Rock Composition Differences and Diagenesis in Different Lithofacies Reservoir of Glutenite Body-An Example of Urho Formation of Mahu Depression in Junggar Basin

Abstract

Urho formation of the Mabei slope zone in Junggar basin had a stable structure and developed fan delta sedimentary system during the deposition process. Distributary channel and fan River constitute the sedimentary framework Urho formation. The research on diagenesis of Urho reservoir based on a large number of thin section and core analysis is conducted by different means of experiments such as scanning electron microscopy, X-ray diffractions and cathode luminescence, etc. The results show that the influence of diagenesis on the reservoir is duality. The effect of compaction (pressure solution) in the study layer is mainly controlled by the difference of vertical burial. The calcite cementation is mainly formed at the early stage of burial. Since the late-early diagenetic stage to the intermediate diagenetic stage, large scale of acidic dissolution and alteration occurred in Urho formation. Acid dissolution mainly exists in widely developed volcanic rocks and zeolite cements, which greatly reforms the physical properties of the reservoir. Sedimentary diagenesis plays a decisive role in the distribution of oil and gas.