Sedimentary Facies And Reservoir Characteristics Of The Carboniferous Bachu Formation In The Xianbaza Area

The geological characteristics of the Tarim Basin are complex and it experienced a long time tectonic evolution.The Bachu uplift is a best special one of the large number of Primary tectonic units.Bachu uplift contains rich resources,and it's reforemed a special “nosal uplife”by different Geological history.This article is based on the number of courses studied during the undergraduate school.The research direction of the project is based on The evaluation of the Paleozoic traps in the Bachu west section of the Xianbaza.The sedimentary facies characteristics and sequence stratigraphy and reservoir characteristics of the Upper Carboniferous Bachu Formation in the Xianbaza area of the Tarim Basin are studied.Based on the theory of sedimentary petrology,and the paper with drilling and logging.The petrological characteristics are studied in depth.With the help of microscope,The standard limestone section,the mudstone section,the bioclastic limestone section and the mix of mudstone and clastic that occurred in the bottom are described in detail.In addition,the internal structure and microstructure of the rock are analyzed and summarized.Combined with various types of sedimentary facies signs,This article also analyzes the different style of sedimentary facie.Through those deposition characteristics of single well even wells,it‘s comprared some short layer,fanding these same way.According to the different depositional environment,four phase belts are divided.There are local facies,open platform facies,evaporative facies and tidal flat facies.And further according to the micro-changes in the lithology of the strata,divided the tide,intertidal,inter-sea,Taiwan,the lagoon and other subfamilies.According to the identification method of the sequence interface,There are three sequences of changes in the region.They are unconformity surface,the largest sea surface,deposition surface of the conversion.With the change of the sequence interface,the variation of the sedimentary system domain was analyzed.The sequence of small sequence is precisely located by the change of sedimentary system in single well and connected wells.In order to analyze the oil and gas storage of the Carboniferous in the Xianbaza area for more detail.In this paper,the reservoir characteristics of the Bachu Formation are analyzed roughly from the three aspects of rock characteristics,pore characteristics and diagenesis.The results show that the biodegradation of the bioclastic limestone in the Bachu Formation of the Carboniferous system is very good,and most of the mudstone reservoirs are poor in reservoir property,which is not conducive to the formation of oil and gas.