We have recovered legacy 2D seismic data from the Kalahari Karoo Basin, Botswana, which show signatures associated with the coalbed-methane-bearing seams of the Mmamabula and Morupule formations. These deeply buried coal seams (∼ 500 m below surface) may represent a new alternative source of energy for the region. Prior to interpreting the seismic data, we improved imaging of the coal seams by attenuating noise with the curvelet transform. The data were transformed to the curvelet domain, and scale and angular direction thresholds were selected and applied, thereby removing previous processing artefacts and noise. The resulting denoised seismic data are characterised by a high signal-to-noise ratio, showing a clear continuity of the seismic reflections associated with the coal seams. We constrained the seismic interpretation with borehole logs, which confirmed the locations of the coal sequence at the top of the Mmamabula and Morupule formations. The curvelet-denoised seismic sections enable a more reliable mapping of the coal zone, which is displaced by major faults with throws of up to ∼ 500 m. Following these encouraging results, we emphasised the value of enhancing and reinterpreting legacy data, as it is a cost-effective and environmentally-friendly method for deep coal seam and mineral exploration.

中文翻译：

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遗留反射地震数据的叠后去噪：对煤层气勘探的影响，Kalahari Karoo 盆地，博茨瓦纳

我们已经从博茨瓦纳的 Kalahari Karoo 盆地恢复了遗留的 2D 地震数据，这些数据显示了与 Mmamabula 和 Morupule 地层的含煤层气的煤层相关的特征。这些深埋煤层（地表以下约 500 m）可能代表该地区新的替代能源。在解释地震数据之前，我们通过使用曲波变换衰减噪声来改进煤层的成像。将数据转换到曲波域，并选择并应用尺度和角度方向阈值，从而消除先前的处理伪影和噪声。所得去噪地震数据的特点是信噪比高，显示出与煤层相关的地震反射的清晰连续性。我们用钻孔测井来约束地震解释，这证实了 Mmamabula 和 Morupule 地层顶部煤层序的位置。曲线波去噪地震剖面能够更可靠地绘制煤层，煤层被主要断层取代，距高达约 500 m。根据这些令人鼓舞的结果，我们强调了增强和重新解释遗留数据的价值，因为它是一种用于深部煤层和矿产勘探的经济高效且环保的方法。