Transient multiphase flow modeling of gas well liquid loading
TNO Industrie en Techniek
Gas well liquid loading occurs when gas production becomes insufficient to lift the associated liquids to surface. When that happens gas production first turns intermittent and eventually stops. Hence in depleting gas reservoirs the technical abandonment pressure and ultimate recovery are typically governed by liquid loading. To date, most methods for predicting liquid loading have followed Turner et al. (1969), which describe liquid loading as the point where the liquid droplets suspended in the gas flow start moving downward rather than upward. This paper presents (offshore) liquid loading field data that exceed the Turner predicted values by on average 40%, and analyses the sensitivity of the liquid loading gas rate for different well parameters. It subsequently presents the results of steady state and transient multiphase flow modeling, carried out to identify the influence of the same well parameters. A modified Turner expression is proposed that best fits the liquid loading field data and broadly agrees with the results of a multiphase flow model that uses a modified version of the Gray outflow correlation. The results of transient flow modeling support the flow loop observation that liquid loading occurs due to liquid film flow reversal rather than droplet flow reversal. The impact of these findings on gas well deliquification is explored. Copyright 2009, Society of Petroleum Engineers.
To reference this document use:
Offshore Europe Oil and Gas Conference and Exhibition 2009, OE 2009, 8 September 2009 through 11 September 2009, Aberdeen. Conference code: 79786, 1, 174-187