THE USE OF CEMENT MIXTURES TO ELIMINATE ABSORPTION DURING DRILLING

Abstract

In the practice of drilling wells to combat loss, two methods are used: isolation of loss zones with cement mixtures and overlapping them with a casing string.

Cement mixtures with high water loss and structural properties are highly effective in eliminating absorptions. Increasing the plugging ability of cement slurries with high water loss is possible due to the introduction of flocculants into them (particles sticking together) that can accelerate the process of solid phase flocculation. During isolation work, polymer-based reagents known in drilling practice, such as hypan, polyacrylamide, metas, CMC, starch, can be used as flocculants. In the conditions of a fractured formation, when in contact with a permeable rock, the clay solution with a flocculant is dehydrated, forming dense impermeable bridges in the channels to absorb the drilling fluid and prevent the drilling fluid from leaving the formation.