Linear Regression to Predict Two-Phase Relative Permeability of Fracture Network

The process mechanism of two-phase flow through fractures is soimportant under reservoir conditions. Studies using synthetic fracturesand various fluids have yielded different relative permeability-saturationrelations at different conditions. In this study, we use a data set ofnitrogen-water experiments, which were obtained for both smooth andrough parallel plates (Gracel P. Diomampo 2001), under imbibition anddrainage process. For both smooth and rough-walled fractures a clearrelationship between relative permeability and saturation was observed.In the absence of laboratory measured data or for having moredescription of fluid flow characteristic, empirical relative permeabilitycorrelations become useful. Linear regression model approach can be used to develop prediction equations for water-oil, gas-oil, gas-water,and gas-condensate relative permeabilities from experimental data.Objective of this study is develop fracture relative permeability (FRP)models. Developed FRP equations were obtained from smooth-wall andrough wall fracture of both imbibition and drainage processes, show anacceptable compatibility with the experimental data and anotheranalytical and experimental equations. However, instead of X-model, thedeveloped equation can be used in commercial simulators as a basicequation to obtain better results.

Keywords:

Smooth-Wall , Rough-Wall , Imbibition , Drainage , Fracture Relative Permeability