铜川地区油页岩地层电性断面特征及勘查

摘要

In order to study the suitability and resolution of resistivity sounding method in oil shale region,we carried out the resistivity sounding in Tongchuan Area,the south of Ordos Basin. Combined with drilling mud logging and discovery ore situation,analysis of the oil shale section resistivity features by two methods is made,and the specific areas of oil shale layer in the electrical section are selected. Oil shale layer thickness is thin and high resistance layer in target body,compared to bury depth. In the obtained electrical section,the resolution of high resistance electrical oil shale layer is not very clear,but resistivity isoline change of gradient zone corresponds well to oil shale layer position,indicating the oil shale layer position indirectly. And through the comprehensive analysis of lithology and logging parameters,we think the gradient changes of resistivity values with depth changes resistivity value with depth describes from electrical aspect the evolution of oil shale layer from shallow lake sedimentary environment to half deep lacustrine environment. Therefore we conclude that resistivity sounding method can achieve the purpose of the exploration of oil shale layer.%为了研究电阻率测深方法在油页岩地区的适用性及分辨率，在鄂尔多斯盆地南缘铜川地区开展了电阻率测深工作。结合钻孔录井和见矿情况，分析了油页岩地段两种勘查方法获得的电阻率断面特征，在电性断面上圈定了油页岩层的特定部位。油页岩层厚度相对埋深而言属薄层、高阻目标体，其厚度与埋深纵向比小，在获得的电阻率测深断面上，高阻电性的油页岩层在电阻率测深断面上分辨率不清晰，其层位与电阻率等值线梯度变化带对应较好，从而间接指示了油页岩层位置。同时，通过岩性与测井参数综合分析，认为测深断面上这种电阻率值随深度的渐变特征，从电性角度描述了油页岩层由浅湖沉积环境到半深湖环境的变迁过程，提出电阻率测深方法可以达到勘查油页岩层之目的。