The objective of this study is to improve the performance of water-based drilling fluids for high temperature, salt and calcium resistance in the exploration of deep and ultra-deep wells. In this study, poly(anionic cellulose), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), diallyldimethyl ammonium chloride (DMDAAC), N,N-dimethylacrylamide (DMAA), sodium p-styrene sulfonate (SSS) and silica nanoparticles were used as raw materials to form copolymer PAC-DDAS-SiO₂ by free radical copolymerization in aqueous solution. Using X-ray photoelectron spectroscopy (XPS), Monomers were polymerized successfully. The rheological properties of the drilling fluid were maintained after the addition of copolymers to the drilling fluid, the filtration volume after aging at 260 ℃ is only 8 mL. At the same time, the 35 wt% Cacl₂ copolymer base slurry aged at 200 ℃ showed a filtration loss of only 14.4 mL. The polymer helped the drilling fluid resist 10 wt% Nacl at 260 ℃. Analysis of the filter cake after ageing, the microscopic morphology of clay-polymer interactions in the drilling fluid after ageing and the particle size of the drilling fluid was carried out. The presence of a large number of anionic groups in the chains on the copolymer spheres formed hydrogen and ionic bonds with the clay, adsorbed Na⁺ and Ca²⁺ and prevented the intrusion, thus ensuring the normal size of the clay particles, resulting in the formation of a wider particle size distribution phenomenon in the drilling fluid, dense filter cake and reduced filtration volume.

本研究的目的是提高水基钻井液在深井和超深井勘探中的耐高温、耐盐、耐钙性能。在本研究中，聚（阴离子纤维素）、2-丙烯酰胺基-2-甲基丙磺酸（AMPS）、二烯丙基二甲基氯化铵（DMDAAC）、N,N-二甲基丙烯酰胺（DMAA）、对苯乙烯磺酸钠（SSS）和二氧化硅纳米粒子是用作原料在水溶液中通过自由基共聚形成共聚物PAC-DDAS-SiO ₂。使用 X 射线光电子能谱 (XPS)，单体成功聚合。在钻井液中加入共聚物后钻井液的流变性能保持不变，在260℃老化后的过滤体积 ℃ 仅为 8 mL。同时，在 200 ℃下老化的 35 wt% Cacl ₂共聚物基础浆料 的过滤损失仅为 14.4 mL。聚合物帮助钻井液在 260  ℃抵抗 10 wt% Nacl 。对老化后的滤饼、老化后钻井液中粘土-聚合物相互作用的微观形貌和钻井液的粒径进行了分析。共聚物球体链中存在大量阴离子基团，与粘土形成氢键和离子键，吸附Na ⁺和Ca2 ⁺ 并防止侵入，从而保证粘土颗粒的正常尺寸，导致在钻井液中形成更宽的粒径分布现象，滤饼致密，过滤量减少。