High-Resolution Sequence Stratigraphy In Putaohua Reservoir And Profitable Area Predication In Riverside Areas In Daan Oilfield

On the basis of the theory of high resolution sequence stratigraphy and fine sedimentary study, the paper refers to the scheme of Putaohua reservoir formation in Xinzhan area of Daqing oilfield and sets up high resolution sequence stratigraphy framework of Putaohua reservoir in study area. The paper optimizes DA26 well as type well among key wells, which have high vertical separability, enough and concentrated sandbodies, and obvious cycles, in Putaohua reservoir in the in Riverside Areas in Daan oilfield.The paper divides the Putaohua reservoir in DA 26 well into 13 short scale base level cycles. The paper adopts means of "closed framework profile controlling correlation", and chooses 3 vertical sections from north to south and 2 cross sections from east to west to make closed framework profile in study area.The method of work makes sure unity in correlation of formations in the north of the Daan oilfield, in the Daan oilfield, Nanshanwan oilfield and Xinzhan oilfield. To make provenance analysis,the paper adopts the method of heavy mineral combination and horizontal distribution in the sedimentary sandstone content and sandstone ration in formation. After analyzing, we conclude that the west area in the study area is controlled by northwest provenance and the east area is controlled by northeast provenance. After plane sedimentary microfacies analying by cores and well logging data,the paper has confirmed there is shallow-water delta sedimentary system in study area.The paper has identified 1 facies,2 subfacies and 12 microfacies in study area.After making study in reservoir microcharacteristics in Putaohua reservoir, the paper has confirmed low compositional maturity, high textural maturity, low porosity and ultra-low permeability reservoir and A substage of middle diagenetic stage in the study area.The study area develops shallow-water delta deposition, the physical property in that area is not very well. Profitable area mainly distributes distributary channel, sill-like sandbody controlled by river and main part of sill-like sandbody, whose physical property is well, belonging to classⅡreservoir.