Based on the principle that natural gamma and acoustic time difference curves have nice logging response in tight sandstone reservoirs, three methods named experience trial and error, the degeneralization method based on the non-homogeneousnature of the reservoir and sonic porosity method were adopted to transform the natural gamma and acoustic time difference curves in an oilfield area of Ordos Basin into new curves to propose a logging curve dimensionless rendezvous method, and two kinds of “sweet spots” indexes named heterogeneity evaluation index (HEI) and porosity-permeability comprehensive evaluation index (PPI) were constructed to evaluate the tight sandstone reservoirs quantitatively. A new means was explored to identify the “sweet spots” of tight sandstone reservoirs by using dimensionless rendezvous method and “sweet spots” indexes to carry out reservoir classification, evaluation and “sweet spots” prediction in the study area. The conclusions of this research are in good agreement with the measured data in the mine, which will provide an important theoretical and practical basis for the prediction of “sweet spots” in the tight sandstone reservoirs.

基于自然伽马和声波时差曲线对致密砂岩储层具有良好测井响应的原理, 采用经验试错法、基于储层非均质性的归一化法和声波孔隙度法3种方式, 将鄂尔多斯盆地某油田区块的自然伽马和声波时差曲线变换成新曲线, 提出测井曲线无量纲交会法, 构建得到非均质性评价指标(HEI)和孔?渗综合评价指标(PPI)两个“甜点”指数, 对致密砂岩储层进行定量评价。探索综合运用无量纲交会法和“甜点”指数判别法来识别致密砂岩储层“甜点”的新方法, 对研究区储层进行分类评价及“甜点”预测。研究结果与矿场实测数据吻合度较高, 可为致密砂岩储层“甜点”预测提供较重要的理论和实践依据。