Continuous capillary pressure (Pc) curves of subsurface rock formations adjacent wells are determined based on translation relaxation time (T2) data from nuclear magnetic resonance (NMR) and from wireline well logs, such as resistivity logs, to obtain water saturation (Sw) of the rock in the formations. The T2 data and the hydrocarbon density, water density, free water level, and paleo-water level of the formation are processed to obtain parameters of Thomeer hyperbolas that closely conform to water saturation values obtained from the other well logs. The Thomeer hyperbolas so determined are converted to capillary pressure curves.