Analysing and characterising horizontal well performance in rectangular closed gas reservoirs considering non-Darcy flow conditions

摘要

This paper investigates the impact of non-Darcy flow, represented by rate-dependent skin factor (DQ(SC)), on pressure profiles, flow regimes, and productivity indices of horizontal wells extending in conventional and unconventional gas reservoirs. It introduces a new simplified technique for characterising reservoir performance under different non-Darcy flow impacts. The outcomes of this study are summarised as: 1) understanding the conditions at which non-Darcy flow could have considerable effects on reservoir performance; 2) estimating the deviation in productivity index caused by non-Darcy flow. The most interesting points in this study are: 1) the ability to estimate rate-dependent skin factor from well test analysis by observing early time radial flow regime; 2) all flow regimes, unlike pressure behaviors and productivity index, are not affected by non-Darcy flow; 3) productivity index declines sharply for high rate-dependent skin factor at early production time while pseudo-steady state productivity index is not affected by non-Darcy flow. [Received: April 12, 2018; Accepted: May 9, 2018]