Scientific and operational consequences of non-conventional model testing in deepwater ocean basins Antonio Carlos Fernandes LabOceano & LOC, COPPE/UFRj. Rio de Janeiro, Brazil E-mail: acfernandes@oceanica.ufrj.br Abstract This paper aims to recall several lively studies made at MARIN, LabOceano and LOC in the last ten years. The following are the experiences to be addressed: the feasibility and installation of the BSR (Buoy to Support Risers); the feasibility and operability of the PIM (Pendulous Installation Method) and the directional stability of the torpedo anchor during launching. The paper describes the model tests, the properties of each system and several scientific achievements and actual installations in full scale. Keywords Model testing; BSR; PIM; torpedo anchor; VIV; fluttering; directional stability. 1 Introduction The offshore industry offshore in Brazil has grown very fast in the last ten years. Even before the discoveries in Pre-Salt this was a fact. However, this growth was not only quantitative. Due to new challenges to face the deepwater scenario, new developments have been necessary. New deepwater wave basins come along at the same time and they have been used wisely to support this new technology. In fact, the basin could anticipate problems such that, when finally going to full scale, the uncertainty is very small. The present paper addresses three non-conventional concepts that did not exist a decade ago but are now concrete reality in full scale. In particular, to have their feasibility assured, they have in common extensive model testing in deepwater model basins such as the one in LabOceano. The paper reviews the concepts, it reviews the model tests results and it indicates both scientifically and operationally the consequences. The three concepts are the following: the BSR, the PIM and the torpedo anchor. They are described briefly here. Later the paper presents more details. The BSR (Boia deSuporte de Risers- Buoy to Support Risers) is a submersed buoy (typically lOOm - 250m below the free surface) that is held in place by tendons connected to the sea bottom. It supports two risers systems, the SCR (Steel Catenary Riser) system from the BSR to the sea bottom and the jumper system that connects the BSR to the FPSO (Floating Production, Store and Offloading). See Figure I. The PIM (Pendulous Installation Method) is an alternative procedure to install heavy devices (typically 300 tons) on the sea bottom from the free surface. See Figure 9. Finally, the torpedo anchor is a pile that is installed in the sea soil due the kinetic energy that it acquires after launching above the sea bottom (typically 100 m). See Figure 16. Manuscript submitted to MS&OT on July 04, 2013. Accepted on February 25, 2014. Editor: MarceJo A. S. Neves. AArtic1e posted on1ine on August 21,2014. URL: www.sobena.orgbr/msot/v01ume.htm. Vol. 9 No. 1 pp. 59·69 June 2014 Marine Systems & Ocean Technology 59