Combustion Efficiency Dashboard using Combustor

In the UK, the regulatory guidance on Flaring states that “operators should meter, monitor and manage their flare gas composition and flare combustion efficiency to ensure minimum greenhouse gas emissions resulting from flare activity”.

To help operators meet the requirements of the North Sea Transition Authority (NSTA) Flare and Venting Guidelines and the Oil and Gas UK Methane Action Plan (OGUK MAP), Accord have developed Combustor, a dynamic process simulation model that enables oil and gas operators to calculate combustion efficiency and provide a mechanism to reduce Methane emissions from their flaring operations.

In 2023, as part of a Net Zero Technology Centre (NZTC) project, Accord configured Combustor for five operating assets across the North Sea for bp, Harbour Energy, Ithaca Energy, Serica Energy and TotalEnergies. In each case, Combustor calculated the combustion efficiency, CO2, Methane, CO2e emissions and uncertainties.

The project included full integration of Combustor with PI Vision to provide an online, live calculation for the TotalEnergies Culzean field. PI calls the Combustor service every minute to calculate the current combustion efficiency and emission rates. The results are returned to PI, recorded and stored as cumulative figures against a PI tag allowing other management systems to trend and report detailed emissions data. A PI Vision dashboard displays the data graphically and provides feedback which can be used to optimise the combustion efficiency of flaring operations to reduce the overall emission rates of CO2 and Methane.

The dashboards provided real insights into flare emissions during the autumn 2023 storms.

The image above shows the online calculated Combustion Efficiency increasing over time as wind speeds from storm Babet dropped. Emission rates and cumulative totals for CO2, Methane and CO2e can also be seen.

The Combustor cloud-based architecture supports easy integration with most systems. In this case, Combustor was integrated with PI to support minute by minute calculations and the accessibility of the results through PI Vision.

The implementation project included:

• Working with Engineering Team to define the key asset elements and input data required for the process simulation model. This stage involved review of existing HYSYS models, gathering of key input data for testing and any available composition measurements.
• Configuration and of the CHARM process model which will be used in Combustor to calculate the LHV of the flare.
• Test runs to support validation of the model by the Engineering team;
• Addition of tags in PI for key input data including windspeed and flare exit velocity and the outputs from Combustor (Methane, CO2, CO2e, Combustion Efficiency, calculated uncertainties)
• Configuration of the Combustor calls to integrate the calculation within PI and write the results into PI tags
• Configuration of a PI Vision dashboard display the data in real-time.

TotalEnergies were looking for a solution that could provide near real-time calculation with online displays supporting decision-making in the control room. Combustor is a cloud-based service with excellent response times – typically around 0.5 seconds. The project team configured Combustor calls every one minute as the optimum level for the dashboard reporting.

Combustor requires no physical installation of equipment or software on the asset. The underlying CHARM model calculates the LHV at the flare tip removing the need for additional chromatographs and ensuring that all compositional changes are reflected e.g. nitrogen. Combustor is cloud-hosted so there is no need for any local software installation. This approach is highly efficient from the point of view of cost and timescales. The Culzean project was delivered in under 4 weeks.

At the heart of Combustor is the combustion efficiency equation derived from a publicly available peer-reviewed study published by the University of Alberta. This approach provides a transparent and traceable methodology satisfying the OGMP 2.0 guidance to meet Level 4 Gold Standard reporting. Combustor also calculates the uncertainty and can be used to determine optimum flare rates.