Patent ID: 6668929
Filing Date: 2003-12-30
Classification: C04B,C09K,Y02W

Abstract:
A method of cementing a pipe string in a well bore containing oil-containing drilling fluid comprising the steps of:preparing an oil-containing settable spotting fluid composition comprising an oil external emulsion which comprises oil, water and an emulsifying surfactant; a hydraulically settable component; and a de-emulsifying surfactant for de-emulsifying said oil-external emulsion when the emulsion is cured; pumping said oil-containing settable spotting fluid composition into the annulus between said pipe string and the walls of said well bore to displace at least a portion of said drilling fluid out of said annulus; pumping said cement composition into said armulus whereby said drilling fluid and said settable spotting fluid are displaced except for portions of said settable spotting fluid which remain in fractures or other permeable zones therein; and allowing said cement composition in said annulus and any settable spotting fluid composition remaining in said fractures or other permeable zones therein to set.