Non-Darcy flow increases the pressure drop required to establish a desired gas well production rate, thus decreasing productivity. This increased pressure drop is exacerbated by the liquid drop-out and build-up which occurs in gas condensate wells. The additional pressure drop caused by the two phase non-darcy flow can have a dramatic effect on the flowing bottom hole pressure required to maintain producing rates, especially in high rate gas condensate systems. Neglecting or underestimating this effect will cause optimistic predictions of the maintenance of gas rate plateau. Literature values for measured inertial coefficients, (which quantify non-Darcy flow pressure drops) show a scatter of a one to two orders magnitude for a given permeability. Measurements of inertial coefficients (betas) may or may not agree with literature reported values. Use of literature reported permeability - beta relationships to calculate beta may not be appropriate and may lead to significant errors. These errors increase with increasing flow rate and decreasing permeability.
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