METHOD OF CASING CEMENTING Russian patent published in 1998 - IPC

FIELD: casing and cementing of oil and gas wells, more specifically, cementing of casing in oil and gas wells. SUBSTANCE: method includes cementing of lower part of intermediate and final casing strings with surface casing run and cemented preliminarily by injection into intermediate and final casing strings and subsequent forcing into casing string-borehole annulus of grouting mortar until its setting, and cementing of lower part of intermediate and final casing strings. Grouting mortar is raised above shoe of preceding string and hydrofrac of formation under shoe of preceding casing strings by injection of grouting mortar into casing string-borehole annulus carried out in the period from beginning of thickening to beginning of setting of grouting mortar. EFFECT: higher efficiency. 2 dwg