Reservoir Characteristics And Control Effects Of Sinian—Lower Palaeozoic Erathem In The Central Of Sichuan Basin

The Anyue Sinian-Cambrian super-giant gas field was discovered in Sichuan basin,and the natural gas exploration potential is tremendous.But since the formation of sinian system-lower palaeozoic deposit,it has experienced many times of tectonic movement,leading to the strong heterogeneity of the reservoir.Therefore the study of the complex geological characteristics of reservoir in the studied area and the main factors controlling the reservoir development system is in urgent need.The paper analysis the Characteristics of the reservoir based on previous studies,illustrates the the geological characteristics and formation conditions of high porosity and high permeability super-giant marine carbonate gas fields in Sichuan basin.The results showed that:(1)The lithology of dengying and longwangmiao group is mainly dolomite,the reservoir has low porosity and low permeability,local develop solution pores which is formed by the dissolution.(2)Different lithology of reservoir have different physical properties,the porosity of arene dolomite of dengying and longwangmiao formation are higher in gaoshiti-moxi area.(3)Reservoir development degree and physical properties of dengying and longwangmiao formation are controlled by tectonism,sedimentation and diagenesis,grain beach subface and high beach subfacies is the basis of high quality reservoir development,tectonic uplift makes the reservoir of denger and dengsi section suffered weathering denudation and atmospheric fresh water leaching.(4)The distribution of gas reservoir is controlled by reservoir lithology,physical property and karst,the gas reservoir are often distributed in the granular beach subfacies?high beach subfacies,arene dolomite and high hole high permeability.