The Study Of Sequence Stratigraphy, Lithologic Hydrocarbon Reservoir Discrimination And Evaluation Of Jurassic System In Block Ⅰ In The Backland Of Junggar Basin

The Jurassic System in backland of Junggar basin is abundant in oil and gas resources. The swelling area of basin backland is provided with high degree of exploration, while the slope area conjoint with swelling area and low-lying area between different swelling areas lack in exploration. Lithologic hydrocarbon reservoir or compound structural and lithologic hydrocarbon reservoir originated from various kinds of non structural traps are the main targets for oil and gas exploration. In order to offer strategic formations and zones for regional exploration, a hard nut to crack is to clarify the classification and distribution of Jurassic sedimentary facies and sedimentary microfacies and to improve the resolution of seismic data to determine the relation between oil and gas distribution, sequence strata, sedimentary system, second-order structure zone and reservoir-seal assemblage. The paper takes block I in the backland of Junggar basin as the subject investigated. The investigation begins with the establishment of high-resolution sequence strata framework, followed by analysis on the classification and distribution of sedimentary microfacies of sand body in different high frequency sequence units. Based on the above work the seismic and geologic interpretation model is built up for skeleton profiles. The integrated research of 3D seismic data processing and interpretation is carried out to accomplish refined description of traps in favorable reservoir development area. Combination with analysis on reservoir generation conditions results in specific exploration target. Based on conventional geologic research, the following techniques and approaches have been employed: 1) high-resolution sequence stratigraphic correlation and classification; 2) analysis on sedimentary microfacies distribution and sand superposition pattern based on base level cycle movement; 3) establishment of seismic and geologic model based on 3D profiles; 4) integrated research of 3D seismic data processing and interpretation; 5) prediction and evaluation of oil and gas in traps with multi sciences and multi parameters. During the application of techniques mentioned above, the emphasis has been put on the integration of geologic data and seismic data as well as integration and mutual verification of research findings and exploration practices. Some conclusions are reached: 1) the Jurassic System in backland of Junggar Basin could...