南黄海中、古生界地震反射特征模拟分析与勘探对策

Analog Analysis and Exploration Solution of Seismic Reflection Characteristics of Mesozoic-Paleozoic in South Yellow Sea

南黄海中部隆起地区新生界陆相沉积地层直接覆盖在中生界三叠系海相石灰岩地层之上,而新生界地层与中、古生界海相地层速度差异很大,特殊的地质特点使得由海面、海底以及新生界底界组成3个强烈波阻抗差异界面,形成了最为强烈的多次反射,并对能量的下传造成屏蔽。本文根据该区地质情况并结合以往采集实践,分析了南黄海中、古生界地震反射特征并进行了波动方程正演,在分析成像原因差的基础上进行了地震采集设计,利用双检拖缆采集技术进行本次地震资料的采集,最后对本次采集的成果与2002年采集的成果进行了对比分析,提出了进一步努力的方向。

Cenozoic terrestrial sediment directly overlies on Mesozoic marine limestone of Triassic System in the central uplift region of South Yellow Sea. The difference in velocity is quite big between Cenozoic formations and Mesozoic-Paleozoic marine formations. The special geological characteristics enable sea surface, sea bottom and Cenozoic bottom sediment to form three strong wave impedance differential interfaces, leading to the strongest multi-reflection and screening energy propagation downward. Based on the geological conditions in this region and seismic acquisition experience in the past, this article analyzes the seismic reflection characteristics of Mesozoic-Paleozoic in South Yellow Sea and makes wave equation forward modeling. The design for seismic acquisition is made on the basis of the efforts to analyze the reasons why the imaging quality is poor. The double geophone tow-cable acquisition technique is used for seismic data acquisition at this time. Finally, comparison is made between the results of acquisition at this time and the results achieved in 2002, coming up with the orientation for further efforts.