准噶尔盆地南缘高泉构造三维地质力学建模及深探井风险应用

井眼不稳定易导致严重钻井复杂事故，并极大增加钻井成本，而准确的地质力学模型能够为钻井提供技术支撑。应用准噶尔盆地南缘深探井测井数据、地质力学测试结果、地层破裂压力测试和钻井日志得出邻井的岩石力学性质和压力剖面，构建一维地质力学模型，进而应用多井地质力学剖面来建立整个井区的三维地质力学模型。以三维地质力学模型为基础，可以减少超深井因异常地层压力、井壁坍塌和其他复杂钻井问题引起的井眼不稳定问题。三维地质力学模型用于实钻，与邻井相比，因复杂导致的非生产时间降低了25.3%。该方法为南缘高泉构造深探井钻井液密度优化、风险评估和高温高压井安全评估提供了便利的手段, 为降低钻井风险和改善钻井情况提供了指导。

Three-dimensional geomechanical modeling of Gaoquan structure along the southern margin of the Junggar Basin and its application to the risk evaluation of deep exploration wells

Borehole instability tends to cause severe downhole troubles and increases the drilling costs greatly. Accurate geomechanical model can provide the technical support for well drilling. In this paper, the logging data, geomechanical testing results, formation fracturing pressure testing results and drilling log of the deep exploration well along the southern margin of the Junggar Basin were adopted to plot the rock mechanical property and pressure profile of its neighboring well and establish the one-dimensional geomechanical model. Then, the three-dimensional geomechanical model of the whole well block was established by virtue of the multi-well geomechanical profile. Based on the three-dimensional geomechanical model, the borehole instability problems of ultradeep wells caused by abnormal formation pressure, hole wall collapse and other downhole troubles can be reduced. When the three-dimensional geomechanical model is used for practical drilling, non-production time caused by downhole troubles is 25.3 % less compared with the neighboring well. This method provides the convenient means for the drilling fluid density optimization and risk evaluation of deep exploration wells in Gaoquan structure along the southern margin of the Junggar Basin and the safety evaluation of high temperature and high pressure wells, as well as the guidance for diminishing drilling risks and improving drilling situations.