Hydrocarbon exploration using controlled-source electromagnetic method:
From introduction to advances in modeling/inversion
Piyoosh Jaysaval (UTIG)
Fri, March 2, 2018, 10:30am - 11:30am
Host: Adrien Arnulf
Abstract:
Marine controlled-source electromagnetic (CSEM) surveying is now an important technique for petroleum exploration. The technique uses a strong electric current source to probe subsurface resistivity and has proven to be very useful for detecting resistive petroleum reservoirs. In this technique, the data are recorded in the form of electric and magnetic fields, which must be inverted to obtain an image of the subsurface resistivity distribution.
To recover a geologically consistent resistivity image of subsurface, CSEM inversion algorithms usually require a significantly large number of forward simulation of CSEM responses over different resistivity models. Therefore, having a fast and accurate forward modeling scheme is a key ingredient for a reliable inversion and interpretation of the recorded CSEM data.
In this talk, I will present an introduction of CSEM method and its application for petroleum exploration. Thereafter, I will present two novel forward modeling approaches: (1) a Schur complement based fast multi-model finite-difference (FD) modeling scheme developed to reduce total modeling time in a constrained inversion (the method can be applied to any multi-model forward modeling problems), and (2) an exponential FD modeling scheme developed based on the oscillatory and exponentially decaying behaviors of the EM fields to get more accurate results or to reduce modeling time. I will then conclude the talk by presenting an application of CSEM method for subduction zone imaging.
