P14: Geophysical modeling helps interpret subsurface data: example from North Oman

Abstract

Geophysicists use numerous assumptions and simplifications to help them interpret geophysical data collected from subsurface and relate them to geology. However, due to geological complications and geophysical over simplification, the data interpretation faces many challenges such as non-uniqueness, uncertainty, etc., Geophysical modeling plays a key role in reducing challenges associated with interpretation. In this study, resistivity data is collected from two sites in North Oman. The first site is characterized by tilted thin layers that differ in lithology from sandstone, to dolomitic conglomerate, to claystone. Resistivity method is conducted to delineate groundwater in the area. The second site is near a cavity that is exposed on surface. The layers in that site vary from limestone to conglomerate and Marl. Resistivity is conducted in this site to detect the cavity and predict its extension. We conduct geophysical modeling to help us interpret the resistivity data collected from the two sites. The modeling results from the first site showed that the resistivity is highly influenced by the dip of the formations as well as their petrophysical properties (porosity, permeability, saturation etc.) that vary laterally and vertically. As for the second site, the modeling helped us gain a good understating of the cavity response and its lateral and vertical extension.