Favorable Areas Prediction Of Yan9Reservoir In Gaojiagou-Qingyangeha Area

Yan9reservoir of Yanan Group is one of the main development layers in Gaojiagou-Qingyangcha area, the exploitation of which is significant for the production increasing of target area. However, along with the further exploitation and development, current research on the Yan9reservoir can not meet the demand of expanded production. Aiming at above problems, based on the data of core and logging analysis, this paper studies on the characteristics of the sedimentary, petrology, pore structure, diagenesis, physical property and heterogeneity of Yan9reservoir, then evaluates the target reservoir via multifactorial comprehensive evaluation method. Especially, this paper lunches detailed researches on the reservoir type, pool forming geological conditions and hydrocarbon enrichment regulation of Yan9reservoir, also gives particular researches on hydrocarbon pooling pattern and the effects on hydrocarbon enrichment of Yan9paleogeomorphology reservoir. Finally, based on above researches, this paper predicts several favorable areas of Yan9reservoir combining various data of oil/gas shows such as formation testing, production testing and logging.The result shows that:Yan9formation can be subdivided into Yan91and Yan92; because of the denudation resulting from Indo-China movement in late Triassic Period, the Yan10and Fuxian Group formation of target area suffers a sedimentary gap, what makes a typical palaeogeomorghology landscape; reservoir sandstone is mainly arkose, has the characteristics of well sorted, high maturation and good physical property; the main pore type of Yan9formation is intergranular pore and dissolved pore, and Yan9reservoir is severe inhomogeneous; through multifactorial comprehensive evaluation method, Yan9Formation is divided into four types, Type Ⅱ dominates the target formation, and the next is Type Ⅰ; the main reservoir type of Yan9reservoir is structural-lithologic reservoir, the next is structural reservoir, paleogeomorphology reservoir also can be found in Yan92reservoir; the hydrocarbon pooling pattern of paleogeomorphology reservoir in Yan9reservoir consists of buried highland flank reservoir and buried highland top reservoir; the control factors of hydrocarbon enrichment of Yan9reservoir are various, structural altitude is the main controlfactor of Yan91, and the main control factors of Yan92are structural altitude andpaleogeomorphology; finally, based on the abundant detailed researched mentioned above,this paper provides favorable areas of Yan9reservoir, which consist of two Type Ⅰareas, fiveType Ⅱ areas and two Type Ⅲ areas, the total acreage of all favorable areas is about98.27km2.The research of this paper can provide a theoretical supporting for further oil fieldexploitation.