Technology Focus: Wellbore Tubulars (June 2018)

Abstract

Technology Focus We are at the cusp of Industrial Revolution 4.0, with the cyber-physical system establishing a synergy between computation and physical components. In lock-step with the technologies, as we move toward Well Construction 4.0 coupled with 360° well-engineering optimization for the ultimate delivery of partial to full automation, an important but complex component to be considered is tubulars in the well. Tubulars are associated with the drilling system, which is complex and dynamic, with a ratio of length to diameter greater than 100,000. For comparison, for a human hair to have the same length-to-diameter ratio, it would have to be 60 ft long. So, reliability is important in such a highly oscillatory, uncertain, high-dimensionality framework. Tubular modeling should bridge deterministic models and data-informed models. This calls for data-informed, engineering-guided, reinforced reliability- or risk-supported models to describe the non-Gaussian drilling system more realistically. Risk-based design is very important, especially for these complex systems, because a deterministic approach may not provide a strong underpinning to the reliability estimation of the downhole tools. We have to reduce the probability of failure. One of the areas that needs to be considered is a risk-based design for tubulars that formally identifies the elements and areas of risks by using probability of failure to capture uncertainties rather than incorporating safety factors in the deterministic calculations. Risk should be considered during the design phase, which will allow more freedom to make adjustments, and during the drilling phase. Doing so will also help improve the 360° well-engineering optimization and the additional computational components needed for the future cyber-physical system. I have selected papers that are structured toward this approach with example problems and solutions. Recommended additional reading at OnePetro: www.onepetro.org. SPE 188321 Intelligent Drilling System: Expanding the Envelope of Wired Drillpipe by O. Sehsah, Saudi Aramco, et al.