摘要：Efficient filtration control of water-based drilling fluid under high temperatures is always a challenge in oil and gas drilling engineering. In this study, p-cyclodextrin polymer microspheres (P-CDM) were synthesized by crosslinking between P-cyclodcxtrin (p-CD) and epichlorohydrin (EPI) using inverse emulsion polymerization. The CDPMs were characterized with Fourier infrared spectrum (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and particle size distribution measurement. The effect of p-CDMs on the filtration properties of water-based drilling fluid was investigated according to the standard American Petroleum Institute (API) filtration test. The results indicated that |3-CDMs have a uniform particle size and good sphericity, with an average particle size of 42.88 ^m, and thermal stability. The microspheres can effectively reduce the filtration of water-based drilling fluid after thermal aging at 220 °C and 240 °C, respectively, without significant impact on the rheological properties. The P-CDMs can absorb a large number of water molecules to form deformable elastic microspheres, which reduces the free water of the system, and improves the compressibility of mud cakes. More importantly, the microspheres partially degrade at high temperatures and generate nanoparticies, which in turn favorably plug the micro-pores of mud cake and effectively reduce filtration loss.
关键词：p-cyclodextrin;Polymer microsphere;Water-based drilling fluid;Filtration control;High temperature
