钻井液与完井液2023，Vol.40Issue(6)：693-702,10.DOI:10.12358/j.issn.1001-5620.2023.06.001
微球聚合物强化水基钻井液流变稳定性及其分子模拟研究
Study on Polymer Microspheres for Their Action in Enhancing Rheology Stability of Drilling Fluids Through Molecular Simulation
摘要
Abstract
The spatial configuration transformation of polymer molecules from linear one-dimension to spatial three-dimension is a new clue for the molecular design of oilfield chemical additives through modification of conventional oilfield chemicals,and this method is beneficial to the development of new multi-functional polymeric water-based drilling fluid additives.To illuminate the morphological characteristics of the spatial polymers and the effective functions of these polymers as drilling fluid additives,studies on strengthening the stability of water based drilling fluids with polymer microsphere PAA-AM-AMPS are systematically conducted using methods such as experimental synthesis,structure characterization,performance evaluation and molecular simulation.First,the polymer microsphere PAA-AM-AMPS is synthesized.The microstructure of the polymer microsphere as well as the core role that the polymer microsphere plays in constant-rheology and ultra-high-temperature water based drilling fluids are examined.Then,based on the model of the"compensation effect"prevailed in the spaces of the spatial polymer groups,the strengthening effect of the spatial configuration on the adsorption of polymer molecules onto the bentonite layers is revealed from molecular point of view.The study shows that the synthesized spatial polymer PAA-AM-AMPS is spherical with a core-shell structure,with an average particle size of 198.3 nm.Its thermal degradation includes 5 steps,and the spatial configuration shows good thermal stability.The polymer microsphere molecule has a spatial configuration of"internal compactness and external sparsity".The distribution of the active groups such as—COOH,—CO(NH2)and—SO3H on the shell of the microsphere determines the active position of the spatial structure.In these groups,the carboxyl group C=O is the dominant active group.Comparison of the chain and spheric structure shows that the spheric structure has smaller gyrational radius Rg and bigger radial distribution function g(r),indicating that the spheric configuration not only improve the thermal resistance of the structure,it also is beneficial to the retention of the number of the active groups on the surface of the shell,thereby ensuring the adsorption and association between the polymer molecules and the clay particles,and thus improving the stability of the macro-properties of the water based drilling fluid.关键词
微球聚合物/水基钻井液/流变稳定性强化/构效关系/分子模拟Key words
Polymer microsphere/Water-based drilling fluid/Strengthening of rheology stability/Structure-activity relation/Molecular simulation分类
能源科技引用本文复制引用
许林,许力,吴舒琪,包宇,王晓棠,沈佳敏,孟双,王浪..微球聚合物强化水基钻井液流变稳定性及其分子模拟研究[J].钻井液与完井液,2023,40(6):693-702,10.基金项目
舟山市科技计划项目"海洋油气井密封损伤的压力控释靶向修复技术研发"(2019C21006)、浙江省基础公益研究项目"海洋油气开发微泄漏压差激活密封剂及其自适应修复机理研究"(LGG20E040002). （2019C21006）
