高压深井试气期间裸眼井壁稳定性分析

高压深气井裸眼试气期间，由于井内液柱压力较低，不能很好地支撑井壁，裸眼段可能发生井壁坍塌。在非均匀构造应力作用下井壁周围地应力分布的基础上，考虑井壁周围地层温度变化引起的热应力场和高压流体渗流引起的渗流应力场，并结合Mohr-Coulomb准则，可以确定防止高压深井试气期间井壁坍塌的井内当量流压，依此指导垫液、压井液的密度和高度，可确保测试工作顺利进行。 

ANALYSIS ON OPEN HOLE STABILITY OF A DEEP GAS WELL WITH HIGH PRESSURE DURING TESTING

During testing of the open hole of high pressure and deep gas well, borehole collapse may occur in open-hole sections, because borehole fluid pressure was too low to support the borehole wall. Based on stress distribution near wellbore area under non-uniform tectonic stresses, seepage stress field caused by high-pressure fluid flow through porous medium and thermal stress field due to temperature changes, and combined with the Mohr-Coulomb criterion, we can determine the well equivalent flow pressure which can prevent collapsing. In addition, it may guide density and height of fluid cushion and well control fluid, which will ensure work smoothly.