CAPILLARY PRESSURE AND RELATIVE PERMEABILITY ASSESSMENT ON WHOLE CORE SAMPLES FROM A GIANT MIDDLE EASTERN CARBONATE RESERVOIR UTILIZING DIGITAL ROCK PHYSICS

摘要

Digital Rock Physics(DRP)has significantly evolved in the last few years and added invaluable contributions in improving core characterization and in providing high quality advanced SCAL measurements,emphasized through various studies/papers(SCA-2012-03 Kalam et al). This paper represents a unique DRP SCAL study that includes primary drainage capillary pressure(Pc)as part of Swi establishment and relative permeability(Kr)measurements done on four whole core(WC)samples from two different carbonate formations with a stylolite layer in between. The aim of the study was to evaluate how DRP results would compare with physical SCAL measurements done – on the same WC samples as a composite,as well as on plug samples from the same formations/layers – in a leading international core analysis lab in USA. The DRP results were up-scaled to the individual WC level and compared with the SCAL results from the corresponding layers. The DRP technology in this study also provided the capability of up-scaling the results to the WC composite which was used by the lab to assess the effect of the stylolite layer on the water flood. The comparison showed excellent matches between the physical and DRP-derived Pc and Kr data. The paper outlines the DRP methods used to determine the SCAL properties of the three formations. The laboratory measurements of SCAL properties took six years while the DRP work that followed blindly(without any knowledge of the laboratory results)was completed in six months. This demonstrates the effectiveness of the DRP technology in providing high quality SCAL data in a timely fashion regardless of sample size. Impact of possible wettability changes and sensitivities on one of the WC composite constituent component was also easily established unlike the high risk laboratory tests. This is the first water-oil displacement validation study results on reservoir whole cores of four inch diameter at full reservoir conditions using DRP.