Study On Remaining Oil Distribution Characteristics Of S?-P? Formation In The East Of Beierxi Block

Daqing Oilfield has been already developed since 1959 year,and has been in the the extra high water-cut stage.Nearly 70% of the remaining reserves is mainly distributed in the interior of the thick reservoirs in this stage,which is more important foundation to maintain40 millon tons of oil and gas sustained and stable production.Although the oilfield has adopted different methods and measures such as the secondary encryption,the third encryption,layer adjustment and EOR,a large amount of residual oil is poorly used through the observation of the closed coring wells.The paper uses the core data of the inspection wells,detaily sums up the sedimentary model of the block,draws the sedimentary microfacies,identifies the different types of single sandbody distribution,conducts the internal heterogeneity of sandbody,researchs the vertical,plane and core scale distribution characteristics of residual oil in the different development stages and sandbodies after the high water-cut stage.According to the results of the fine core description by more than 700 meters core in the inspection wells group,the lithofacies characteristics of different channel types are summarized,and the lithofacies assemblage patterns of braided river,meandering river and distributary river are deduced in the study area.The main factors of residual oil are the shelter of the abandoned channels,the shelter of the sand between channels,the river edge of the core variation,and the shelter of the lateral sandwichs in the first kind of oil layers.The main factors of residual oil are the thin injection and thick mining,the thin injection and thick and thin mining,the thick injection and thin mining,the thick injection and thin and thick mining,the sedimentary pinchout,and the sedimentary dead position in the second and third kind of oil layers.According to the residual oil distribution of various reservoirs,some development measures are finally proposed such as filling holes,changing the direction of seepage flow,reducing space of wells,and horizontal wells.