摘要
利用法国斯仑贝谢公司在我国四川油气井服务时所作的四臂井径测井曲线,分析了四川盆地中井位附近的地壳水平主应力方向.共分析了12口井的井径测量曲线,测量深度从地表下约2,000 m至4,700 m,各井的测量段从50 m左右至1,360 m不等.编制了对测量曲线采样、插值并作简单统计处理,从而获得崩落孔孔径平面投影图的计算机程序.处理结果表明,大多数孔显示了NNW-SSE或近N-S向的优势崩落方向,说明四川盆地最小水平主应力即为此方向.此结果与由平均震源机制结果得出的四川附近地壳区域应力场图象大体协调一致.
Schlumberger company conducted well logging service in China's Sichuan oil field. Four-arm caliper logging records at 12 wells are available to us for the purpose of crustal stress study. The logging depths are generally from 2,000 down to 4,500 meters beneath the ground surface,with different logging intervals. The longest interval is more than 1,300 meters.The logging records are digitized,and plotted to get plane projections of the measured well-diameter for the whole logged intervals. Most projections show prominent elongation of the well bores in the NNW-SSE or nearly N-S direction. Following the common explanation that in the direction of elongation lies the minimum horizontal principal stress axis,we get the feature of the stress axis orientations in the Sichuan basin which gererally agrees with the pattern of regional tectonic stress in Sichuan and the surrounding regions obtained from composite focal mechanism analysis.
出处
《地震学报》
CSCD
北大核心
1990年第2期140-147,225,共8页
Acta Seismologica Sinica
基金
地震科学联合基金
