Gas Condensate Blockage A worked example using a simplified simulation model to demonstrate the fundamental relative permeability relationship affecting condensate blockage. The fundamental relationship which determines condensate blockage is krg as a function of the ratio krg/kro. In the condensate bank, the ratio krg/kro (a sort of fractional flow) can be determined from the flowing OGR (rp) and the PVT properties

Rel perms for Condensate Blockage Consider two different sets of gas-oil rel perm curves. The blue curves have a critical condensate saturation of 20% The blue curves have a critical condensate saturation of 10%

Rel perms for Condensate Blockage But both sets of rel perm curves have the same krg vs krg/kro behavior

Simulation calculations Run 1D Sensor model for 10 md reservoir with these two sets of rel perms Original (blue) rel perms Modified (red) rel perms Or use these output files for Case A and Case B. Compare oil saturations at 4 years and gas production profiles.

Oil saturations after 4 years’ production Different rel perms give different saturations in the condensate bank…

Gas production profiles … but the different rel perms give almost identical gas production profiles. krg vs krg/kro is the primary relationship which determines the effect of condensate blockage. Saturations (including critical condensate saturation) are much less important,

References Modeling Gas Condensate Well Deliverability Gas Condensate Relative Permeability for Well Calculations Measurement of Relative Permeability for calculating Gas Condensate Well Deliverability Notes