This fly-through covering 500 square kilometres of west central Algeria illustrates the massive amount of varied topographic and geological information that satellites can provide in order to more effectively pre-plan a seismic survey campaign for oil and gas exploration.
It begins with a space-derived Digital Elevation Model (DEM), used for assessing gradient and hence accessibility and safety – note the high limestone outcrop on the east side of the image.
Next comes an enhanced visible image from Landsat data showing ground cover, useful for overall planning. After that appears an ERS-based guide to ground roughness, crucial for good seismic coupling. The roughness shown here corresponds to the weathered limestone outcrop.
Then comes a combination of bands highlighting vegetation, which can be linked to buried water channels that can degrade seismic signals. Next comes a chart of short-wave infrared (SWIR) lithology, highlighting the limestone outcrop in red. Thermal infrared (TIR) can also be utilised to study buried mineral deposits.
Out of these and other potential satellite inputs can come relevant outputs such as this image showing hard rock data quality based on dip, roughness and the presence of limestone. The final image predicts soft rock potential problems – soft rock can cause vibration trucks base plates to sink into it, or absorb part of the seismic signal.