Nov 1, 2022 · The dynamics characteristics of BHA related to the drill bit cutting rock from soft to hard formation in air drilling: (a) axial displacement of drill string; (b) radial displacement of BHA; (c) whirling velocity of BHA; (d) the rotation velocity of BHA.

Dec 1, 2024 · In this study, short wellbores with a length of 110 mm are established near each drill string node. Since the lateral displacement of the top drill string node is restricted and a wellbore is not established at this node location, the number of short wellbores is 99.

Li et al. (2021) utilized Miner's linear cumulative curve to predict the cumulative damage of drill string under continuous vibration. Huang et al. (2023) found that the lateral deformation increases with the weight on the bit (WOB), while the rotational speed has a …

Jan 25, 2023 · The lateral displacement of drill string reaches the highest at a water depth of around 1300 m. If the current velocity is larger, then lateral displacement of drill string is greater. When the current velocity is 1.21 m/s, the maximum …

Sep 25, 2024 · Based on Fig. 5(a), it can be observed that the lateral displacement of the drill string remains within the gap between the drill string and borehole wall, indicating that in a vertical well, the drill string moves close to the center of the borehole without colliding with its walls.

Taking the drill string as a pinned-pinned rod its lateral vibrations and resonance regimes on basic and higher (the third) frequencies are modelled. The classical Galerkin technique and the method of harmonic balance are utilized.

Eccentric loading configurations which include the lateral reaction to mud flow pressure, compression, bending forces and twisting moments are incorporated in the derivations. The bending- buckling deflections and twist angle dynamics following drill string drive motor voltage changes are provided.

Jan 1, 2012 · Mihajlović et al. [11] conducted a series of experiments to understand friction-induced vibrations and self-sustained lateral vibrations due to an unbalanced mass in the rotor system. They carried out numerical investigations and studied coupled torsion–lateral vibrations.

Lateral vibration of the drillstring is known to result in fatigue failures, excessive wear, washouts and measurement while drilling (MWD) tools failures. It often results from drillcollar eccentricity, leading to centripetal forces during rotation, named as whirling.

According to the Laplace transform method and the relationships among parameters of the model, the solutions to complex impedance at the bottom of the drill string are obtained, and then the comparison results are analyzed, which is the lateral inertia efect …