A Comprehensive Approach on Determining Correlations between Sonic- and Density-Log Measurements from the Gulf of Mexico and North Sea Fields for Improved Reservoir Descriptions

摘要

In the past, numerous relations between sonic velocity (i.e., an inverse of sonic travel time, DT) and rock density were developed that were suitable for certain fields or certain rocks only. In this paper, the correlations between sonic- and densitylog measurements were investigated again using the data information from multiple fields in the Gulf of Mexico (GoM) and North Sea (NS). For sandstone-shale sequences, the dominant linear relationships between travel time (DT) and formation density (RHOB) were observed and compared with the popular Gardner’s method (Gardner et al. 1974) along with other known methods. The implications of data clusters distinguished by formation lithologies and rock mechanical strengths were revealed from a cross-plot analysis. The probabilities and uncertainties of the developed correlations were determined using the actual histograms from the collected data of the GoM and NS fields coupled with Monte Carlo simulations.