oa Improving understanding of 3-D distribution of diagenetic processes with digital outcrop modeling: Example from the Natih Formation, Jabal Madmar, Oman

One of the challenges in carbonate reservoir characterization is to quantify the 3-D distribution of diagenetic processes responsible for determining poroperm distributions. Digital outcrop modeling techniques (GPS, Lidar) are normally used to map the 3-D distribution of depositional facies, but can be also used to quantify the extent of diagenesis, associated diagenetic products and processes. Commonly, the interiors of Middle East carbonate platforms are modeled in a homogeneous layer-cake fashion. Nevertheless, several km-scale (i.e. inter-well-scale) outcrops of epeiric platform carbonates revealed a complicated internal stratigraphic architecture, comprising depositional geometries such as platform-top incisions and clinoforms. These clinoforms<br>and incisions have a wide range of heterogeneities due to the diagenetic overprint, such as dolomitization, early meteoric cementation, silicification and late leaching. One of the objectives of this study was to quantify the diagenetic processes observed in the field and determine their origin in the context of structural and basin evolution. These data then can be used to improve subsurface reservoir models in inter-well correlations, and can provide analogue data for exploration and appraisal. Digital outcrop modeling combined with detailed sampling, petrography (transmitted-light, ultravioletfluorescence, and cathodoluminesce microscopy), and geochemistry (stable carbon and oxygen isotopes, fluid inclusions, X-ray, and BSEM) was used to determine the 3-D distribution and origin of dolomitized incisions and silicified clinoforms of the outcrops of Jabal Madmar, Oman. These data have been linked with the structural evolution and basin evolution of the field area, in order to provide predictive rules for the subsurface.