Modeling gas condensate well deliverability
This paper gives an accurate method for modeling the deliverability of gas condensate wells. Well deliverability is calculated using a modified form of the Evinger-Muskat pseudopressure (originally proposed for solution gas drive oil wells). The producing GOR is needed to calculate pseudopressure, together with PVT properties (black-oil or compositional), and gas-oil relative permeabilities. The proposed method is successfully tested for radial, vertically fractured, and horizontal wells. The effect of near-wellbore damage, vertical fracture, or flow improvement due to horizontal well trajectory is readily incorporated into the rate equation as a constant skin term. The effect of gas-oil relative permeability is studied. We show that well deliverability impairment due to near-wellbore condensate {open_quotes}blockage{close_quotes} is only dependent on the relative permeabilities within the range defined by 10.3) only affect deliverability for richer gas condensates (with maximum liquid dropout of 10% or greater). A key observation and conclusion from this study is that critical oil saturation has no direct effect on well deliverability. We also show that IFT-dependence of relative permeability has little or no effect on gas condensate well performance (e.g. length of plateau production). The most important application of this study is to provide a simple method for calculating bottomhole flowing pressure (BHFP) in coarse-grid models. Based on our analysis of the three basic flow regions of a gas condensate well, and the large effect of near-wellbore condensate blockage on well deliverability, we propose an experimental procedure for measuring relative permeabilities (specifically for modeling well deliverability).
- OSTI ID:
- 199438
- Report Number(s):
- CONF-951002--
- Country of Publication:
- United States
- Language:
- English
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