Wellbore Tubulars-2018

We are at the cusp of Industrial Revolution 4.0, with the cyber-physical system establishing a synergy between computation and physical components. In lockstep 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.

This Month's Technical Papers

Study of Expandable-Tubular Collapse Leads To Risk-Based Strength Development

Risk-Based Statistical Approach To Predict Casing Leaks

Reliability-Based Casing Design Unlocks Reserves in a High-Pressure Gas Field

Recommended Additional Reading

SPE 188321 Intelligent Drilling System: Expanding the Envelope of Wired Drillpipe by O. Sehsah, Saudi Aramco, et al.

Robello Samuel, SPE, is a technology fellow at Halliburton based in Houston. He has more than 30 years of multidisciplinary experience in domestic and international oil and gas drilling and, for the past 12 years, has held concurrent adjunct-professor appointments at the University of Houston and the University of Southern California. Samuel has published 13 books and more than 270 technical publications. In 2013, he received the SPE Gulf Coast Section Drilling Engineering Award, and, the following year, he was named an SPE Distinguished Lecturer. Samuel holds BS and MS degrees in mechanical engineering and MS and PhD degrees in petroleum engineering from The University of Tulsa and is a member of the JPT Editorial Committee. He can be reached at robello.samuel@halliburton.com.