The operator's drill rate management process is designed to maximize rate of penetration (ROP) in every foot of hole drilled. Due to its quantitative nature and the degree to which it is incorporated into all phases of the drill well process, the operator believes it to be the industry's first comprehensive ROP design process. The workflow is being implemented uniformly across an organization drilling approximately 4.5 million feet of hole per year in a wide range of rock types, directional profiles, and international locations. The results to date have been similar in most applications with significant gains in ROP, bit life, and reduction in tool failures related to vibrations.
The workflow evolved from surveillance techniques the operator developed to utilize Mechanical Specific Energy (MSE) surveillance to evaluate drilling performance in real-time(1),(2). MSE surveillance proved to be an effective aid in identifying bit and system inefficiency. However, having this knowledge does not ensure the team knows why the inefficiency is occurring, or how to correct it. There are organizational processes that must also be considered when mitigation of the problem involves increased mechanical risk, significant changes in established practices, or a high level of technical training. MSE is a technology, while the ROP management process is a broad workflow designed to ensure MSE and numerous other sources of data are used effectively to maximize ROP. Consistent implementation of the workflow has been shown to achieve consistent increases in ROP. The key elements of the workflow required to achieve this performance are discussed.
Over 40 categories of ROP-limiters have been identified, of which only 4 are directly related to the bit. The ROP in a large portion of footage drilled is constrained by factors other than bit performance, which are referred to as non-bit limiters. The workflow addresses both bit and non-bit limiters equally, and includes a simple model to aid drill teams in prioritizing the large number of potential ROP-limiters so resources available for surveillance and redesign are used most effectively.
Performance improvements have been sustained since the staged rollout began in late 2004, and additional gains are continuing. Performance data is included, as well as a discussion of key implementation learnings.