On the Road to Net-Zero Carbon Emissions: A Cementing Emissions Assessment Tool for Quantifying, Evaluating, and Helping Decarbonization

Abstract

Abstract An important step in decarbonization is using an end-to-end approach to quantify carbon emissions during cementing operations. By careful analysis of the entire cementing operations process, it is then possible to measure and compare carbon emissions at various stages of the operation. Understanding and isolating the main drivers of the carbon emissions footprint enables making better choices and developing best alternatives with lower environmental impact. The methodology considers the lifecycle assessment of cement from quarry extraction to well abandonment, and includes steps such as manufacturing of raw materials, transportation and logistics, and operations in the field. For these stages, careful quantification of emissions is performed based on the manufacturer's carbon emissions of cementing products, transportation (distance and means) to the bulk plant and rig site, and equipment-related emissions such as blending and pumping units. In some cases, when assessing the footprint of different technologies, a sensitivity analysis can be carried out to compare the operation-related emissions based on a field case. Using an assessment tool during key cementing operations allows for identifying the main contributors to greenhouse gas (GHG) emissions. In most cases, the embodied carbon in the cement slurry itself outweighs the operational emissions (on an average, one ton of CO2e is emitted for every ton of Portland cement produced). The embodied carbon of cement systems mainly depends on the data quality of the emission factors of the slurry components. These factors are not yet broadly available and until then, correct proxies are needed to perform such studies. Besides the embodied carbon, the assessment tool also quantifies other elements of the cementing operations. Examples of sensitivity analysis will be presented in this paper, covering aspects such as an optimal transportation choice from the supplier location to the implementation site. Furthermore, the tool supports the selection of cementing technologies, integrating performance and larger impacts, such as a change in the well design or elimination of remedial operations during the life of a well. The cementing emissions planner supplies a platform for consistent and transparent quantification and comparison of cementing technologies supporting an effective environment action. This tool embraces forward-thinking and innovative cementing solutions that help decarbonization in the oil and gas industry in achieving net-zero carbon emissions.

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