Sedimentary Microfacies And Analysis On Development Potential In The3rd Member Of Qingshankou Formation In The Qianbei Area, The Southern Songliao Basin

Taking high-resolution sequence stratigraphy theories and fine sedimentology theoriesas guidance, this study comprehensively used full and accurate well core, well logging and the3-D seismic data, etc in higher exploration degree area. Through depositional dynamicanalysis of different grades base level cycle and identification of interface, high-resolutionsequence stratigraphic framework in the3rd member of Qingshankou formation in theQianbei area of the southern Songliao Basin is established. Within the fine sequencestratigraphic framework, sources of sediments, depositional system and distribution ofsedimentary facies are analyzed. As the basis,study on sedimentary microfacies and ofidentification of monosandbody was carried out. It shows that the composite debouch barcomposed of multi-branch and independent single debouch bar. The distribution of asingle debouch bar was narrow-banded in source direction, within classification ofobvious energy unit. Single debouch bar was mainly reservoir sandbodies in the3rd memberof Qingshankou formation in the Qianbei area. Banded (underwater) distributary channelsandbody and single debouch bar with their distributions being multiple and independent inplane as well as narrow-banded in source direction is immediate reason of complicate andversatile reservoirs. It has practical significance for a clear understandingof the reservoir origin and distribution, oil/water distribution and oil controlling factorsof lithologic reservoirs. Through systematically analyzing types of found reservoirs and itsdistribution characteristics, the minimum oil-controlling unit was single lithologic traps,whichIt was formed by single debouch bar under different hydrocarbon accumulation conditions.Spatial complicated superposition of vertical multi-layer and planar multi-branchmonosandbody traps and mis-traps is essential reason of complicated distribution of oil andwater. It is supported an important realistic significance to complicated exploration anddevelopment of lithologic reservoirs.