Study On The Sedimentary Facies Of Chan’ Gannuoer Sub-sag Of Gaolihan Depression In The First Member Of Tenggeer Formation, Erlian Basin

Gaolihan depression is one of the most largest oil-rich depression in Erlian Basin, whowas located in the northeastern of Wunite depression, in the southern of the uplift of theGreater khingan mountains, in the northern of the uplift of the Sunit, in the eastern of the bulgeof the Huretu and connected with the Bayehua and the Diyeao depression. The studiedintervals in the study area in Erlian Basin is the Lower Cretaceous of the first member ofTenggeer Formation. According to the theory of modern sedimentology and petroleumgeology, the depositional facies and reservoir characteristics was systematically studied in thefirst member of Tenggeer Formation, combining with logging, well logging, seismic andvarious analysis assay data and tectonic characteristics and other aspects. This study showedthat there mainly developped four sedimentary system in the study area, i. e. braided riverdelta depositional system, alluvial(diluvial)fan depositional system, braided-river deltadepositional system and lakes sedimentary systems. A variety of sedimentary facies andsedimentary microfacies also were identified gradully. At this sedimentary period of the firstmember of Tenggeer Formation of under section, water body was shallow and the fan deltaand the subaqueous fan was developped well in its south slope zone; The lacustrine shale wasdevelopped well in the depression;The thin layer of fan delta facies was also developped wellin northern ramp zone. On the contrary, with the deepening of water body during thissedimentary period of the first member of Tenggeer Formation of upper section, at this time,the depression turnned into a deep lake sedimentation; Fan-delta front sub-facies wasdevelopped well in its south slope zone; The thick layer of the braided river delta system wasalso developped well in north-eastern region and was outspread. Through the analysis of thelithology and oil-bearing showed that, there were some area and interva, who could be used asa favorable reservoir areas.,such as the first member of Tenggeer Formation of under sectionin the northern Chan’gannuoer sub-sag and the first member of Tenggeer Formation of uppersection in the east-central Halagentu’ sub-sag of the braided stream delta front, the fan deltafront, the paleoalluvio-diluvial fan and subsea apron.