Developing Earth models with full waveform inversion

Exploration in more geologically complex areas requires new methodologies. In its quest to answer these new challenges, the oil and gas industry has moved from raybased imaging to finite-difference, wave-equation migration to achieve better subsurface descriptions of target zone and reservoirs. Notable in this progression is the movement from ray-traced Kirchhoff algorithms through one-way wave-equation methods to use the acoustic two-way wave equation.

Although migration has advanced quickly with increased computer power, constructing the Earth model is still largely ray-based, using gathers from advanced migration algorithms. Recently, there has been more emphasis on using the two-way wave equation for migration and for velocity model building. One advanced tool for velocity determination is full waveform inversion.