CN110080688A - A kind of slim hole completion tubing string and construction method - Google Patents

Abstract

The present invention is a kind of slim hole completion tubing string and construction method, is particularly suitable for the sidetracked hole of petroleum industry, can be improved the cementing quality of slim hole well.Extension hanger, hydraulic centralizing device, ball seat, float collar and mud cake removal device in this completion tubular column pass through small casing and are sequentially connected；Inlet opening one and inlet opening two are respectively equipped on the central tube of hydraulic centralizing device and the tube body of support sleeve, fluid cylinder is arranged with relief hole, and hydraulic centralizing device is capable of forming two-stage hydraulic device, is hingedly connected between lower piston set and lower contact；Circulation of drilling fluid channel and rotation scraping mechanism are equipped in mud cake removal device, the scraping block rotated in scraping mechanism can be freely rotated outside mandrel.This completion tubular column can be in slim-hole between two parties by hydraulic centralizing device, the mud cake removal device of bottom can effectively remove the mud cake of open hole wall, it significantly improves the cleaning effect of the borehole wall and can be combined with conventional drilling liner cementing construction technology, live adaptable, using effect is significant.

Description

A kind of slim hole completion tubing string and construction method

Technical field

The present invention relates to the completion tubular column of petroleum industry slim hole well and construction technology, especially a kind of slim hole completion pipe Column and construction method, are particularly suitable for sidetracked hole, can be improved the cementing quality of slim hole well.

Background technique

Sidetracked hole has that small investment, well construction period be short, the technical advantages such as quick, becomes and produces in each oil field old increasing the storage Important means, the slim hole completions such as sidetracked hole mainly have the complete well of casing cementing, the complete well of screen casing crest water flooding mud, suspension sieve tube completion Etc. completion modes, wherein casing cementing completion mode is occupied an leading position using largest, but passes through cementing quality statistical The problems such as analysis, sidetracked hole cementing quality is generally relatively low, alters slot outside pipe has seriously affected sidetracked hole and has normally produced.Its reason is main Are as follows: one, sidetracked hole wellbore it is small, but in order to which later period production operation is convenient, big orifice cased hole completion is generally pursued in each oil field, this just makes Packaged tube and bore hole annulus gap are small, and casing stabbing board tripping in is more difficult.To avoid encountering card resistance, sidetracking during casing tripping in Generally not placing casing stabbing board, casing in the completion tubular column of well cannot be placed in the middle, when this makes cementing forerunner just for drilling fluid, set Pipe bias causes drilling fluid displacement to be not thorough, forms drilling fluid stagnant area, will form slurry band, the cementing matter of Behavior of Hardened Cement Paste after cementing It is poor to measure, and seriously affects cementing quality.Two, it since casing and bore hole annulus gap are small, is limited by circulation discharge capacity, flushing liquor when well cementation Turbulent condition is not achieved in replacement, and wall cake cleaning efficiency is low, and cement slurry is obstructed by mud cake, can not contact with stratum, and well cementation is waited After solidifying, mud cake is shunk, and generates micro chink with Behavior of Hardened Cement Paste, causes well cementation second contact surface bonding quality poor.

The Chinese patent of application number 2012203897068 discloses a kind of " eddy flow casing centering that cementing quality can be improved Device ", the tool include centralizer body, and righting band and V-arrangement circulatory flow are machined on centralizer body, and righting, which takes, to be equipped with Drag reduction idler wheel guarantees casing centralization when the smooth tripping in and well cementation of casing, reduces the frictional resistance during casing tripping in.Due to using The mode of V-arrangement circulatory flow is processed on centralizer body, therefore can achieve apparent eddy flow effect in circulation of drilling fluid, And then wellbore is in good purification condition before ensure that well cementation, improves Cementation Quality.But the technology there are it is following not Foot: righting band outer diameter is greater than completion casing ontology, and tripping in is extremely difficult in the slim-holes such as sidetracked hole, is likely to encounter card resistance, complete It is not in place under well casing column.

Application No. is 2012103595062 Chinese patents to disclose " hydraulic casing pipe centering device ", by a center Installing the mechanisms such as fluid cylinder, piston, inclined plate and righting arm on pipe additional, pressure of spraining in casing after cemented up, piston pushes inclined plate mobile, The movement of inclined plate pushes out righting arm branch Xiang Jingbi by force, forces bunch tube placed in the middle, and casing centralization is effectively ensured, and guarantees casing Cement thickness between wellbore is uniform, to improve cementing quality.The technology has the disadvantage that the 1, present invention cannot use In slim hole well；2, it can only build the pressure after cemented up and push righting arm open, casing during displacement drilling fluid before cementing Column is constantly in eccentric state, and drilling fluid displacement is not thorough, and still remains drilling fluid stagnant area, will form slurry after cementing Band makes casing centralization again at this time, even if casing and bore hole annulus gap are uniform, can also have slurry band, seriously affect Behavior of Hardened Cement Paste Bonding quality；3, the centralizer, which only designs, one group of fluid cylinder, and hydraulic action sectional area is small, and the thrust very little of generation is simply possible to use in Casing centering in straight well, it is difficult to meet the casing centering requirement in high angle hole and horizontal well.

" oil drilling technology " the 4th phase of volume 37 in 2015, the technical papers delivered " help by horizontal cementing hydraulic casing The improvement and application of positive device " provides a kind of hydraulic casing centralizer, mainly by central tube, fluid cylinder, piston, retaining ring, help The composition such as positive, wiper block, its working principle is that tool tripping in is suppressed afterwards in place, hydraulic coupling pushes piston motion, to boost Body resistance-strengthening tablets lift casing between two parties.Tool is equipped with backing stop structure, prevents body resistance-strengthening tablets from springing back, and guarantees righting effect.This is hydraulic to help Positive device can before cementing righting casing, improve drilling fluid Flooding Efficiency, but there are still following deficiencies: 1, interior latus rectum ratio Casing string is small, and there are steps in inner cavity, and tripping in power tool will receive many limitations when production operation is constructed；2, outer dimension Greatly, the 139.7mm casing stabbing board of minimum dimension series, maximum outside diameter reach 185mm, and it is small to be far from satisfying sidetracked hole etc. The requirement of wellbore, up to the present there are no a kind of centralizers that can adapt to slim hole well completion tubular column；3, using list Grade thrust fluid cylinder, it is big to reach the hydraulic pressure difference that ideal casing centralization effect needs, not with live cementing operation technique Match.

For the cementing quality for improving the slim-holes such as sidetracked hole, needs to invent a kind of completion tubular column suitable for slim-hole and apply Work method can make completion tubular column placed in the middle in slim-hole, to expand the application field of the Slimhole Technologies such as sidetracked hole, reach drop The development effectiveness of this synergy.

Summary of the invention

The object of the present invention is to provide a kind of slim hole completion tubing string and construction methods, solve current slim hole well completion tubular Column sleeve pipe is placed in the middle, cementing quality difference problem, improves the effect of completion tubular column casing centralization, improves cementing quality, for The Small Well Normal production after the eye complete well of well lays the foundation.

In order to achieve the above object, the technical scheme is that

A kind of slim hole completion tubing string, including extension hanger, small casing, ball seat and float collar are additionally provided in completion tubular column hydraulic Centralizer and mud cake removal device, extension hanger, hydraulic centralizing device, ball seat, float collar and mud cake removal device pass through small Casing is sequentially connected；Central tube in hydraulic centralizing device and inlet opening one and inlet opening two are respectively equipped on the tube body of support sleeve, Fluid cylinder is arranged with relief hole；Top connection, retaining set, central tube, support sleeve and lower contact in hydraulic centralizing device are sequentially connected, outside Piston bush, fluid cylinder set and lower piston set are installed in face, install sealing ring in retaining set, fluid cylinder set and lower piston set, being capable of shape At two-stage hydraulic device, it is hingedly connected between lower piston set and lower contact；Circulation of drilling fluid channel is equipped in mud cake removal device, The lower part of mud cake removal device is guide shoe, and the rotation scraping mechanism and non-return seat being mainly made of scraping block and mandrel are connected to and mention It rises between connector and guide shoe, the scraping block rotated in scraping mechanism can be freely rotated outside mandrel.

A kind of construction method of slim hole completion tubing string is:

A, the side tracked slim hole in former wellbore casing, tripping in completion tubular column；

B, completion tubular column is after design well depth, turn on pump circulating fluid, after circulation is abundant, puts into ball seat ball sealer, small displacement It pumps on ball seat ball sealer to ball seat；

C, ground is suppressed into completion tubular column to 9MPa-11MPa, starts extension hanger, while pushing completion tubular column to make tail pipe Hanger is sufficiently set；

D, continue to suppress to 14MPa-16MPa and pressure stabilizing 4min-7min, set hydraulic centralizing device；

E, after the completion of hydraulic centralizing device is set, continue to suppress the ball seat ball sealer destroyed in ball seat to 17MPa-19MPa, establish Termination of pumping behind circulation of drilling fluid channel, above mentions drill string, and the point of neutralization is made to fall in the top of extension hanger；

F, it rotates forward the circle of drill string 30~50 and is buckled to completion tubular column of giving up, judgement is opened with drill string tieback completion tubular column again after giving up successfully Beginning cementing operation；

G, it replaces first into flushing liquor, flushing liquor opens the removing of the float collar ball sealer and mud cake removal device of completion tubular column lower end float collar Device ball sealer, the annular space entered between completion tubular column and slim-hole by circulation port simultaneously form eddy flow, by former wellbore casing and small Drilling fluid displacing in wellbore comes out；

H, cement slurry is injected after the completion of rinsing, cement slurry discharges drilling rod rubber plug, drilling rod rubber plug downlink and extension hanger after having infused Hollow rubber plug it is compound after continue traveling downwardly, reach ball seat and realize bruising, cementing terminates；

I, well head pressure release, pulling out of hole, it is solidifying to wait.

Significant using effect of the invention is: the present invention can significantly improve the cementing quality of slim hole well, major embodiment In the following areas: one, completion tubular column can be placed in the middle in slim-hole, and the mud cake removal device of bottom can effectively remove open hole wall Mud cake, significantly improve the cleaning effect of the borehole wall, drilling fluid can be clean by displacement；Cement slurry can be filled with stratum when well cementation Tap touching will not form slurry band with cement slurry, can effectively improve the bonding quality of well cementation second contact surface.Two, hydraulic centralizing device Body diameter be less than the hole diameter and conventional centralizer of slim hole well, can the smooth tripping in the slim-holes such as sidetracked hole, reduce Tubing string is hampered risk, and designs and have double-stage hydraulic device, and identical pressure difference can generate the lateral support doubled, Neng Gou Tubing string self weight is overcome in high angle hole and horizontal well, effectively to completion tubular column righting, improve the centralizer of small casing tubing string, from And drilling fluid displacing efficiency is effectively improved, it can finally effectively improve cement sheath bonding quality.Three, after completion tubular column is placed in the middle, wellbore Annular clearance is uniform, and the cement thickness of formation is significantly uniform compared with the prior art, can effectively improve cementing quality.Four, the borehole wall Mud cake is clean by scraping, and cement slurry can come into full contact with stratum, effectively increases the bonding quality of well cementation second contact surface, can have Effect avoids altering slot outside pipe, for lower step normal production establish it is good using basic and can be avoided subsequent relevant workover treatment Construction.It five, can be with routine since the component outer diameter connected in this completion tubular column is less than the hole diameter size of slim hole well Drilling liner cementing construction technology combines, and scene is adaptable, it is easier to large-scale promotion application.It is shown in conclusion the present invention has The using effect of work simultaneously can generate significant economic benefit.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of completion tubular column of the present invention.

Fig. 2 is the structural schematic diagram of hydraulic centralizing device in completion tubular column.

Fig. 3 is the structural schematic diagram of mud cake removal device in completion tubular column.

Specific embodiment

The present invention is described in detail below in conjunction with attached drawing, is not limited the scope of the invention.As described below is only of the invention Preferred embodiment, other use equivalence changes of the invention, are within the scope of protection of the invention.

Referring to Fig. 1 to Fig. 3, a kind of slim hole completion tubing string includes extension hanger 1, small casing 4, ball seat 6 and float collar 7, Hydraulic centralizing device 5 and mud cake removal device 8, extension hanger 1, hydraulic centralizing device 5, ball seat 6, float collar 7 are additionally provided in completion tubular column Small casing 4 is passed through with mud cake removal device 8 to be sequentially connected；Central tube 5.8 and support sleeve 5.12 in hydraulic centralizing device 5 Tube body on be respectively equipped with inlet opening 1 and inlet opening 2 5.17, fluid cylinder set 5.10 is equipped with relief hole 5.11；Hydraulic centralizing device Top connection 5.1, retaining set 5.2, central tube 5.8, support sleeve 5.12 and lower contact 5.16 in 5 are sequentially connected, and outside is installed Piston bush 5.6, fluid cylinder set 5.10 and lower piston set 5.13 are covered in 5.2, fluid cylinder set 5.10 and lower piston set 5.13 in retaining and are installed Sealing ring 5.7, is capable of forming two-stage hydraulic device, and hinge 5.15 is connected between lower piston set 5.13 and lower contact 5.16；Mud Circulation of drilling fluid channel is equipped in cake remover 8, the lower part of mud cake removal device 8 is guide shoe 8.13, mainly by scraping block 8.6 and core The rotation scraping mechanism and non-return seat 8.8 that axis 8.2 is constituted are connected between lifting sub 8.1 and guide shoe 8.13, rotate scraping Scraping block 8.6 in mechanism can be freely rotated in the outside of mandrel 8.2.

The hydraulic centralizing device 5 is at least connected with a set of in completion tubular column, is connected to ball seat 6, float collar 7 and mud cake removal device Small casing 4 between 8 only connects one, is connected between hydraulic centralizing device 5 and hydraulic centralizing device 5 is hanged with ball seat 6 and tail pipe The quantity of small casing 4 between hanging device 1 is at one or more；The outer diameter of hydraulic centralizing device 5 and mud cake removal device 8 in completion tubular column The respectively less than hole diameter of slim-hole 3.

Top connection 5.1 and retaining set 5.2, central tube 5.8, support sleeve 5.12 and lower contact in the hydraulic centralizing device 5 5.16 are successively threadedly coupled, top screw thread, the screw thread in top connection 5.1 and the lower part spiral shell of lower contact 5.16 of retaining set 5.2 Line is casing threads；The top outer circle of upper piston set 5.6 is threadedly coupled with lock ring pressure cap 5.5, lower part inner circle and fluid cylinder set 5.10 are threadedly coupled, and the lower part inner circle of fluid cylinder set 5.10 is threadedly coupled with the top outer circle of lower piston set 5.13；Lock ring pressure cap 5.5 It is connect by shear pin 5.3 with retaining set 5.2, between 5.5 middle part inner circle lower end surface of lock ring pressure cap and the upper surface of upper piston set 5.6 The groove of formation is provided with lock ring 5.4.

The inner circle of the lock ring 5.4 is equipped with the retaining that retaining screw thread covers 5.2 middle part outer circles with retaining and is threadedly engaged, and makes lock ring 5.4 can only move downward, and cannot retract upwards；After retaining set 5.2, central tube 5.8, support sleeve 5.12 and lower contact 5.16 connect The interior latus rectum formed is identical as the interior latus rectum of small casing 4.Hydraulic centralizing device 5 is consistent with the interior latus rectum of small casing 4, after capable of facilitating Continuous operation, guarantees the smooth tripping in of power tool.

The lower end surface of the lower piston set 5.13 and the upper surface of lower contact 5.16 are equipped with the plug socket of protrusion；Hinge 5.15 set there are two chain link, and the both ends of a chain link are equipped with engaging lug, and one end of another chain link is that engaging lug, the other end are Plug socket, the engaging lugs of two chain links are connect with plug socket grafting and by pin shaft 5.14, the engaging lug at 5.15 both ends of hinge with Plug socket in lower piston set 5.13 and lower contact 5.16 is connected by pin shaft 5.14；The total length of hinge 5.15 is equal to upper piston Set 5.6 be located at top dead-centre when, lower piston cover the distance between 5.13 and lower contact 5.16, the hinge being connected to outside support sleeve 5.12 Chain 5.15 is at least provided with three.When initial installation, hinge 5.15 is tightly attached in the outer circle of support sleeve 5.12, and outer diameter is helped with hydraulic The body diameter of positive device 5 is consistent, is conducive in the smooth tripping in slim-hole 3 of hydraulic centralizing device 5.

The inlet opening 1 is located at the upper end of central tube 5.8, fluid cylinder set concordant with the upper surface of fluid cylinder set 5.10 5.10 are sleeved on the outside of central tube 5.8 and are equipped with the retaining that inside and outside two seals 5.7 are equipped with sealing ring 5.7 with lower part outer circle Set 5.2 constitutes first order hydraulic device；Lower piston 5.13 top outer circles of set are connect with fluid cylinder 5.10 lower threads of set, its screw thread connects The place of connecing is sealed by sealing ring 5.7, and lower piston set 5.13 is sleeved on outside support sleeve 5.12, and 5.12 upper end of support sleeve is provided with inlet opening 2 5.17, the inlet opening 2 5.17 is concordant with the upper surface of lower piston set 5.13, and lower piston covers 5.13 tops and is equipped with inside and outside twice The composition second level hydraulic device of central tube 5.8 of sealing ring 5.7 and lower part outer circle equipped with sealing ring 5.7；5.10 middle part of fluid cylinder set The outer circle step of inner circle step and central tube 5.8 forms confined space, and relief hole 5.11 is provided with fluid cylinder and covers 5.10 middle part inner circles The lower section of step.So that the liquid in confined space is discharged by relief hole 5.11, is conducive to fluid cylinder and covers 5.10 smooth downlinks. It when beating hydraulic inside this tubing string, is acted on the upper surface of fluid cylinder set 5.10, is pushed under fluid cylinder set 5.10 by inlet opening 1 Row；The liquid suppressed inside tubing string simultaneously is acted on the upper surface of lower piston set 5.13 by inlet opening 2 5.17, under promotion 5.13 downlink of piston bush, the hydraulic action are superimposed with the hydraulic action of first order hydraulic device, and same pressure difference is enable to produce Raw double hydraulic thrust, improves the setting force of hydraulic centralizing device 5.

The rotation scraping mechanism of the mud cake removal device 8 is additionally provided with pressure cap 8.3, rotary sleeve 8.4 and little spring 8.5, rotation Set 8.4 outer circle be equipped with scraping block mounting groove, the scraping block mounting groove be axial groove, at least be arranged three, scraping block 8.6 it is interior Wall is equipped with blind hole, and little spring 8.5 is mounted between the blind hole and the bottom surface of scraping block mounting groove；Pressure cap 8.3 set there are two, it is symmetrical The both ends of rotary sleeve 8.4 are mounted on, two pressure caps 8.3 are threadedly coupled with rotary sleeve 8.4, scraping block 8.6 is mounted on rotation In the scraping block mounting groove of set 8.4, rotary sleeve 8.4 and pressure cap 8.3 are sleeved on the outside of mandrel 8.2；The outer arc of scraping block 8.6 Face is equipped with the wiper that can connect with two sides above and below extrados, on the plate body of the scraping block 8.6 of the wiper two sides Drainage hole 8.7 is set, the liquid in scraping block mounting groove is enable to be discharged by drainage hole 8.7.When the well for encountering hole diameter and becoming smaller Duan Shi, scraping block 8.6 invaginates after compressing little spring 8.5, and to prevent tubing string to be hampered, drainage hole 8.7 is discharged in scraping block mounting groove Liquid be conducive to scraping block 8.6 to contract.

Scraping block 8.6 outside the rotary sleeve 8.4 at least installs three sets, the upper end of the pressure cap 8.3 on 8.4 top of rotary sleeve Face and the lower end surface of lifting sub 8.1 abut against, and play thrust bearing, the lower end surface of the pressure cap 8.3 of 8.4 lower part of rotary sleeve with The outer circle step of 8.2 lower part of mandrel matches, and also plays thrust bearing；Rotate scraping mechanism in mud cake removal device 8 extremely Connect less it is a set of, 8.2 lower end outer circle of mandrel be equipped with tubing round thread, 8.1 upper end inner circle of lifting sub be equipped with tubing round thread, make to rotate It can be connected by tubing round thread between scraping mechanism and rotation scraping mechanism, the lowermost rotates scraping mechanism and non-return seat 8.8 are connected by tubing round thread, and more set rotation scraping mechanisms are connected in mud cake removal device 8 can further improve mud cake removal effect Fruit.

Downward conical seal (contact) face is equipped in the non-return seat 8.8, the conical seal (contact) face and remover ball sealer 8.9 match It closes；The body lower part of non-return seat 8.8 is equipped with circulation port 8.11, ontology lower end is connect with guide shoe 8.13 by tubing round thread.

The top of the guide shoe 8.13 is connect with non-return seat 8.8 by tubing round thread, middle part inner circle is assembled equipped with spring base Step is equipped with circulation port 8.11 on the ontology below spring base assembly step, the circulation in non-return seat 8.8 and guide shoe 8.13 Hole 8.11 is at least provided with three.

Circulation port 8.11 in the non-return seat 8.8 and guide shoe 8.13 is the ontology with non-return seat 8.8 and guide shoe 8.13 Axis spends the inclined hole being obliquely installed upwards, while the radial line relative to non-return seat 8.8 and guide shoe 8.13, circulation port at 30 degree -45 8.11 axis is biased to the radial line side of non-return seat 8.8 and guide shoe 8.13 in the same direction again.Circulation port 8.11 be both on Tiltedly it is capable of the inclined hole of deflection to the left or to the right again, when circulation of drilling fluid can generate eddy flow effect, and cementing operation replaces drilling fluid When can be improved flush efficiency.

Spring base 8.12, bullet are housed between the spring base of 8.8 lower end surface of non-return seat and guide shoe 8.13 assembly step Spring abutment 8.12 is ⊥ type seat, and the top cylinder of ⊥ type seat is equipped with axial vertical slot, is equipped with liquid flow hole or slot, lower disc in the disk body of lower part The lower end outer wall of body is stuck in the centre bore of spring base assembly step；The top cylinder extracorporeal set big spring 8.10 of ⊥ type seat, clearly Except device ball sealer 8.9 is mounted between big spring 8.10 and the conical seal (contact) face of non-return seat 8.8, big spring 8.10 can will be removed Device ball sealer 8.9 is held out against on the conical seal (contact) face of non-return seat 8.8, prevents liquid from flowing backwards；In the ⊥ type seat of spring base 8.12 Axial vertical slot and liquid flow hole or slot in the disk body of lower part and circulation port 8.11 constitute circulation of drilling fluid channel.

Below by taking sidetracked hole as an example, illustrate the construction method of this completion tubular column.

For a kind of construction method of slim hole completion tubing string, it is:

A, side tracked slim hole 3, tripping in completion tubular column in former wellbore casing 2；During tubing string tripping in, on mud cake removal device 8 It scrapes to chip and 8.6 is supported on scraping mud cake on the open hole wall of slim-hole 3, rotary sleeve 8.4 is on mandrel 8.2 while scraping mud cake Rotation prevents from being pasted by mud cake.When encountering the small well section of hole diameter, 8.6 inside retractions of chipping are scraped, prevent tubing string by card；In addition, Hinge 5.15 on hydraulic casing pipe centering device 5 is tightly attached in the outer circle of support sleeve 5.12, keeps consistent with the external diameter of centralizer steel, Prevent completion tubular column by card.

B, completion tubular column is after design well depth, turn on pump circulating fluid, the dirts such as mud cake that mud cake removal device 8 is scraped Circulation is taken out of outside pit shaft, after circulation is abundant, puts into ball seat ball sealer, small displacement pumps on ball seat ball sealer to ball seat 6, ball seat 6 Confined space is formed in above tubing string.

C, ground is suppressed into completion tubular column to 9MPa-11MPa, starts extension hanger 1, while pushing completion tubular column Set extension hanger 1 sufficiently.

D, continue to suppress to 14MPa-16MPa and pressure stabilizing 4min-7min, set hydraulic centralizing device 5；Hydraulic centralizing at this time Inlet opening 1 and the transmitting of inlet opening 2 5.17 in device 5 is hydraulic, is respectively acting on the fluid cylinder set 5.10 of first order hydraulic device Upper surface and second level hydraulic device lower piston set 5.13 upper surface on, downward hydraulic thrust pass through upper piston set 5.6 are transferred to lock ring pressure cap 5.5, cut shear pin 5.3.Lock ring pressure cap 5.5, upper piston set 5.6, fluid cylinder set 5.10 and lower work at this time The downlink simultaneously of plug sleeve 5.13, hinge 5.15 is pushed out to open is supported on the borehole wall, thus force completion tubular column placed in the middle, hydraulic centralizing After device 5 is set in place, lock ring 5.4 is locked on the retaining screw thread of retaining set 5.2, it is ensured that the reliability set.

E, after the completion of hydraulic centralizing device 5 is set, continue to suppress the ball seat sealing destroyed in ball seat 6 to 17MPa-19MPa Ball establishes termination of pumping behind circulation of drilling fluid channel, above mentions drill string, and the point of neutralization is made to fall in the top of extension hanger 1；Ball seat ball sealer After falling into the ball basket of lower section, the abrupt pressure reduction in tubing string, it was demonstrated that circulation of drilling fluid channel has been established.

F, it rotates forward the circle of drill string 30~50 and is buckled to completion tubular column of giving up, judgement uses drill string tieback completion tubular after giving up successfully again Column starts cementing operation；

G, replace first into flushing liquor, flushing liquor open completion tubular column lower end float collar 7 float collar ball sealer and mud cake removal device 8 it is clear Except device ball sealer 8.9, the annular space entered between completion tubular column and slim-hole 3 by circulation port 8.11 and eddy flow is formed, Jiang Yuanjing Drilling fluid displacing in cylinder casing 2 and slim-hole 3 comes out；Due to completion tubular column by 5 righting of hydraulic centralizing device placed in the middle, completion tubular column Annular gap between slim-hole 3 is relatively uniform, and the flow velocity of fluid is relatively also relatively uniform in annular space, and drilling fluid can be rinsed Fully displacement is clean for liquid, not will form drilling fluid stagnant area.

H, cement slurry is injected after the completion of rinsing, cement slurry discharges drilling rod rubber plug after having infused, drilling rod rubber plug downlink and tail pipe are outstanding It is continued traveling downwardly after the hollow rubber plug of hanging device 1 is compound, reaches ball seat 6 and realize that bruising, cementing terminate.

I, well head pressure release, pulling out of hole, it is solidifying to wait.At this point, the remover ball sealer 8.9 of mud cake removal device 8 is withstood on only in completion tubular column It returns on the conical seal (contact) face of seat 8.8, prevents cement slurry from flowing back, play the role of float shoe, in addition, float collar 7 is also reversed ball seat knot Structure can also prevent cement slurry from flowing back.

The embodiment described above is only exemplary embodiments, but the present invention is not limited only to these embodiments, this field Technical staff can make modification without departing from the spirit and inspiration of the present invention.There may be many for aspect disclosed herein Change, combination and modification, and be within, therefore, protection scope is not limited only to explanation above.

Claims (13)

1. a kind of slim hole completion tubing string, including extension hanger (1), small casing (4), ball seat (6) and float collar (7), feature That hydraulic centralizing device (5) and mud cake removal device (8) are additionally provided in completion tubular column, extension hanger (1), hydraulic centralizing device (5), Ball seat (6), float collar (7) and mud cake removal device (8) pass through small casing (4) and are sequentially connected；In hydraulic centralizing device (5) Inlet opening one (5.9) and inlet opening two (5.17), fluid cylinder set are respectively equipped on the tube body of central tube (5.8) and support sleeve (5.12) (5.10) relief hole (5.11) are equipped with；Top connection (5.1), retaining set (5.2), central tube (5.8) in hydraulic centralizing device (5), Support sleeve (5.12) and lower contact (5.16) are sequentially connected, and piston bush (5.6), fluid cylinder set (5.10) and lower piston are installed in outside It covers (5.13), sealing ring (5.7) is installed in retaining set (5.2), fluid cylinder set (5.10) and lower piston set (5.13), are capable of forming Two-stage hydraulic device, hinge (5.15) are connected between lower piston set (5.13) and lower contact (5.16)；In mud cake removal device (8) Equipped with circulation of drilling fluid channel, the lower part of mud cake removal device (8) is guide shoe (8.13), mainly by scraping block (8.6) and mandrel (8.2) the rotation scraping mechanism and non-return seat (8.8) constituted is connected between lifting sub (8.1) and guide shoe (8.13), is revolved Turning the scraping block (8.6) in scraping mechanism can be freely rotated outside mandrel (8.2).

2. a kind of slim hole completion tubing string as described in claim 1, characterized in that the hydraulic centralizing device (5) is in completion tubular It is at least connected with a set of in column, the small casing (4) being connected between ball seat (6), float collar (7) and mud cake removal device (8) only connect one Root is connected to the small set between hydraulic centralizing device (5) and between hydraulic centralizing device (5) and ball seat (6) and extension hanger (1) The quantity of (4) is managed at one or more；The outer diameter of hydraulic centralizing device (5) and mud cake removal device (8) in completion tubular column is respectively less than small The hole diameter of wellbore (3).

3. a kind of slim hole completion tubing string as claimed in claim 1 or 2, characterized in that upper in the hydraulic centralizing device (5) Connector (5.1) is successively threadedly coupled with retaining set (5.2), central tube (5.8), support sleeve (5.12) and lower contact (5.16), only Top screw thread, the screw thread in top connection (5.1) and the lower thread of lower contact (5.16) of drill drift (5.2) are casing spiral shells Line；The top outer circle of upper piston set (5.6) is threadedly coupled with lock ring pressure cap (5.5), lower part inner circle and fluid cylinder set (5.10) screw thread Connection, the lower part inner circle of fluid cylinder set (5.10) are threadedly coupled with the top outer circle of lower piston set (5.13)；Lock ring pressure cap (5.5) is logical It crosses shear pin (5.3) to connect with retaining set (5.2), the upper end of inner circle lower end surface and upper piston set (5.6) in the middle part of lock ring pressure cap (5.5) The groove formed between face is provided with lock ring (5.4).

4. a kind of slim hole completion tubing string as claimed in claim 3, characterized in that the inner circle of the lock ring (5.4) is equipped with only It moves back screw thread and the retaining of outer circle in the middle part of retaining set (5.2) is threadedly engaged, move downward lock ring (5.4) can only, cannot move back upwards It returns；The interior latus rectum and small set formed after retaining set (5.2), central tube (5.8), support sleeve (5.12) and lower contact (5.16) connection The interior latus rectum for managing (4) is identical.

5. a kind of slim hole completion tubing string as claimed in claim 3, characterized in that the lower end surface of the lower piston set (5.13) The plug socket of protrusion is equipped with the upper surface of lower contact (5.16)；Hinge (5.15) is set there are two chain link, and the two of a chain link End is equipped with engaging lug, and it is plug socket that one end of another chain link, which is engaging lug, the other end, the engaging lug of two chain links and grafting Seat grafting is simultaneously connected, the engaging lug at hinge (5.15) both ends and lower piston set (5.13) and lower contact by pin shaft (5.14) (5.16) plug socket in is connected by pin shaft (5.14)；The total length of hinge (5.15) is equal to upper piston set (5.6) positioned at upper When dead point, the distance between lower piston set (5.13) and lower contact (5.16), be connected to the external hinge of support sleeve (5.12) (5.15) at least provided with three.

6. a kind of slim hole completion tubing string as claimed in claim 5, characterized in that the inlet opening one (5.9) is located at center The upper end, concordant with the upper surface of fluid cylinder set (5.10) of (5.8) is managed, fluid cylinder set (5.10) is sleeved on the outside of central tube (5.8) And it is hydraulic to be equipped with retaining set (5.2) the composition first order of inside and outside two seals (5.7) with lower part outer circle equipped with sealing ring (5.7) Device；Lower piston set (5.13) top outer circle is connect with fluid cylinder set (5.10) lower thread, its threaded connection place is by sealing ring (5.7) it seals, lower piston set (5.13) is sleeved on support sleeve (5.12) outside, and support sleeve (5.12) upper end is provided with inlet opening two (5.17), the inlet opening two (5.17) is concordant with the upper surface of lower piston set (5.13), and lower piston set (5.13) top is equipped with interior Central tube (5.8) the composition second level hydraulic device of outer two seals (5.7) and lower part outer circle equipped with sealing ring (5.7)；Liquid Inner circle step and the outer circle step of central tube (5.8) form confined space in the middle part of cylinder sleeve (5.10), and relief hole (5.11) is provided with The lower section of inner circle step in the middle part of fluid cylinder set (5.10).

7. a kind of slim hole completion tubing string as described in claim 1, characterized in that the rotation of the mud cake removal device (8) is scraped It cuts mechanism and is additionally provided with pressure cap (8.3), rotary sleeve (8.4) and little spring (8.5), the outer circle of rotary sleeve (8.4) is pacified equipped with scraping block Tankage, the scraping block mounting groove are axial grooves, are at least arranged three, and the inner wall of scraping block (8.6) is equipped with blind hole, little spring (8.5) it is mounted between the blind hole and the bottom surface of scraping block mounting groove；Pressure cap (8.3) set there are two, be symmetrically mounted on rotary sleeve (8.4) both ends, two pressure caps (8.3) are threadedly coupled with rotary sleeve (8.4), scraping block (8.6) are mounted on rotary sleeve (8.4) in scraping block mounting groove, rotary sleeve (8.4) and pressure cap (8.3) are sleeved on the outside of mandrel (8.2)；Scraping block (8.6) extrados is equipped with the wiper that can connect with two sides above and below extrados, the scraping block in the wiper two sides (8.6) drainage hole (8.7) are set on plate body.

8. a kind of slim hole completion tubing string as claimed in claim 7, characterized in that the external scraping of the rotary sleeve (8.4) Block (8.6) at least installs three sets, the lower end surface of the upper surface and lifting sub (8.1) of the pressure cap (8.3) on rotary sleeve (8.4) top It abuts against, plays thrust bearing, the lower end surface of the pressure cap (8.3) of rotary sleeve (8.4) lower part and the outer circle of mandrel (8.2) lower part Step matches, and also plays thrust bearing；Rotation scraping mechanism is at least connected with a set of, mandrel in mud cake removal device (8) (8.2) lower end outer circle be equipped with tubing round thread, lifting sub (8.1) upper end inner circle be equipped with tubing round thread, make rotate scraping mechanism with It can be connected by tubing round thread between rotation scraping mechanism, the lowermost rotation scraping mechanism and non-return seat (8.8) pass through oil Pipe screw thread connection.

9. a kind of slim hole completion tubing string as claimed in claim 1 or 8, characterized in that be equipped in the non-return seat (8.8) to Under conical seal (contact) face, which matches with remover ball sealer (8.9)；The body lower part of non-return seat (8.8) is set There are circulation port (8.11), ontology lower end to connect with guide shoe (8.13) by tubing round thread.

10. a kind of slim hole completion tubing string as claimed in claim 9, characterized in that the top of the guide shoe (8.13) with only It goes back to seat (8.8) and spring base assembly step is equipped with by tubing round thread connection, middle part inner circle, below spring base assembly step Ontology is equipped with circulation port (8.11), and the circulation port (8.11) in non-return seat (8.8) and guide shoe (8.13) is at least provided with three.

11. a kind of slim hole completion tubing string as claimed in claim 10, characterized in that in non-return seat (8.8) and guide shoe (8.13) circulation port (8.11) in is spent at 30 degree -45 to updip with the body axis of non-return seat (8.8) and guide shoe (8.13) The inclined hole being tiltedly arranged, while the radial line relative to non-return seat (8.8) and guide shoe (8.13), the axis of circulation port (8.11) again with It is biased to the radial line side of non-return seat (8.8) and guide shoe (8.13) in identical direction.

12. a kind of slim hole completion tubing string as claimed in claim 11, characterized in that in non-return seat (8.8) lower end surface Spring base (8.12) are housed between the spring base assembly step of guide shoe (8.13), spring base (8.12) is ⊥ type seat, ⊥ type seat Top cylinder be equipped with axial vertical slot, be equipped with liquid flow hole or slot in the disk body of lower part, the lower end outer wall of lower part disk body is stuck in spring base In the centre bore for assembling step；The top cylinder extracorporeal set big spring (8.10) of ⊥ type seat, remover ball sealer (8.9) are mounted on Between big spring (8.10) and the conical seal (contact) face of non-return seat (8.8)；Axial vertical slot in the ⊥ type seat of spring base (8.12) and Liquid flow hole or slot and circulation port (8.11) in the disk body of lower part constitute circulation of drilling fluid channel.

13. construction method is for a kind of slim hole completion tubing string described in claim 11:

A, side tracked slim hole (3), tripping in completion tubular column in former wellbore casing (2)；

B, completion tubular column is after design well depth, turn on pump circulating fluid, after circulation is abundant, puts into ball seat ball sealer, small displacement It pumps on ball seat ball sealer to ball seat (6)；

C, ground is suppressed into completion tubular column to 9MPa-11MPa, is started extension hanger (1), while pushing completion tubular column to make Extension hanger (1) is sufficiently set；

D, continue to suppress to 14MPa-16MPa and pressure stabilizing 4min-7min, set hydraulic centralizing device (5)；

E, after the completion of hydraulic centralizing device (5) is set, continue to suppress the ball seat sealing destroyed in ball seat (6) to 17MPa-19MPa Ball establishes termination of pumping behind circulation of drilling fluid channel, above mentions drill string, and the point of neutralization is made to fall in the top of extension hanger (1)；

F, it rotates forward the circle of drill string 30~50 and is buckled to completion tubular column of giving up, judgement is opened with drill string tieback completion tubular column again after giving up successfully Beginning cementing operation；

G, it replaces first into flushing liquor, flushing liquor opens the float collar ball sealer and mud cake removal device (8) of completion tubular column lower end float collar (7) Remover ball sealer (8.9), enter annular space between completion tubular column and slim-hole (3) by circulation port (8.11) and form rotation Stream, the drilling fluid displacing in former wellbore casing (2) and slim-hole (3) is come out；

H, cement slurry is injected after the completion of rinsing, cement slurry discharges drilling rod rubber plug, drilling rod rubber plug downlink and extension hanger after having infused (1) it is continued traveling downwardly after hollow rubber plug is compound, reaches ball seat 6 and realize that bruising, cementing terminate；

I, well head pressure release, pulling out of hole, it is solidifying to wait.