An international Energy Company & independent engineering company have performed preliminary studies for an In-Line Robot (ILR) Project including: feasibility study, turbine design (with CFD calculations and flow assurance) and Energy Balance Assessments. This Robot will be a tetherless autonomous device capable of travelling with/against production flow to accomplish pigging and inspection missions inside pipelines with minimum production impacts. This is particularly adapted for single line long tie-backs, thanks to regenerative power management but the complexity of subsea architecture, flow conditions & fluids services raises some challenges.

The ILR development is programmed over five phases (Feasibility study, Preliminary Systems design & Energy Balance Assessment, Flow Loop Bench Testing, Prototype Testing and Commercialisation). Phase 2 utilised Computational Fluid Dynamics (CFD) simulation models to assess power extraction levels from production flow across various scenarios whilst minimising pressure drop.

The results obtained included the turbine CFD models that were coupled to power conversion and storage modules in order to ensure that system drive and power managementwere captured in a closed loop. An operational envelope was established considering the preliminary turbine design simulations as well as the associated energy balance.

This paper will present the results to date along with the key design features of the ILR and how the data will be used to verify the operational envelope during the next phase, Flow Loop Bench Testing which is due to start in late 2019. This will provide data to configure and predict operational envelopes of the robot for different flow patterns and fluid types.

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