四川盆地须二段储层孔隙演化定量描述

我国低渗透气藏产气量在天然气总产量中所占比例越来越大，研究低渗透气藏的形成机理及形成过程是非常必要的。四川盆地上三叠统须家河组二段是重要的含气层位，但由于其储层具有非均质性强、且具低孔低渗的特点，不仅储层预测难度大，而且开发的效果也差。因此需要研究其形成过程，提高储层预测精度以改善开发效果。以储层岩石学特征、孔隙类型及分布特征、胶结物充填次序及充填时间等研究为基础，定时、定量地研究孔隙的整个演化历史，描述了孔隙在不同历史阶段的大小及变化原因，从而再现了储层形成历史，为下一步须二段气藏有效储层的预测与有效开发打下基础。

GEOLOGICAL REGIONAL SELECTION AND AN EVALUATION METHOD OF RESOUR-CE POTENTIAL OF SHALE GAS

With the quickening step of China’s shale gas exploration and development, the establishment of evaluation criteria of shale gas and the evaluation method of specific geological constituencies has become the prerequisiteand foundation of exploration and development. The optimization of favorable area can provide an important basis for further decision-making of the exploration and further study. According to a large number of foreign shale gas exploration and development cases, the main geological characteristics of shale gas are summarized. Based on the shale gas development practice of foreign countries, geological and geochemical parameters and the specific geo-logical conditions of domestic basins, six evaluating parameters for selecting favorable shale gas area are optimized according to their generating capacities, storage capacities and easy exploitations. At the same time, the evaluating index is defined, and the grading standards are established. Meanwhile, a simulation of the application of the evaluation method in selecting the favorable geological zones has been carried out in a certain region of a basin. Finally,the common quantitative calculation methods of shale gas potential are summarized systematically. Considering the complex geological backgrounds of China and the status that shale gas is less explored and developed, the analogy method and volume method are recommended to be used comprehensively to calculate the resources.