Understanding SMS Behavior to Define the Subsea Mining Operating System

摘要

Seafloor deposits are a very promising source of mineral ore for the near future, discovered over the last 40 years. In particular, Seafloor Massive Sulphides (SMS) are very high grade hydrothermal mineral deposits distributed on the mid ocean ridges, arc and back arc basins in the deep confines of the world oceans. The most commercially attractive minerals are copper and gold, combined with large quantities of lead, zinc and silver. The first deposits that will be developed are located in 1600 to 2000 m water depth. Production will start on a commercial level by 2011.Applicable cutting and lifting technologies must be defined and tested rapidly so that the full production system can be engineered and built in a very short time frame. Existing oil and gas deep water developments is a proven source of technology that can be used as the basis of knowledge and experience to meet this challenging schedule.As a company at the forefront of deepwater developments, Technip is deeply committed to this new industry. A strong and comprehensive R&D effort has been put together to characterize the ore, its behaviour under load, its effect on the lift system and all related flow behaviour within the riser system.The R&D effort is split in four topics, all closely inter-related:A - Rock characterization performed in cooperation with Ifremer which has made available its SMS samples gathered over 30 years of deepsea exploration campaigns to determine mechanical and chemical behaviour of the SMS.B - Crushing test in hyperbaric conditions to evaluate the effect of pressure on cutting forces and determine rock size distribution.C - Slurry transportation models were performed using state of the art CFD modelling, both in two-phase and three-phase flow. This will be confirmed through large scale test loop experiments.D - Abrasion tests have been performed to select the preferred liner material for jumpers and risers. These liners will be tested in the test loop to confirm their behaviour over time.This paper describes the test program, provides the main available results and identifies the way forward to meet this technological challenge.