This month, I would like to bring out some thoughts on the advancements that have been made in the tubular area, an important and complex system that has a very, very small diameter/length aspect ratio and a high slenderness ratio, making it a thin wall.
Sometimes, while flying at an altitude of 35,000 ft, I think of a drillstring and the fact that, if I could hold it from the plane, it would be touching the ground. Amazingly, we are trying to predict the health of this long string in a constrained wellbore with a few sensors at the bottom. It is like saying I will touch your toe with a few instruments and then predict the health of your whole body. The greatest challenge is being able to bring together all aspects of tubulars to advance in lockstep with one another. We have advanced tremendously not only in the modeling but also in materials and manufacturing technologies. Tubular manufacturing, recommended practices for material strength, and wear are important for drillstring integrity. We have seen in recent years many technological advancements in tubular-manufacturing technology. Tubulars also have become part of the data-transmission network and slowly will converge with the data-handling and data-transmission systems. Common thoughts for drilling engineers—when it comes to planning and drilling—often focus on torque and drag, which concern tubulars. Even though we have advanced in the prediction of torque, drag, and hookload estimation, challenges remain concerning drillstring integrity, such as prediction of tool failures, buckling, and string stability.
Can we couple fewer casings? Various underlying arguments could be made to answer this question. In the world of exponential technologies, there are many opportunities where we are breaking the status quo to reduce nonproductive time by providing shorter connection times. One of the emerging technologies is brazing of the connection, leading the way to coupling fewer casing runs, which can be automated very well in the future with an autowelding tong on the rig floor instead of casing tongs as the casings are run into the hole.
I have selected papers that present a balanced perspective on the advancement of tubulars technology. Also, I would like to encourage attendance at the tubular session in the upcoming SPE Annual Technical Conference and Exhibition in San Antonio.
This Month's Technical Papers
What Vacuum-Insulated Tubings and Casings Bring to Thermal Wells
Improving Casing Integrity by Induction Brazing of Casing Connections
Collapse Analysis of Perforated Pipes Under External Pressure
Recommended Additional Reading
SPE 180437 Structural-Casing/Soil Interaction Effects on Wellhead Motion by Udaya B. Sathuvalli, Blade Energy, et al.
