On the operation of cement stone in well and modern strategy of selection of backfill materials

Abstract

A long way of development of cementing technology providing the advancement of backfill materials, the methods of preparation, chemical treatment and transportation of plugging material into the borehole annulus of the well did not solve all the problems of the quality isolation of formations. There are neither justified physical criteria nor accurate methods of estimation of supporting quality, as it is quite troublesome to set well conditions while conducting experimental works towards specifying the large number of the factors simultaneously affecting the longevity of well support. In this regard, there is no generally accepted method of testing backfill materials and the issue of necessary sustainability of stone from various bakfill materials designed for cementing of columns and setting cement bridges is not solved as well. Leading drilling service companies (Schlumberger, Halliburton etc.) of the world do not use special cement types and instead, prepare their own mixture for each cementing process on the basis of cement of selected for these oil-gas fields. As a result of mixing various types of weighting agents and other additives with base cement, a backfill system necessary for specified well is obtained. These systems are produced on specially equipped facilities in the world. The researches carried out justify that it is possible to obtain high quality simplified and weighted cement slurries on the basis of domestic raw materials with state-of-the-art technologies and equipment.