Cooperative fuzzy-guided focused inversion for unstructured mesh modeling of potential field geophysics, a case study for imaging an oil-trapping structure.

This work illustrates the application of a fuzzy-guided focused technique for cooperative 2D modeling of magnetic and gravity data on common geological sources responsible for anomalous observation, whereby a well-known fuzzy c-means clustering tool is inserted in the center of the inversion mechanism to search different clusters of geophysical properties which are magnetic susceptibility and density contrast within several zones. An unstructured meshing is performed with triangular cells which captures the accurate borders of a rugged topography area and any complex-shaped sought sources. The efficiency of the proposed cooperative inversion algorithm is examined along 2D profiles with simulation of several synthetic sources by which the retrieved geophysical properties indicate sharp edges, correct depth and shape pattern of the sought sources. Imposing a model stabilizer, a depth weighting function and petrophysics constraints of physical models within the clustering inversion, greatly promotes the performance of the constructed models over the outputs of running individually each data set. Of note is that a conjugate gradient solver is utilized here with a preconditioner to estimate approximately sought physical properties from an objective function with two constituents that are a model and a misfit norm. Ground-based gravity and magnetic observations over a plausible oil-trapping structure are investigated at the Kifl region, situated in Iraq. Cooperative inversion output can pave the way for imaging of a fault feature which has been filled by a thick sequence of sediments, presenting a configuration of a graben-horst structure. The main notable output of this work proves the existence of an oil-trapping structure responsible for a distinct potential field geophysics anomaly. [ABSTRACT FROM AUTHOR]