The Study Of Seismic Acquisition Method In Complicated Structural Background

The purpose of this thesis is to discuss the collection ways of seismic acquisition data in areas which have complicated structural background. Based on the demonstration of acquisition parameters on geological models in different structural units, various observation systems can be designed. And they can be gradually corrected during the analyses and comparison.In practice, based on field investigation, data collection and combined cooperation with geological researchers, structural features and deep seismic characteristics are analyzed in four areas which are south abrupt slope in Biyang depression, block 1 of Katake in Tarim basin, Caohu depression in Tarim basin and Nanxiang basin. With consideration of static correction coupling and velocity analyses in the design proposal of observation systems, geological models can be built by using advanced softwares such as GMG-MESA and KLSeis.During the study on various design proposals, structural factors, which are stratigraphic dip, buried depth of target and wave impedance coefficients, are mainly considered to adjust the observation system in different area.To optimize the observation system, linear experiment is operated to demonstrate the justifiability of it. And when seismic data is collected, the quality of it is examined simultaneously in order to adjust and improve the observation system in the place where the quality of seismic acquisition data decreases seriously. This course can make seismic acquisition data with good quality, and it avoid the economic waste generated by seismic data with poor quality.Based on the designation, demonstration and optimization to observation systems in the four areas, problems of seismic imaging can be solved in many complicated structural positions such as weak wave impedance interface, shallow targets, complex fault-block, high angle fault section and buried depth with large difference.In complicated structural areas, the array length and the effective offset space should be considered in the designation of an observation system. And the apply of small bins can solve resolution problems and improve signal/noise performance. When structural types and buried depth vary greatly, the proposal of observation system must be designed in accordance with the geological features in different blocks or sections.The quality of seismic section collected in the four area are improved greatly, and the anticipated geological tasks are accomplished with the usage of the observation system.