Reservoir Character And Prospecting Advantageous Regions In Xujiahe Formation At Guanyinchang To Washi Area In South Of Sichuan Province

The Xujiahe formation in the south of Sichuan basin is very important area and layer.The formation was buried deeply, and its diagenesis is strongly..The reservoir is usually low porosity and permeability tight reservoir.,so it is difficult to exploit,and the study area of Xujiahe formation is less exploration, so it is indispensable to study facies,reservoir characteristics,distribution in Xujiahe formation of study area.With full using of field profile,drilling core data,logging and indoor testing of various types of information,using the study of sign in sedimentary facies on the basis,combining with previous research,the Xujiahe formation of the upper triassic in Guanyinchang~Washi area is divided into delta and lake facies,and characteristics of various types of microfacies studied in detail. In the sedimentary facies based on the types and characteristics,Combining the deposition of single well and the relative ratio of well,Guanyinchang~Washi area Xujiahe the sedimentary facies distribution and vertical evolution were studied in detail. In the end, the delta, lake depositional model are established in Guanyinchang~Washi area. On the basis of the types and Characteristics of the sedimentary facies,Show that: the Xujiahe reservoir sand mainly to II,IV and VI section. Judging from the genetic types include: delta plain distributary channel, delta front of the underwater distributary channel, mouth bar sand body and the channel with the overlay type (distributary channel and distributary channel,underwater underwater distributary channel and distributary channel)the overlay of mouth bar and the mouth bar and the combinations between underwater distributary channel and mouth bar. Refering the sand bodies in the preparation of the isopach map, reservoir sand distribution of the plane has been studied, and the reservoir sand bodies in three-dimensional spatial distribution characteristics has been revealed in the study area.On the basis of the the lots of cores observation, refering ordinary sheet , casting thin sections, SEM and analysis of various test. The sand reservoir rock characteristics, physical properties pore structure have been studied Systematically in study area Xujiahe,and we conclude that the rock types is mainly feldspar and lithic sandstones, lithic sandstone. Xujiahe region are low porosity and low permeability reservoirs,and the original porosity of the reservoir pore is the main,the secondary porosity is supplemented. Dissolution, chlorite rim and siderite cementation metasomatism Contribute to physical properties of the reservoir.The sufficient basis of facies, porosity, permeability, effective thickness, reservoir type and test the oil, gas production results and other factors,the benefit gas area has been integrated forecast in the study area.