Evaluation of IOR Projects with Focus on Energy and CO2 Intensity using eCalc

Summary The energy efficiency and CO2 emission are important constrains for oil and gas development and operations, alongside with the traditional Net Present Value - NPV. The required energy for field operation is normally produced with fossil fuel, such as gas turbines, often using its own produced but also important gas and diesel. The latest trend of full or partial field electrification on the Norwegian Continental Shelf (NCS) to reduce the GHG emission also poses new need for energy saving by optimization of the onboard energy consumers. The CO2 intensity, independing on the energy source, together with the energy efficiency which is a direct measure of the field operation performance are there gaining their attention more than ever. This paper will present a methodology on creating a energy and CO2 emission map (EC-map) of each of the main field production steps (production, processing, export, injection, base load, etc) allocating the energy consumption and associated CO2 emission by calculating the surface system response for improved production and when introducing additional IOR operations. The OpenSource eCalc® software is used to perform the energy and CO2 allocations. The subsurface responses from IOR methods can be evaluated based on the output from reservoir modelling and then screed by using income from the incremental hydrocarbon to increase NVP AND counter-balanced with the energy and CO2 intensity. The EC-map which identifies the largest energy and CO2 intensity contributors, such as injection pumping energy, produced water treatment, gas compression for export, etc. can be used to further optimize the proposed IOR methods. The proposed methodology may form a screening tool for IOR implementation and future field operation optimization of the energy and CO2 intensity. A few examples inspired by real field cases will be presented to demonstrate such a screen process of IOR evaluations with ranking of energy and CO2 intensity. On the other hand, the source of energy spending and optimization, e.g. from gas turbines in combination with electricity import can also be fine tuned for reducing the energy and CO2 intensities for the entire field life time, potentially also its extension by new tie-ins (new energy consumers) and by co-use (CO2 injection) to leverage the already invested surface facility. The methodology in this paper is therefore also relevant for planning of the efficient future field energy systems.