Transient pressure test analysis of horizontal wells in gas condensate reservoirs: Evaluation of conventional multi-phase pseudo-pressure solutions

The results show that, during early radial flow, once bottom-hole pressure falls below dew-point, pressure data shows a composite behavior; however, two phase pseudo-pressure responses calculated by both steady-state and 3-zone solutions, can accurately correct the effect of liquid saturation. In the result, reservoir permeability is estimated with a good accuracy. The study also expressed that, during other flow regimes, deviation from single phase flow due to condensate accumulation cannot be corrected using conventional solutions of two-phase pseudo-pressure function. The reason is that fluid composition is not constant during any of the flow regimes except radial flow. Though, constant fluid composition is the basic assumption for the conventional solutions. Moreover, the result shows that non-Darcy effect in two-phase flow is less than single-phase. Also, positive coupling effect around horizontal wells is not as much significant as vertical wells.