SU1640362A1 - Method and apparatus for controlled placing of cement bridging plugs - Google Patents

Abstract

The invention relates to the construction of oil and gas wells and is intended for the installation of cement bridges (CM) in them. The goal is to improve the quality of the cement bridge. In the well to the bottom mark set by the CM lowering the casting column 2 with a flow-through cylindrical body 1 with a calibrated central hole. Then, the tampon solution and the separation plugs (RP) 4 and 6 are pushed. When the solution passes through the calibrated central hole, signals are received about the beginning of its exit into the annulus and the end of

Description

The invention relates to the construction of oil and gas wells and can be used for fastening them, in particular, for installing cement bridges.

The aim of the invention is to improve the quality of the cement bridge.

The drawing shows a device for controlled installation of a cement bridge.

The device for controlled installation of the cement bridge consists of a flow-through cylindrical body 1, the upper end of which is connected to the lower end of the casting column 2. The body 1 is equipped with an internal annular protrusion 3 with a calibrated central hole for controlling the passage through the device of the upper 4, an additional intermediate 5 and the lower 6 separation plugs, between which the tampon solution 7 is placed. The housing 1 in the lower part is made with the upper 8 and lower 9 rows of radial holes, as well as cylindrical The shell 10 with a central hole and pins 11 connecting the housing 1 with the shell 10 and installed with the possibility of cutting them with increased pressure when the intermediate separating plug 6 is fitted on the shell 10 made of soft drilled metal. The shell 10 is equipped with an elastic uncoupler 12 made in a truncated cone with open bases, of which the small base is rigidly connected to the said shell, and the large one is directed upwards and has a diameter larger than the diameter of the well to interact with nkami well.

In the proposed method, controlled installation of a cement bridge, including the descent into the well to the lower mark of the installed bridge of the pouring column with a flow-through cylindrical body with a calibrated central hole, pushing cement slurry and separating plugs, signals that the output had started passing through the calibrated central hole cement slurry into the annulus and the end of its pushing, raising the filling column to the upper mark, the wellbore at the level of the lower mark cement bridge overlap overlap, pumped cement in the volume

,, H (тгР2Ц -4Q) v f4U

where H is the height of the cement bridge installation, m;

U is the target extraction rate of the pouring column, m2 / s;

Q - the performance of cementing units, m;

D - borehole diameter, m, forcing an additional intermediate separation plug, pumping the rest of the cement slurry, after receiving the Stop signal when the additional separating plug passes through the calibrated central hole, extract the casting column at a given speed to the upper mark of the cement bridge installation with simultaneous displacement cement mortar.

A controlled installation of cement bridges is carried out as follows.

First, a pouring column 2 with a device for controlled installation of a cement bridge is lowered down the well to the lower mark of the cement bridge to be installed. At the same time, the cavity of the column 2 is filled with the well fluid through an opening in the shell. Then begin the displacement of the cement slurry 7, located between the upper 4, intermediate 5 and lower b separating tubes. When the cement slurry moves in the casting column, not 2 drilling fluid located under the lower plug 6. Through the radial 8 and 9 holes in the sidewall enters the annulus. In this case, the liquid jets exiting through the openings 8 tightly press the elastic uncoupler 12 against the borehole wall, and the liquid itself rises through the annulus. When the bottom plug 6 of the inner annular protrusion 3 of the housing 1 is reached, the plug 6 stops, as a result of which, at the wellhead, a signal is received that the cement slurry begins to exit into the annulus.

As the fluid pressure in the column 2 increases, the plug 6 is forced through the annular protrusion 3 and moves down in the housing 1 all the way into the shell 10. Moreover, during the movement of the plug 6 from the annular protrusion 3 to the shell 10, the upper row of holes closes the plug 6 and the liquid leaves through the opening 9, and the pressure of the liquid in the column 2 decreases to a value corresponding to the pressure of the liquid when the plug moves from the wellhead to the annular protrusion 3. Thus, a hydraulic shock is prevented.

After stopping the plug 6 into the shell 10, the cement slurry begins to pass only through the radial holes 8 and enters the annular space until the separating plug 5 passes the protrusion 3, not with the pieces on the plug 6 and does not block the radial holes 8. At this moment By increasing the pressure, the pins 11 are cut off and the shell 10 together with the disconnector 12 and the separating plugs 5 and b are forced down the trunk, the radial holes 8 and 9 are opened and the cement slurry 7 re-enters the annulus. At the same time, the upper separation plug 4 reaches the inner annular protrusion 3, and a pressure increase signal is received at the mouth, which decreases after the plug 4 passes protrusion 3, which indicates the end propelling cement slurry.

The economic efficiency of the invention is due to the time and material cost savings for re-potting.

Claims (2)

1. The method of controlled installation of cement bridges, including the descent into the well to the lower mark of the installed cement bridge of the pouring column with a flow-through cylindrical body V with a calibrated central hole, the displacement of the cement slurry and separation plugs, receiving, when passing through the calibrated central hole, signals of the beginning of the exit of the cement slurry into the annular space and the end of its displacement. raising the casting column to the upper mark, characterized in that, in order to improve the quality of the bridge, the wellbore at the level of the lower mark of the cement bridge installation is blocked, the cement slurry is pumped in the volume N (l: P2C-4Q) 4U where H is the height of the cement bridge installation, m; D - borehole diameter, m; U is the target extraction rate of the pouring column, m / s; Q - the performance of cementing units, m, pushing an additional intermediate separation plug, pumping the remaining volume of the cement slurry, after receiving the Stop signal when the additional splitting plug passes through the central calibrated orifice, the casting column is removed at a given speed to the top mark of the cement bridge installation while the cement slurry is displaced. 2. A device for controlled installation of a cement bridge, containing an inlet cylindrical case mounted on a casting column with a calibrated central hole, upper and lower plugs, characterized in that it is equipped with an additional intermediate plug, its lower part is made with two Radi holes and a cylindrical shell with a central hole made of soft drilled metal and equipped with pins connecting the case with the shell and installed with It is possible to cut them by increasing the pressure when the intermediate plug fits on the shell, the latter having an elastic disconnector made in the form of a truncated cone with open bases, of which the small base is rigidly connected to the said shell and the larger one is directed upwards to interact with the walls of the well.