COMPOSITION FOR PRESERVATION OF STABILITY OF WELL WALLS (VERSIONS) Russian patent published in 2016 - IPC C09K8/502 E21B33/138 

FIELD: oil and gas industry; construction.

SUBSTANCE: group of inventions relates to construction of oil and gas wells, in particular, to production of compositions for preserving stability of walls of wells in clay rocks. Disclosed compositions can be employed with elimination of annular pressure when pumping liquid for hydraulic lock. Composition for preservation of stability of walls of wells in clay deposits contains a mixture of biosol with a polybasic alcohol in following ratios of components, wt%: biosol from 30 to 49 or from 51 to 70, polybasic alcohol - balance. In said composition, polyatomic alcohol used is either glycerine or triethylene glycol or propylene glycol or diethylene glycol. In version 1 composition for preservation of stability of walls of wells in clay deposits contains a mixture of tall oil with polytal, with following ratios of components, wt%: tall oil from 30 to 49 or from 51 to 70; polytal - balance. In version 2 composition for preservation of stability of walls of wells in clay deposits contains a mixture of biosol with polytal in following ratios of components, wt%: biosol from 30 to 49; polital - balance.

EFFECT: preservation of stability of clay rocks due to improved strength thereof.

4 cl, 1 tbl