Characteristics and controlling factors of the reservoir rocks from the Jurassic Badaowan Formation in the Shixi region, Junggar Basin, Xinjiang

The characteristics and controlling factors are dealt with for the reservoir rocks from the Jurassic Badaowan Formation in the Shixi region, Junggar Basin in the light of cores, well logs, cast thin sections and SEM techniques. The reservoir rocks in the Formation are primarily made up of feldspathic lithic sandstone and lithic sandstone. The reservoir spaces consist of primary intergranular pores, intergranular solution openings, intragranular solution openings and and microfractures, suggesting medium-to low-porosity and medium-to low-permeability reservoir rocks. The main controlling factors include the lithology, sedimentary facies, diagenesis and early hydrocarbon filling. The favourable reservoir rocks are considered to be developed in the braided delta front subaqueous distributary channel deposits in the first member (J₁b¹)and third member (J₁b³)of the Jurassic Badaowan Formation.