页岩吸附水机理及其动力学研究

The water adsorbed in shale is the result of the interaction between clay mineral particles and water molecules, and it has special structure and complex physicochemical characteristics, which affects the physical and mechanical properties of shale such as adsorption, hydration swelling, shrinkage, plasticity, strength and deformation. The understanding of adsorption and mechanical mechanism of adsorbed water in shale is still uncertain as yet, and there lacks the corresponding kinetic models to characterize adsorbed water. Thus, the research studies the Silurian Shale in China, making use of experimental tests, theoretical analysis and numerical simulation methods, and the experimental test of adsorbed water in shale was carried out. Combined with the thermogravimetric analysis, the types and dividing line of adsorbed water in shale were determined, and the hydration behavior between adsorbed water and shale was studied. And the kinetic mechanism of adsorbed water was analyzed. The related kinetic model was established, and the adsorption and mechanical mechanism of adsorbed water in shale was revealed. This work can not only benefit to evaluate the abilities of adsorption and flow in shale gas accurately, but also provide basis for the wellbore stability design in the development of shale gas reservoirs, which is important theoretical and practical significance to guide the development of shale gas reservoirs efficiently.

页岩吸附水是黏土矿物颗粒与水分子相互作用的产物，具有特殊的结构和复杂的物理化学特性，影响着页岩的吸附、水化膨胀、收缩、塑性、强度和变形等物理力学特征。目前对页岩吸附水机理和力学机制的认识尚不明确，缺乏相应的动力学模型进行表征。因此，本研究拟选取我国志留系页岩为研究对象，采用实验测试、理论分析和数值模拟相结合的方法，开展页岩吸附水实验测试，结合热失重分析，确定页岩吸附水类型和界限，研究吸附水与页岩的水合行为，分析页岩吸附水的力学机制，建立吸附水的动力学模型，揭示页岩中水的吸附机理和力学机制。这不仅有利于准确地评价页岩气的吸附流动能力，而且能为页岩气藏开发中井壁稳定性设计提供依据，对页岩气藏高效地开发具有重要的理论和现实意义。

页岩吸附水是黏土矿物颗粒与水分子相互作用的产物，具有特殊的结构和复杂的物理化学特性，影响着页岩的吸附、水化膨胀、收缩、塑性、强度和变形等物理力学特征。针对上述科学和技术难题，本课题以我国志留系页岩为研究对象，采用实验测试、理论分析和数值模拟相结合的方法，开展页岩吸附水实验测试，确定了页岩吸附水类型，分析吸附水与页岩的水合行为，揭示页岩吸附水的力学机制，建立页岩吸附水的数学模型。.按照项目计划，完成了制定的目标，取得了一系列创新成果，相关成果用于分析我国川南地区龙马溪组页岩孔隙水赋存及其流动能力影响分析，深化了川南地区页岩气藏开发机理认识，为页岩气藏开发优化设计提供了指导。取得的创新成果如下：（1）定量表征页岩吸附水类型，明确页岩吸附水的特征，建立页岩吸附水的数学模型；（2）分析了页岩水分吸附-解吸机理，明确吸附水与扩散双电场的关系模型，揭示吸附水与页岩中黏土矿物水合机制；（3）明确页岩吸附水力学传输机制，建立页岩吸附水扩散数值模型。.本课题系统分析了页岩吸附水机理，建立了页岩吸附水的数学模型，揭示了页岩吸附水力学机制，相关研究成果在我国川南地区龙马溪组页岩孔隙水赋存及其流动能力影响分析得到了具体应用，为我国页岩气藏高效开发理论基础和关键技术的进步提供了支持。在项目执行期间，共发表期刊论文 13 篇，其中 SCI检索 10 篇，发表会议论文4篇；申请发明专利 2 项；相关成果获得省部级科技奖励二等奖1项；培养硕博士研究生 3名，参加国际国家级学术会议交流4人次。