Reservoir characteristics of carbonates build-ups in southern Central Luconia Province: A study based on different scales

Abstract

This paper discusses the reservoir distribution and characteristics of different carbonate build-ups/morphologies in Central Luconia Province, focusing on two carbonate build-ups in the southern part of the province. Both geological (core) and geophysical (seismic and well logs) data were used throughout the study to provide different scales and resolution of the study area. The evaluation of reservoir qualities for each carbonate build-ups in this area was done for Cycles III and IV carbonates. The findings showed that both fields have different reservoir distribution in terms of porosity and lithology. Pinnacle build-ups has fair to good porosity with decreasing occurrence of dolomite relative to depth while the carbonate platform has poor to fair porosity due to higher mud content compared to the pinnacle-type. Cleaner carbonates can be found in the pinnacle platform with lower gamma ray log reading. Different lithologies can also be observed in these two fields. For example, the pinnacle platform has lithology ranging from packstone to rudstone while the carbonate platform has lithology of packstone to grainstone with a higher mud content. The result concluded that the reservoir quality of the pinnacle build-up is better than the carbonate platform.