Heterogeneity quantification, fine-scale layering derived from image logs and cores.

ABU Dhabi (United Arab Emirates); UNITED Arab Emirates

The article reports that fine-scale layering results in an improved static geological model that, in turn, improves reservoir simulation in a large oil field offshore Abu Dhabi, United Arab Emirates. A study conducted by ZADCO illustrates an approach to improve carbonate reservoir characterization of an offshore Abu Dhabi oil field, by quantifying fine-scale heterogeneity using borehole image logs and core measurements. The reservoir under study ranges from mud-supported to grain-supported limestones with variable degrees of grain sorting and cementation. The study is based on detailed analysis of six wells, four from the eastern area and two from the western area. The Lower Cretaceous reservoir was deposited within a regionally extensive, low-energy, shallow-water carbonate ramp on the Arabian cratonic margin. Cyclicity patterns in the study area occur at a variety of scales, some of which are appropriate for reservoir layering, while others are cither too fine or too gross-scaled. The estimation of reservoir layering using conventional wireline logs is possible, although low vertical resolution limits their utility for characterizing fine-scale heterogeneity that exists in most carbonate reservoirs.