Abstract
Drilling practices continue evolving with a global quest for efficiency and an increased focus on the lower total cost of ownership. This leads to equipment/electronic upgrades on rigs and the use of new methodologies or tools in oil and gas well drilling. These have a potential to induce substantially higher loads throughout the string, which can remain invisible to the driller but have consequences on the drill stem product connections. As an original equipment manufacturer (OEM), we have noticed an increase in the number of queries related to connection backoff in the well. We would like to take this educational opportunity to share with the industry, especially younger generations, the most common root causes of loosening and/or backing off a connection down hole and ways to address them.
Over decades we have gained experience when dealing with our customers/users who have experienced connection loosening or backing off. We saw that every connection technology, from the API rotary shouldered connection to the premium ultra-high torque connections, could be exposed. Through investigations, rig visits, analysis, and adjustments made to the drilling practice, we have helped numerous players address this effect on land and offshore. As a result, we have identified several causes that can lead to these incidents.
Sometimes, basic physical principals can be overlooked. Often, dynamic phenomenon downhole is not captured, thoroughly understood, or ignored until they impose themselves. Finally, the running practice and connection torque management on surface can often be improved. With a minimum of preliminary planning at the time of well design, by embracing best industry practices on the rig floor and by monitoring what is happening, one can greatly reduce the chances of experiencing downhole back-offs and/or be in a position of making better decisions when they occur. This paper discusses, in detail, the likely root causes and offers ways to address these. While it will not completely eliminate the risks, our experiences and related investigations indicate that it will reduce the effect.
