Effect of liquid drop-out on the productivity of a rich gas condensate reservoir

A 2-D radial compositional simulator was used to investigate the effect of liquid drop out on the productivity of a rich gas condensate reservoir. A seven layer reservoir model was constructed based on well logs and core analysis data. A two phase relative permeability model was used to generate the relative permeability curves for the oil and gas phases assuming the initial water saturation is immobile. The pore size distribution index required in the relative permeability model was calculated by finding the slope of the log-log plot of the J-function versus normalized water saturation obtained from the air displacing brine experiment. Major objective of this study includes identification of parameter controlling the productivity of the gas condensate well, evaluation of the effect of condensate dropout near the wellbore on well productivity, determination of optimum production rate and investigation of the extent of condensate banks in different layers. It was concluded that gas condensate well productivity is reduced as the critical condensate saturation increases. Gas production rate more than 40MMSCF/D offers no significant improvement on cumulative gas and condensate produced, Ninety-one percent (91%) reduction in gas flow productivity was observed for all production rates investigated. The percent liquid condensed near the wellbore in all layers ranged between 37 to 44 percent and there are noticeable changes in pressure distribution near the wellbore in all layers though it remains the same at a distance more than 100 ft away from the wellbore.