海岸与内陆萨布哈的地震特性：对静校正的启示
Seismic Properties of Coastal and Inland Sabkhas: Implications for Static Corrections
AI总结：
本研究调查成熟与发育中萨布哈的地震特性，采用高分辨率与常规地震实验，发现部分饱和带影响静校正精度，高分辨率调查可更可靠描绘速度，是萨布哈环境静校正的必要手段。
AI中文摘要：
萨布哈环境是干旱沿海地区普遍存在的地形特征。沿阿拉伯湾分布的萨布哈覆盖着大量油气藏，具有复杂的岩性特征和极浅的地下水位，这些因素会导致地震速度升高和信号失真。静校正是地震反射处理中至关重要的初始步骤，用于减轻近地表层的影响。本研究调查了成熟和发育中萨布哈最上部的地震特性变化，采用检波点间距为10cm的高分辨率地震实验探测上部数十厘米的范围，同时辅以检波点间距为2m的常规调查以研究更深层。两种萨布哈均存在一个独特特征——部分饱和带，该带会影响地震速度，导致速度降低，进而影响静校正的准确性。高分辨率调查在确定部分饱和带顶部和硬地层方面比常规方法精度更高，因此能更可靠地描绘速度分布。此外，与发育中的内陆萨布哈相比，常规法、替换法和层析成像法得到的速度在成熟海岸萨布哈中会导致不可靠的静校正，这归因于成熟海岸萨布哈环境特有的显著地质复杂性。因此，在萨布哈环境中开展高分辨率地震调查对于减轻近地表速度影响是必要的。
英文摘要：
Sabkha environments are a prevalent topographic feature in arid coastal areas. Along the Arabian Gulf, sabkhas overlie substantial hydrocarbon reservoirs and exhibit intricate lithological characteristics and an extremely shallow water table. These factors contribute to elevated seismic velocities and signal distortion. Static correction, a crucial initial step in seismic reflection processing, is employed to mitigate the impact of shallow surface layers. In this study, we investigate the variations in seismic properties along the uppermost part of mature and developing sabkhas. We employed high resolution seismic experiments with geophone spacing of 10 cm to explore the upper tens of centimeters. Conventional surveys with a 2m spacing complement this approach to investigate deeper layers. Both sabkhas exhibit a unique characteristic of a partially saturated zone, which affects the seismic velocity, leading to lower velocities and consequently influencing the accuracy of the static correction. The high resolution surveys demonstrated superior accuracy to conventional approaches in determining the top of the partial saturation zone and hardground layer, hence resulting in a more reliable velocity delineation. Moreover, velocities derived from conventional, replacement, and tomogram approaches resulted in unreliable static corrections in mature coastal sabkha compared with developing inland sabkha, attributed to the considerable geological complexity that is characteristic of mature coastal sabkha environments. Carrying out a high resolution seismic survey in sabkha environments is therefore necessary to mitigate near surface velocity effects.
