CONTROLLING FACTORS OF PORE DEVELOPMENT OF THE SHAN 2 MEMBER IN YULIN GAS FIELD
榆林气田山西组2段孔隙发育的控制因素分析

Yulin gas field is one of the important gas fields in Ordos basin.Permian Shan 2 member sandstone is the main reservoir,and the diagenesis process of the member was complicated.For uncover the main controlling factors of pore development in this gas field,on the basis of thin section examination of rock,we analyzed Shan 2 member sandstone by multiple stepwise regression,divided the affecting factors of pore growth into three: sediment variable,acidic variable and reductive variable,and discovered the prime reason why the two sections of sand body have different porosity within the same sediment environment.The conclusion is that the porosity of this reservoir was dominated by both sedimentation and diagenesis.In the case of sedimentary environment is advantaged,whether or not happened erosion effect,the porosity is developed and primary porosity is dominant;in the case of acidic variable is high,whether or not the sedimentary environment is advantaged,the porosity is developed and secondary porosity is dominant.The successful application of the multiple stepwise regression analysis not only was guiding the exploration in the studying area,but also offered the reference model for similar problem in other area.