RESEARCH AND APPLICATION OF CEMENTING TECHNOLOGY IN SIDE-DRILLED HOLE IN OLD WELL

This paper summarizes and analyses the characteristic and difficulty of the adjusted and renewed wells and side-tracked well cementing, and researches the dual thickening time cement slurry system for preventing oil-reservoirs from gas migration by the laboratory test, and tests the high effective washing and spacer fluid, and raises the cementation quality of two interfaces. The displacement technology of the turbulent flow and plug flow slurry and the technology of balanced pressure cementing in side-tracked of were applied. Forty six wells were cemented in the field and the qualification rate can be one hundred percent once, the high quality rate can be more than ninety percent. The side-drilled well cementing technology and concerned slurry system research provide the theoretical foundation and technology support for the cementing of Changqing multi-pressure layer system, lost-circulation zone under low pressure, the water-oil-gas active zone and long open-hole complicated wells. The technology also raises the cementing quality and reduces the cementing cost.