Controlling the filtration of water-based drilling fluid effectively in high temperature environment is a great challenge in drilling engineering. In this study, β-cyclodextrin polymer microspheres (β-CDPMs) were synthesized by crosslinking between β-cyclodextrin and epichlorohydrin via inverse emulsion polymerization and employed as filtration reducers. The standard American Petroleum Institute filtration test showed that the β-CDPMs can only perform the enhanced filtration control ability at temperatures above 160 °C, and can tolerate the temperature resistance up to 240 °C without significant influence of rheology. As the thermal aging temperature is above 160 °C, numerous nano carbon spheres and nanostructured composites generated due to the occurrence of hydrothermal reaction. These high temperature stable nanoparticles bridged across the nano sized gaps and participated into forming dense filter cake, contributing to excellent filtration control. The filtration control mechanism proposed in this study opened a novel avenue for high temperature filtration control in water-based drilling fluids.

在高温环境中，有效控制水性钻井液的过滤是钻井工程中的巨大挑战。在这项研究中，β-环糊精聚合物微球（β-CDPMs）是通过反相乳液聚合法在β-环糊精和环氧氯丙烷之间交联而合成的，并用作过滤还原剂。标准的美国石油协会过滤测试表明，β-CDPMs仅在160°C以上的温度下才能发挥增强的过滤控制能力，并且能够耐受高达240°C的温度，而不受流变性的影响。当热老化温度高于160°C时，由于发生水热反应，产生了许多纳米碳球和纳米结构复合材料。这些高温稳定的纳米颗粒跨接在纳米间隙上，并参与形成致密的滤饼，有助于出色的过滤控制。本研究提出的过滤控制机制为水基钻井液的高温过滤控制开辟了一条新途径。