Satellite Sensing: Risk Mapping for Seismic Surveys
Stephen Coulson Ola Gråbak
European Space Agency Frascati, Italy
Andrew Cutts Denis Sweeney Gatwick, England
Ralph Hinsch
Martin Schachinger Rohöl-Aufsuchungs AG Vienna, Austria
Andreas Laake Cairo, Egypt
David J. Monk Apache Corporation Houston, Texas, USA
Jeff Towart Apache Egypt Cairo, Egypt
Oilfield ReviewWinter 2008/2009: 20, no. 4. Copyright © 2009 Schlumberger.
For help in preparation of this article, thanks to Steven Covington, US Geological Survey (USGS) and Darrel Williams, National Aeronautics and Space Administration (NASA), Greenbelt, Maryland, USA; and David Morrison, Abu Dhabi, UAE.
Petrel is a mark of Schlumberger. Google is a mark of Google Inc.
Satellite imaging of the Earth’s surface provides an invaluable view from on high. The colorful and sometimes artistic images result from combinations of data from different portions of the electromagnetic spectrum. Geoscientists use these to discriminate land use, type of vegetation, lithology, elevation and surface roughness. By evaluating these remotely sensed attributes, they establish risk factors for seismic source and receiver signal quality, for vehicular and personnel access and for potential survey damage to the environment.
Remote sensing by orbiting satellites provides input to seismic survey planning for all four components of QHSE: quality, health, safety and environment. Data from satellite surveys give map and elevation views of features on and just below the surface, as well as an indication of rock type. These images from above replace detailed ground evaluations, a key benefit in remote or hazardous locations.
The risk of low-quality seismic data because of poor coupling between the ground and a seismic source or receiver is inferred from satellite imagery using a rock physics model of the inter - preted lithology. The ability to locate dangerous terrain is essential for protection of the health and safety of survey personnel. That information,
along with interpretations of terrain stability, determines safe deployment of seismic acquisi - tion vehicles and associated equipment. Finally, remote-sensing data can identify environ mentally sensitive areas and, through their use in survey planning, minimize the negative impact of seismic acquisition on these areas. Satellite images of the Earth’s surface have become familiar to many people through Web services such as Google Earth. However, remote sensing is more than just a map image: Satellite images present a continuous view across an area in multiple spectral bands. Typically, these include reflected radiation in the visible, infra - red and microwave bands. Some satellites also obtain radar images to map tectonic elements or
> Lithology map overlain on a digital elevation map obtained by remote sensing. The arid region of Ghazalat in the Egyptian Western Desert has limestone heights over a sandstone plateau. A steep escarpment separates a depression with a sabkha base (bottom right) from the plateau.
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