塔里木盆地塔东地区油气地质条件与有利地质体资源潜力OA北大核心CSTPCD

The main part of Tadong exploration area of Daqing Oilfield is located in Manxi platform margin in plat-form-basin transition zone of Tarim Basin,with low exploration degree and large resource potential.The exploration is mainly concentrated in Gucheng area,without significant breakthrough.In recent years,through re-examination of old wells and structural-lithofacies paleogeography research,basic hydrocarbon geological conditions in platform margin are clarified,favorable plays for hydrocarbon accumulation are determined,and new exploration type in Cambrian is expanded.The results show that several sets of source rocks develop in Tadong exploration area,in-cluding Yuman and Yudu rift basin facies,and slope-shelf facies.High-energy reef-beach develops inherited in Cambrian-Middle and Lower Ordovician platform margin belt,with several sets of strike-slip faults controlling reser-voir,accumulation and enrichment.2 sets of regional cap rock of"black quilt"shale and"white quilt"gypsolyte are widely distributed,forming complete source-reservoir-seal assemblages,and providing conditions for large-scale accumulation.Vertically,oil and gas are controlled by strike-slip faults and regional cap rock,mainly distrib-uted in Middle-Lower Ordovician carbonate strata.Horizontally,large-scale oil and gas enriched centering around Yuman and Yudu rift troughs.Fault-karst in upper member and reef-beach-fault-karst complex bodies in lower mem-ber of Yuman Ordovician Yingshan Formation have superior accumulation conditions and develop condensate gas reservoirs,being the most realistic benefit exploration field in Tadong area.Cambrian pre-salt reef-beaches and fault-controlled mound-beach belt have good source-seal assemblage and large resource potential,and can serve as replacement field for increasing reserves and production.Tadong exploration area presents resource scale of trillions cubic meters in many fields,and is expected to build an important base in a short period for stabilizing oil produc-tion and increasing gas production in Daqing Oilfield.