EMinar 1.25: Randy Mackie - Geol.-consistent inversion of geophys. data; a role for joint inversion

The joint interpretation of multiple geophysical data sets, over single domain exercises, offers a path to increased fidelity of the final earth model. There are many integration methodologies from simple sequential cooperative interpretation/inversion through to more complex simultaneous joint inversion schemes. Joint inversion workflows are hampered, though, by the lack of constitutive petrophysical relationships between rock properties, for example seismic velocity and electrical resistivity. In these situations, alternate techniques are used, such as cross-gradients to promote structural similarity of property volumes, independently from petrophysical links. The focus here is on work using cross-gradients, both in a true joint inversion scheme and then also using reference models to guide the inversion to a more geologically reasonable model.