How Superior Water-Based Fluids Can Reduce CO2 Emissions and Drilling's Environmental Impact?
Authors: Geri Mohammed Ba , Amer Ahmed , Bussaglia Lucio 
Published: June 2024

The oil and gas industry faces mounting pressure to reduce its environmental footprint, particularly concerning greenhouse gas (GHG) emissions contributing to climate change. Drilling operations represent a significant source, accounting for an estimated 11.6% of emissions within the industry's upstream activities. This study investigates quantifying the potential reduction in carbon dioxide (CO2) emissions and overall environmental impact by transitioning from nonaqueous (oil/synthetic-based) to aqueous (water-based) drilling fluids.

A multi-phase analysis was conducted to develop a comprehensive carbon emissions calculator for the entire lifecycle of nonaqueous fluids used in deep-water drilling operations in the U.S. Gulf of Mexico. Across six lifecycle stages, from raw material transportation to disposal/reuse, the calculator quantifies CO2 emissions based on activity data and emission factors. Preliminary findings indicate rig operations (62%) and solids control/cuttings management (29%) contribute 91% of total calculated emissions.

Case studies are presented demonstrating the emissions reduction potential of aqueous fluids. In the Gulf of Mexico, sustainable water-based mud eliminated operational steps like pit cleaning compared to nonaqueous fluids, reducing associated emissions. For a 12-well campaign in the Permian Basin, aqueous fluids reduced drilling days per well from 20 to 13 on average versus nonaqueous, resulting in a 37% reduction in CO2 emissions.

The study proposes adapting this calculator framework to model representative aqueous fluid systems, enabling direct comparison of emissions profiles across all stages. Aqueous fluids’ inherent nature suggests reducible impacts through lower transportation volumes, less energy-intensive preparation, enhanced drilling performance, minimized rig time, and more straightforward waste management.

However comprehensive comparative data is ongoing, aqueous fluids demonstrate compelling potential to lower the substantial carbon footprint associated with drilling activities. This rigorous methodology enables evidence-based decisions on drilling fluid selection to align with sustainability initiatives and improve environmental stewardship.

The study proposes adapting this calculator framework to model a representative aqueous fluid system for the same drilling application. The potential environmental benefit achieved by using an aqueous fluid can be quantified by directly comparing the emissions profiles across all lifecycle stages. Aqueous fluids are expected to reduce impacts through lower transportation volumes, less energy-intensive preparation, enhanced drilling performance, minimized rig time, and more straightforward waste management.

While comprehensive data is still needed for the complete comparative analysis, the inherent nature of aqueous fluids strongly suggests they offer a viable pathway to lowering the carbon footprint associated with drilling activities. This study establishes the foundational methodology to evaluate such environmental impacts rigorously, enabling operators to make informed decisions when selecting drilling fluid systems to improve sustainability practices.