The water production profiles for gas-condensate fields are notoriously difficult to predict. Irrespective of this fact, design premises need to be established for the development of such fields. In operation, the production facilities will have built-in limitations with respect to formation water tolerance. Several of Statoil's ongoing field developments are gas-condensate fields with a high gas volume fraction (GVF). Some of these fields involve long distance carbon steel multiphase pipelines connecting the subsea wells to the downstream processing plant For these cases even small amounts of saline formation water will be critical, and therefore this water production needs to be detected. The continuous water production from gas-condensate reservoirs will typically consist of fresh water that condenses from the gas as pressure and temperature decreases throughout the production system, as well as salt water from the formation (connate water). In addition, some fields may experience more massive saltwater production as a result of water breakthrough in (some of) the wells. This saltwater production is difficult to predict, both in terms of the maximum amount and the volumetric flow rate versus time. In this context, formation water is the salt connate water plus the saltwater resulting from a potential free water break-through. Statoil has experienced that multiphase meters do not handle GVFs exceeding 90 to 95%. That is, above 95% GVF, none of today's multiphase meters can meet the accuracy needed for formation water detection or the accuracy needed for production allocation purposes.
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