针对钻井中井壁失稳问题开展井壁稳定性研究 ,文中就井壁应力状态和失稳类型进行分析计算 ,并结合测井资料和岩心的室内实验结果进行分析 ,建立了一套计算地层坍塌压力的方法 ,结合盐城地区 3口井应用对比 ,坍塌压力剖面基本吻合现场实际 ,为钻井液密度设计提供了一定的依据 Aiming at the instability of borehole in borehole, the stability of borehole wall is studied. In this paper, the stress state and instability type of borehole are analyzed and calculated. Based on the analysis of well logging data and laboratory test results, a set of methods to calculate the formation collapse pressure Method, combined with the application of the three wells in Yancheng, the collapse pressure profile is basically consistent with the actual field, which provides a basis for drilling fluid density design