Study Of Impermeability Polymer Latex Cementing Slurry System

In the process of drilling and well completion, gas channeling is one of the involved problems, especially in the large top-bottom temperature difference of cementing segment. Gas channeling can always be followed by the serious accident, for instance, high pressure of the well-head, flowage of gas, or even abandonment of whole well. Therefore, it is vital to avoid gas channeling in the cementing operation.This paper, through theoretical analysis and experimental study, developed a impervious polymer latex slurry system, which displays a good wealth of unique properties: (1) Compatibility involving latex and polymer filtrate reducer agents not only effectively improves the stability of latex system but reduces latex dosage and filtrate loss, and finally strengthen cementing systematic performance; (2) The latex cementing system possesses temperature adaptation. It can effectively improve and stabilize the latex systems from 36℃to 89℃;(3) The defoaming agent matched this latex system demonstrates more prominent defoaming effect;(4) The novel bulking-agent (EXPS) is prepared to match such system, showing the excellent expansion effect, which reveals outstanding environmental adaptability and innocuity to the cement;(5) The other set of additives such as dispersants, retarder and filtrate reducer, show the separately good function, all of which display an excellent cooperavitivity. The prepared cement system has performable thickening time at high or low temperature. In addition, the system shows the excellent anti-gas channeling effect.In view of the theoretical analysis , EXPS slurry expansion agent shows the properties of mircro-pressure gas expansion and coagulation expansion, as well short-range and long-range expansion. With the impervious agent adding, it can improve and enhance the the connection between cement particles and the latex particles, reduce the penetration performance of the cement, and dispaly the functions of anti-gas channeling effectively.In view of the laboratory conclusions, the impervious polymer latex cement system can play an important role in anti-gas channeling, and shows wide application potential in drilling and completion operation.