Resolution of a Multi-Set, Strike-Slip Dominated Fault System, Identified from 3D Seismic, in Early Cretaceous Carbonate Reservoir Sequences of a Giant Offshore Field in Abu Dhabi

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractRecent mapping of fault patterns from picked surface attribute analysis ('difference' maps, spectral decomposition, isochron maps) and time slices over a giant offshore field in Abu Dhabi has recognized a complex multi-set pattern of faults at reservoir level. As well as providing additional seismic scale faults, linear features (proposed subseismic faults and fracture systems) have been identified. These patterns are best described in terms of strike-slip geometries; however, many display components of both dip-slip and strike-slip over their movement history. In different parts of the field dominant fault directions displaying dextral transtension, dextral transpression, trapdoor hinge faulting and oblique-slip keystone graben generation are observed. Fault throw statistics and segment growth history in the most important mapped zones typify components of strike-slip along with local shear and segment termination at cross-fault zones. The prevalent fault trends are roughly orthogonal NE-SW and NW-SE systems that dissect the field. Superimposed on this geometry is an array of distinctly en-echelon WNW-ESE and WSW-ENE structures that link to steep zones at deeper levels. Within sub-regions of the field other trends are also present, including NNE-NNW to N-S, NNW-SSE and E-W. These sets do not form a radial pattern; they are distributed spatially within field domains and involve complex systems and layerrelated rheologically controlled deformation.

The impact of permeability heterogeneity on water-alternating-gas displacement in highly stratified heterogeneous reservoirs

“…The static models were constructed by extrapolating well log data across reservoir. The recent advance technologies such as 3D deconvolution and Radon demultiple were used to interpret faults, fracture, structure, HKS/dolomite mapping and rock typing (Sultan et al 2005;Al Shateri et al 2009;Yamamoto et al 2012;Miyamoto et al 2017). Reservoir facies, matrix permeability, initial water saturation were populated using sequential indicator simulation, sequential Gaussian simulation with co-kriggged with acoustic impedance and saturation height function derived from capillary pressure, respectively (Bushara et al 1997;Venkitadri et al 2005;Ghedan et al 2006;Al-Suwaidi et al, 2010;Bachar et al 2011;Al-ameri et al 2011;Voleti et al 2014).…”