Abstract: One of the methods to keep wellbore stability during drilling is to select the proper muddensity.In this paper the stress around a deviated wellbore was analyzed according to the Mohr-Coulomb failure criterion when considering the strain soft character of damaged rockmaterials.

Key words: damage wellbore stability well pressure drilling mud density

摘要： 钻井施工中保持并眼稳定的措施之一是确定合适的钻井液密度.本文采用摩尔-库仑屈服条件,考虑材料损伤后的应变软化特性,对井壁岩石进行力学分析,给出维持井壁稳定的泥浆密度.

关键词: 损坏, 井眼稳定, 井压力, 钻井液, 密度