Research On High-Resolution Sequence Stratigraphy Of Putaohua Oillayer In Synclinal Area, Sanzhao Sag

Putaohua oillayer is the main hydrocarbon-bearing layer of Sanzhao Sag in Songliao Basin, and oilfield of Songfangtun, Shengping, Xujiaweizi, Yongle, Zhaozhou, Weixing have been found since Songfangtun experimental site was explored in 1979. As the exploitation of favorable structure and sndbody development blocks, surplus unused and blank areas are mainly in slopes and middle syncline. Thin and superposition of sandbody and mustone here restricted hydrocarbon exploration and development. This paper did comprehensive research on Putaohua oillayer of synclinal area and predicting favorable reservoir, providing guidance for development zones extension and disposing wells.Based on high-resolution sequence stratigraphy and reservoir sedimentology, utilizing cores, borehole log and well logging, this thesis divides Putaohua oillayer into one LSC, two MSC, four SSC and twelve SSSC, discusses formation and superposition style of stratum in different base level cycle scale in detail, sets up high-resolution stratigraphic framework using SSSC as the time unit and puts forward sedimental model of Putaohua oilayer is that stratum thin from north to south influenced by syndepositional tectonic elevating which is controlled by source from the north.We have drawn plane view of twelve time-unit microfacies of Putaohua oillayer, using base level cycle as the unit, based on building of high-resolution isochronal stratigraphic framework. And get Putaohua oillayer mainly develops typical shallow-water delta controlled by river, sedimental array in vertical is dereliction followed by advance, and facies is from predelta, delta plain and inner delta front to predelta.According to value of A/S and structure of cycles, we draw favorable sandbody develops in late decline hemisphere and early rising hemisphere of MSC in early rising hemisphere of LSC. Associating the physical properties and oil testing data of drilled wells, we get sandbody in SSSC8(Pâ… 41) and SSSC9(Pâ… 3) are the places favorable for hydrocarbon gathering, and in plane, distributary channel of delta plain and front is the best microfacies for reservoir development.