Frontier Exploration In Oman Mountains With Innovative Field And Geophysical Techniques

Oman Mountains form a classical example of ophiolite nappes obducted upon the Arabian continental margin. Earlier exploration discovered some gas pools beneath nappes in the frontal zone of the Mountain area. Richer oil and gas fields are found in the SW foreland of the Mountains. Inner Mountain areas were not tested for this play. Because of great tectonic complexity, the area has high risk and was under-explored. Our exploration area contains the central ridge and northeast slope of the Mountains. This area also comprises two major antiformal tectonic windows and the post-obduction sediments on the Batinah Plain. Innovative geologic mapping and geochemical work helped to shape new play concepts in the Mesozoic subthrust section and in the Tertiary post-obduction section as follows. Tertiary play was upgraded due to good gas-prone source rock, fractured carbonates complex tectonics with strike slip, normal slip faults and tilting. Sampled gas seep proves a working hydrocarbon system. Original Mesozoic subthrust play was upgraded due to extensive geological mapping in the tectonic windows. Structural evolution indicates a Late Cretaceous tectonic burial for no more than 10 Ma, followed by tectonic unroofing and domal uplift. Maturity studies indicate dry gas maturity stage for potential source rocks. Source rock fragments and dry oil seeps from an evaporitic detachment, and gas seeps from hot salty water indicate a working hydrocarbon system. Fractured reservoirs are the primary deep objectives beneath the exposed nappes. Cutting-edge geophysical techniques such/as magnetotelluric sounding help to delineate the traps at depth in a rugged mountain area not easily imaged by seismic. High quality seismic is shot in more accessible areas. MOG of Oman is thanked for support and permission for publication.