The Study On The Shu 266 Area's Reservior And Surplus Oil Distributing In Shuguang Oilfield

With the continuous develop of the Shu 266 area in the Shuguang oilfield, most of the producing wells become into the middle or high-water-cut stage. Because of the high oil recovery and the serious reservior heterogeneity, It is more and more difficulty of the reservior develop and the reservior production rate's reduces much more quickly.The Dujiatai oil layers in the Shu 266 fault block are fan delta front facies, locating on the edge of the fan delta front in the areal. Its microfacies mainly are subaquatic distributary channels and subaquatic interdistributary embayments. The Shuguang oilfield's major reservior is Shu 266 fault block whose reserviors develop.very well. Its distribution is wide but the reservior's heterogeneity is very serious, which results in surplus oil's unhomogeneous distributation. The Dujiatai layers are the serious heterogeneity reserviors. The inner and inter layers' heterogeneity is moderate to serious. Choosing the proper parameters characterizing the heterogeneity, This paper preferably characterized the reservior's heterogeneity. In addition to it, the paper also ran five models which include the porosity, permeability, floodout status, water saturation and surplus oil saturation.This area's structure altitude is generally high in the west and low in the east. Thus most of the surplus oil should distribute in the west. The some high parts of altitude in the east also are favorable zone of surplus oil distribution. The Dujiatai layers mainly are the subaquatic distributary channels, which result in their serious heterogeneity. Though the water saturation is very big, the surplus oil also exists in the subaquatic distributary channel sandbodies, especially the top of the thick subaquatic distributary channel sandbodies. Because there isn't fault in this area but the edge of it blocked by faults, some of the surplus oil should distribute near the faults, mainly the high altitude faults. The serious heterogeneity, especially the very serious interbedded heterogeneity leads that multiple sand exploitation covers up the exist of the low-pemeability layers which are the favorable bed distributing surplus oil.Because the total water saturation is high and surplus oil saturation is some lower in this area, it is considered to using the tertiary recovery method and improving the injectant's performance, such as polymer solution driving, to maintain the production. The tertiary recovery method is very expensive, so it is important to have experiments to simulate the effect of tertiary recovery. In a word, no matter which method to be used, it is necessary to clear about the reservior heterogeneity and synthetically analyse every well.