The Stratigraphy Comparison And Sedimentary Characteristics Of Block123and Block124,Biyang Depression

Block123and Block124in Gucheng Oilfield are the most enrichmentblocks ofviscous oil resource in Henan Oil Field. The oil-bearing area is2.2km~2, and they haveall entered into high water-cut stage after over twenty years’ water injectionexploitation. Fault block123-124has many exploited horizons and largethickness.Because of the development faults、complex structure、small oil-bearingsand body、low pressure level、serious heterogeneity of the oil layer、prominent profilecontradiction and large oil flow ratio, it causes injection fluid serious waterchanneling and polymer single dash and during the exploitation process of waterinjection and polymer. With the application of new oil recovery technology and newprocess, the former cognition of reservoir geologic characteristic still can’t satisfy thepresent development form. So we are in need of further improvement. In this situation,we need to classify strata more penetratingly and detailed.Against the problems existing for the study area, after collecting a lot ofresearch data, this article describes the geological features and tectonic framework ofthe study area, the developmental characteristics and distribution of the formation andthe profiles of the deposition zone by the theoretical guidance of high-resolutionsequence stratigraphy, sedimentology, sedimentary facies and paleogeographicreconstruction. The paper also grasps the geological conditions of this area. Analyzingthe distribution of heavy minerals, petrography, lithology and sedimentary subfaciesof delta front, the microfacies types in this area has been understood. Thehigh-resolution sequence stratigraphic framework could be set up after selection andidentification of sequence boundaries, class division of the sequence andidentification of base-level cycles. Analysis of the distribution about the sand bodiesand the distribution characteristics of the sedimentary microfacies in the sequencestratigraphic framework can provide a theoretical basis for the development of thesrudy area.This article regards high resolution sequence stratigraphy as guides, establisheshigh resolution division and correlation between stratigraphic framework and base level cycle. By macroscopical and microcosmic analysis of11wells and comparativeanalysis to lithofacies-electrofacies、sedimentary facies sequences and genesis of133wells in study area, strengthen the research of thick oil-reservoir partition, find outsedimentary microfacies characteristics and sand body combination characteristic ofsmall sand body, provide basis for the next dynamic regulation and specificcountermeasure of Block123and Block124.