X-Ray Tomography Results Validate Numerical Modeling of Flow in Fractures

Spontaneous imbibition plays a very important role in the displacement mechanism of non-wetting fluid in naturally fractured reservoirs. To understand and quantify this spontaneous imbibition process, we developed a 2D two-phase numerical model. In building the numerical model, we started with the basic equation of fluid flow and developed a numerical approach of solving the non-linear diffusion saturation equation. We compared our numerical model with the analytical solution of this equation to ascertain the limitations of the assumptions used to arrive at that solution. The unique aspect of this paper is that we validated our model with X-ray computerized tomography (CT) experimental data where two simultaneously varying parameters of weight gain and CT water saturation were used. This requires us to undertake extensive sensitivity studies on key parameters before a successful match could be obtained. We also successfully captured our own X-ray computerized tomography (CT) laboratory experiment on a fractured core.