Relative permeability predicted using resistivity index and capillary pressure data

Capillary pressure and relative permeability are key parameters that govern the fluid flow in geothermal reservoirs. Relative permeability data are used to predict the most effective hydrocarbon displacement mechanisms and the most efficient methods for extracting oil or gas from the reservoir. Determination of capillary pressure and relative permeability are traditionally conducted in the laboratory; however, in many cases these measurements are expensive, difficult, and time consuming. Theoretical models show that capillary pressure and relative permeability could be inferred from resistivity data. In fact, if one of these three parameters is known, the other two can be determined. In this study, laboratory measurements of the resistivity index, capillary pressure, and relative permeability were conducted on samples from two oil fields representing Libyan sandstone (A) and carbonate (B) reservoirs in order to review the analytical mathematical models correlating these variables. The results of the relative permeability calculated using these models were analysed and compared with experimental data obtained in the lab. The results showed that permeability can be calculated from experimental data of either resistivity index or capillary pressure. Good matching was observed between relative permeabilities and those calculated from with experimental data.