A NOVEL EXPERIMENTAL APPROACH FOR INVESTIGATING TORSIONAL VIBRATION IN A CASING STRING DURING ROTATION

Abstract

This paper introduces an experimental model of a casing string designed to analyze and understand its dynamic behavior during installation operations that necessitate rotation. Casing rotation is a known method to reduce axial drag and reach TD, especially in MFHW. Implementing this technique as part of routine drilling procedures has only been hampered by “the will to do it” and the availability of tools that make it easy. The severity of this procedure is that the casing string cannot be tripped to a target depth with low wellbore quality or a large, relatively displaced vertical ratio, which may lead to severe consequences such as non-productive time (NPT), additional cost, complications in the bottom hole, abandoning the wellbore, and many others.By focusing on torsional vibrations, we aim to uncover key insights into the frictional interactions and vibration modes that occur during casing running situations, especially rotating while running. We developed an experimental setup that simulates the dynamic behavior of a running casing string. Using aluminum alloy tubing to represent downscaled casing stiffness, the setup incorporates rotary sensors along the tubing and an electromagnetic brake at the lower end to generate torque, which creates the frictional resistance between the casing and walls of the wellbore. This system replicates the interactions between rotation speed and torque. We capture real-time and high sampling rate data and analyze how these variables affect the system’s dynamic performance during casing running. The experiments revealed a direct correlation between rotation speed, acceleration, system friction, and torque in casing running operations. As the speed increased, torque increased, indicating higher frictional resistance and a reduction of torsional vibrations. The setup effectively simulated the operational dynamics, showing that increasing rotation speed reduces torsional vibrations, which can positively improve operational efficiency and load handling across the casing string. These insights are crucial for optimizing parameters to minimize vibrations, enhance performance during casing runs, and avoid damage.