Abstract
Hydraulic submersible pumps are an artificial lift mechanism that can be used as an alternative to gas lift or electric submersible pumps. This paper presents a method for the rigorous evaluation of hydraulic submersible pumps (HSPs) during the concept selection phase of a project. The method couples multiphase flow simulations with the operation of the pump and turbine to identify feasible system designs. The paper explains how the flow assurance engineer must consider the two new constraints of system design pressure and power water to produced fluid ratio when sizing multiphase flowlines, rather than the normal constraints of capacity, back-pressure and turndown. An example demonstrates why a holistic approach to the design of the system, from the sandface through to the production separator and incorporating the power water delivery system, is crucial in assessing concepts involving HSPs.
The introduction of large volumes of water into the production system presents new challenges to the management of flow assurance. The influence of emulsions, the potential advantages of lowering the fluid viscosity if operating in the water continuous phase and the impact on the processing facilities will all be discussed. Further advantages have been identified for fields with waxy crudes, where hot water can be used to drive the HSPs whilst introducing heat into the system. The results of detailed thermal-hydraulic modelling (using the transient multiphase flow simulator, OLGA) will be presented to demonstrate the feasibility of this approach.
