CN2693936Y

CN2693936Y - Elastic centralizer for sidetracked hole

Info

Publication number: CN2693936Y
Application number: CN 200320124705
Authority: CN
Inventors: 张恒; 辛秀勤; 于成水; 常青
Original assignee: Drilling & Extracting Tech Ins; Dagang Oilfield Group Co Ltd
Current assignee: Drilling & Extracting Tech Ins; Dagang Oilfield Group Co Ltd
Priority date: 2003-11-28
Filing date: 2003-11-28
Publication date: 2005-04-20
Anticipated expiration: 2013-11-28

Abstract

The utility model relates to a casing centralizer in the course of the well completion and the well cementing of a sidetracked hole. Because the diameter of the windowing position after sidetrack drilling is short, and the diameter of the wellbore of an inclined well segment after the sidetrack drilling is longer than the diameter of a straight well segment, a normal elastic centralizer can be resisted on the windowing position of the sidetracked hole; even though the regular elastic centralizer can pass through the windowing position, and the regular elastic centralizer cannot have the action of centralizing a casing as a consequence of the diameter of the wellbore of the inclined well segment longer than the diameter of the straight well segment. The technical proposal is that the utility model is composed of nesting joints, a spring lamination and a supporting ring, and each nesting joint is provided with a ring groove, a groove and a key groove; the two ends of the spring lamination are respectively inserted in the corresponding grooves of the nesting joints at the two ends of the casing centralizer, and the spring lamination and the nesting joints are connected together by connecting nails arranged on the ring grooves; when the casing centralizer is arranged on the casing, the two ends of the centralizing strip of the supporting ring are respectively inserted in the corresponding key grooves of the nesting joints at the two ends of the casing centralizer. The utility model provides the elastic centralizer which is applied to the well cementing of the sidetracked hole and a close clearance well.

Description

The sidetracked hole elastic centralizer

Technical field

The utility model relates to the casing stabbing board of using in a kind of sidetracked hole completion well cementation process, belongs to the special tool in the petroleum drilling engineering.

Background technology

Centralizer is used to set upright sleeve pipe, and it is placed in the middle in well to be beneficial to sleeve pipe, and good mud flow passage is provided, thereby improves the oil well cementing quality.Conventional elastic centralizer, elastic centralizer or bouble-bow elastic centralizer etc. as braiding all are installed on the casing coupling, for straight well, the top mineshaft diameter is greater than the bottom mineshaft diameter, can adopt above-mentioned conventional elastic centralizer, but for sidetracked hole, because the diameter at the place of windowing behind the sidetracking is little, and the borehole diameter of the lower curved section behind the sidetracking is bigger than straight well section diameter, conventional elastic centralizer can be hampered at the place of windowing of sidetracked hole, even by the place of windowing, also can be owing to the borehole diameter of lower curved section is bigger than straight well section diameter, and do not have the effect of setting upright casing centralization.

Summary of the invention

The utility model purpose is to provide a kind of elastic centralizer that can be applicable to sidetracked hole, the well cementation of little gap well, effectively solves the difficult problem of above-mentioned construction.

The utility model adopts following technical scheme:

A kind of sidetracked hole is made of nested joint, shell fragment and support ring with elastic centralizer, have cannelure, groove and keyway on the nested joint, insert respectively in the nested joint corresponding groove at centralizer two ends at the shell fragment two ends, and shell fragment is linked together with nested joint by the connected nail that is arranged on the cannelure, when centralizer is installed on sleeve pipe, the righting strip two ends of support ring are inserted respectively in the keyway of nested joint of two ends correspondence.

The utility model is on the mounting sleeve box cupling, and is mounted in sleeve pipe, and centralizer can slide on sleeve body, plays the effect of setting upright sleeve pipe at the sidetracking lower curved section.In nested joint end one slope angle is arranged, slope angle is 10 °～45 °, can reduce to be lowered at sleeve pipe that centralizer prevents engineering accident to the scratching of sidetracking window in the process.

The structure of shell fragment dependence itself and the cannelure and the groove fit of nested joint can not thrown off it when stressed.Support ring is when centralizer is contained on the sleeve pipe, can fix, otherwise be movable, and support ring and shell fragment are located fluted in the same way, provide bigger activity space to shell fragment.Support ring relies on 4 righting strips at two ends to be connected with nested joint, 4 righting strips of support ring are greater than the maximum axial deflection that shell fragment is out of shape with nested joint length of fit, otherwise, when shell fragment is pressed also, support ring cooperates with nested joint and can lose efficacy, and the ability that elastic centralizer is set upright sleeve pipe also lost efficacy.

Structure design of the present utility model has realized that shell fragment utilizes elasticity to set upright the effect of sleeve pipe.The major function that nested joint cooperates with support ring has two: the torque that the first, two nested joint relatively rotates generation is born by support ring, and can not pass to shell fragment, and the second, during the centralizer axial compression, pressure is also passed to support ring, does not pass to shell fragment.

Description of drawings

Fig. 1, sidetracked hole elastic centralizer assembling drawing

Among Fig. 1, nested joint 1, shell fragment 2, support ring 3, connected nail 4, cannelure 5, groove 6, keyway 7 and righting strip 8.

The specific embodiment

Sidetracked hole is made of nested joint (1), shell fragment (2) and support ring (3) with elastic centralizer, have cannelure (5), groove (6) and keyway (7) on the nested joint, insert respectively in nested joint (1) corresponding groove (6) at centralizer two ends at shell fragment (2) two ends, and shell fragment is linked together with nested joint by the connected nail (4) that is arranged on the cannelure (5), when centralizer is installed on sleeve pipe, righting strip (8) two ends of support ring (3) are inserted respectively in the keyway (7) of nested joint (1) of two ends correspondence.

Sidetracked hole is installed on the sleeve body with elastic centralizer, and there is a slope angle nested joint (1) end, 15 ° of slope angles.

Claims

1, a kind of sidetracked hole is made of nested joint (1), shell fragment (2) and support ring (3) with elastic centralizer, it is characterized in that having on the nested joint cannelure (5), groove (6) and keyway (7), insert respectively in nested joint (1) corresponding groove (6) at centralizer two ends at shell fragment (2) two ends, and shell fragment is linked together with nested joint by the connected nail (4) that is arranged on the cannelure (5), when centralizer is installed on sleeve pipe, righting strip (8) two ends of support ring (3) are inserted respectively in the keyway (7) of nested joint (1) of two ends correspondence.

2, sidetracked hole elastic centralizer as claimed in claim 1 is characterized in that there is a slope angle nested joint (1) end, and slope angle is 15 °.

3, sidetracked hole elastic centralizer as claimed in claim 1 is characterized in that righting strip and nested joint (1) length of fit are greater than the maximum axial deflection of shell fragment (2) distortion.