Proactive Prevention of Ferromagnetic Iron-Induced RSS Tool Failures Using Novel Testing Techniques and Operational Modifications.

Abstract

The ubiquity of complicated and extended-reach horizontal wellbores with tighter windows has spurred the copious use of the rotary steerable system (RSS) in drilling operations. This magnetic-powered RSS technology, initially designed for the offshore drilling market, has proven to be an effective solution to the increasingly complex challenges in the land-based market. Although durable, as with other mechanical devices, equipment failure and malfunction may occur during drilling operations. The impairments of these expensive high-end systems while drilling often lead to costly trips and NPTs, which can be avoided with regular maintenance practices. Apart from these regular maintenance practices, it is also paramount to devise proactive techniques while drilling that will enhance the life cycle of these systems and prevent rampant and uneconomical trips. This paper presents a proven methodology that was used to eliminate the rampant RSS tool failures encountered on multiple rigs in Southern Alberta, Canada. While RSS tool failures have traditionally been attributed to the barite and mud system, scientific root cause analysis showed that ferromagnetic iron metal generated from different sources while drilling induced these failures. Ferromagnetic Iron has the potential to cause interference with downhole magnetic tools, causing them to fail and have solids entrapped in them. An ingenious operational procedure was devised and implemented using strategically generated magnetic fields in the mud circulation system at different locations. These magnetic fields strip the mud system of ferromagnetic materials to prevent damage to RSS tools. This procedure was also backed up with a novel testing technique that identifies and quantifies the presence of ferromagnetic materials in the mud system, which can be tracked on the daily drilling report or posted on a digital database. The test results help engineers detect the buildup of ferromagnetic iron in the mud system (indicating the strength of the magnetic fields) and the appropriate mitigation strategy to employ, which may include strengthening the magnetic fields and using centrifuges depending on the scenario. This successful approach eliminated RSS tool failures on multiple rigs and reduced Tool-Failure NPTs drastically by over 47% on average. This paper breaks down, showcases, and elucidates a practical engineering solution to a prevalent drilling problem, with easy-to-follow steps that can be replicated by mud engineers and technicians anywhere in the world.