Sedimentary facies of Donghe Sandstone in the Upper Devonian-Lower Carboniferous and discovery of Hadexun Oilfield in Tarim Basin
Shen Yinmin1,2, Jia Jinhua3, Qi Yingmin2, Sun Xiongwei2, Zhou Bo3, Ma Debo3, Gao Li3
1 School of Earth and Space Sciences，Peking University，Beijing 100871 2 PetroChina Tarim Oilfield Company，Korla 841000，Xinjiang 3 Research Institute of Petroleum Exploration & Development，PetroChina， Beijing 100083
Abstract：The Hadexun Oilfield is one of the biggest integrated oilfield in the Tarim Basin.Its reserves exceeds one hundred million tons.The sedimentary facies and its changing regularity of the Donghe Sandstone plays an important role in the discovery of the Hadexun oilfield.The Donghe Sandstone was deposited in the transgressive background during the Late Devonian to the Early Carboniferous.It is mainly the beach sandbody of littoral facies.The Donghe Sandstone is a distinct diachronous in the whole basin.The Donghe Sandstone is chiefly terrigenous littoral to shallow marine facies.They overlaped thinning from lower to higher paleogeomorphic unit.Sedimentary facies is dominated by shoreface to foreshore intercalated with backshore of the littoral beach facies on the adjacent paleo-coastline.There are offshore mudstones and carbonate platform towards the basin area.The sandbody was controlled by the paleo-geomorphology，eustatic movement，and provenance.The sandbody thickness decreased on the gentle slope side，and increased on the steep slope side，thinning out on the solitary island and big terrace area.In the early transgressive stage，the Donghe Sandstone distributed in the west of Lunnan Uplift.The sandbody spreaded in north-south direction，with wide distributing and large thickness.The sandbody distributed in west-east direction along the paleo-coastline in the early to middle transgressive stage.In the middle to late transgressive stage，the paleo highland was flooded into many island by the sea water.The carbonate platform emerged towards the sea.The sedimentary facies and its variation of the Donghe Sandstone has provided good geologic conditions for forming litho-stratigraphic petroleum reservoirs.
Shen Yinmin,Jia Jinhua,Qi Yingmin et al. Sedimentary facies of Donghe Sandstone in the Upper Devonian-Lower Carboniferous and discovery of Hadexun Oilfield in Tarim Basin[J]. JOPC, 2011, 13(3): 279-286.
