BEST PRACTICES FOR PREPARATION OF SAMPLES FOR LABORATORY ANALYSIS

Core analysis is performed to measure petrophysical properties of rock samples in order to ultimately be used in reservoir characterization, modeling, and performance predictions. In this study, the petrophysical properties of a set of eleven samples are measured through a well-defined methodology: at first, the dimensions and dry weight of each sample are measured, then the porosity is estimated using two methods: through grain volume measurement, then through pore volume measurement. Then, the permeability to gas is measured and corrected to liquid through the use of Klinkenberg correlation. Finally, each sample is saturated at atmospheric pressure, then dried and saturated again under pressure, all the while recording the saturation time for each step of the process. Using the wet weight at which the sample is fully saturated and the dry weight, a third porosity measurement method is applied. The time at which each sample reaches 100% water saturation is interpolated, or extrapolated in some specific cases, and it is plotted against different petrophysical properties to visualize any relationship between the time needed to reach 100% water saturation and any properties. The results were that a correlation was possibly found between saturation time and absolute permeability, but the relationship between saturation time and porosity was less evident. Furthermore, atmospheric pressure was not enough to fully saturate samples even when left for a relatively long time. Overall, this study provides suggestions on how to manage the saturation of a rock sample using water and investigates the possible issues that can be encountered while doing it.