海底地震仪双检合并技术与应用

海底地震仪(OBS)技术是近年来新引入我国南海水合物地震勘探中的调查方式，其“密点放炮、稀疏点接收”的观测方式，导致一次反射波浅层照明范围窄；基于下行波与上行波具有相同的震源，且下行波的传播路径更长的特征，利用下行波成像可有效地解决照明范围窄的问题，提升成像精度。针对OBS水检分量气泡严重的特点，设计合理的气泡压制算子，对水检数据进行气泡压制；在此基础上基于双检合并技术进行上行波、下行波波场分离；对下行波数据进行成像处理，获得了很好的成像效果；且最终的成像数据具有丰富的低频信息，能有效地弥补常规拖缆缺失的低频信息，利于后续进行储层反演研究

STUDY ON DUAL-SENSOR SUMMATION TECHNOLOGY AND ITS APPLICATION TO OBS

The ocean bottom seismograph (OBS) is a new equipment currently used for hydrate seismic exploration in the South China Sea. It is characterized by dense shooting and sparse receivers, which leads to narrow illumination of reflection wave in the shallow area. In the performance, the down-going and up-going waves share same wave source, and the down-going wave passes a longer distance, therefore, it may effectively solve the problem of narrow illumination and improve imaging accuracy. In this article, a reasonable de-bubble operator is designed for suppress of serious bubble of the P component; then the wave fields are separated by the dual-sensor summation; and finally the down-going wave data are processed and good imaging results gained. Moreover, the final imaging data is rich in low-frequency information, which can effectively make up for the low-frequency information missing in conventional towing cables and facilitate subsequent reservoir inversion studies.