The Study Of Seismic Reservoir Prediction For The 1st And 2nd Members Of Xujiahe Formation In Baimamiao Region In The West Of Sichuan

This paper based theoretical study of seismic reservoirs prediction, and analysised reservoir of the 1st and 2nd members in Xujiahe formation in Baimamiao area in the west of Sichuan, and had achieved satisfactory results.Region of Baimamiao, located in Qionglai, Pujiang, Dayi, Xinjing county of Chengdu city. The region was relatively flat terrain, the surface seismic geological conditions was complexity. Waterway transport is developed. The constructure of the Baimamiao is located in western Sichuan depression, south to the potential for a wide broken nose uplift, sandwiched between the Bear slope construction and Daxing West constructure, One Northeast Daxing 5 reverse faults throughout the whole area.Based on the Previous study of geological, seismic and log data characteristics in Xujiahe formation, after testing and optimization of seismic inversion methods, the use of stack-based model of wave impedance inversion technique, combined with the GR inversion technique the reservoir sandstone distribution forecast; the use of stacked reservoir sandstones predicted on the basis of seismic attributes detection by optimizing sensitive property, the instantaneous frequency attribute to the 2nd member reservoir sandstones in the oil and gas detection; In addition, due to the 2nd member is sand and shale reservoirs, the physical features of the low porosity and permeability, cracks and dissolution porosity is the main controlling factors of the reservoir, so used the orientation of the pre-stack seismic prediction of fracture density and orientation for fracture detection. For the 1st member, because no actual drilling drilled to the 1st member, had no drilling and logging information and had reservoir seismic prediction difficult. On the basis of understanding the feature information of the adjacent areas shall be a period of strata, of the Builded curves of virtual wells after learned to the 2nd member reservoir seismic prediction technology for the 1st member exploratory research. Based on the model wave impedance inversion method using virtual well predicted reservoir sandstone distribution characteristics, and compared with post-stack recursive inversion technique; Used poststack seismic attributes detection techniques predicted oil and gas distribution characteristics; also used the pre-stack seismic azimuthal anisotropy fracture detection techniques predicted distribution characteristics. Achieve the purpose of exploratory research for the 1st member.Finally, used integrated information technology in the study area, After comprehensive analysis and evaluation structural characteristics, characteristics of reservoir development, oil and gas concentration, the crack development characteristics; preferred favorable construct, reservoir development, fracture development, oil and gas anomalies common favorable exploration zones. In addition, through the analysis of the common favorable exploration area, designed three proposed well location, Provided well placement basis for follow-up exploration and development.