An extended JBN method of determining unsteady-state two-phase relative permeability

作者：Chen Xiongyu^*; Kianinejad Amir; DiCarlo David A

来源：Water Resources Research, 2016, 52(10): 8374-8383.

DOI：10.1002/2016WR019204

• relative permeability
• two-phase displacements
• JBN method extension
• capillary end effect
• section-wise pressure drop
• local saturation and phase flux

Relative permeability is the reduction of permeability of porous media when subjected to multiphase flow and a key parameter in subsurface hydrology. The JBN method is a well-known method of obtaining relative permeability, which measures the overall pressure drop and the effluent phase ratio versus time during two-phase displacements. By assuming no capillary pressure or gravity, the JBN method obtains the relative permeabilities to both phases at the core outlet. Since data across a range of saturations are acquired in a relatively short time, this method is widely used. This work extends the JBN method by having (1) section-wise pressure drop measurements between the core inlet, four pressure taps on the core and the outlet, (2) local saturation measurements, and (3) local phase fluxes. With these data, the extended JBN method can determine relative permeabilities to both phases at each pressure tap of the core (not just at the core outlet). The JBN extension is shown using a data set where CO2 invades a brine-filled core. From this it is found that the advantages of the extended JBN method over the regular JBN method are: (1) four times more data are obtained, and (2) data are more accurate because the capillary end effect is experimentally avoided. Avoiding the end effect results in tripling the saturation range, and obtaining relative permeabilities that are consistent with steady-state measurements and roughly 40% higher than those from the regular JBN method.

• 出版日期2016-10