2 is the structural schematic diagram of controllable confining original state in the embodiment of the present invention；

Fig. 3 is the structural schematic diagram that controllable confining sets state in the embodiment of the present invention；

Fig. 4 is that the inner sliding sleeve component of controllable confining in the embodiment of the present invention is connected to each other the touch-control system set non-slip-down state of component Structural schematic diagram；

Fig. 5 is that the inner sliding sleeve component of controllable confining in the embodiment of the present invention is connected to each other state after touch-control system set component glides Structural schematic diagram；

Fig. 6 is the partial enlargement diagram of Fig. 4；

Fig. 7 is the partial enlargement structural representation of Fig. 5, and schematically shows controllable confining and set state and suppress liquid The flow trace of body；

Fig. 8 is the structural schematic diagram of the sleeve of controllable confining in the embodiment of the present invention；

Fig. 9 is the A-A of Fig. 8 to schematic cross-section.

Description of symbols:

A- bottom valve, B-K344 packer, C- first order controllable confining, D- first order sanding machine, E- are controllably sealed the second level Every device, the second level F- sanding machine, G- sand-proof hydraulic anchor, H- hydraulic safety connector, I- oil pipe；1- top connection, 11- adjust ring, 2- Packing element component, the upper rubber tube seat of 21-, 22- packing element, 23- lower rubber cylinder seat, 24- slide baffle ring, 3- contact control set component, 31- conversion Connector, the second ring recess of 311-, 32- lock ring, 33- contact sleeve, the first ring recess of 331-, 34- connecting cylinder, 4- inner sliding sleeve component, 41- set Cylinder, 411- open a window, 42- variable diameter ball seat, 421- wedge block, 43- guide cylinder, 44- spring, 45- end cap, 46- shear pin, connect under 5- Head, the gap 51-, 6- central tube.

Specific embodiment

It should be noted that in the absence of conflict, the feature in embodiment and embodiment in the present invention can phase Mutually combination.

In the description of the present invention, it is to be understood that, term " center ", " longitudinal direction ", " transverse direction ", "upper", "lower", The orientation or positional relationship of the instructions such as "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outside" is It is based on the orientation or positional relationship shown in the drawings, is merely for convenience of description of the present invention and simplification of the description, rather than instruction or dark Show that signified device or element must have a particular orientation, be constructed and operated in a specific orientation, therefore should not be understood as pair Limitation of the invention.In addition, term " first ", " second " etc. are used for description purposes only, it is not understood to indicate or imply phase To importance or implicitly indicate the quantity of indicated technical characteristic.The feature for defining " first ", " second " etc. as a result, can To explicitly or implicitly include one or more of the features.In the description of the present invention, unless otherwise indicated, " multiple " It is meant that two or more.

In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, term " installation ", " phase Even ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or be integrally connected；It can To be mechanical connection, it is also possible to be electrically connected；It can be directly connected, can also can be indirectly connected through an intermediary Connection inside two elements.For the ordinary skill in the art, above-mentioned term can be understood by concrete condition Concrete meaning in the present invention.

In the description of the present invention, term " original state " refers to the off working state of packer or controllable confining.

Bottom valve, K344 packer, sanding machine, sand-proof hydraulic anchor, hydraulic safety connector and oil pipe of the present invention are Common accessory in Completion Operations, it is commercially available.

The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

Specific embodiments of the present invention:

Embodiment 1

As shown in figs 1-9, a kind of high temperature and pressure stepped setting of the present embodiment unseals multistage fracturing tubing string, the pressure break pipe Comprising several to setting up and down and matching used controllable confining and sanding machine, the fracturing string sequentially connects column from the bottom to top It is connected to bottom valve A, packer B, several to the matching used controllable confining and sanding machine, sand-proof hydraulic anchor G, hydraulic safe Connector H is connected by oil pipe I between above-mentioned each tool；

The inner sliding sleeve component 4 that can be glided with respect to controllable confining main body, the inner sliding sleeve are equipped in the controllable confining It is fixedly connected between component 4 and the controllable confining main body by shear pin 46, the inner sliding sleeve component 4 and the controllable confining The inlet that can be opened is equipped between main body, the inlet sets space with the intracorporal liquid of controllable confining master and is connected to, Variable diameter ball seat 42 is equipped in the inner sliding sleeve component, the variable diameter ball seat 42 becomes larger with the downslide internal diameter of the inner sliding sleeve component 4；

The application method of the fracturing string of the present embodiment is as follows:

(1) according to the reservoir situation of oil/gas well, prepare the controllable confining and sanding machine of corresponding number, by bottom valve A, K344 The matching used controllable confining and sanding machine, sand-proof hydraulic anchor G, hydraulic safety connector H of packer B, corresponding number It is assembled on oil pipe I, forms it into fracturing string；

(3) beaten into oil pipe I hydraulic, K344 packer B is set, and each controllable confining on the top K344 packer B is not sat Envelope can carry out pressing crack construction to No. zero interval of the bottommost of reservoir by bottom valve, after No. zero interval pressing crack construction, oil pipe Liquid in I suppresses state still in not termination of pumping, so that the K344 packer B is still in setting state；

(4) first order low-density ball is put into oil/gas well by the pitching plug valve of well head, falls in the first order and controllably seals Every on the variable diameter ball seat 42 of device C, because fluid pressure effect then builds the pressure and cuts shear pin 46 in oil pipe, 4 phase of inner sliding sleeve component It glides to the controllable confining main body, variable diameter ball seat 42 glides therewith during controllable confining main body glides, and becomes 42 internal diameter of diameter ball seat expands, and at the same time, inner sliding sleeve component 4 and the intersubjective inlet of controllable confining are opened, and suppresses liquid It is set in space by the liquid that inlet enters controllable confining main body, packing element then expands, and realization is set, and can to this The leakproofness of control packer is targetedly detected；

First order low-density ball is continued traveling downwardly to matching used first order sanding machine D's after 42 internal diameter of variable diameter ball seat expands It on sliding sleeve tee, and builds the pressure and cuts shear pin, first order low-density ball glides together with sliding sleeve tee, the spray in sanding machine main body Sand mouth is opened, and first order low-density ball is slid under continuing together with sliding sleeve tee in the K344 packer B of lower part, and is located at At the lower contact of lower part K344 packer, to block following channel, bottom K344 packer B and the first order are controllably insulated at this time Device C is in the state of setting, and fracturing fluid enters No.1 interval from sand jet outlet, carries out pressing crack construction, No.1 interval pressing crack construction knot Liquid in Shu Hou, oil pipe I suppresses state still in not termination of pumping, so that bottom K344 packer B and the first order are controllably sealed Every device C still in setting state；

(5) second level low-density ball being relatively large in diameter is put into oil/gas well by the pitching plug valve of well head, repeats to walk Suddenly (4), second level low-density ball can be such that second level controllable confining E sets in succession and open the spray of second level sanding machine F in turn Sand mouth, second level low-density ball is slid under continuing together with sliding sleeve tee in the first order controllable confining C of lower part, and is located at At first order controllable confining C lower contact, to block following channel, bottom K344 packer B is then unsealed, and the first order is controllable Packer C and second level controllable confining E is in setting state, and fracturing fluid enters No. two intervals from sand jet outlet, carries out pressure break and applies Work, after No. two interval pressing crack constructions, the liquid in oil pipe I suppresses state still in not termination of pumping, so that the first order is sealed Every device C and second level controllable confining E still in setting state；

(6) step (5) can be repeated to more intervals and pressing crack construction operation is carried out to it, thus completing fracturing string step by step While pressing crack construction, the stepped setting and gradually deblocking of packer and each controllable confining are realized.

Embodiment 2

The controllable confining include top connection 1, packing element component 2, contact control set component 3, inner sliding sleeve component 4 and under connect First 5；

The top connection 1 seals the upper end for being fixedly arranged on central tube 6；

2 sealing shroud of packing element component is set to the periphery of central tube 6, is formed between the packing element component 2 and the central tube 6 Liquid sets space；

The contact control set component 3 is fixedly arranged on the peripheral lower end of central tube 6, sets inside the contact control set component 3 There is feed pathway；

The inner sliding sleeve component 4 is fixedly arranged on contact control set component 3 by the way that shear pin 46 is opposite, the inner sliding sleeve component 4 The inlet that can be opened, the inlet and the feed pathway and the liquid are equipped with described contact between control covers component 3 Set space connection；

The inner sliding sleeve component 4 includes sleeve 41, variable diameter ball seat 42, guide cylinder 43, spring 44 and end cap 45；

The sleeve 41 is fixedly connected by shear pin 46 between control set component 3 with described contact, the upper end of the sleeve 41 Portion periphery is tightly connected with control set 3 inner wall of component is contacted；41 middle part of sleeve is circumferential to be equipped with 6 windowings 411, the variable diameter Ball seat 42 is 6 wedge blocks 421, and the wedge block 421 is located at by 411 insertion of windowing, a part of the wedge block 421 In the windowing 411, another part is located in the sleeve 41, periphery and 34 inner wall of connecting cylinder of the wedge block 421 Face contact, the wedge block 421 are located at the section lower in the sleeve 41 equipped with inclined-plane；

The guide cylinder 43 is located inside the sleeve 41, and is bonded with 41 inner wall of sleeve, in the guide cylinder 43 Equipped with spring 44, the upper surface of the guide cylinder 43 abuts limit by the inclined-plane of the wedge block 421, the end cap 45 with it is described 41 lower end inner wall of sleeve is to be threadedly coupled, and the lower end surface of the guide cylinder 43 is abutted with the interior shoulder of the end cap 45, described The lower end of sleeve 41 is abutted with the outer shoulder of the end cap 45, compression of the spring 44 by the end cap top surface.

The lower contact 5 seals the lower end for being fixedly arranged on the contact control set component 3, and 5 inner wall of lower contact is equipped with Gap 51, after the relatively described contact control set component 3 of the inner sliding sleeve component 4 glides, the wedge block 421 is located at the sky In gap 51.

The assembling process of the controllable confining of the present embodiment of the controllable confining of the present embodiment is as follows:

(1) top connection 1 is fixed on bench vice；

(2) installation center pipe 6,1 lower end of top connection are threadedly coupled with 6 upper end of central tube, top connection 1 and central tube 6 Between pass through sealing ring seal；

(3) packing element component 2 is installed, the packing element component 2 after vulcanization is sleeved on the periphery of central tube 6, packing element component 2 with above connect It is sealed between first 1 by sealing ring；

(4) installation contact control set component 3, contact control set 3 upper end of component are threadedly coupled with 6 lower end of central tube, It is sealed between contact control set component 3 and central tube 6 by sealing ring；Contact control set 3 lower end of component and 5 upper end of lower contact It is threadedly coupled and fixes, sealed between contact control set component 3 and lower contact 5 by sealing ring；

(5) inner sliding sleeve component 4 is assembled, 6 wedge blocks 421 are inserted into 41 corresponding 6, sleeve windowings 411；It will guiding Cylinder 43 is inserted into sleeve 41, and the upper end of guide cylinder 43 abuts with the inclined-plane of wedge block 421, spring 44 is placed in guide cylinder 43, End cap 45 is threadedly coupled with 41 inner wall lower end of sleeve, and is fixed by jackscrew, is screwed the process into sleeve 41 in end cap 45 In, 45 top surface compressed spring 44 of end cap, the elastic force of the spring 44 resists the inclined-plane of wedge block 421 by guide cylinder 43；It will Shear pin 46 is fixed in several fixation holes that 41 periphery of sleeve is arranged circumferentially；

(6) the assembled inner sliding sleeve component 4 of installation steps (5), by the top insertion contact control set group of inner sliding sleeve component 4 The lower part of part 3, during insertion, wedge block 421 is controlled set 3 inner wall circumferential direction inward pressure of component, i.e. wedge by contact Shape block 421 forms fixed variable diameter ball seat under the collective effect of guide cylinder 43 and contact control set component 3；

(7) lower contact 5 is installed, 5 upper end of lower contact covers 3 lower end of component with control is connect for threaded connection, lower contact 5 It is sealed with connecting between control set component 3 by sealing ring.

(4) first order low-density ball is put into oil/gas well by the pitching plug valve of well head, falls in the first order and controllably seals Every on the variable diameter ball seat 42 of device C, because fluid pressure effect then builds the pressure and cuts shear pin 46 in oil pipe, 4 phase of inner sliding sleeve component It controls set component 3 to the contact to glide, the operation of end cap 45 to the recess in lower contact 5 of 41 lower part of sleeve stops, at this time variable diameter Ball seat 42 comes downwards in the gap 51 of lower contact, and several wedge blocks 421 are flared out by windowing 411,42 internal diameter of variable diameter ball seat Expand；At the same time, sleeve 41 is opened with the inlet contacted between control set component 3, is suppressed liquid and is connect by inlet entrance Touch-control system covers in the feed pathway of component 3, and the liquid eventually entered between packing element component 2 and central tube 6 is set in space, packing element Component 3 then expands, and realization is set；

(5) second level low-density ball being relatively large in diameter is put into oil/gas well by the pitching plug valve of well head, repeats to walk Suddenly (4), second level low-density ball can be such that second level controllable confining E sets in succession and open the spray of second level sanding machine F in turn Sand mouth, second level low-density ball is slid under continuing together with sliding sleeve tee in the first order controllable confining C of lower part, and is located at At the end cap 45 of first order controllable confining C sleeve, to block following channel, bottom K344 packer B is then unsealed, and first Grade controllable confining C and second level controllable confining E is in setting state, and fracturing fluid enters No. two intervals from sand jet outlet, carries out Pressing crack construction, after No. two interval pressing crack constructions, the liquid in oil pipe I suppresses state still in not termination of pumping so that this Level-one packer C and second level controllable confining E is still in setting state；

Embodiment 3

Wherein, the top connection 1 seals the upper end for being fixedly arranged on central tube 6；

Further, it is additionally provided in the top connection 1 and adjusts ring 11,11 lower end of adjusting ring and the packing element component 2 Upper end it is adjacent, 11 inner wall of adjusting ring is threadedly coupled with 1 periphery of the top connection.

Wherein, the packing element component 2 includes through vulcanizing the upper rubber tube seat 21 being connected as one, packing element 22 and lower rubber cylinder seat 23。

Further, the sliding baffle ring 24 to prevent the packing element component circumferential direction sliding is additionally provided on the packing element component 2, The sliding baffle ring 24 is connect with the 23 lower end inner thread of lower rubber cylinder seat, and the sliding baffle ring 24 is located at the lower rubber cylinder Seat 23 with it is described contact control cover component 3 between.

Wherein, the contact control set component 3 includes crossover sub 31, lock ring 32, contact sleeve 33 and connecting cylinder 34；

31 upper end of crossover sub is connect with 6 lower end outer periphery threads of central tube；

The contact sleeve 33 is sheathed on the periphery of 4 upper end of inner sliding sleeve component, and 33 periphery of contact sleeve is equipped with the One ring recess 331,31 inner wall of crossover sub are equipped with the second ring recess 311, and the lock ring 32 is located at first ring recess 331 and institute In the lock space for stating the formation of the second ring recess 311,32 surface of lock ring is equipped with elastic rubber layer, and the is equipped in the contact sleeve One feed pathway, is equipped with the second feed pathway in the crossover sub, the lock space be located at first feed pathway and Between second feed pathway, and it is connected with the two.

The upper end of the connecting cylinder 34 is adjacent with the lower end of the lower rubber cylinder seat 23, the upper end of the connecting cylinder 34 It is connect with the outer periphery threads of the crossover sub 31, the upper end screw thread of the lower end of the connecting cylinder 34 and the lower contact 5 Connection.

Further, the contact sleeve 33 is slot pipe structure, and the slot is wire cutting, if first feed pathway is Do the liquid-retaining volume that the slot is formed.

Wherein, the inner sliding sleeve component 4 includes sleeve 41, variable diameter ball seat 42, guide cylinder 43, spring 44 and end cap 45；

Be fixedly connected between the sleeve 41 and the connecting cylinder 34 by shear pin 46, the upper end periphery of the sleeve 41 with 31 inner wall of crossover sub is tightly connected；41 middle part of sleeve is circumferential to be equipped with 6 windowings 411, and the variable diameter ball seat 42 is 6 wedges Shape block 421, the wedge block 421 are located at the windowing 411 by 411 insertion of windowing, a part of the wedge block 421 Interior, another part is located in the sleeve 41, periphery and the 34 inner wall face contact of connecting cylinder of the wedge block 421, described Wedge block 421 is located at the section lower in the sleeve 41 equipped with inclined-plane；

Wherein, the upper end of the lower contact 5 is connect with the 34 lower periphery thread seal of connecting cylinder, the lower contact Gap 51 is equipped between 5 inner walls and the connecting cylinder 34, when the relatively described contact control set component 3 of the inner sliding sleeve component 4 glides Afterwards, the wedge block 421 is located in the gap 51.

Above-mentioned threaded connection place is equipped with jackscrew and is fixed in the present embodiment.

The assembling process of the controllable confining of the present embodiment is as follows:

(1) top connection 1 is fixed on bench vice；

(3) installation and adjustment ring 11, adjusting ring 11 is to be threadedly coupled, and fixed by jackscrew with top connection 1；

(4) packing element component 2 is installed, the packing element component 2 after vulcanization is sleeved on the periphery of central tube 6, upper rubber tube seat 21 with it is upper It is sealed between connector 1 by sealing ring；

(5) crossover sub 31 is installed, the upper end of crossover sub 31 is to be threadedly coupled with the lower end of central tube 6, is converted It is sealed by sealing ring between connector 31 and central tube 6 and lower rubber cylinder seat 23；

(6) installation sliding baffle ring 24, sliding baffle ring 24 with to be threadedly coupled, and consolidated by jackscrew between 23 lower end of lower rubber cylinder seat It is fixed；

(7) assembly for organizing sleeved 41, contact sleeve 33, lock ring 32, shear pin 46 and variable diameter ball seat 42, by 33 sets of contact sleeve Loaded on 41 upper end of sleeve periphery, lock ring 32 is fixed at first ring recess 331 on 33 top of contact sleeve, by 6 wedge blocks 421 In 41 corresponding 6, sleeve windowings 411 of insertion；Shear pin 46 is fixed in several fixation holes that 41 periphery of sleeve is arranged circumferentially；

(8) assembly of installation steps (6) is inserting the lower part of 41 top of the sleeve insertion crossover sub 31 of assembly During entering, extruding of the lock ring 32 by 31 inner wall of crossover sub, when lock ring 32 is inserted into crossover sub 31 and contact sleeve 33 Between lock space when, the rubber layer on 32 surface of lock ring is released, and is made relatively solid between crossover sub 31 and contact sleeve 33 It is fixed；

(9) connecting cylinder 34 is installed, the upper end of connecting cylinder 34 is connect with 31 outer periphery threads of crossover sub, and is consolidated by jackscrew Fixed, in installation process, wedge block 421 is by 34 inner wall circumferential direction inward pressure of connecting cylinder；

(10) guide cylinder 43, spring 44 and end cap 45 are installed, guide cylinder 43 is inserted into sleeve 41, the upper end of guide cylinder 43 It is abutted with the inclined-plane of wedge block 421, spring 44 is placed in guide cylinder 43, end cap 45 and 41 inner wall lower end screw thread of sleeve connect It connects, and is fixed by jackscrew, during end cap 45 is screwed into sleeve 41,45 top surface compressed spring 44 of end cap, the spring 44 elastic force resists the inclined-plane of wedge block 421 by guide cylinder 43；I.e. wedge block 421 is in guide cylinder 43 and connecting cylinder 34 Fixed variable diameter ball seat is formed under collective effect；

(11) lower contact 5 is installed, 5 upper end of lower contact and 31 lower end of crossover sub are is threadedly coupled, lower contact 5 and turn It is sealed between changing-over head 31 by sealing ring.

(4) first order low-density ball is put into oil/gas well by the pitching plug valve of well head, falls in the first order and controllably seals Every on the variable diameter ball seat 42 of device C, because fluid pressure effect then builds the pressure and cuts shear pin 46 in oil pipe, 4 phase of inner sliding sleeve component It controls set component 3 to the contact to glide, the operation of end cap 45 to the recess in lower contact 5 of 41 lower part of sleeve stops, at this time variable diameter Ball seat 42 comes downwards in the gap between lower contact 5 and connecting cylinder 34, and several wedge blocks 421 are flared out by windowing 411, becomes 42 internal diameter of diameter ball seat expands；At the same time, inlet between sleeve 41 and contact sleeve 33 is opened, suppress liquid by inlet into Enter in the first feed pathway of contact sleeve 33, and enter in the second feed pathway of crossover sub 31 via lock space, then The liquid eventually entered between packing element 22 and central tube 6 is set in space, and packing element 22 then expands, and realization is set；

First order low-density ball is continued traveling downwardly to matching used first order sanding machine D's after 42 internal diameter of variable diameter ball seat expands It on sliding sleeve tee, and builds the pressure and cuts shear pin, first order low-density ball glides together with sliding sleeve tee, the spray in sanding machine main body Sand mouth is opened, and first order low-density ball is slid under continuing together with sliding sleeve tee in the K344 packer B of lower part, and is located at At the lower contact of lower part K344 packer B, to block following channel, bottom K344 packer B and the first order are controllably sealed at this time It is in the state of setting every device C, fracturing fluid enters No.1 interval from sand jet outlet, carries out pressing crack construction, No.1 interval pressing crack construction After, the liquid in oil pipe I suppresses state still in not termination of pumping, so that bottom K344 packer B and the first order are controllable Packer C is still in setting state；

It should be noted that in the above various embodiments the assembling process of controllable confining only be for the present patent application can Several feasible assembling process of packer are controlled, are not invented to limit, all assembling process to correspond to actual needs, and Any same replacement, the improvement etc. that accessory therein is carried out in the assembling process, it is within the scope of the present invention.

In the above various embodiments the application method of fracturing string be only can for the several of fracturing string of the present patent application The description of capable pressing crack construction process, not to limit invention, all pressing crack construction processes to correspond to actual needs, Yi Ji In the pressing crack construction process to accessory therein carry out it is any it is same replacement, improve etc., protection scope of the present invention it It is interior.

The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the invention Within mind and principle, any modification, equivalent replacement, improvement and so on be should all be included in the protection scope of the present invention.

Claims

1. a kind of high temperature and pressure stepped setting unseals multistage fracturing tubing string, it is characterised in that: the fracturing string includes several right Setting up and down and matching used controllable confining and sanding machine, the fracturing string have been sequentially connected with bottom valve, envelope from the bottom to top Every device, several to the matching used controllable confining and sanding machine, sand-proof hydraulic anchor, hydraulic safety connector, the bottom valve, Packer, sanding machine, sand-proof hydraulic anchor, passes through oil pipe between hydraulic safety connector and connects controllable confining；

Be equipped in the controllable confining can the inner sliding sleeve component that glides of opposite controllable confining main body, the inner sliding sleeve component and It is fixedly connected between the controllable confining main body by shear pin, is equipped between the inner sliding sleeve component and the controllable confining main body The inlet that can be opened, the inlet set space with the intracorporal liquid of controllable confining master and are connected to, the inner sliding sleeve Variable diameter ball seat is equipped in component, the variable diameter ball seat becomes larger with the downslide internal diameter of the inner sliding sleeve component；

The sliding sleeve tee that can be glided with respect to sanding machine main body, the sliding sleeve tee and the sanding machine master are equipped in the sanding machine It is fixedly connected between body by shear pin, the sanding machine main body is equipped with the open sandblasting that can glide by the sliding sleeve tee Mouthful；

Variable diameter ball seat before the controllable confining variable diameter is identical with the internal diameter of the sliding sleeve tee of the matched sanding machine used；

The controllable confining main body includes top connection, packing element component, contact control set component and lower contact；

The packing element component sealing shroud is set to the periphery of central tube, forms liquid between the packing element component and the central tube and sets Space；

The contact control set component is fixedly arranged on central tube periphery lower end, and the contact control set component internal is logical equipped with feed liquor Road；

The inner sliding sleeve component is fixedly arranged on contact control set component by the way that shear pin is opposite, and the inner sliding sleeve component is contacted with described Control set inter-module is equipped with the inlet that can be opened, the inlet and the feed pathway and the liquid sets space company It is logical；

2. a kind of high temperature and pressure stepped setting as described in claim 1 unseals multistage fracturing tubing string, it is characterised in that: in described Slide bushing assembly includes sleeve, variable diameter ball seat, guide cylinder, spring and end cap；

It is fixedly connected between the sleeve and the controllable confining main body by shear pin；It is circumferential in the middle part of the sleeve to be equipped with several open Window, the variable diameter ball seat are several wedge blocks, and the wedge block is inserted by the windowing, and the peripheral and described of the wedge block can Packer body inner wall face contact is controlled, a part of the wedge block is located in the windowing, and another part is located at the sleeve Interior, the wedge block is located at the section lower in the sleeve equipped with inclined-plane；

The guide cylinder is located at the sleeve inner, and is bonded with the sleeve lining, and spring is equipped in the guide cylinder, described The upper surface of guide cylinder abuts limit, the end cap and sleeve lower end inner wall by the inclined-plane of the wedge block as screw thread company It connects, the lower end surface of the guide cylinder is abutted with the interior shoulder of the end cap, the between outer land of the lower end of the sleeve and the end cap Shoulder abuts, compression of the spring by the end cap top surface.

3. a kind of high temperature and pressure stepped setting as described in claim 1 unseals multistage fracturing tubing string, which is characterized in that the glue Cartridge module includes through vulcanizing the upper rubber tube seat being connected as one, packing element and lower rubber cylinder seat.

4. a kind of high temperature and pressure stepped setting as claimed in claim 3 unseals multistage fracturing tubing string, which is characterized in that described to connect It includes crossover sub, lock ring, contact sleeve and connecting cylinder that touch-control system, which covers component,；

The contact sleeve is sheathed on the periphery of inner sliding sleeve component upper end, and the contact sleeve periphery is equipped with the first ring recess, institute Crossover sub inner wall is stated equipped with the second ring recess, it is empty that the lock ring is located at the locking that first ring recess and second ring recess are formed In, it is equipped with the first feed pathway in the contact sleeve, is equipped with the second feed pathway, the lock space in the crossover sub Between first feed pathway and second feed pathway, and it is connected with the two；

The upper end of the connecting cylinder is adjacent with the lower end of the packing element component, the upper end of the connecting cylinder and the conversion The outer periphery threads of connector connect, and the lower end of the connecting cylinder is threadedly coupled with the upper end of the lower contact；

It is fixedly connected between the sleeve and the connecting cylinder by shear pin, the upper end periphery of the sleeve and crossover sub inner wall It is tightly connected；Circumferential in the middle part of the sleeve to be equipped with several windowings, the variable diameter ball seat is several wedge blocks, and the wedge block is by institute Windowing insertion is stated, a part of the wedge block is located in the windowing, and another part is located in the sleeve, the wedge block Periphery with the connecting cylinder inner wall face contact, the wedge block be located at the section lower in the sleeve be equipped with inclined-plane；

The guide cylinder is located at the sleeve inner, and is bonded with the sleeve lining, and spring is equipped in the guide cylinder, described The upper surface of guide cylinder abuts limit, the end cap and sleeve lower end inner wall by the inclined-plane of the wedge block as screw thread company It connects, the lower end surface of the guide cylinder is abutted with the interior shoulder of the end cap, the between outer land of the lower end of the sleeve and the end cap Shoulder abuts, compression of the spring by the end cap top surface；

The lock ring surface is equipped with elastic rubber layer.

5. a kind of high temperature and pressure stepped setting as claimed in claim 4 unseals multistage fracturing tubing string, which is characterized in that described to connect Touching set is slot pipe structure, and the slot is wire cutting, and first feed pathway is that the liquid that several slots are formed holds Receive space.

6. a kind of high temperature and pressure stepped setting as claimed in claim 4 unseals multistage fracturing tubing string, which is characterized in that under described The upper end of connector is connect with the connecting cylinder lower periphery thread seal, is equipped between the lower contact inner wall and the connecting cylinder Gap, after the relatively described contact control set component of the inner sliding sleeve component glides, the wedge block is located in the gap.

7. a kind of high temperature and pressure stepped setting as claimed in claim 4 unseals multistage fracturing tubing string, which is characterized in that the glue The sliding baffle ring to prevent the packing element component circumferential direction sliding, the sliding baffle ring and the lower rubber cylinder are additionally provided on cartridge module Seat lower end inner thread connection, the sliding baffle ring is between the lower rubber cylinder seat and the crossover sub.

8. a kind of high temperature and pressure stepped setting as described in claim 1 unseals multistage fracturing tubing string, which is characterized in that on described Adjusting ring is additionally provided on connector, the adjusting ring lower end is adjacent with the upper end of the packing element component, the adjusting ring inner wall It is to be threadedly coupled with the top connection periphery.

9. a kind of user of high temperature and pressure stepped setting deblocking multistage fracturing tubing string as described in claim 4,5,6,8 is any Method, including following order step:

(1) according to the reservoir situation of oil/gas well, prepare the controllable confining and sanding machine of corresponding number, by bottom valve, packer, right The matching used controllable confining and sanding machine, sand-proof hydraulic anchor, hydraulic safety connector for answering quantity carry out on oil pipe Assembling, forms it into fracturing string；

(2) by the pit shaft of assembled fracturing string tripping in oil/gas well, make the sand jet outlet of the sanding machine of every level-one fracturing string It is corresponding with the reservoir fragment position in oil/gas well；

(3) hydraulic, packer setting is beaten into oil pipe, each controllable confining on packer top is not set, can pass through bottom valve pair No. zero interval of the bottommost of reservoir carries out pressing crack construction, after No. zero interval pressing crack construction, liquid in oil pipe still in State is suppressed in not termination of pumping, so that the packer is still in setting state；

(4) first order low-density ball is put into oil/gas well by the pitching plug valve of well head, falls in first order controllable confining Variable diameter ball seat on, because fluid pressure effect then builds the pressure and cuts shear pin in oil pipe, the relatively described contact of inner sliding sleeve component Control set component glides, and the end cap of lower cartridge, which is run to recess in lower contact, to be stopped, and variable diameter ball seat comes downwards to lower contact at this time In gap between connecting cylinder, several wedge blocks are flared out by windowing, and variable diameter ball seat internal diameter expands, at the same time, set The inlet of cylinder and contact inner room is opened, and is suppressed liquid and is entered in the first feed pathway of contact sleeve by inlet, and via Lock space enters in the second feed pathway of crossover sub, and the liquid then eventually entered between packing element and central tube sets space Interior, packing element expansion, realization is set；

First order low-density ball is continued traveling downwardly to the sliding sleeve tee of matching used sanding machine after variable diameter ball seat internal diameter expands, and It builds the pressure and cuts shear pin, first order low-density ball glides together with sliding sleeve tee, and the sand jet outlet in sanding machine main body is opened, the first order Low-density ball continues to be snapped down in lower packer together with sliding sleeve tee, and is located at the lower contact of lower packer, from And following channel is blocked, bottom packer and first order controllable confining are in the state of setting at this time, and fracturing fluid is from sand jet outlet Into No.1 interval, pressing crack construction is carried out, after No.1 interval pressing crack construction, liquid the beating still in not termination of pumping in oil pipe Pressure condition, so that the bottom packer and first order controllable confining are still in setting state；

(5) second level low-density ball being relatively large in diameter is put into oil/gas well by the pitching plug valve of well head, repeats step (4), low-density ball in the second level can be such that second level controllable confining sets in succession and open the sand jet outlet of second level sanding machine in turn, Second level low-density ball continues to be snapped down in the first order controllable confining of lower part together with sliding sleeve tee, and is located at first At the end cap of grade controllable confining sleeve, to block following channel, bottom packer is then unsealed, first order controllable confining And second level controllable confining is in setting state, fracturing fluid enters No. two intervals from sand jet outlet, carries out pressing crack construction, No. two floor After section pressing crack construction, the liquid in oil pipe suppresses state still in not termination of pumping, so that the first order packer and second Grade controllable confining is still in setting state；

(6) step (5) can be repeated to more intervals and pressing crack construction operation is carried out to it, thus completing fracturing string pressure break step by step While construction, the stepped setting and gradually deblocking of packer and each controllable confining are realized.

10. a kind of application method of high temperature and pressure stepped setting deblocking multistage fracturing tubing string as claimed in claim 9, feature It is, the packer is K344 packer.