Wet Gas Compressor Model Validation

Abstract

The continuous demand for oil and gas forces the petroleum industry to develop new and cost-efficient technologies to increase recovery from new fields and enhance extraction from existing fields. Subsea wet gas compression stands out as a promising solution to increase field extraction, utilize remote regions and reduce costs. Today, a few subsea compressor systems are already operating while several new installations are expected within the next years. This creates a need for dynamic simulation tools to ensure proper system design and facilitate production. This paper presents the model setup for the wet gas compressor test facility at the Norwegian University of Science and Technology (NTNU). The test facility is an open loop configuration consisting of a single shrouded centrifugal impeller, a vaneless diffuser and a circular volute. The fluid is a mixture of ambient air and water. The analysis presented here validates the dynamic model behavior against transient experimental test cases, which include step changes in liquid content and driver trip in both wet and dry conditions. Further, the discharge valve performance has been analyzed in both dry and wet gas flow. The test reveals that the dynamic model is able to operate in a stable manner while showing a close correspondence to the transient test cases. Care should be taken in utilizing dry gas valve characteristics in multiphase flows as increased liquid content has a distinct impact on the valve performance.