SU1659627A1 - Method of placing bridging plug - Google Patents

Abstract

This invention relates to methods for installing a separation bridge in a well. The goal is to increase the efficiency of cement bridge installation work by making it possible to control cement slurry structure formation processes. A cement slurry is poured into a predetermined well interval. Then, holes are made in the well walls by successive explosions of cumulative charges in the cement slurry during the waiting period for solidification. Formed holes are immediately filled with cement slurry, the unbound filtering begins mixing fluid into the crushed mountain massif, which entails the acceleration of the structure formation of the composition. By varying the density of the holes, their depth can be controlled by the processes of structure formation of the cement slurry.

Description

The invention relates to the drilling and operation of oil and gas wells, in particular, to methods for repair and insulation works.

The purpose of the invention is to increase the efficiency of work on the installation of cement bridges by providing the ability to control the structure-forming processes of cement slurry.

The method is carried out as follows.

At a given interval of the well, the calculated amount of cement slurry is poured into the wellbore using a primer or borehole. In order to prevent displacement with the contacting liquids, the bridge installation interval can be isolated by sealing, for example, viscoelastic compositions. which are immediately filled with the cement slurry. In this case, the uncoupled trapping fluid is filtered out into the fragmented massif, which is echet for a rapid gelation varying the composition of the density of openings, their depth can be controlled processes of structure grout After perforator of rise from the bridge zone wellbore allowed to OZTS, terms which in this case is substantially sokraschayuts

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Then the cement slurry hardens, forming a bridge of increased bearing capacity.

Example. Allowed it is necessary to install a cement bridge in a well that has been dried with a 146 mm column, in the depth interval of 2000–2025 m. First, below the estimated bridge installation interval using a casting pipe string (mm), a retaining and replenishing tampon is installed, for example, in zko-elastic composition. As such, for example, an aqueous solution of polyacrylamide (PAA) with the addition of salts of polyvalent metals can be used. Then, having placed the end of the pouring column at a depth of 2025 m, proceed to the process of installing the bridge.

Buffer fluid is alternately pumped into the specified interval of the well, into the other sealing composition, the calculated amount of pumping solution (0.23 m), the buffer fluid, and the sales solution. After the tubing is lifted out of the bridge zone, it goes down through the well with a perforator, for example, PC-65, the outer diameter of which allows free passage through the tubing. Consecutive, single shots are made, and holes are made in the borehole walls. At the same time, the limiting sealing compositions prevent mixing of the cement slurry with the contacting liquids.

Punched holes are immediately filled with cement mortar. Filtering off unrelated

solidification liquids in the rocks, which leads to an acceleration of the structure formation of the composition. At this time, the perforator is extracted to the surface and the well is left at 03 ° C.

The proposed method of installing the separation bridge is characterized by the fact that it is possible to control the process of structure formation of the cement slurry, due to its forced dewatering of rocks, reduces the time required to install the bridge, since the holes are made during the period 03 C. the ability to shorten the deadlines for RPTs, the bearing capacity of the bridge is increased by increasing the strength of the stone from the dehydrated composition, the positive effect of the explosion on the properties of ment solution.

All this leads to a significant increase in work efficiency.

Claims (1)

Invention Formula The method of installation of the separation bridge in the well, which includes making holes in the well walls, pouring cement slurry at a predetermined interval, characterized in that, in order to increase the efficiency of cement bridges installation by allowing the control of the cement slurry formation process, the holes are made after it is filled by successive explosions of cumulative charges in the cement slurry during the waiting period for hardening of the cement slurry .