Seismic attributes have become successful in illuminating subsurface features and are widely used for identifying hydrocarbon reservoirs. The present work delivers case study carried out in the Mahanadi offshore basin lying in the eastern margin of India to delineate gas hydrates bearing zones using high resolution 2D seismic data. The presence of gas hydrates is identified by a bottom simulating reflector (BSR) on seismic section based on its characteristic features. Seismic attributes are computed to ascertain whether the BSR is related to gas hydrates. The data is conditioned using several post-stack processing steps such as detailed and background steering. The conditioning begins by steering of seismic data, which stores dip and azimuth information at every sample location. The Original seismic data is then filtered using a statistical filter to generate the dip-steered median filter data for extracting the instantaneous amplitude, instantaneous phase, instantaneous frequency, RMS amplitude and sweetness attributes. These are then used in demarcating the zones of gas hydrates or free gas occurrences. The low amplitude, high frequency and low sweetness attributes characterize the presence of gas hydrates. Whereas, free gas zones are characterized by bright amplitudes associated with low frequency and high sweetness below the BSR.

中文翻译：

---

表征天然气水合物的地震属性：印度Mahanadi近海的一项研究

地震属性已成功地阐明了地下特征，并被广泛用于识别油气藏。本工作提供了在印度东部边缘的Mahanadi近海盆地进行的案例研究，目的是使用高分辨率2D地震数据来描绘含天然气水合物的区域。天然气水合物的存在通过地震剖面上的底部模拟反射器（BSR）的特征来识别。计算地震属性以确定BSR是否与天然气水合物有关。数据使用多个堆栈后处理步骤进行处理，例如详细和背景控制。调节从地震数据的导向开始，该地震数据在每个样本位置存储倾角和方位角信息。然后，使用统计滤波器对原始地震数据进行滤波，以生成浸入转向中值滤波器数据，以提取瞬时振幅，瞬时相位，瞬时频率，RMS振幅和甜度属性。然后将它们用于划分天然气水合物或游离气发生区域。低振幅，高频率和低甜度属性表征了天然气水合物的存在。而自由气体区域的特征是明亮的振幅，与低于BSR的低频和高甜度相关。高频率和低甜度属性表征了天然气水合物的存在。而自由气体区域的特征是明亮的振幅，与低于BSR的低频和高甜度相关。高频率和低甜度属性表征了天然气水合物的存在。而自由气体区域的特征是明亮的振幅，与低于BSR的低频和高甜度相关。