Development and Evaluation of A Torsional Mechanical Oscillator

Yan Wei

《淡江理工學刊》 24卷4期 (2021/08) Pp. 483-489

https://doi.org/10.6180/jase.202108_24(4).0004

摘要

Self-locked of the coiled tubing regularly occur in the long horizontal interval caused by both spiral deformation and poor performance of hydraulic oscillator, resulting that the drilling hole cannot reach a predetermined position. In order to prevent the coiled tubing from self-lock, a torsional mechanical oscillator was developed by combining the spring storage structure and the tooth staggered structure. Operational principle of the torsional mechanical oscillator was proposed. A calculated model to determine the maximum running depth of the coiled tubing in horizontal section was established, on the basis of the impact load theory and the helical buckling friction theory. The maximum running depths under three different conditions were calculated respectively, including bare pipe, hydraulic oscillator and mechanical oscillator. The calculation results show maximum running depth of the mechanical oscillator increased by 94.7% compared with the bare pipe and increased by 78.1% compared with the hydraulic oscillator. The performance of the torsional mechanical oscillator was evaluated by field test. The field application indicated that the performance of torsional mechanical oscillator is well, and the accuracy of the theoretical calculation is verified.

關鍵字

Coiled tubing ； Self-lock ； Mechanical oscillator ； Impact load ； Running depth