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Research On The Characteristics Of Tight Reservoir And Log Predicting For Xujiahe Formation In Southern Sichuan Basin

Posted on:2009-12-12Degree:DoctorType:Dissertation
Country:ChinaCandidate:L XiaoFull Text:PDF
GTID:1100360242493057Subject:Sedimentology
Abstract/Summary:PDF Full Text Request
The reservoir of Xujiahe Formation of the Upper Triassic clastic reservoir is one of the key stratum series in the southern Sichuan basin. Due to the pay formation was buried deeply and violent diagensis, it is the reservoir with low porosity and low permeability, which is very difficult to explore. Therefore, it is necessary to make research into Xujiahe Formation of the Upper Triassic reservoir characteristics and distribution.Base on the sedimentology, reservoir geology, logging, other theories and methods , the sedimentary facies, reservoir characteristics and reservoir logging prediction of Xujiahe Formation in the southern Sichuan have been stduied.One group sedimentary facies, two sedimentary facies and many subfacies, microfacies types have been recognized and the depositional models have been established by macroscopical and microcosmic research methods, basing on the detailedly observation of field profile and core, combinated with the data of mud log, conventional log and regional geological condition.The types of petrology in the study area are mainly lithic feldspar sandstone and feldspar lithic sandstone, which overall properties is poor, and belongs to the low porosity and a low-permeability reservoirs. The main pore spaces are intergranular pore, intragranular dissolved, porosity, Molds hole, intergranular porous, grain -edged fractures and fractures. And its pore structure is poor,which belongs to medium-thin throat-eyelet type mainly.Based on the comprehensive analysis of the characteristics and stage of diagenesis, The diagenetic stage of Xujiahe Formation is mainly in the middle diagenetic A period . It is the dissolution of feldspar and the strong chlorite-cement ring that plays an important role to the development of the reservoir. The sedimentary facies, diagenesis, and tectonic are the main cont rolling factors of the reservoir quality. On the basis of detailedly analysis the corresponding relation among the "four charater" about reservoir characteristics and the pore structure characteristics, the lower limit of reservoirs have been studied, which porosity is 5%. The Xujiahe Reservoir were divided into four categories, and the reservoir of study area is mainly reservoir II - III.Having the system, further analysis to logging quantitative prediction of reservoir, on the basis of logging data standardization, and analysis the core properties, establishing the reservoir log interpretation models, and analysis reliability of the model, then the distribution of reservoir can be forecasted. According to distribution of sedimentary facies and reservoir , with the results of diagenesis facies research, the favorable area of the reservoir in southern Sichuan Xujiahe Formation can be predicted.
Keywords/Search Tags:Southern Sichuan, Xujiahe Foramtion, Sedimentary facies, Reservoir characteristics, Logging reservoir prediction, Favorable area
PDF Full Text Request
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