SEDIMENTARY CHARACTERISTICS AND TECTONIC ENVIRONMENT OF CRETACEOUS RESERVOIRS IN THE QIAOGU AREA OF THE KUQA STRUCTURAL BELT.

The Kuqa Depression is an important oil-gasbearing area in the Tarim Basin. The gas-producing layers are mainly the Cretaceous and Lower Tertiary of the Mesozoic and Cenozoic. It is a typical highquality sandstone reservoir with the characteristics of excellent reservoir and large resource. This paper takes the newly explored Qiaogu area in the Kuqa structural belt as the research object. Using experimental methods such as core analysis, scanning electron microscopy, casting thin sections, and mercury intrusion testing, combined with the relevant theories of sedimentology and petrology, the sandstone reservoirs of the Cretaceous Bashkirqike Formation are analyzed and studied. The research shows that the porosity of sandstone reservoir cores in the Bashkirqike Formation is distributed between 18 and 24%, with an average value of 20.29%. The permeability distribution is between 100 and 1000%0-3pm2. with an average value of 273.05%0-3pm2. The core pore type is simple, and the pore connectivity is good. The Cretaceous Bashkirqike Formation is a braided river delta facies sedimentary system. The Cretaceous sediments are mainly transported by the gradient suspension of the traction current. The sedimentary microfacies can be divided into underwater distributary channel, mouth bar and underwater distributary bay, and front edge sheet sand. The main diagenesis of the Cretaceous includes compaction, cementation, and dissolution. The differences in reservoir properties are jointly controlled by sedimentary microfacies and lithology, tectonic compression, dissolution, and burial, and are mainly controlled by dissolution and burial vertically. [ABSTRACT FROM AUTHOR]