The
Rest of Geophysics
There are many contexts where
seismic technology, despite its many capabilities, falls short of full
description of the subsurface. For example, the seismic data may be of
sufficient quality to provide an acceptable seismic image, but not
of enough quality to enable physical
characterization of the subsurface, in terms of fluids, pressures, etc. In
many such cases, one or another non-seismic technique may be useful. Of
course, each subsurface problem lends itself to a particular technology, or
not, depending on the problem to be solved.
The classic non-seismic methods are
gravity, magnetics, and resistivity methods; of these, gravity shows
the most progress these days, for hydrocarbon exploration and exploitation,
because of the development of new instrumentation, the new access to
instrumentation developed by the military during the Cold War, and the possibility
to conduct time-lapse surveys ("4D gravity"). If you are interested
to learn more about the application of these techniques to your problem,
perhaps you should consult with Delta
Geophysics
However, the most exciting new non-seismic
technology is Continuous-Source Electromagnetics ("CSEM"). New
developments have recently allowed the extension of classic borehole-based
methods for Direct Hydrocarbon Detection (the original basis for the entire
logging industry!) to application from the surface, to identify hydrocarbon
reservoirs at depth. Of course, these methods lack the spatial resolution of seismic
images, but they show the electrical resistivity (rather than the elastic
impedance) at depth, which translates, in many geologic contexts, to
hydrocarbon fluids at depth. Coupled with seismic imaging, these methods, now well-established after some early stumbles,
constitute a powerful new tool for reducing risk in drilling decisions.
We have been leaders in establishing the second
generation of CSEM technology. Just as refraction seismics was replaced by
reflection seismics, we think that these new methods will become the
tool-of-choice in many contexts. The essence of the new thinking is the realization that, as in seismics,
the subsurface signal is very weak, so that it is best detected if the source is off when it arrives.
This leads to a recommendation for Impulsive Sources ("ISEM") (rather than Continuous Sources), and to seismic-style imaging and
processing for subsurface characterization (as opposed to formal mathematical inversion of the data).
This technology is in its infancy, so there are many current opportunities for First-Mover advantage to be seized.
See Thomsen (2014) and
Neese and Thomsen (2014) for further discussion.
We are now free of previous proprietary and
non-compete restrictions on our use of these ideas, and would be pleased to
help
you use them to solve your exploration and production problems.