RU2431732C1 - Device for cementing shank end in well - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: invention refers to device designed for cementing shank end in well. The device consists of shank end with a funnel on top and with a pressure seat beneath, and also of pipe string with a nipple pressure tight interacting with the funnel of the shank end. A disconnector interconnects an upper part of the shank end and a lower part of the pipe string and is made in form of a hollow case with a circular waist wherein there are made radial windows and with a hollow bush inserted into the circular waist and performing pressure tight travels downwards limited with a stop. The hollow bush is fixed with a shear element. Also, the hollow bush with conic external surface narrowing upwards in its lower section has radial channels coming out from the circular waist of the hollow case, when the hollow bush travels downwards. A seat for fall ball is made beneath the hollow bush. In transport position holders entering outside into a circular groove of the funnel are arranged in radial windows of the hollow case; from inside the holders, when sliding, interact with conic surface of the hollow bush. The holders travel inside under force of conic surface of the hollow bush transferred downwards and in working position they come out from interaction with the circular groove of the funnel.

EFFECT: simple design and reduced number of round trips which reduces material expenditures and total time for operations.

2 dwg

Description

The invention relates to the oil industry, specifically to the construction and repair of wells, including directional.

It is known "Device for cementing the liner in the well" (RF patent No. 2289677, IPC 8 ЕВВ 33/14, published in bul. 35 dated 12/20/2006), including the liner with the string of tubing (tubing) deflated into it of limited length, a disconnector in the form of an adapter, connected by the upper part to the lifting pipes, and the lower one - to a tubing of limited length, equipped with an external left-hand thread for connection through a sleeve with the upper end of the shank, and a shoe with a passage channel and a sleeve, while it is equipped with a packing unit consisting of body, hard mouth tained therein the upper retaining sleeve, the cylindrical elastic sleeve with internal annular grooves, the bottom resting in movable inner sleeve, between which and an end face disposed below the movable outer sleeve installed snap ring with notches and incisions are made in opposite directions on the housing; the movable outer sleeve is provided with shear screws located in the longitudinal grooves of the housing and connected by other ends of a smaller diameter with a guide sleeve mounted inside the housing and connected with shear elements; the case of the packer assembly with the lower part is connected to the filling sleeve provided with radial channels, which, in turn, is connected to the perforated section of the shank, and the latter to the shoe; a string of tubing of limited length through a stepped sub is connected to a nipple, which is a pipe with radial channels in the middle part, seated in the initial state by a saddle, the pipe is equipped with sealing elements above and below the radial channels, tightened by nuts; the nipple at the bottom is connected to the tip; in the coupling connecting the shoe to the perforated portion of the shank, a support sleeve is installed with a central passageway through which a tip is passed, equipped with shear screws, which are connected to the lower clamping nut of the nipple in a section of a smaller diameter.

The disadvantages of this design are:

- firstly, the complexity of the design, due to the large number of nodes and parts;

- secondly, the complexity of manufacturing and assembly;

- thirdly, the complexity of the technological process of its application.

It is known "Device for cementing the liner in the well" (utility model patent No. 44348, IPC 8 ЕВВ 33/14, publ. Bull. No. 7 of 03/10/2005), including a liner with a tubing string lowered into it ( Tubing) of limited length and a disconnector in the form of an sub connected by the upper part to the lifting pipes, a valve assembly connected to the lower part of the shank and consisting of upper and lower bodies interconnected by shear elements in which two spring-loaded check valves are mounted on top of each other, etc than the lower body is installed inside the upper, with limited longitudinal displacement and is provided with radial channels communicating with the inner space of the device borehole zone; the disconnector is equipped with an external left-hand thread for connection with the upper end of the shank, and the lower part of the disconnector is connected to the tubing string, which is slightly shorter than the shank, while the valve assembly from the bottom is connected to a shoe equipped with a filter.

The disadvantages of this device are:

- firstly, the uncontrolled process of turning the left sub after filling the shank with cement, in addition, sometimes it is almost impossible to turn the left sub due to the large set of curvature of the zenith angle of the well;

- secondly, because due to the curvature of the well it is impossible to turn the left sub with the tubing string, a guaranteed delivery requires the delivery of drill pipes, a square working pipe (“square”), and a wellhead hydraulic rotor, which leads to an increase in well repair time and, as a result, additional material and financial costs.

The closest in technical essence is the "Device for cementing the liner in the well" (utility model patent No. 72715, IPC 8 Е21В 17/06, published in Bulletin No. 16 of 04/27/2008), including a liner, a pumping string compressor pipes (tubing), a disconnector connecting the upper part of the liner and the lower part of the tubing string, a valve assembly connected to the lower part of the liner and consisting of upper and lower housings in which two spring-loaded check valves are mounted one above the other, while the valve bottom connection the inen with a shoe and is equipped with a filter, wherein the disconnector is made in the form of a docking unit consisting of an upper funnel with slots and an internal releasing catcher installed at the end of the tubing string, and the latches of the internal releasing catcher are placed in the slots of the funnel, and the docking unit is disconnected by dropping the ball from the wellhead into the tubing string and creating hydraulic pressure in the tubing string with its subsequent extraction together with the internal releasing catcher, etc. This cement slurry before injection into the shank descends column casting pipe, equipped nipple having a possibility of interaction with funnel sealing connection node, wherein the shank above the valve assembly equipped with pressure testing unit consisting of the pressing of the pressing saddle and extracted cork.

The disadvantages of this design are:

- firstly, the complex and time-consuming technological process of cementing the liner, associated with the fact that an internal releasing catcher, tubing string, throw ball, funnels with slots are used for its implementation;

- secondly, in the process of work two tripping operations are performed:

- the first, descent to the bottom of the liner with the catcher on the tubing string, followed by disconnecting the catcher from the liner and removing the catcher with the tubing string from the well;

- the second, the descent of the filling pipes with a nipple to interact with the funnel of the shank's docking unit, followed by cementing the shank, cutting and removing the nipple with the filling pipes from the well.

The objective of the invention is to simplify the technology of cementing the shank and reduce tripping operations carried out in the process of cementing the shank.

The problem is solved by a device for cementing the liner in the well, including a liner with a funnel at the top and a compression saddle at the bottom, a pipe string with a nipple made with the possibility of tight interaction with the liner funnel, a disconnector connecting the upper part of the liner and the lower part of the pipe string, valve assembly with spring-loaded valves, connected to the bottom of the shank on top and a filter with a shoe on the bottom.

What is new is that an annular groove is made in the funnel, and the disconnector is made in the form of a hollow body located on the pipe string above the nipple, with an annular narrowing in which radial windows are made, and a hollow sleeve inserted into the annular narrowing with the possibility of limited tight stop downward and fixed by a shear element, while in the hollow sleeve on the outer surface there is a conical tapering surface upward, below which there are radial channels configured to exit from the annular narrowing of the housing when moving down the hollow sleeve, at the bottom of which a saddle is made for the throw ball, and in the radial channels of the housing there are latches that enter the funnel’s annular groove from the outside - the transport position, and from the inside interact with the possibility of sliding with the conical surface of the hollow sleeve, while the latches are made with the possibility of moving inward under the action of the conical surface of the hollow sleeve moving downward, with the exit from the interaction with the annular groove of the funnel - working dix.

Figure 1 shows the upper part of the device.

Figure 2 shows the lower part of the device.

A device for cementing a liner in a well consists of a liner 1 (see Fig. 1) with a funnel 2 at the top and a crimping seat 3 at the bottom, as well as a pipe string 4, for example a tubing string (see Fig. 2) with a nipple 5, made with the possibility of tight interaction with the funnel 2 of the shank 1 (see figure 1). The valve assembly 6 (see Fig. 2) is connected to the lower part of the shank 1 and consists of an upper 7 and a lower 8 bodies, in which two spring-loaded check valves 9 and 10 are installed one above the other, respectively, while the valve assembly 6 is connected to the shoe from below 11, equipped with a filter 12, and an aluminum plug 13 is screwed onto the lower end of the shoe 11. An annular groove 14 is made in the funnel 2.

The disconnector 15 (see figures 1 and 2) connects the upper part of the shank 1 and the lower part of the pipe string 4 and is made in the form of a hollow body 16 located on the pipe string 4 above the nipple 5 with an annular narrowing 17, in which there are radial windows 18, and a hollow sleeve 19, inserted into the annular narrowing 17 with the possibility of limited hermetic stop 20 tight movement down and fixed shear element 21.

A conical tapering surface 22 is made in the hollow sleeve 19 on the outer surface, below which there are radial channels 23 made with the possibility of exiting the annular narrowing 17 of the hollow body 16 when moving down the hollow sleeve 19, below which a seat 24 is made for the throw ball 25.

In the radial windows 18 of the hollow body 16, latches 26 are placed, which are located externally into the annular groove 14 of the funnel 2, the transport position, and from the inside interacting with the possibility of sliding with the conical surface 22 of the hollow sleeve 19. The latches 26 are arranged to move inward under the action of the conical surface 22 of the hollow sleeve 19, moved downward, with the exit from the interaction with the annular groove 14 of the funnel 2 - working position.

In order to exclude unauthorized fluid flows, the mating surfaces are provided with o-rings 27, 28.

The device operates as follows.

First, a device for cementing a liner in a well, as shown in FIGS. 1 and 2, is mounted in the well. To do this, first fill the well with technological fluid, for example, waste water, and then lower one liner pipe 1 into it (see FIG. 2), equipped with a shoe 11 with a filter 12 and an aluminum plug 13, as well as a valve assembly 6 and a crimping seat 3 and placed on it a removable crimping plug 29.

By pumping the process fluid into the annulus of the well (not shown in FIGS. 1, 2, 3), the valve assembly 6 is pressurized, i.e., it is checked under the pressure expected on the valve assembly 6 after the cement slurry has been injected into the annulus of the well, the leakproofness of the check valves 9 and 10, with no gaps allowed.

After verifying the tightness of the valve assembly 6, all the pipes of the liner 1 with the funnel 2 (see Figs. 1 and 2) are lowered into the well with the process fluid added to it, and then the liner pipes are pressure tested 1. Then they are lowered into the liner 1 from the wellhead any known fishing tool (for example, a catcher on a rope) and produce capture and extraction of the extracted crimping plug 29 from the well.

Next, lower the end of the pipe string 4, which should be the estimated length depending on the length of the shank 1, into the liner 1, is equipped with a centralizer (not shown in FIGS. 1 and 2) and is 3-5 meters higher than the crimping seat 3 of the liner 1. After which proceed to the connection of the pipe string 4 with the upper end of the shank 1. Assemble the upper part of the device, as shown in figure 1.

Next, lower the assembled assembly (liner 1 with a string of pipes 4) until it stops at the bottom of the wells, which is controlled by the weight indicator (not shown in Figs. 1 and 2) located at the wellhead. Then make the separation of the pipe string 4 from the shank 1.

From the wellhead into the pipe string 4, a ball 25 is dropped (see FIG. 1), which sits on the seat 25 and overlaps the central hole 30 of the hollow sleeve 19, after which the pipe string 4 is refilled with process fluid, for example, waste water, and is created in it with using a pump unit (for example, ЦА-320) located at the wellhead, hydraulic pressure (5-6 MPa), first, shear elements 21 are destroyed, for example, the pressure at which they are destroyed is, for example, 3-4 MPa and then the latches 26, occupying the transport position and p located in the radial channels 18 of the hollow body 16 and entering from the outside into the annular groove 14 of the funnel 2, occupy a working position in which the latches 26 are moved radially inward under the action of the conical surface 22 of the hollow sleeve 19, which is moved down under the action of hydraulic pressure inside the hollow sleeve 19 and the column pipes 4.

As a result, the latches 26 go out of interaction with the annular groove 14 of the funnel 2, while the radial channels 23 of the hollow sleeve 19 are lower than the lower end 31 of the hollow sleeve 19, for which they are fixed with a snap ring 32.

Raise the pipe string 4 upwards by about 1 meter to make sure that the pipe string 4 is disconnected from the shank 1, which is controlled by a sharp decrease in weight on the weight indicator, since the pipe shank 1 is disconnected from the pipe string 4 and rests against the bottom with the bottom end (in Fig. 1 and 2 not shown), while the lower end of the hollow body 16 must tightly with the help of the sealing rings 28 to interact with the inner walls of the shank 11.

Fill the pipe string 4 (see FIGS. 1 and 2) with process fluid and cause a circulation by direct flushing through the pipe string 4, radial channels 23 of the hollow sleeve 19, liner 1, valve assembly 6, filter 12 through the annulus of the well at the wellhead. Then, the calculated amount of cement mortar is pumped into the pipe string 4 and squeezed by a squeezing fluid into the annulus of the well (not shown in FIGS. 1 and 2).

After pumping cement into the annular space of the well, the pipe string 4 with the nipple 5 is raised by 1-2 meters so that the lower end of the nipple 5 is higher than the upper end of the funnel 2.

Next, by direct washing along the pipe string 4, the excess cement mortar is washed out of the inner cavity of the liner 1.

Then, the pipe string 4 with the disconnector 15, made in the form of a hollow body 16 connected from the bottom to the nipple 5, is completely removed from the well, after which the well is left waiting for the cement to harden (OZZ).

At the end of the time, the OZZ crimping seat 3, valve assembly 6 and aluminum plug 13 are drilled.

The proposed device for cementing the liner in the well has a simple technology of work, which allows to reduce the material costs of cementing the liner in the well, and the reduction of hoisting operations carried out in the process of cementing the liner will reduce the total time of work and reduce the financial cost of repairing the well .

Claims (1)

A device for cementing a liner in a well, including a liner with a funnel at the top and a crimping saddle at the bottom, a pipe string with a nipple made with the possibility of tight interaction with the liner funnel, a disconnector connecting the upper part of the liner and the lower part of the pipe string, valve assembly with spring-loaded valves connected to the lower part of the shank on top and the filter with the shoe bottom, characterized in that the funnel is made of an annular groove, and the disconnector is made in the form of a hollow of the housing located on the pipe string above the nipple, with an annular narrowing in which radial windows are made, and a hollow sleeve inserted into the annular narrowing with the possibility of limited tight stop movement down and fixed with a shear element, while the conical tapering is made in the hollow sleeve on the outer surface upward is the surface below which radial channels are made, capable of exiting the annular narrowing of the housing when moving down the hollow sleeve, below which a saddle is made under an axial ball, and in the radial channels of the casing there are clamps that enter the funnel’s annular groove from the outside — the transport position, and from the inside — interact with the possibility of sliding with the conical surface of the hollow sleeve, while the clamps are made to move inward under the action of the conical surface of the hollow sleeve down, with the exit from the interaction with the annular groove of the funnel - the working position.

Images