High-resolution Sequence Stratigraphy Urho Formation Reservoir In The Eight Districts

Wuerhe formation in Permian is one of the most important conglomerate reservoir productive series in northwestern margin of Junggar basin, especially in 8th District, it develops typical reservoir in lower Wuerhe formation and has an enormous oil reserve. There display voidage-injection imbalance and water-flooding ineffectiveness in many well when product, because of the thick sedimentation and rough subdivision of strata series. In recent years, high resolution sequence stratigraphy indicates superiority in subdivision of strata, and become the premier way to build strata framework.Based on high resolution sequence stratigraphy theory and comprehensive application of core, logging and 3D seismic data, build fine strata framework in the area, divide three types of microfacies in lower Wuerhe formation, reveal the distribution of microfacies and sandy body inner fine strata framework. It provides a geological foundation for development adjustment scheme in 8th District for lower Wuerhe formation and also obtains effective result in field. Meanwhile, all the achievement of research theory and method have inductive signification for other similar reservoir in fine subdivision and microfacies.There obtain many achievements in the dissertation, such as:(1)According to sequence interface research, it can be divided into one second-order sequence, two third-order sequence, and twenty two subsequences for lower Wuerhe formation. Identify low stand system tract, transgressive system tract, high stand system tract in I # third-order sequence, and transgressive, high system tracts in II # third-order sequence.(2) Based on energy integral logging, combination logging and seismic data, also sedimentation characteristic, lower Wuerhe formation divided into five member, twenty two sublayers, which corresponded to the five tracts and twenty two subsequences. By the research of logging response and comparison marker bed, using seismic data, establish strata comparison framework in the entire district.(3)Establish microfacies type according to core reserve and analysis, and build combination model between microfacies and logging response. Process and interpret all the logging and microfacies data at last. Identified microfacies type inner sublayer, predict and reveal facies distribution in interwell and space.(4)It proved in field implementation that the reservoir description coincide with the real character, and will induct the third infilling adjustment for lower Wuerhe formation in 8th District.