Study on Sedimentary Microfacies and Impact on Development of Chang 6₁ Reservoir in Shijiapan Area, Ordos Basin

It is of great practical significance to re-recognize the sedimentary environment, sedimentary microfacies and distribution characteristics of the reservoir in the middle and late development stages, which is important for identifying the remaining oil distribution and well deign. By systematically collecting and arranging the core, mudlog and logging data in this studying area, the strata have been divided in detail. On the basis of establishing the relationship between rock and electricity, the sedimentary microfacies of Chang 6₁ reservoir in Shijiapan area, Ordos Basin have been systematically studied. In addition, the production status over the years, water injection efficiency characteristics and formation energy in this area have been counted and analyzed. The results show that the Chang 6₁ reservoir is a deltaic sedimentary system, developing deltaic subfacies, with the main microfacies composed by distributary channel and river floodplain. And then, the sedimentary microfacies plan of various layers have been further prepared, the sedimentary characteristics sand body of Chang 6₁ and the plane distribution characteristics of sedimentary microfacies have been analyzed. Finally, the relationship between sedimentary microfacies and oil-bearing properties, and the role of sedimentary microfacies in resolving major development contradictions and problems at present have discussed which will provide a reliable geological basis for the adjustment of later-stage oilfield development programs.