Study On Sedimentary Micro-facies And Reservoir Characteristics Of The1^st Member Of Qingshuihe Formation Of Lower Cretaceous In Hong003Well Block, Hongshanzui Oilfield In Northwest Margin Of Jungar Basin

Based on grasping and collecting regional geological data, along with previousresearch results of the study area, combining with drilling and loggingdata,stratigraphic classification and contrast of Qingshuihe formation have beenfinished in the study area.According to comprehensive studies of well logs, cores and other previous study,this study focuses on characteristics of sedimentary facies and sand body distributionrule. Through the comprehensive analysis,the author concluded that the type ofdepositional system is the middle part of alluvial fan in the1stmember of Qingshuiheformation and it could be further classified into three types of micro facies as thebraided channel, the sand-bars and the overflow deposition.And we regard thesand-bars sandbody reservoirs as the best.The observation of casting thin sections and rock thin section shows that thereservoir of the study area mainly developed seriate lithic sandstone and glutenite,conglomerate. The cements in the sandstone reservoir are dominated by calcite.Composition maturity and structure maturity of rocks are low. For different lithology,physical properties of the reservoir has a lot of differences. The rock particles finer, thethe porosity greater. The rock permeability of grit is higher than glutenite, permeabilityof glutenite is higher than fine sandstone and medium sandstone. The comprehensiveanalysis of reservoir control factors shows that the sedimentation and diagenesis are theimportant factors to control the distribution and development of the reservoir in thestudy area.Based on the comprehensive analysis of the previous reservoirclassification,combining the four-property relationship of reservoir in this area, thereservoir classification standard is determined.The reservoir of Qingshuihe formation is divided into Ⅰ-class reservoir, Ⅱ-class reservoir, Ⅲ-class reservoir and Ⅳ-classreservoir. Reservoir classification results show that K1q11and K1q12almostly have noreservoir. There is Ⅲ-class reservoir locally distributed in K1q12.In the K1q13and K1q14mainly is type Ⅰ-class reservoir and type Ⅱ-class reservoir.The distribution map of thereservoir classification in this aera is established based on the analysis results of thesingle well reservoir classification, combining with the characteristic of porosity andpermeability in every layer. And it could provide a basis for efficient exploration anddevelopment of this aera.