STEADY-STATE IMMISCIBLE OIL AND WATER-FLOW IN A SMOOTH-WALLED FRACTURE

Steady state immiscible oil/water flow experiments were conducted in h orizontal smooth-walled fractures. The effects of fracture aperture, i njection rate and injection method on the immiscible flow characterist ics were investigated. The experimental data were analysed using a por ous medium approach and an equivalent homogeneous single-phase method. The pressure gradients predicted by the latter are in good agreement with those measured in the experiments. Contrary to the well-known Rom m's relative permeability versus saturation correlation, the experimen tal data indicated that the sum of the relative permeabilitiesis less than one over a range of saturation, which is attributed to the effect of phase interference on the immiscible flow. The effect of phase of interference is more significant in the case of well mixed oil/water f low than otherwise. The results also indicate that the fracture apertu re does not have a significant influence on the relative permeabilitie s of oil and water flow in smooth-walled fractures.