Reservoir Properties Of Dujiatai Oilbed In Northern Shuangtaizi Du124Block Liaohe Oilfield

Northern Shuangtaizi Du124Block of Liaohe Oilfield locates in the middle to north ofQishu lower step, southern slope of Dujiatai buried hill tectonically. Two sets of oil-bearingseries developed including Dalinghe and Dujiatai oil beds, belonging to structure lithologyreservoirs. Complex tectonic background leads to uneven reserve recovery and water injectionutilization rate, bad natural energy driving effects, resisting in low development indicators.The main problem lies on the deep burial and complex reservoir distribution. The key pointand crux of the subject is to improve developing effects.On the basis of applying tectonic geology, petroleum geology, sedimentology andlogging geology, utilizing drilling, seismic, logging, testing and producing data, reservoircharacteristics were deeply studied from formation, sedimentation, oil pool, microscopic andmacroscopic reservoir characters. Results show that Dujiatai oil bed is composed of interbedsof shallow grey, brown grey, grey yellow glutinite and sandstone, dark grey, brown grey, bluegrey mudstone. Monocline developed east-northtern strikely and west-southern diply.East-northern faults controlled the shapes and distribution of oil and water for their longperiod movements, big fault throws and elongations. Fan delta fronts formed includingbraided distributary channels, interchannel, river mouth bars and thin sheet sand subfacies.Reservoirs exist in river mouth bars and distributary channel sandstones. Lithology mainlyincludes lithic arkose and litharenite composed of quarts feldspar and lithic debris withmiddle ingredient and structure maturity. Clay minerals are mainly kaolinite, with minor illitemontmorillonite and chlorite. Reservoir contains high content of mud and carbonate, withrudimental intergranular pores and solution pores as its main reservoir space, intercrystallinepore and mircofractures exist partilly. The oil and water distribution is decided by structurepattern and reservoir characters. No uniform oil-water contacts develop, and its reservoirtypes include bedded structure mainly, structure lithology secondarily and lithic reservoirspartly.