1. Seismic Geophysics

Geophysics plays a central role in the modern hydrocarbon exploration and production industry. A brief overview of gravity and electromagnetic geophysical methods is followed by in-depth discussion of seismic geophysics. The elastic seismic wavefield is generated and measured so as to isolate and enhance P-wave energy. The acquisition of land or marine 3D seismic data is a large-scale experiment involving source activation and simultaneous recording of many thousands of sensors. Each sensor (or array) generates a seismic trace whose geometry is defined by the source and sensor coordinates. The complete survey can consist of several billion individual traces that require significant processing to create a subsurface geological image. The natural domain of seismic data is reflection time that must be tied to geology through a synthetic seismogram. Frequency, resolution and vertical exaggeration of seismic data set limits on interpretation. Rock mineralogy, porosity and pore fluids all influence the seismic response, primarily encoded in seismic amplitude data. Basic interpretation methods involve horizon tracking, fault network mapping, identifying direct hydrocarbon indicators, and geobody extraction. Additional processing of the amplitude data leads to a universe of seismic attributes that aid interpretation.