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Study On Sedimentary Microfacies Of "basin - Rich Sand - Rich" Strata

Posted on:2015-10-13Degree:MasterType:Thesis
Country:ChinaCandidate:Y ZhongFull Text:PDF
GTID:2270330434454831Subject:Mineral prospecting and exploration
Abstract/Summary:PDF Full Text Request
The study of "Basin-Scale Sand Deposition" has been many views, Through the analysis of microfacies and evolution of member2of Xujiahe Formation in Hechuan area, the author of the paper attempts to provide a new idea for favorable sandbody distribution and prediction of sand-rich deposition.In order to the theories and methods of Sequence stratigraphy, sedimentary petrology and Structural geology as a guide, comprehensive utilization of well drilling, core, logging, seism and regional geological background, Restored the palaeogeomorphological features before Xujiahe Formation deposit with the impression method which based On the thickness of member1and member2of Xujiahe Formation in Hechuan area. The member1and member2each can be divided into a third-order sequence SQ1,SQ2by T-R sequence base on the analysis of sediment filling which conrrolled by paleotopography, the member2can be further divided into6high frequency fourth-order T-R sequence. In order, SQ2.1、SQ2.2、SQ2.3、SQ2.4、SQ2.5、SQ2.6from bottom to up.The well-tie sequence contrasting and the isochronal stratigraphic framework have been done on the basis of analysis of the single well sequence, the spatial distribution has been defined. Through the analysis of outcrops observing, core describing, electrofacies and seismic facies, to analyses the rock structure types feature and defines the type of facies, subfacies and microfacies with the macro and micro method on the basis of analysis of sedimentary setting, the author proves several facies in Hechuan area, including braided river, shallow braided river delta and lake., the Shallow braided river delta and lake are dominant, the two facies can further divide into the subfacies, including shallow braided river delta plain and shore shallow lake,the subfacies can divide into microfacies such as distributary channel, interdistributary bay and shore shallow lake shale. The single well facies analyse and the division and correlation of well-tie facies have been done on the basis of analysis of sedimentary facies. Editing the plans of sedimentary facies of the member2of Xujiahe Formation in Hechuan area with sequence-sedimentary facies mapping method which is "based on the type of Sandbody overlay" to analyse the plane distribution rule of the sedimentary facies and establishes the sedimentary evolution model of member2of Xujiahe Formation in Hechuan area,it indicates that the early sedimentary feature is under obverse control of paleotopography.
Keywords/Search Tags:Basin-Scale Sand Deposition, Xujiahe Formation, paleotopography, braidedriver delta, sedimentary facies mapping, sedimentary model
PDF Full Text Request
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