DeFACTO - Demonstration of Flow Assurance for CO₂ Transport Operations

DeFACTO is a vertical flow facility that enables the circulation of CO₂ through a 90 meters deep U-tube loop (depicted in the figure). The loop is instrumented with over 100 high precision-fast response pressure and temperature sensors, allowing to measure pressure waves with a high degree of accuracy.

The vertical flow loop is connected to a 139 meters long horizontal flow loop, located on top of the facility. The horizontal flow loop enables circulation of CO₂ with precisely controlled parameters (contaminants, temperature, pressure, gas to liquid ratio).

The CO₂ is then circulated through the vertical loop where its behaviour can be analysed at different depths. Each tube in the U-loop can be isolated and pressurised or depressurised individually.

The data collected help understanding when and how the CO₂ freezes under depressurisation, cavitation phenomena, two-phase and transient flow behaviour, and ultimately assist engineers in the design of safer and more efficient CO₂ transport and storage systems. 

Experiments that can be performed through DeFACTO both with pure CO₂ and with impurities (N2, up to 20% CH4)

•        Both single and two phase flow. 
• Steady state flow at different T/P conditions and gas to liquid ratios.

•     Transient: 

  •     Shut in and first fill

  •     Depressurisations

  •     Blowouts

  •     Fluid hammers

•     Estimation of heat transfer coefficient under controlled conditions.

•     Reservoir backflow.

Datasheet, DeFACTO flow loop (EX-proof).

• U tube largest ID, 32 mm smallest ID, 16 mm
• Pressure, FV to 160 bar
• CO₂ process temperature, -60 to +60 C
• Controlled temperature in hole, 5 to 35 C
• Design flow, 10 kg/min (0.2 kg/s)
• Ready for water injection (well control and hydrates formation investigations) to increase understanding of interaction between CO₂ rich well flows with reservoir water.

          Questions we can answer: 

How much will a depressurisation cool the pipe?

• Current pipelines are designed to -78C, which requires at least a 3.5 Ni steel. Up to -60 C fine grain steel can be used, reducing the cost of the pipeline.

Will dry ice / hydrates form during depressurisation?

• The formation of hydrates during depressurisation helps defining how dry the transported CO₂ must be, which can reduce the cost of CO₂ dehydration.
• Pressure profile and Joule Thomson effect during leakages and emergency depressurisations determine the temperature design of the transport system.

Will water hammer effects be significant when closing valves? 

• Pressure surges inside the lines determine the design pressure of the pipeline, driving the CAPEX.

The project builds on earlier BIP project CO₂ IT IS competence and infrastructure. 

SINTEF is responsible for constructing the facility at Gløshaugen in Trondheim and executing the experimental campaign. SINTEF contributes with expert knowledge on infrastructure design of CO₂ transport systems and modelling and simulations of pipe dynamics, as well as fluid properties. In-house codes for fluid dynamics and thermodynamics are used for planning, design verification and comparison of results.

DeFACTO is a CLIMIT Demo project which is partially funded by Gassnova, SINTEF Energi AS, Equinor ASA and Total E&P Norge AS are partners.