Decarbonization and Successful Zonal Isolation of a Challenging Well Using a High-Performance Low-Carbon Emission System Containing Less than 30% Portland Mass

Abstract The implementation of a novel technology that reduced Portland cement content by up to 70% was pumped in a complex 9 5/8-in. casing section of an offshore well, which resulted in a significant reduction to carbon footprint. As the oil and gas industry faces the challenges of decarbonization, one of the focus areas that remains is carbon emissions generated by the cement industry. The innovative and tailored system described in this study is designed to deliver high performance at a lower density than conventional systems for improved barrier dependability. Proven laboratory results show that the system enables higher compressive strength at a lower density, increases ductility, and reduces permeability and corrosion resistance. The main engineering and operational advantage of this system is its capability for deployment without the requirement for specialized or additional equipment, which provides an operationally efficient and sustainable barrier. The primary challenge cementing this section was to reduce the equivalent circulating density (ECD) caused by the elevated risk of losses predicted by offset wells. This required the use of a specialized low-density slurry system with durable mechanical properties. Another challenge was to lower carbon emissions associated with large slurry volumes because conventional high-Portland content cement systems do not align with sustainability goals. Modern technology was applied, and the well was successfully delivered with all achieved objectives. This case demonstrated that sustainable technology is not only efficient to reduce carbon footprint, but also to successfully achieve zonal isolation without downgrading the final cement quality compared to conventional cement systems. Cement production accounts for approximately 8% of global anthropogenic carbon dioxide (CO2) emissions annually (Abdelaal et al.). The benefits of the application of this innovative technology in future wells are discussed, which can help reduce carbon footprint while slurry performance to achieve the zonal isolation.