The Research On 3D Seismic Data Acquisition Method In South-East Area Of Biyang Depression

This dissertation is a study on 3D seismic acquisition method in south-east area of Biyang depression. The research objective is that by choosing and reasoning the field acquisition geometry, LVL investigation and shooting parameters, designing a set of 3D seismic acquisition method suited for the area, meeting the need of the new geological task for high resolution and high S/N ratio seismic data.Biyang depression, a part of the small Neozoic fault depression, is a secondary structural unit of Nangxiang basin. From the north to the south, it is divided into three secondary structural units that are south steep slope region, central deep-seated region, and north ramp region. The south steep slope region is a long and narrow area which parallels the southern faults belt of basin.South-Eest Area of Biyang Depression is the part of the south steep slope region in south-east area, located in the faults turning point with the complex geophysical condition. The faults have a large scale, steep slop (30°-60°) and a big incline angle (nearly 90°.the deep geophysical structure of area includes faults, up-layers and down-layers. The south-eastern area is border upon the mountain; the down-layers is made of rock; the up-layers is aggraded layers. The shooting and receiving condition is bad as the near surface is mainly covered with mountain.The former seismic sections shows blunt in refraction and low resolution, can not meet the need foe new geological researching. The exploration for oil and gas in area is not successful.The research studied the problem of former data, adopted the former successful ideas and method in seismic exploration, and designed a set of 3D seismic acquisition method suited for the area, meeting the need of the new geological task.the contents of result include:(1)the research on acquisition parameter involved in geological task, geophysical condition and data processing & interruption(2)the research on dividing the block(3) the research on boundary of acquisition and perfecting on 3D geometry in south steep slop area(4) the research on the acquisition parameter demonstrate and forward modeling in east faults belt(5) the research on dispersion modeling in east faults belt(6) the research on optimizing primary geometries in east faults belt (7) the research on LVL investigation and shooting hole depth design.Synthetically, the conclusions and recognitions are given as follows:( 1) analyzing and studying on former data and new geological task thoroughly is a necessary preparation for new design idea (2) the target parameter designing which based on the request of task and data processing & interpretation for new acquisition parameters is a key factor in improving data quality(3) the designing idea which applying the acquisition parameter demonstrate and forward modeling software combined the field condition is a efficiency way(4)accurate LVL investigation and per shooting hole depth design are special methods for static correction and improving the quality of shooting in complex near surface area .