High-resolution seismic surveys were carried out at the Paranaguá Estuarine Complex (Southern Brazil) to map the intrasedimentary shallow gas. The seismic signatures representing gas accumulation were separated according to the upper gas boundary characteristics in acoustic blanking with sharp top, acoustic blanking with diffuse top, turbidity pinnacles, and black shadows (gas accumulation at the water/sediment boundary). The main source of the gas has been recognized here as Pre-Holocene continental deposits. These deposits were capped by a seismic unit interpreted as a regressive mud deposited over the last 5000 years. This seismic unit is quite heterogeneous, the gas being trapped in its different internal layers. Each gas signature represents the efficiency of the sealing layer and has specific locations and burial depths. The results point to different phases of gas migration along with the sedimentary layers. Thus, we proposed a gas migration and accumulation model based on acoustic data and sedimentary inferences within the Paranaguá Estuarine Complex.

在巴拉那瓜河口综合体（巴西南部）进行了高分辨率地震勘测，以绘制沉积内浅层气体图。根据尖顶声消隐、弥散顶声消隐、浊度尖峰和黑影（水/沉积物边界气藏）中的上气界特征分离代表气藏的地震特征。天然气的主要来源在这里被认为是全新世前的大陆沉积物。这些沉积物被一个地震单元覆盖，解释为过去 5000 年沉积的回归泥浆。这个地震单元非常不均匀，气体被困在不同的内部层中。每个气体特征代表密封层的效率，并具有特定的位置和埋藏深度。结果表明，随着沉积层，气体运移的不同阶段。因此，我们提出了一种基于巴拉那瓜河口杂岩内的声学数据和沉积推断的气体运移和聚集模型。