Research On Distribution Characteristics Of Residual Oil Of Well Area In Xifeng Oilfield

The Chang 8₁ reservoir in M well area of Xifeng Oilfield belongs to a low-permeability lithologic reservoir,and it has strong reservoir heterogeneity,poor reservoir properties and development of micro-fractures.In the early stage of the M well,the diamond-shaped anti-nine injection well pattern was used.Due to the development of micro-fractures,oil wells in the direction of the fracture after flooding is fast,the production of fractured lateral wells is low,and the water flooding effect is poor,when water is injected.According to the actual production conditions,flooding oil wells were injected,which makes most of the M well area form linear water injection,but located in the fracture lateral wells are still not effective.With the data of core,logging,the target layer of M well area is fine divided and contrasted,the whole area stratigraphic framework is established,and the sedimentary microfacies and sand body distribution characteristics of each small layer are analyzed,and the heterogeneity of the reservoir is studied.Based on the three-dimensional geological modeling,the residual oil distribution in the M well area are analyzed by using numerical simulation methods combined with dynamic monitoring data.Well-balanced well pattern areas,well-free controlled reserves areas,reservoir edges,and scattered distribution of reserves Zones,cracks,etc.distribute the residual oil enriched;After comparing the three small layers,the residual oil saturation is the best at Chang 8₁³.Based on the residual oil distribution characteristics,the development countermeasures were proposed:encryption adjustments were made to increase the extent of the utilization of fracture lateral reserves,the development of unutilized areas was increased,development of non-primary layers was increased,profile adjustment was performed,and the degree of water drive was increased.