Design and operation of gas-condensate pipelines presents many challenges to the flow assurance engineer and pipeline operator. Important challenges are accumulation during low production and the removal of liquid during a ramp-up operation.
Previously the connection between the behavior during a ramp-up scenario and multiple solutions for the steady-state fully-developed approximation was shown in [1],[3]. In this paper we will study the behavior during a ramp-down scenario where a pipeline or a well starts to accumulate liquid. The focus will be on understanding the phenomena. We will show how the steady-state fully-developed approximation can predict the behavior of a full transient simulation and we will make comparisons with laboratory experiments for different ramp-down scenarios.
Simulation of multiphase gas-condensate pipeline transport with low liquid loading is a challenging task. Important properties are the pressure drop for high rates and liquid accumulation at low rates which contribute to determining the operational envelope of the field.