Gas Processors Association Europe

Sigbjørn Svenes, Statoil, Trondheim, Norway

The production rates from the Midgard and Mikkel gas fields are expected to decline as the reservoir is depleted. These fields are produced through two 20 inches, 40 km flowlines to Åsgard B.
Several tracer tests have been performed to calculate liquid accumulation in the flowlines at different rates. At low rates, large accumulation of both condensate and MEG/water in the flowlines was measured and large surge waves of MEG/water were observed at the receiving facilities.

These surge waves constitute a production challenge as they exceed MEG regeneration and buffer capacities. A model predictive controller has been implemented to avoid shut downs during surging by choking back production before reaching any of the limitations of liquid handling. The controller was tested in a field test with good results.