Main Controls On The Quality Reservoir Of Permian-triassic In Turpan Depression,Tuha Basin

This paper mainly studies the quality reservoir of the Permian-Triassic in the Turpan depression,especially the main controls of T₂k quality reservoir.Based on the definition of the effective reservoir thickness distribution characteristics,the quality reservoir division criteria are established based on the production dynamic data,and then sedimentary facies types and diagenesis types that have important influence on the formation of T₂k quality reservoir are studied.Finally,the distribution of quality reservoir in T₂k is predicted,and the controls of quality reservoir are analyzed.Through analysis,the characteristics of quality reservoir in the study area are clarified:?1?T₂k reservoir rocks are dominated by feldspathic lithic sandstones,followed by feldspar lithic sandstones.In terms of physical properties,T₂k reservoir in Tainan sag is a mesoporous infiltration,and Taipei sag and Toksun sag are low-porosity and low-permeability reservoir.The reservoir type of reservoir is mainly residual intergranular pores,intergranular dissolved pores,intragranular dissolved pores and a few fractured pores;?2?The analysis of various methods shows that the lower limit of T₂k effective reservoir porosity is 8%,the lower limit of permeability is 1m D.And the quality reservoir division standard is established based on the production dynamic data,where the porosity is greater than 15%and the permeability is greater than 10 m D.?3?The main sedimentary facies of P₃w reservoir in Turpan depression are fan delta deposits,and T₂k reservoir in Turpan depression are braided river delta deposits.The distributary channel microfacies and the estuary dam microfacies are the main sedimentary environments for quality reservoir.?4?There are three kinds of diagenesis:compaction,cementation and dissolution,it has an important influence on the quality reservoir performance.The diagenetic evolution stage of T₂k reservoir is mostly in stage A of middle diagenesis,and that of P₃w reservoir is mostly in stage B of middle diagenesis;?5?The quality reservoir of the Triassic Karamay formation are mainly controlled by various factors such as sedimentary conditions,diagenesis,temperature and pressure,and tectonic action,and the quality reservoir are mainly distributed in the Luketun structural belt,the Yubei structural belt and the Ying'er structural belt.