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Research On Reservoir Characteristics Of Chang 7,Chang 6 And Chang 3 Reservoir Groups In Weibei Area Of The Southern Ordos Basin

Posted on:2016-06-28Degree:MasterType:Thesis
Country:ChinaCandidate:M ZouFull Text:PDF
GTID:2180330461456218Subject:Sedimentology
Abstract/Summary:PDF Full Text Request
The sedimentology, reservoir sedimentology, petroleum geology and other theoretical knowledge and methods are applied in this paper. On the basis of the predecessors’ research, and with a variety of test and analysis methods such as core observation, logging interpretation, thin section observation, scanning electron microscopy, mercury injection, sedimentary facies, reservoir characteristics and main controlling factors of reservoir in Chang 7, Chang 6 and Chang 3 reservoir groups of Yanchang Formation of the Upper Triassic in Weibei area are studied deeply.Chang 7, Chang 6 and Chang 3 reservoir groups are mainly composed with braided river delta and lacustrine facies depositional system in the study area, they are further divided into third subfacies and eight microfacies. Sand is mainly controlled by subaqueous distributary channel of delta front, mouth bar and shallow lake sand dam. The sand reservoir physical property in subaqueous distributary channel is the best, and in the sequence with mouth bar and shallow lake beach-bar, the reservoir physical property of shallow lake mud, interdistributary bay and semi-deep lake mud is the worst.The componential and textural maturities of the sandstone in Chang 7, Chang 6 and Chang 3 reservoir groups in the study area is lower and lithological types are lithic feldspathic sandstones and feldspathic lithic sandstones. The pore types are mainly primary intergranular pores, feldspar and lithic fragment intragranular dissolved pore, intergranular dissolved pore. The sandstones has good sorting and median radius is lesser, so belong to fine pore and micro throat, slightly rough slanting degrees. The main diagenesis includes the compaction and pressure solution, cementation, dissolution and metasomatism. The study area is situated in the diagenesis stage A.Through thin section observation, scanning electron microscopy analysis and the research of sedimentary and diagenesis, it brings forward that the sedimentation is the main influencing factors of reservoir. The diagenesis is the key factors to control the preservation of original pores and the development of secondary pores in sandstone reservoir. Compaction, pressure solution and cementation is the main factor to decreasing reservoir property while dissolution can result in abundant secondary pores, which improved effectively physical property of the reservoir.After a comprehensive analysis and evaluation, the reservoir of Chang 7, Chang 6 and Chang 3 reservoir groups can be divided into four categories, and the reservoir property of I is the best, the sequence with the II to IV types and so on. The type of I and II develop in Janzhuang- Silangmiao- Yaoping. The type of III develop in Pianqiaozhen and its surrounding areas. The type of II and III exist in the south area of Yijun.
Keywords/Search Tags:Weibei area, Yanchang Formation, Reservoir characteristics, Diagenesis, Mian control factors
PDF Full Text Request
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