| Carbonate reservoirs hold enormous hydrocarbon wealth, yet they are often not fully understood due to their complex lithologies. Reservoir characterization is conventionally done through core and log analysis, which can be costly and time consuming, and is often not accurate for carbonates. Low field nuclear magnetic resonance is a technology that has been used in the past to characterize sandstones with encouraging success. However, when NMR is used in carbonate reservoirs, the results have been discouraging. This is because the interpretation methods were developed for sandstones, which have simpler pore structures. Thus the sandstones based models cannot capture the complexity of carbonates reservoirs. This thesis focuses on developing new interpretation techniques for carbonates. Models have been developed to estimate bound water, vuggy and nonvuggy porosity fractions and permeability using NMR data of fully saturated cores. The proposed models give better properties predictions over existing models in literature and could be used in logging tools to characterize carbonate reservoirs. |
