Test Production System

Namdeb

The Ultra Shallow Water Test Production System Feasibility Study was the design of a jacking and walking platform with 3 mining systems and a primary scalping plant for use within the ultra shallow water surf zone done for Namdeb in 2008.

The 8 legged mining and process plant had a modular design for dismantling for long distance site relocation. The Test Production System was designed to obtain a maximum mining federate of 400 tph

Key Specifications

Operational Criteria:
- Maximum mining depth -16m below platform deck level
- Maximum operating depth -7m
- Maximum operational wind speed 25m/s, maximum survival wind speed 40m/s
Platform General Particulars:
- Total platform mass operational 830T, total operational payload 750T
- All 8 legs have jacking & walking capability. 3m jacking length, 2.3m sliding length
- Legs 20m long overall and round rolled pipe Ø900
- Modular design for dismantling for long distance site relocations
- On-board 525V MCC and dedicated platform Hydraulic Power Unit with ring main.
- Fully automated jacking/walking, positioning and platform leveling system
- Platform water supply 3400m³/hr max.
Design Criteria:
- 3D solidworks modeling, full design verifications
- Platform design according to American Bureau of Shipping (ABS) for Mobile Offshore Drilling Units (MODU) and all classification society approvals required
Mining Method:
- Mining front end based on Vertical Attack Mining method
- Three identical Hybrid 250mm annular jetpump & Warman 14/12 3-vane open vane impeller gravel pump arrangements, can pass a 200mm particle. Hydraulic drive
- Hydraulic tool deployment, static head - jetting water
Mining Rate:
- Min. mining rate 23.7m²/hr (at 80% utilization), system utilization min. 76%
- Aver. Slurry feedrate 300tph, max. 400tph. Coarse Slurry aver. 100tph, max. 250tph
Primary Screening:
- Primary scalping done on platform to treat fractions +2mm to -25m
- Scalped oversize overboard, screened product pumped to shore DMS & WIFS plant via floating gravel hose
- Product primary scalping per individual mining system (3-off)
Secondary Plant:
- Beach based Wet Infield Screening Plant infrastructure (WIFS)
- 50T Dense Media Separation Plant (DMS)
- Concentrate transported to centralized recovery plant
Platform Services:
- Beach based skid mounted gravel hose Reel with 350m hose capacity
- All platform consumables supplied via a multi service umbilical hose mounted onto a beach skid with emergency generators, MCC and crew facilities
- Skid mounted gravel booster station
- 30kV/525V Transformer and Switch Gear skid
- Offshore moored plant seawater intake barge with umbilical hose to platform
- Aerial Ropeway System for transfer of personnel and equipment from beach to platform