Effects of nonlinear friction of passive heave compensator on drilling operation — Part I: Modeling and analysis. (1st October 2020)

• Record Type: Journal Article
• Authors: Sánchez, William Humberto Cuéllar; Neto, André Benine; Fortaleza, Eugênio Libório Feitosa
• Is Part Of: Ocean engineering. Volume 213(2020)
• Publication Date: 2020-10-01
• Subjects: Ultra-long drill string -- Compensator-Induced Vibration (CIV) -- Heave compensator -- Longitudinal natural vibration -- Seal friction; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2020.107743
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: This article investigates two effects of seal friction of hydropneumatic Passive Heave Compensator (PHC) during offshore drilling for contact and non-contact operations. The first is the attenuation rate variation of the transmitted heave movement in function of the amplitude of the platform motion. The second is the Compensator-Induced Vibration (CIV), which induces longitudinal oscillations of frequencies higher than the heave motion. These phenomena are explained by an analysis of PHC forces (linearization and frequency spectra) and a modal analysis of the drill string dynamic with PHC (mode shapes and boundary conditions). An active controller is proposed to mitigate the seal friction of PHC in part II of this two part paper series. Highlights: Explanation of two phenomena caused by the seal friction of heave compensators. First: high frequency oscillations of WOB, named Compensator-Induced Vibration (CIV). Second: attenuation variation of the transmitted motion to the crown block as a function of the heave amplitude of platform. Modal analysis of drill string and Passive Heave Compensator ensemble.