Hyperspectral Remote Sensing for the Characterization of Dolomite Bodies: A Case Study in the Central Oman Mountains - Lower Khuff Analogue

Abstract

AbstractRecent ground-based studies of quarry cliff faces suggest hyperspectral imaging to be a convenient tool to distinguish highly similar carbonate phases in vertical cliff faces within short distances (Kurz et al., 2012). We take the technique further and use ground-based hyperspectral imaging to identify the presence of dolomite bodies along weathered and irregular shaped cliff faces. Dolomite bodies hosted in limestone successions, common in for example Khuff and Arab Formations in the Middle East, represent a challenging feature with respect to the characterisation and exploration of hydrocarbon reservoirs. For example, dolostones interfingered with limestones are present in the Ghawar and South Pars fields (Dasgupta et al., 2002; Ehrenberg, 2006; Ehrenberg et al., 2007). Detailed descriptions of fracture related dolomite bodies in the Ghawar field have been published by Cantrell et al. (2001), whereas Jones et al. (2011) recognized dolomite bodies in the North Field in Qatar. Other studies showed lithofacies controlled dolomitization in the Arab Formation (Clark et al., 2004; Honda et al., 1989). The exceptional importance of dolomite bodies is based on a potential increase of porosity of 13% or more (Weyl, 1960) compared to the non-dolomitized host rock. However, due to their commonly sub-seismic size these potentially highly porous zones often stay undetected on seismic profiles and thus require careful investigation. In this study, the distribution and shape problem has been approached by delineating dolomite bodies hosted in Lower Khuff outcrop analogues in the Central Oman Mountains by applying hyperspectral remote sensing. We examine the degree of precision of the remote sensing detection and characterisation of dolomite bodies at varying distances to the cliff face and assess its impact on a 3D geocellular model.