Session: 06-09-01 Offshore Industry: Aquaculture, Mining, etc. I

Paper Number: 120922

120922 - Design Challenges of Riser and Lifting System for Ultradeep Sea Mining 

Recent exploration has generated a resurgence of interest in ultradeep sea mining. Deepsea mining industry has revealed many potential fields in the water depth of 4,000 to 6,000 meters. Different from risers used in the oil and gas industry, deepsea mining risers will be towed to cover fields with areas many times of a football field. The bottom end of the riser needs to be freely moved both vertically and horizontally. This paper investigates design challenges of a riser and lift system used for ultradeep sea mining.

As application moves to ultra deepsea, design challenges of a Riser and Lifting System (RALS) increase in terms of riser design, analysis, installation and global performance. This paper first introduces the state of the art of a typical Riser and Lifting System (RALS) used for ultradeep sea mining. The RALS design issues cover riser wall thickness, tension limits, and high payload. The installation concerns come from hook capacity limit, riser Vortex-Induced Vibration (VIV) when the riser is disconnected, and riser bottom drift caused by vessel motion during installation. This paper further investigates the coupling between the risers and floating platform, riser VIV, and riser dynamic performance. Examples are given to illustrate design challenges of the RALS in ultradeep sea mining.

This paper finally summarizes the design challenges of RALS for ultradeep sea mining. In addition, this paper also explores likely solutions to the design challenges.

Presenting Author: Chenteh Alan Yu American Bureau of Shipping

Presenting Author Biography: Alan Yu is the manager for global engineering and was the Subsea Director for ABS responsible for the development of subsea related business and as a subject matter expert for riser and subsea equipment related engineering for the client. Alan has more than 35 years of riser and subsea engineering experience since he graudated from Ohio University with a MSME degree in the early 80's. He worked through design, project engineer, engineering manager, and project manager for deepwater riser and well system projects; Hoover, Holstein, and Perdido oil and gas projects and Nautilus Mineral's deepsea mining project. Alan is actively participating API 2RIM and API Standard 2RD task groups for contributing to the formulating and reviewing of both standards. Alan has published more than 15 technical papers and has 5 US patents.

Authors:

Jing Hou CNOOC
Chenteh Alan Yu American Bureau of Shipping
Yongming Cheng Beaver Offshore, LLC
Cheng Zhang South China University of Technology