Linear dynamics of gas condensate well deliverability

Abstract

The dynamics of fluid flow in gas condensate reservoirs are investigated by way of analytical description of radial two phase flow. Based on a single phase semi steady-state solution, the application of Kirchhoff's transformation and a simple dynamic model of reservoir oil saturation, revised calculations of the bottom hole pressures and additional production volumes from initially condensed oil, are performed. The above model is presented in great detail and various tests involving different parameters are performed. Tests with respect to critical oil saturation and saturation profiles are presented for both light and heavy gas condensates. Calculations are based on assumptions about shape and profile of the condensed oil saturation in the reservoir; S o (r, t). The model shows how pressure draw-down and oil/gas production can be revised given the information about this saturation profile. In the model is all condensed oil not contained within the saturation profile, produced to the surface. The model might be of interest in early well pressure and production forecast simulations and as a tool in analysis of well-pressure-test data. 376 J. R. Ursin Nomenclature B o , B g : Volume factors for oil and gas; [Rm 3 /Sm 3 ]

Gas-condensate banking and well deliverability - a comparative study using analytical- and numerical models

“…The LD-model is presented in quite some detail in an earlier publication [15]. It should therefore be sufficient, in this article, to point at the main items characterizing the LD-model.…”

“…The wellbore radius, r w is constant while the position in the reservoir where the oil saturation reaches its critical level, represented by r co , and the position where the pressure drops below the dew-point pressure, given by r dew , are both functions of time, indirectly dependent on the pressure development in the reservoir [15].…”