The main disadvantage of commingled production is the loss of individual zone production data, making reservoir management more uncertain and complex. In many cases this added uncertainty and complexity is offset by the advantages, in particular by the ability to clean out wells that are prone to liquid loading. Wells subject to liquid-loading create significant difficulty for reservoir managers in their own way.

In general, operators should pursue commingling production, including requesting approval from the appropriate governing bodies, except under the following circumstances:

Situations Where Commingled Production May Not Be Advised

• Zones with a reservoir pressure that is less than the current wellhead flowing pressure (gas or water production may flow from one zone into another, called cross-flow),
• Wellbores that have large differences in individual zone reservoir pressures, particularly where the well may be off-production for extended periods, during which time cross-flow of gas or water may occur,
• Zones within the same well that have different working interests or royalty ownerships, because allocation issues can be difficult and confrontational,
• Zones with a high water-gas-ratio that may be detrimental to other zones with which they may be commingled,
• Any other possibility where the combined commingled production from the zones leads to a lower production rate or ultimate recovery than producing them sequentially or simultaneously in segregation. Determination of this requires a comprehensive understanding and forecast for the zones individually and together in a commingled state.