Characteristics Of Jurassic Reservoir In Dunhuang Basin

The Dunhuang basin is a Mesozoic and Cenozoic sedimentary basins from the Mesozoic Jurassic.Previous studies on oil and gas resources in the basin started earlier,but the research level is low and has not been really exploited.Judging from the current exploration results of conventional oil and gas reservoirs in the basin,the basin has the basic geological background of oil and gas formation.Based on the previous research results and existing data,the reservoir characteristics and main controlling factors of the main oil and gas reservoirs in the Dunhuang basin were further studied by carrying out the research on the stratum development,sedimentary type and characteristics and reservoir basic parameters of the Dunhuang basin.Reservoir evaluation and prediction of favorable reservoir development and distribution characteristics in the study area,and provide favorable target area for the next oil and gas exploration.Some new understandings have been made on the study of field geological,stratigraphic and sedimentary facies and reservoir physical,pore and diagenetic effects in Dunhuang basin:(1)The reservoirs of the Jurassic reservoir in Dunhuang basin are generally poor,the average porosity of the reservoir is 2.21%,and the average permeability is 0.128 mD,which belongs to the typical special low porosity and low permeability reservoir.(2)The porosity of Jurassic reservoir in Dunhuang basin is mainly secondary pore,intergranular dissolution,intergranular dissolution pore,tectonic fractures,and intergranular pores such as kaolinite intergranular pores.(3)The diagenesis of Jurassic reservoir in Dunhuang basin mainly includes compaction,cementation,dissolution,metasomatism and tectonic stress.(4)Diagenesis is the most important factor affecting the reservoir performance,and the fractures produced by the tectonics have a good effect on the reservoir.(5)the Lower Jurassic favorable facies is mainly distributed in the braided river delta and the shallow lake-the semi-deep lake,and the favorable reservoirs are the Middle Jurassic and the Lower Jurassic black plate,Lu grass ditch section area.