渗流作用下井筒周围岩石内弹塑性应力分布规律及井壁稳定条件
ROCK ELASTIC-PLASTIC STRESSES AROUND A WELLBORE AND WELLBORE STABILITY UNDER PERMEATION OSMOSIS
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摘要: 将地层岩石视为多孔介质,考虑了孔隙压力和渗流作用的影响,根据弹性理论和摩尔一库仑屈服条件以及岩石损伤后的软化特性,对井筒周围岩石进行了弹塑性力学分析,给出了井壁稳定条件。Abstract: To keep wellbore stability is important in oil drilling and production.In this paper,an incompressible fluid to flow radially into or out of a wellbore being allowed,the elas-tic and plastic stresses around the wellbore were analysed according to the Mohr-Coulomb failure criterion and the condition of stability of the wellbore is discussed.