SU646034A1 - Device for inverted cementation of casing columns - Google Patents

Description

I

The invention relates to drilling and relates to a device for reverse cementing casing.

A device for re-cementing casing strings is known, which includes a filter screen installed at a predetermined interval of casing l.

The disadvantage of the device is the poor quality of cementing due to the impossibility of using a check valve.

It is also known a device including a check valve with a seating seat in the upper part and a mechanism for opening circulating channels for the period of cementation 2.

A disadvantage of this device is the low efficiency of cementing due to the impossibility of controlling the height of the cement cup in the casing.

The aim of the invention is to increase the effectiveness of cementing

by allowing the excess cement slurry to be removed from the column.

This goal is achieved by the fact that the mechanism for opening the circulation channel is made in the form of a propelling column with a landing cone having radial holes and installed in its lower part of the stem-pusher.

The drawing shows a device for reverse cementing casing, a general view.

The casing back cementing device consists of a check valve 1 with a seating seat 2 in the upper part, a locking element 3 of the circulating valve of the check valve and a flushing column 4 with a landing cod 5. The landing cone has radial holes 6 communicating with the internal cavity of the flushing pipe. In the lower part of the planting cone, the push rod 7 is installed.

Device; works in an efficient way.

Before cementing, the wash column 4 with the cone 5 and the push rod 7 is lowered all the way into the saddle 2. Then the ZAT column is slightly raised. In this case, the locking element 3 of the check valve 1 is rolled back by the push rod 7, and the circulation channel creating the reverse circulation condition is open. In this position, the reverse cementing is performed. By. the end of the injection of the required volume of cement mixture that is installed, for example, at the exit at the mouth of the signal fluid, forced by the drilling fluid in an amount equal to the internal volume of the casing, onycKj T until the stop. At the same time, the cone sits in the upper seat of the check valve, closing its circulation channel and blocking the access of the cement slurry to the casing. Excess cement slurry is then removed from the casing through the industrial colum and radial holes of the planting cone. At the end of the wash, the wash column is removed.

The described device improves the efficiency of cementing and eliminates the need for the cement glass to be excavated in the casing.

Claims (1)

Invention Formula A casing back cementing device that includes a check valve with a seat in the upper part and a mechanism for opening the circulation channel for the period of cementing, in particular, in order to increase the efficiency of cementing due to the possibility of removing excess cement mortar from the column the opening of the circulation channel is made in the form of a wash column with a landing skull having radial holes and installed in its lower part of the stem-pusher. Sources of information taken into account in the examination 1, copyright certificate No. 248589, class, E 21 V 33/14, 1966, 2, Copyright certificate No. 261313, class, E 21 V 33/14, 1968,