Abstract

General Material Balance for Gas Condensate Reservoir and its GIIP Estimations

Bilal Shams, Jun Yao and Li Aifen

As now-days drilling depths penetrating deeper for exploiting more reserves, hence the gaseous phase exist especially whose phase envelop lies near to critical point. From available literature, it is evident that near critical fluids are of complex phenomena due to intensive compositional change even with respect to very little change in pressure gradient. Hence for gas condensate reservoirs, especial methods for PVT analysis like Whitson and Torp K-Value method is currently used in industry to evaluate effectively the PVT properties even below the saturation pressure. On the basis of Whitson and Torp method and their available PVT equations, the material balance equation for gas condensate reservoir is required and explained in this paper as the conventional material balance is not applicable on near critical fluid reservoirs because it does not contain standard PVT properties solutions below the saturation pressure. The application of material balance equation for gas condensate reservoirs is highlighted to calculate the initial reserves and gas in-places that valuably assist in designing production development strategy and economic evaluations. Gas in-places are estimated and calculated by using application of Havlenah-Odeh plot methods and compared with conventional analysis of Pressure Decline method. Paper explanations are raised with intentions of good assistance to the petroleum industry in estimating gas condensate reserves to implementing pragmatic future development decisions.