CN2122990U

CN2122990U - Self-grouting back-pressure valve

Info

Publication number: CN2122990U
Application number: CN 92214477
Authority: CN
Inventors: 吴俊杰; 姜良; 杨加林; 曾凡富
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-04-22
Filing date: 1992-04-22
Publication date: 1992-11-25

Abstract

The utility model relates to a self-grouting back-pressure valve used in the work of well cementing casing pipe. The utility model comprises a one-way valve core which has an elastic hinge and a control mechanism under the one-way valve core. The control mechanism comprises a ball seat valve core, a blocking hole ball, a barrier and a cutting pin. The valve core can keep open through the blocking of the barrier, and the requirement of self-grouting and positive circulation in midway can be answered. After a casing tube is in the position, the one-way valve core can be released and closed through pressing and cutting the cutting pin by the blocking hole ball, and the goal of prevent the cement in ring cavity from back flowing.

Description

Self-grouting back-pressure valve

The utility model relates to a kind of back-pressure valve of grouting formula certainly that well cementation is used during casing job in drilling technology.

Chinese patent CN2061235U discloses a kind of " the sleeve pipe back-pressure valve of mud grouting automatically ", by boss being set on the valve seat of original enclosed sleeve pipe back-pressure valve, crossing boss and valve core rod and be provided with to install in through hole, the through hole and cut keeper, by break pin spool is fixed in valve seat, make spool under the effect of break pin, overcome the active force of its spring and be normally open, mud enters in the casing string automatically when reaching casing running, make the inside and outside pressure of casing string keep relative equilibrium, avoid sleeve pipe by the danger of pressure break or distortion.When needs are closed back-pressure valve, move down by the bruising plug in the cementing job and to be depressed into the back-pressure valve valve rod and to make it to move down the cut-out break pin, and when cutting off, close pump, and remove the pressure that acts on the valve rod, make valve rod under the effect of spring, drive spool and close back-pressure valve.Thisly utilize displacement fluid to promote the bruising plug to be depressed into valve rod and it to be moved down directly cause the control mode that break pin is cut off and pressure is removed in termination of pumping when cutting off to be difficult for grasping, and being difficult to realize---lower shearing force is difficult to reflect on Pump pressure meter, and higher shearing force easily makes valve core rod impaired with cover spring thereon again; Do not close in time that pump also may cause the excessive descending of bruising plug and whole spool destroyed to cause back to close fail, in case and this thing happens then can't remedy.

The purpose of this utility model provides a kind of simple in structure, easy formula back-pressure valve that is in the milk certainly of control operation.

The formation that realizes the formula of being in the milk the certainly back-pressure valve of the purpose of this utility model comprises valve body, valve seat, the spool control mechanism of nonreturn valve core and the action of controlling non-return valve core, nonreturn valve core is hinged on the lower end surface of valve seat by an elastic hinge, the spool control mechanism is by a ball seat spool that is arranged on nonreturn valve core below, ball valve seat, shear pin, pin and plugging ball constitute, the ball seat spool has a through hole that can be blocked up by the plug-hole ball sealing, be connected in ball valve seat by shear pin and the hinge level that is oppositely arranged, one end of pin vertically is fixed in the upper-end surface of ball seat spool, and the other end that protrudes upward keeps off before the upper-end surface of nonreturn valve core and the active force that makes nonreturn valve core overcome elastic hinge is normally open.During work this back-pressure valve is connected on the lower end of casing string, the plugging ball of valve places the ball valve seat top, when casing string moves downwards in well, mud in the well jack-up that can easily plugging ball be made progress, enter in the casing string by the back-pressure valve that is opening state, thereby the relative equilibrium of the inside and outside pressure of maintainance set tubing string, connect the slurry pump circulating mud up to sleeve pipe down to the postpone of planned well deep-seated, the through hole of plugging ball shutoff valve with ball seat core under the effect of its pressure, pump straightening to the shear pin that will be connected between ball seat spool and the ball valve seat of spraining is cut off, the ball seat spool is rotated around its hinge to be free shape and to be hinged on the ball valve seat, driving the pin be fixed on the ball seat spool simultaneously rotates and leaves nonreturn valve core, remove the pressure of pump when termination of pumping after, nonreturn valve core is closed under the effect of elastic hinge or is tending towards closed condition, at this moment, the utility model becomes an one-way valve that typically only allows the mud direct circulation, behind cement injection and bruising operation, reach the cement slurry that stops in the annular space and return toward the interior purpose of casing string with routine.Plugging ball of the present utility model is made of buoyancy material, and make the diameter of the slurry channel that its diameter closes less than nonreturn valve core, it is swum in the casing running process on the liquid level in the casing string all the time, when the needs circulating mud, can easily plugging ball be taken out, making back-pressure valve is two-way normally open, to carry out circulating mud.Also can be all behind design attitude, again plugging ball be dropped in the casing string before the cement injection at casing string, forgotten taking-up plugging ball (when plugging ball is ball float) or temporary needs circulating mud when avoiding midway circulating mud and can't take out plugging ball (when plugging ball is the gravity ball) and cause spraining in advance of ball seat spool logical.

The utility model is simple in structure, makes easily, use very easily control of operation, and reliability is high.Even taking place, misoperation cause the logical ball seat spool of spraining in advance also can continue operation according to a conventional method and can not cause any harm and influence.In the occasion that need spud in once more, can adopt alloy aluminum, the pig iron etc. easily to bore each parts of material spool of the present utility model, so that directly creep into and avoided time junk mill operation with drill bit.Make the utility model have functions such as automatic grouting, direct circulation midway, easy brill, easy control simultaneously.

Below in conjunction with embodiment and accompanying drawing the utility model is described in further details.

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

Fig. 2 is the A-A view of Fig. 1

Fig. 3,4 is a work schematic representation of the present utility model

Fig. 5 is embodiment's 2 an of the present utility model structural representation

Embodiment 1:

As shown in Figure 1, in the present embodiment, nonreturn valve core 3 is hinged on the lower end surface of valve core case 2 by elastic hinge 14, ball seat spool 8 has one can be by the through hole 15 of plugging ball 5 shutoff, the lower end surface that is connected ball valve seat 6 by the common hinge 16 that is oppositely arranged and shear pin 7, pin 4 vertically is fixed on the upper-end surface of ball seat spool, extends before the upper-end surface of nonreturn valve core 3 on its other end and the active force that makes nonreturn valve core 3 overcome its elastic hinge 14 keeps normally open.Valve core case 2 and ball valve seat 6 is affixed with valve body 1 level, also can with valve body together with making.During casing running the utility model is connected to casing string bottom, in the well through hole of mud by valve body lower end then the valve core case 2 of jack-up plugging ball 5 through being opening state enter and after casing string puts in place, connect the pump circulating mud in the casing string, this moment plugging ball 5 under the pressure of mud with mud through hole 15 shutoff of ball seat spool, stop the circulation of mud, cause the straightening of spraining to cause and cut off shear pin 7, ball seat spool 8 is rotated around hinge 16, referring to Fig. 2-3, driving pin 4 simultaneously rotates, discharge nonreturn valve core 3 and make it close under the effect of elastic hinge that to form be an one-way valve, realize stoping cement slurry in the annular space to return function in the casing string.

Embodiment 2:

As shown in Figure 5, present embodiment and embodiment's 1 structure is basic identical, other parts that different is except that its valve body 1 all adopt as the easy brill material of alloy aluminum, the pig iron or glass fibre reinforced plastics class and make the spool string 17 identical as embodiment 1, and form and valve body by cement 18 cast fix as one.

Claims

1, the back-pressure valve of grouting formula certainly that uses in a kind of casing job of cementing the well, comprise valve body, valve core case, the spool control mechanism of the nonreturn valve core of band elastic reset spare and the action of controlling non-return valve core, it is characterized in that described nonreturn valve core is hinged on the lower end surface of valve core case by an elastic hinge, the spool control mechanism is by a ball seat spool that is arranged on nonreturn valve core below, ball valve seat, shear pin, lever and plugging ball constitute, the ball seat spool has a through hole that can be blocked up by the plug-hole ball sealing, be connected in ball valve seat by shear pin and the hinge level that is oppositely arranged, one end of pin vertically is fixed in the upper-end surface of ball seat spool, the other end retaining that protrudes upward is before the upper-end surface of nonreturn valve core, and the active force that makes nonreturn valve core overcome elastic hinge is normally open.