Well Clean-Up and Flowback Optimization Considering Emission Reductions

Abstract Ultimately, most new wells need to be put into production, whether it is for temporary well testing during the exploration and appraisal phase or during the development phase prior to commercial flows. This process, commonly known as clean-up, encompasses tasks such as handling contaminated fluids, ensuring proper disposal methods, and managing flow instability during the initial stages. These aspects pose various challenges that need to be addressed. Regrettably, the conventional approach to fluid disposal has been through flaring. The primary concerns of cost efficiency and expediting commercial production have outweighed other considerations. However, some commendable local regulations, like the one currently in effect in Brazil or the Gulf of Mexico, have mandated the storage of liquid effluents during these operations. The driving force behind such mandates is primarily focused on reducing the visibility of fluid releases into the environment, rather than addressing the actual environmental impact. It is important to note that these "non-routine" flaring operations contribute to less than 5% of the total emission footprint and should not be overlooked. Based on an analysis of over 300 clean-up operations worldwide, we have concluded that it is feasible to reduce the required amount of flaring for well start-up and clean-up operations by 50%, without compromising the future performance of production systems. The paper illustrates how a thorough assessment of field development architecture, operation scheduling, and overall emission footprint can result in a mutually beneficial solution for clean-up. Interestingly, and somewhat counterintuitively, we demonstrate that it is feasible to minimize the quantity of flared hydrocarbons through an intricate operational sequencing of clean-up operations. These seemingly improbable (and non-intuitive) operational sequences are made possible by implementing remotely controlled and automated choke sequences, coupled with real-time monitoring of well conditions. Accurately measuring the potential reduction in emissions plays a crucial role in successfully implementing these innovative methodologies. The adoption of such approaches by regulators, operating companies, and service providers hinges on the combination of quantifiable environmental impact, operational reliability, safety, and economic considerations. This paper showcases the implementation of these processes in both land and deep-water operations, offering insightful comparisons between different options. The challenges associated with deployment are discussed, and practical lessons learned from the Middle East and deep-water operations are shared, demonstrating how emissions during clean-ups can be reduced by up to 50% while also lowering operational costs.