Study Of Reservoir-forming Of Subtle Oil Reservoir In Shahejie Formation In Bamianhe Region, Dongying Depression

The degree of exploration in Shahejie formation is high and it is more difficult to explor structural oil-gas pool in Bamianhe area, but the subtle oil-gas pools have not been studied enough. This paper deals with a systematically study of sequence stratigraphy, sedimentology and pool-forming of Shahejie formation,and reliances on subtle oil-gas pool exploration are made as a result.Based on the theory of sequence stratigraphy and sedimentology, the third order sequence strata framework and fourth ones have been founded in the Bimianhe area. The Shahejie formation are divided into seven third-order sequences;and further, Es4 are divided into eight forth-order sequences according to thinner geologic strata of gentle slope belt. In the sequence strata framework, two landforms, controlled by lower ditch valley belt and slope break, are identified by ancient geography and deposite system research. At the same time, the distribution mode of the strand shallow lake and the delta deposition system have been established in this region. The research on type and distribution regulation of subtle trap combining with geologic strata structure indicates that the south slope belt, ditch valley belt, Guangbei slope break and southwest of noselike conformation belt are the more advantageous belt to find subtle trap.Crude oil of Shahejie formation in Bimianhe region mainly come from Es4's mature hydrocarbon source rocks of Niuzhuang depression, and part of them come from Guangli depression. So characteristic of crude oil of the region is mainly mature crude oil mixed with little unripened-lower mellow crude oil. A large quantity of the oil which sourced from hydrocarbon source rocks migrated upward along slopes through darrier layers of faults, unconformities and sand bodies, and accumulated in Bamianhe structural belt, forming far-ranging distribution and various kinds of oil and gas reservoirs as a consequence of well trap-source conditions and space-time configuration relation, coupled with superior petroleum reservoir-forming conditions.