Session: 11-07-01 Petroleum Production: Offshore Systems and Subsea Operations

Submission Number: 175152

A Floating Structure with Subdued Vertical Oscillations Under Wave Excitations 

The advancement of reduced-motion floating offshore structures is key to unlocking new frontiers in the marine environment. Primarily, these structures are indispensable for improving offshore operations in ever deeper waters required for petroleum production, ocean energy harvesting, and ocean mining. Critically, these stable platforms are driving the energy transition by facilitating the expansion of the exploitation of renewables, such as offshore wind farms and the utilization of ocean thermal energy, among others. Looking ahead, the use of reduced-motion platforms can be extended to support future resource developments, such as subsea mining in deep and ultra-deep waters, and to ensure the stringent requirements of safety for offshore petroleum wellbore intervention.
Research and developments has been conducted in the past, aiming to efficient and effective solutions for floating structures offering low cost and low downtime in operations. In the present research, an investigation is conducted about the vertical motion behavior of an innovative floating structure equipped with an air chamber in the floater´s hull aiming to reduce the heave motion excited by waves. In a previous study, a mathematical modeling for the air chamber influence on the heave was presented and the fundamentals of the heave oscillation dynamics of the floating structure were studied through laboratory tests in a water tank using a simplified model geometry. Moreover, a numerical routine was also developed to solve the vertical equation of motion of the structure based on simplified formulations to address external oscillatory vertical forces.
In the present study, computer simulations of the heave of the floating structure in waves has been carried out. The vertical motion of the structure is estimated with the modified Morison´s formulations for fluid forces and including the effects of the air chamber. Computer simulations have been run for cases of irregular waves with Jonswap spectrum, in order to show the subduing effect of the air chamber on the heave.

Presenting Author: Celso Morooka University of Campinas

Presenting Author Biography: Bachelor degree in Naval Engineering at University of Sao Paulo (USP), Brazil, 1981
Master of Science degree in Naval and Ocean Engineering at Yokohama National University (YNU), Japan, 1983
PhD degree in Naval and Ocean Engineering at University of Tokyo (UT), Japan, 1986
Professor at University of Campinas (UNICAMP), Brazil, since 1988

Authors:

Pedro Kalid Bacellar University of Campinas
Caio Cesar De Oliveira Trigo University of Campinas
Sergio Nascimento Bordalo University of Campinas
Celso Morooka University of Campinas