Shelf Subsea Pty LtdGeotechnical

Capability Presentation

Overview – Shelf Subsea Capability

Shelf Subsea offers marine and commercialdiving services within both Australia andInternationally. We own and operate our ownvessels, diving and coring equipment, andprovide dedicated, proven assets andexperienced personnel for geotechnical drillingtasks, particularly in the NW Shelf area.

Diver Operated Rig - Specifications

The Shelf Diver Operated Drilling Rig is aproven design with a number of featuresthat provide efficient drilling in a variety ofconditions. Key features include:

1. Compact footprint for easy deployment.

2. Hydraulic head slide and adjustable hydraulic legs

3. Hydraulic breakout tool

4. Lay down, two position mast for launch, recovery, ease of maintenance and transport

5. Two hydraulic supplies for controlled drilling, with main weight in mast for better drilling

6. Both Electric and Diesel power packs and water pumps

7. Mud tanks and drilling fluids

8. Three core barrels

9. 30m of casing and 90m of drill rod

10. SPT hammer and 30m of SPT drill rod

Dive Support Vessels

Shelf own and operate 3 x 26m LandingCraft each fitted with large capacityHIAB cranes suitable for the launchingand recovery of the drilling rig. Theseversatile craft are capable of beachingoperations and can embark a completeoffshore diving spread in addition to allcore drilling equipment.

Proven Experience

Shelf has conducted numerous geotechnical drilling projects in the past fewyears, and can provide a number of experienced personnel who are familiarwith this work.We have previously provided drilling services to URS for the DPA Liquids Berthproject.The next slide provides some details of the performance on this campaignand indicative rates for drilling.

Dampier – URS Drilling Rates

Dampier Port Authority Liquids Berth Project - Geotechnical Investigation for URS

Shift Time Start Drill Meters No: of SPT Holes Drilled Hole No: Depth (m) No: of Days

23-May-03 12hr Mob Day BBH424-May-03 24hr 5 3 BBH4 BBH4 9.00 225-May-03 24hr 4 BBH23 BBH23 12.00 326-May-03 24hr 6.5 4 BBH7 BBH7 6.50 427-May-03 24hr 6.05 1 BBH22 BBH22 12.45 528-May-03 24hr 9 3 BBH10/6 BBH10 9.00 629-May-03 24hr 15.3 4 BBH6 BBH6 23.70 730-May-03 24hr 18 5 BBH11 BBH11 25.00 831-May-03 24hr 14.5 4 BBH5 BBH5 15.25 9

1-Jun-03 24hr 22.95 6 BBH8 BBH8 22.95 102-Jun-03 24hr 10.7 1 BBH9 19.96 113-Jun-03 24hr 12 3 BBH12 BBH12 12.00 124-Jun-03 24hr 1 3 BBH30 135-Jun-03 24hr 14.52 3 BBH30/BBH31 BBH30 26.00 146-Jun-03 24hr 16.51 5 BBH31 BBH31 26.10 157-Jun-03 24hr 13.5 8 BBH15/BBH29 BBH15 8.50 168-Jun-03 24hr 13 6 BBH25/BBH21 BBH25/BBH21 6.5/ 6.5 179-Jun-03 24hr 6.5 3 BBH32 BBH32 6.50 18

10-Jun-03 24hr 16.5 9 CBH4/CBH5/CB CBH4/CBH5/C 5.5/5.5/5.5 1911-Jun-03 24hr 19 8 BBH24/BBH1 BBH24 6.50 2012-Jun-03 24hr 13 8 BBH16/BBH20 BBH16 6.5/6.5 2113-Jun-03 24hr 5.5 4 CBH10 CBH10 5.50 2214-Jun-03 24hr 14.7 3 BBH19/BBH2 BBH19 9.00 2315-Jun-03 24hr 8.2 3 BBH3/BBH18 BBH3 8.20 2416-Jun-03 12hr 2.5 2 CBH2 CBH2 9.58 25

436.67 TOTAL METRES DRILLED

17.47 Daily average drilled metres (assumes 23-5 mobilisation) not including SPT

198.635 SPT metreage

25.41 Total daily Average

URS/GHD – Koolan Island

Shelf demonstrated our abilities to work in remote regions and in adverse conditions by mobilising to Koolan Island, Far North WA.

Scope of Work

• 12 bore holes to 30m

• 1 bore hole to 54m

• 10m tides

• Remote location

• Environmental approvals

• 2 Vessels and DGPS

Shark Bay (Douglas & Partners)

Scope of Work

• 3 x bores to 3m near Bar Flats

• 3 x bores to 3m near Beacon 9

• 2 x 3m and 1 x 15m bore near the existing jetty

• 24hr Operations

• 2 x Vessels

• DGPS survey

Apache Energy Projects

John Brookes Platform Site

• 2 x 75m boreholes in 70m of water

• Completed in Saturation

• Deepest diver drilled boreholes in Australia

• 30hrs to drill 75m

Twickenham Platform Site

• 12 x 4.7m x 8 5/8in Rockbolts

• 18 x 4.7m x 9 1/2in Rockbolt

• 24hr Operations

• 2 Vessels

• DGPS survey

• Environmental approvals

McDermott – Pipeline Stabilisation

Scope of Work

1. Design and manufacture a new twin mast drilling rig

2. Design new power packs, water pumps and umbilicals

3. Install 912 x 4.7m x 8 5/8 Rock bolts

Scope of Work

• 2 x 25m cores

• 4 x 6m cores

• 4 x 6m Vibrocores

• 24hr operations

• 2 Vessels

• DGPS survey

ROC Oil – Cliff Head

Additional Projects

ClientDates of

OperationWorks Description

Chevron 2015 25 pair of rockbolts on the Gorgon Gas export line

Sapura Clough 2013Pipeline stabilisation, diver installation of approx. 1500 pairs of

rockbolts using custom built rockbolting rig

Coffey Geotechnics 2008 Six near shore boreholes drilled to 30m subsea (Cape Lambert)

Maunsell Australia Pty

Ltd2007

Diver operated seabed drill rig for 6 core sample retrieval at the

new Oakajee wharf.

GHD 2006 Three near shore boreholes drilled to 8m (AMC)

Worley / Chevron 2004 Gorgon Nearshore Geotechnical Investigations - 43 boreholes

Mechanical Clam Shell Grabs

• Grab Type Clamshell• Number Wires Single wire lift• Activation Method Surface Supply Hydraulics• Grab Capacity 0.5m3 and .75m3

• Grab Tare Weight 1.0Te to 1.5Te

These two mechanical clamshells grabs were designed and built in 2008 for aproject for Vermilion Oil and Gas Australia.

The project involved the removal of over 170Te of rock dump in 54msw atthe Wandoo B platform prior to the installation on a new drilling template.