METHOD FOR WELL COMPLETION Russian patent published in 1996 - IPC

FIELD: oil well drilling. SUBSTANCE: method for well completion includes well casing with overlapping the producing formation, cementation of flow string by direct method with successive injection of grouting mortar, forcing technological fluid in two portions with observation of condition at which the density of the first portion exceeds that of the second portion to produce total hydrostatic pressure in string exceeding the formation pressure in operated horizon. The first portion of technological fluid is used in form of aqueous or salt solution containing 0.5-1.5 vol.% of water-repelling agent lVV-l - mixture of alkyldimethylbenzylammonium chloride with quaternary ammonium salts of dimethylamine and tertiary amine obtained by condensation of alkyldimethylamine and benzyl chloride. Casing string is subjected to pressure testing and perforation in the interval of producing formation. Then, bottom-hole formation zone is treated with additional injection into formation of the first portion of technological fluid, which, penetrating the pore spaces, causes reduction of surface tension at phase boundaries, pore volume is preserved along with increased permeability through oil section and reduced permeability of formation water. EFFECT: speeded up well completion due to combining several functions by means of technological fluid. 2 tbl