COMPLEX METHOD FOR WELL BORE PREPARATION FOR CASING Russian patent published in 2008 - IPC E21B21/14 

FIELD: oil and gas production industry, particularly oil and gas well construction, namely methods or apparatus for flushing boreholes.

SUBSTANCE: method involves removing mud filter cake; creating mudding screen by water-jet well bore wall treatment; chemically treating well bore walls by serially forcing buffer process water taken in amount of not less than 2 m³, aqueous CaCl₂ solution or reservoir Devonian fluid taken in amount of not less than 2 m³ in casing annulus to obtain equilibrium state; injecting aqueous liquid glass solution including 4-8 kg of polymeric reagent per 30-50 l of aqueous liquid glass in amount of not less than 3 m³; bringing thereof to ground surface.

EFFECT: increased reliability of small pore and fissure plugging in reservoirs in well bore zone without local hydraulic fracturing creation; provision of adhesive drilling mud film modification on well wall.

3 cl