RETROFITTING HORIZONTAL BUFFER VESSELS FOR THREE-PHASE SEPARATION OF GAS CONDENSATE AND WATER-METHANOL SOLUTION AT LOW-TEMPERATURE SEPARATION FACILITIES

The article examines the modernization of horizontal buffer vessels at low-temperature separation facilities to convert them to the three-phase separation mode for gas condensate, water-methanol solution, and gas. The relevance of the study arises from the growing number of failures of standard two-phase units during the injection of surfactant-containing corrosion inhibitors, which cause the formation of persistent emulsions, entrainment of the aqueous phase into commercial condensate, disruption of pump operation, and malfunction of automation systems. The purpose of the study is to develop and verify a set of internals installed within the existing shell, without its reconstruction, to restore stable three-phase separation. The scientific novelty of the work lies in identifying the mechanism of phase-separation failure in the gas condensate–water-methanol solution system under corrosion-inhibitor injection and substantiating vessel retrofitting using a calming partition, a coalescing block, a drainage gutter, and a condensate draw-off cup. Based on 120 days of pilot-industrial operation, the separation of the water-methanol solution was confirmed, its ingress into commercial condensate was eliminated, gas losses to the flare were reduced, and a high economic return on the project was achieved. The article will be useful for engineers involved in field gas treatment, designers of separation equipment, and specialists in oil and gas facility modernization.