Abstract: Through supplementing 89 sedimentary facies maps after finished Class Ⅱ oil reservoir and infill wells, combining with coring data and performance analysis, this paper gives us a brand new recognition of various sand bodies, including the description of lateral morphology and reservoir connectivity. Compared with sand body distribution before and after well pattern thickening, the rules of sand body distribution were summarized. On basis of analysis of injection-production relationship and characteristics of residual oil distribution, measures and advice that will play a significant role for improving field development were put forward.