In 2005 the operator implemented a workflow that ensured drilling performance limiters were identified, redesigned, and extended continuously. The use of mechanical specific energy surveillance to address bit limiters and dysfunction has previously been published. The purpose of this paper is to discuss additional practices that have been developed to extend the non-bit performance limiters, particularly those related to borehole quality.
There have been over 40 non-bit performance limiters identified and redesigned globally. While these are diverse, those with the greatest global impact were found to be tied directly to borehole quality. Consequently, in 2008 the performance management workflow was modified to increase awareness of borehole quality as a performance limiter. The result was that acceptable borehole quality became defined as that which would not limit footage per day. Quality is now redesigned to the "economic limit of performance" in the given interval. The economic limit of performance is a significantly higher standard than the common industry objective for borehole quality, which is to achieve low trouble time and run casing successfully.
The average drilling footage per day drilled by the 23 operations that have been active since the performance management process was implemented has improved by about 63%. Instantaneous drill rates have typically increased 100-300%. Advances in bit and non-bit limiters appear to have contributed equally, and the majority of the gain in non-bit limiters has come from improved borehole quality. Other gains have come from related limiters, such as an increased understanding of the manner in which cuttings transport and tripping operations are controlled by borehole quality.
The paper discusses the technical models that are used to understand the major borehole limiters, the engineering design and the real-time practices that have been developed, as well as the field results.