Favorable Reservoir Prediction For The Lower Urho Formation Of Permian In Eastern Slope Of The Mahu Sag,Junggar Basin

Sedimentary facies characteristics,petrological characteristics,physical properties,diagenesis analysis and diagenetic facies distribution are studied in the Lower Urho Formation of the Permian in the Jungger Basin by using cores,logging,scanning electron microscope and analytical test data in this paper.The results show that the study area mainly developed fan delta,and reservior of target layer is mainly composed of typical sandy conglomerate with argillaceous,sandy and gravel mixed which has a high content of volcanic plastic debris.The reservoir physical properties are quite different,and the overall physical property is low,which reservoir has strong heterogeneity and is greatly affected by diagenesis.Compaction is the main reason of loss of physical property,while dissolution is the key factor of improvement of physical property.The secondary pores are relatively developed,including laumonite and calcite dissolved pores,intergranular pores,feldspar or other unstable minerals dissolved pores and a small amount of microfractures.The pore and throat have well connected condition.On the macro,the formation and distribution of several diagenetic facies are influenced by sedimentary microfacies and reservoir structural characteristics,while in the microcosmic aspect,they are mainly controlled by the composition of fragments particle,mineral composition and size and distribution of pore throat.Based on those,the diagenetic facies types of the Lower Urho Formation are classified,and the main controlling factors of the dominant reservoirs are analyzed,furthermore,the reservoirs are classified and the reservoirs are predicted.Finally,the study provides theoretical basis for favorable zone optimization and increasing potential production.