CN204899842U

CN204899842U - Well cementation cutout

Info

Publication number: CN204899842U
Application number: CN201520572952.0U
Authority: CN
Inventors: 柳进; 钟富林; 杨帆; 黄志强; 张旭龙; 郭修成
Original assignee: CNPC Great Wall Drilling Co
Current assignee: China National Petroleum Corp; CNPC Great Wall Drilling Co
Priority date: 2015-08-03
Filing date: 2015-08-03
Publication date: 2015-12-23
Anticipated expiration: 2025-08-03

Abstract

The utility model relates to a cementing tool, in particular to well cementation cutout. The device's case upper end outer wall threaded connection is on shells inner wall and II sealed through the sealing washer, and the case bottom is sealed, has the clearance between case lower part outer wall and the shells inner wall, and case lower extreme lateral wall week is upwards opened there is the circulation hole, closes the cover through cutting the pin junction on the case inner wall of circulation hole upper end, closes about the cover sealedly through sealing washer I and case inner wall respectively. The utility model discloses a fluid flow direction in the sliding sleeve structural change well exposes in outer sealing contact face and well high -pressure endless fluid to the single current valve originally and keeps apart to guarantee behind the cementing job the become dry reliability of function of the reversion of single current valve, simple structure seals effectually, and it can the reinforce to hold the back pressure, bumps and thoroughly to cut off external pressure in the sleeve pipe after the pressure, prevents that the annular space grout from returning, thereby avoids low and return and stay occurence of failure such as stopper, guarantees the cementing and constructs successfully.

Description

A kind of well cementation cutout

Technical field:

The utility model relates to a kind of oil field well cementation tool, particularly one well cementation cutout.

Background technology:

At present, conventional Well stabilization single pass valve is float-ball type or spring.The general principle that float-ball type ball-and-seat mainly utilizes ball float density to be less than borehole fluid density will to float, lays down pressure after well cementing impact pressure completes, and ball float can float to contact to be formed with ball seat lower surface and seal, thus stops fluid to return; Spring uniflow valves mainly utilizes the retractility of spring, after well cementing impact pressure completes, lay down pressure, and spring can promote the up valve that makes of valve bar and contact to be formed with valve seat lower surface and seal, thus stops fluid to return.There is following defect in these two kinds of ball-and-seats:

1, due to complex structure, widgets is various, virtually adds the seal failure rate of ball-and-seat.

2, because sealing forming surface is exposed among fluid completely, fluid erosion can damage the sealing contact surface of ball-and-seat.

3, because ball float is very easily out of shape under the erosion of fluid, spring very easily follows the string under the erosion of fluid, and once after ball float distortion is serious, spring follows the string, ball-and-seat just cannot form sealing and stop fluid to return.

Therefore, as mentioned above, because no matter existing Well stabilization single pass valve is float-ball type or spring, sealing contact surface is all be exposed among fluid erosion completely, thus causes Well stabilization single pass valve crash rate high.And ball-and-seat just very easily causes once inefficacy and lowly returns and stay the accidents such as plug.

Utility model content:

The technical problems to be solved in the utility model is to provide a kind of well cementation cutout, the arrangement achieves and change borehole fluid flow direction by shift sleeve structure, the fluid isolation that sealing contact surface outside ball-and-seat is exposed to originally and well inner high voltage circulate comes, thus the reliability of the reverse cutout function of ball-and-seat after guaranteeing cementing job, structure is simple, sealing effect is good, hold back-pressure ability strong, sleeve pipe external and internal pressure can be thoroughly cut off after bruising, prevent annular space cement paste from returning, thus avoid lowly returning and staying the accident such as plug to occur, guarantee cementing practice success.Overcoming existing Well stabilization single pass valve sealing contact surface is all be exposed to completely among fluid erosion, the deficiency of easy seal failure.

Technical solution adopted in the utility model is: a kind of well cementation cutout, comprises housing and spool; Spool upper end outer wall thread to be connected in inner walls and to be sealed by sealing ring II, spool bottom end closure, gap is there is between spool bottom outer wall and inner walls, spool lower end sidewall circumference has circulation port, close cover by cut off be connected to circulation port upper end spool inwall on, close cover up and down respectively by sealing ring I and spool inner wall sealing.

The beneficial effects of the utility model are: the utility model changes borehole fluid flow direction by shift sleeve structure, the fluid isolation that sealing contact surface outside ball-and-seat is exposed to originally and well inner high voltage circulate comes, thus the reliability of the reverse cutout function of ball-and-seat after guaranteeing cementing job, structure is simple, sealing effect is good, hold back-pressure ability strong, sleeve pipe external and internal pressure can be thoroughly cut off after bruising, prevent annular space cement paste from returning, thus avoid lowly returning and staying the accident such as plug to occur, guarantee cementing practice success.

Accompanying drawing illustrates:

Below in conjunction with the drawings and specific embodiments, the utility model is described in more detail.

Fig. 1 is structural representation of the present utility model.

Detailed description of the invention:

As shown in Figure 1, a kind of well cementation cutout, comprises housing 1 and spool 2; Spool 2 upper end outer wall thread to be connected on housing 1 inwall and to be sealed by sealing ring II 5, spool 2 bottom end closure, gap is there is between spool 2 bottom outer wall and housing 1 inwall, spool 2 lower end sidewall circumference has circulation port, closing cover 3 is connected on spool 2 inwall of circulation port upper end by cutting off 6, closes cover about 3 respectively by sealing ring I 4 and spool 2 inner wall sealing.

For after mud terminates, cementing plug comes downwards to closes cover 3 upper surface bruising, higher than the highest for pressure 5-10MPa time, spool 2 and close cutting off between cover 3 and 6 will to be cut off, at this moment close cover 3 can under be about to circulation port and close, thus cut off sleeve pipe external and internal pressure.

What the utility model adopted is the sealing of O RunddichtringO, has the following advantages compared with sealing with face contact type: 1, hermetically-sealed construction is reliable, because the fluid erosion in well cannot have influence on potted component, therefore, it is possible to sealing is effective after guaranteeing cementing job; 2, hold back-pressure ability strong, face contact type sealing effectiveness depends on potted component finish and deboost size, once potted component finish is inadequate, or deboost is too little that cementing will be caused to terminate the reverse seepage flow of rear fluid; 3, easy to process, because face contact type sealing needs to carry out vulcanization of rubber processing to sealing surface, make process complicated and cost is high.

Be understandable that, above about specific descriptions of the present utility model, the technical scheme described by the utility model embodiment is only not limited to for illustration of the utility model, those of ordinary skill in the art is to be understood that, still can modify to the utility model or equivalent replacement, to reach identical technique effect; Needs are used, all within protection domain of the present utility model as long as meet.

Claims

1. a well cementation cutout, comprises housing (1) and spool (2); It is characterized in that: spool (2) upper end outer wall thread is connected on housing (1) inwall and is also sealed by sealing ring II (5), spool (2) bottom end closure, gap is there is between spool (2) bottom outer wall and housing (1) inwall, spool (2) lower end sidewall circumference has circulation port, closing cover (3) is connected on spool (2) inwall of circulation port upper end by cutting off (6), close cover (3) up and down respectively by sealing ring I (4) and spool (2) inner wall sealing.