Sandbody’s Growth And Oil Enrichment Properties Of Fuyang Reservoir In The North Of Xingshugang

Guided by the theory of sedimentology and high resolution sequence stratigraphy,based on the seismic,logging,drill core,laboratory analysis and dynamic statistics are fully utilized in this paper to study comparatively the precise classification of subzones and individual sand bodies in fuyang formation.Based on the study of sedimentary micro-facies,sandstone distribution restricted by the framework of high resolution sequence stratigraphy,and based on the analysis of reservoir formed factors of Fuyu oil bed in the studied area,inview of multiple geologic features and their matching relationship between spatial andtemporal,the master control factors in reservoir forming stage were confirmed,the mode ofhydrocarbon accumulation of Fuyu oil bed were established and the hydrocarbon enrichmentpattern of Fuyu oil bed were summarized,and then the favorable oil and gas accumulationzones in the studied area are predicted.Innovation and acquaintance acquired from abovestudy were as follows.(1) On the basis of fully researching sedimentary evolution background, the area has been confirmed as delta distributary plane controlled by north sources and delta front deposits. The main sandbody is defined to be small and mini type river channel sand sediment which is approximately north-south oriented by comprehensively analyzing petrologic characteristics of cores form coring wells, ancient biological fossils, logging facies elements,single sandbody’s characteristics, sedimentary background and facies belts’distribution etc..(2)Based on the observation and description of core and a great quantity of logging data,the rock phase and electrofacies were systematically analysised,the rock-electricity response mode which reflects the different sedimentation effect and sedimentary environment was established.(3)Based on rock phase,electrofacies and rock-electricity response mode,the types and the character of sedimentary micro-facies were in-depth studied.Summarized the shallow lake-delta system depositional model of FuYang oil bed,and the distribution characteristic of reservoir sandstones is analyzed under the control of high resolution sequence stratigraphic framework.(4)Palaeotectonics restoration theory is applied to determine the main evolution phase of today’s formation and on the basis of which a study on hydrocarbon generation stage and hydrocarbon source rock distribution has been carried out, combining with rock structure forming and hydrocarbon expulsion of source rock, to confirm oil source and the main oil accumulation period. The study results indicate that palaeotectonics and hydrocarbon source rock distribution are the main causes for oil-bearing property of Xingbei Fuyang formation whose eastern part contains more oil than the west. Horst fault blocks and lithological reservoirs are deemed to be the most favorable oil accumulation type for oil and gathering in the area.(5)After summing up all the research results, Three favorable areas are optimized.a predication on abundant oil-bearing blocks has been successfully made.