UBO Efficiency: The Art of Building Resilience Through an Operational Buffer While Flow Drilling

Abstract Advancements in technology, shifting drilling environments, and complex reservoirs have transformed the challenges in oil and gas well drilling. Regulations, best practices, and artificial intelligence have emerged to enhance safety. Flow drilling is an Underbalanced Operation (UBO) is defined as drilling an oil and gas well while continuously circulating gas to the surface to be handled by surface separation equipment and ultimately flared. While this practice is a known operation in the oil and gas industry, gas expanding uncontrollably at surface can have catastrophic impacts on lives and the surrounding environment. There are many benefits to utilizing underbalanced operations to create an operational buffer while flow drilling, including allowing for continuous control of the well and faster response times, which aids in maintaining constant bottomhole pressure and preventing any additional influxes from entering the wellbore. This paper discusses the execution of Underbalanced drilling techniques in flow drilling applications in North America and the importance of adaptive control strategies based on a flow drilling matrix. UBO techniques enhance safety during flow drilling operations; however, the significance of an operational buffer helps mitigate the risks associated with well control events. This paper explores the complexities of flow drilling, its drawbacks, and successes in application and focuses on its relevance to underbalanced drilling projects.