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Sedimentary Facies And Reservoir Comprehensive Evaluation Of Chang 8 Section Of Yanchang Formation In Maling Areas

Posted on:2016-12-24Degree:MasterType:Thesis
Country:ChinaCandidate:C ZhangFull Text:PDF
GTID:2180330461956236Subject:Geology
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Maling region, an oil field founded by Changqing Oilfield in recent years from the southwest Mesozoic in Ordos Basin, lied on southwest part of Yishan slope and its main producting layer is Long 8 segment of Triassis Yanchang Formation. Based on many previous research achievements, such as the field investigations and the combination of core observation and logging data and testing data, macro-analysis and micro-analysis,theory and practice combination and research of strati-graphic,sedimentary faces and sandstone distribution of Chang 8 segment oil layer in Maling region, this paper focus on the research of reservoir characteristic, study the main controlling factors of reservoir development, and give a comprehensive evaluation of establishing reservoir in the study area.The study is formed by the following results:Based on the strati-graphic classification plan of Chang 8 segment of Yanchang Formation in Changqing Oilfield, we made a comprehensive analysis of the characteristics of sedimentary faces and microfacies in the different layers for study area’s typical Long 8 oil reservoirs, and compare interwell sedimentary faces. We known that when Long 8 reservoir deposit, the study area is controlled by sources from the west; through the analyses of faces indicator and delta development, we found that study area mainly develop shadow water delta sedimentary system.Via the analyze of reservoir sandstone distribution characteristics and genetic type in study area, we got that reservoir sandstone had a big lateral oscillation, final form were banded in the plane, netted along southwest-northeast and west-east with good lace. Among these, the most favorable reservoir sandstone type for oil and gas existence is underwater distributary channel sand body and debouch bar sand body.According to the analytical data of core and thin slice, it indicate that the reservoir rock types are mainly debris-feldspar and feldspar-debris sandstone, the content of feldspar and lithoclast was fairly high, and low grade of maturity shows in rock structure and contents. The main diagenesis include compaction, cementationand dissolution.The drill core physical property analysis showed that high permeability and prolific zone were developed based on the background of low permeability. Chang 8 reservoir is overall relative low porosity and permeability background, and part of them are in a relative high-permeability zones.The control factors of Chang 8 reservoir development include sedimentary facies zone, lithologic properties and diagenesis. The impact of sedimentary facies zone reflect on that Chang 8 sand body has a wide spans of migration, and then the sand body change quickly, which lead to the formation of partly thicker cuspate shallow water deltaic sand body and reservoir physical properties change quickly.According to the clastic rocks reservoir evalution criterion in the oil industry, and the study of petrologic characteristic, type and structure of pores, and physical properties of sedimentary facies,sand body and reservoir, we established reservoir classification evalution criterion of region of interset, and evaluated reservoir, primary type I and II reservoir.
Keywords/Search Tags:Sedimentary Facies, Comprehensive Evaluation of Reservoir, Chang 8 Oil Reservoir Group, Maling Region, Ordos Basin
PDF Full Text Request
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