Study on Material to Improve the Contamination of Oil-Based Drilling Fluid to Cement Slurry

Due to poor compatibility between oil-based drilling fluid and cement slurry, different degrees of contamination will be produced after mixing, which seriously affects the cementing quality. In order to solve this problem, an anti-contamination material for cementing was synthesized by emulsion polymerization. The molecular structure and thermal stability of the anti-contamination material were tested by FT-IR and TGA, and its effect on the anti-contamination performance of cement slurry was evaluated by CT analysis. Laboratory studies showed that the anti-contamination material was stable at temperature as high as 300 ℃. Compared with conventional cement slurry, cement slurry with anti-contamination material has good adsorption and dispersion effect on the blended oil phase, and even if the volume fraction of the oil phase reaches 50%, it can still form a homogeneous and complete cement stone. In addition, the anti-contamination material has no adverse effect on the cement slurry and meets the requirements of cementing construction. The use of this material provides a new method for solving the problem of contamination, which has broad application prospects.