钻探技术是实现煤层气资源勘探、抽采的重要手段，而孔壁稳定对钻探质量、安全及成本具有较大影响。已有研究表明离子稳定剂可提高地层强度，从而增强孔壁承压能力。本课题以近孔壁煤储层为研究对象，从细观、宏观双重尺度，采用分析化学、损伤力学及钻探工程学等理论方法，对离子稳定剂作用下的煤储层化学特征、细观裂隙演化规律及宏观力学特性展开研究，揭示近孔壁煤储层相变、ξ电位、结合水膜等变化特征；获取加载过程中细观裂隙数量、总面积、定向度、间距等演化规律；完成不同浓度稳定剂作用下的岩心损伤变量和弹性模量、轴向应变关系分析；构建近孔壁煤储层损伤本构模型；建立基于稳定剂浓度、岩心组分、损伤变量、内聚力、摩擦角等参数的孔壁稳定临界荷载计算模型，揭示不同因素对孔壁稳定的影响规律。本课题综合运用多学科理论与方法，探求离子稳定剂对煤层气钻孔的化学和力学护壁机理，拓宽泥浆安全密度窗口，为煤层气钻探的基础研究及工程提供借鉴。

Drilling technology is an important method to achieve coalbed methane exploration and gas extraction. Stability of the drilling borehole wall is the key to keep quality, safety and cost control drilling. Study results have indicated that formation strength can be improved with ion stabilizer, and the borehole wall bearing capacity can be enhanced. The proposal selected coalbed methane reservoirs near the borehole wall as the research object. Analytical chemistry, damage mechanics and drilling engineering, and other theoretical approaches were used from double scales with microscopic and macroscopic. The proposal objectives were achieved chemical properties of coal reservoirs under ion stabilizers as phase change, ξ potential, combined with the water film thickness, etc. Micro fractures like fracture of the total area, the degree of orientation, number, spacing, etc.were also obtained. The evolution of macroscopic mechanical properties stress, strain, strength, cohesion, friction angle, etc. were used to establish damage variable parameter model with ion stabilizer. Borehole wall stability critical load calculation model was based on concentration of stabilizer, core components, and parameters such as damage variable, cohesion, and friction angle. It could reveal the influence degree of different factors on the stability of borehole wall.Multi-disciplinary subject theory and methods were introduced to obtain ion stabilizers on chemical and mechanical mechanisms in the proposal. Thus the study results could expand mud density limit, which could be also helpful for CBM basic research on exploration drilling and gas extraction.