Quantitative classification and characteristics difference of diagenetic facies in Shan 2 sandstone of Shenmu Gasfield, Ordos Basin

In order to probe the quantitative classification method of diagenetic facies, logging data and test results have been used to establish classification standard and state characteristics of diagenetic facies according to diagenesis and logging parameters taking Shan 2 sandstone of Shenmu Gasfield in Ordos Basin as an example. The lithology is lithic quartz sandstone, lithic sandstone and quartz sandstone. It develops lithic dissolved pore, inter-crystalline pore, inter-granular dissolved pore, mixed solution pores and inter-granular pore. Shan 2 sandstone experienced compaction pressure-solution, cementation and dissolution with medium to strong compaction rate, medium cementation rate, moderate to strong dissolution rate, respectively. Five types of diagenetic facies can be classified according to the diagenesis quantitative parameters and diagenetic facies can be effectively distinguished based on natural gamma ray, deep lateral resistivity, acoustic and density logging. The moderate compaction, illite cementation, intergranular pore and dissolution pore facies distributing in the middle of distributary channel sand body is the most favorable diagenetic facies because of the highest pore development degree, the best properties, the widest distribution of pore throat and high content of large pore throat, followed by moderate compaction, illite and kaolinite cementation, dissolution pore and intergranular pore facies. ©, 2015, Science Press. All right reserved.