南海淹没碳酸盐台地地震成像技术分析——以甘泉海台为例

Seismic imaging analysis of submerged carbonate platforms in the South China Sea: a case study of the Ganquan platform

摘要:

淹没碳酸盐台地水深变化大且海底崎岖,地层结构复杂,导致二维反射地震资料发育大量多次波干扰,同时受采集环境影响,反射地震剖面广泛存在噪声干扰和大值干扰,给高分辨率成像带来挑战。甘泉海台作为南海北部典型的淹没碳酸盐台地,对其最新采集资料进行特征分析,采用低截滤波压制强涌浪噪声和异常振幅噪声衰减组合技术以及多步串联多次波压制技术,有效去除噪声干扰、大值干扰和复杂多次波,试验叠前时间偏移各项参数,最终大幅度提高甘泉海台地震剖面分辨率和信噪比,可为后续南海淹没碳酸盐台地二维地震资料处理提供借鉴。

Abstract:

The submerged carbonate platforms in the South China Sea are characterized by significant variations in water depth and a rugged seafloor. These factors create a complex subsurface structure and result in multiple wave interferences in two-dimensional (2D) seismic reflection data. Additionally, the data are often affected by environmental conditions, leading to noise interference and large amplitude interference. These challenges pose difficulties for accurate high-resolution imaging. The Ganquan platform was taken as an example of a typical submerged carbonate platform in the northern South China Sea. The characteristics of the latest collected data for the Ganquan platform were analyzed in this work. The noise, large-amplitude, and multiple wave interferences were removed using low-cut filtering to suppress strong swell noise, anomalous amplitude attenuation, and multistep serial multiple wave suppression technique. The resolution and signal-to-noise ratio of the Ganquan platform seismic profile were greatly improved in this work. These advancements can serve as a valuable reference for the subsequent processing of 2D seismic data from submerged carbonate platforms in the South China Sea.