Although the constitutive relationship of relative permeability as a function of saturation has been examined extensively in soil science and petroleum engineering, there is little information about this relationship for many systems encountered at hazardous waste sites. This lack of data has led to the use of estimation methods for relative permeability without verifying that they are indeed applicable to systems representative of hazardous waste sites. To assess the accuracy of methods commonly used for the prediction of two-phase relative permeabilities, drainage and imbibition relative permeabilities were measured for several organic liquid-water systems. A comparison of these measurements with estimates generated with five common methods showed that these methods are limited in their predictive capabilities. They estimated the relative permeability to the aqueous phase well, but failed to predict the low permeability to the organic liquid. For the relative permeability to the organic liquid to reach the predicted value of unity at the residual aqueous phase saturation, the effective permeabilities must be normalized by the permeability measured in the presence of residual water. The common estimation techniques make no provision for hysteresis. Since the aqueous phase showed little hysteresis, these estimations methods can be applied to both drainage and imbibition processes for this phase. However, the organic liquid phase showed hysteresis, and thus these techniques may only be appropriately applied to drainage for the non wetting phase.

Estimation of two-phase relative permeability relationships for organic liquid contaminants

Multiphase flow behaviour during CO2 geo-sequestration: Emphasis on the effect of cyclic CO2–brine flooding

Intercept Method--A Novel Technique To Correct Steady-State Relative Permeability Data for Capillary End Effects

Effect of residual natural gas saturation on multiphase flow behaviour during CO2 geo-sequestration in depleted natural gas reservoirs

Dependency of Remaining Oil Saturation on Wettability and Capillary Number

The optimum construction methodology of composite cores for multiphase flow tests is an important practical petrophysical concern. The critical feature of construction is the minimization of saturation disturbances which occur due to capillary pressure discontinuities at individual core segment interfaces. The effect of matrix discontinuities on two-phase flow in homogenous composite cores was studied as a function of flow rate and wettability. Five composite cores, representing a range of wettabilities, were prepared. The composite cores were constructed by splicing multiple core segments with bridging materials of differing wettabilities. Saturation profile data we measured with a microwave saturation scanner during imbibition and drainage floods. The interface between core segments had a strong effect on the saturation distributions when capillary contact was not maintained between contiguous segments. Under drainage conditions at low flow rates, each core segment behaved as though it were an independent core experiencing a strong exit end effect. In steady-state fractional flow experiments this occurred only at fractional flows close to unity. The most effective bridging materials for water-wet Berea were thin paper sheets. No bridging material was found to be completely adequate in an oil-wet environment. In the absence of good capillary contact, increasing the flow rate ismore » a practical remedy for the saturation disturbances.« less

R.E. Hinkley

Papers

Capillary pressure discontinuities and end effects in homogeneous composite cores: Effect of flow rate and wettability