12-6-5 AGR Seabed Intervention Track Record seabed Intervention Ltd Union Plaza 1 Union Wynd Aberdeen AB10 1SL, UK Tel: +44 1224 629280 [email protected] SEABED INTERVENTION

AGR seabed Intervention Ltd

Union Plaza

1 Union Wynd

Aberdeen

AB10 1SL, UK

Tel: +44 1224 629280

[email protected]

www.agr.com

SEABED INTERVENTION

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Project name Tangguh Pipeline Trenching & Route Preparation Project

Equipment used SeaVator; V Jets; Dual SeaBat 9002 Sonar

Operator BP

Client Saipem

Location Indonesia

Pipeline diameter 24”

Trench length Multiple short sections of pipeline route preparation – pre-sweeping through sand waves and sediment, dispersing debris and post pipe-lay free-span correction.

Water depth 70m

Soil strength Sand, sediments and soft clays.

Vessel names DSND Surveyor

Comments

This project was undertaken in a very remote location without any regular shore based support. The site conditions were very challenging as the area possessed extremely uneven and rough seabed topography with highly variable soil conditions, including unconsolidated sands and silts, soft mud and stiff clays. Notwithstanding strong seabed currents of up to 1.5m/sec and a 4 metre tidal range the operation was completed successfully.

SeaVator Equipment Spread


Union Plaza

1 Union Wynd

Aberdeen

AB10 1SL, UK

Tel: +44 1224 629280

[email protected]

www.agr.com

SEABED INTERVENTION

Project name Pinghu Oil Pipeline Burial Project (Live Pipeline)

Equipment used SeaVator, V Jet System 1200 HP Version, Dual SeaBat 9002 sonar

Operator China National Offshore Oil Corporation (CNOOC)

Client China National Electronic Equipment Company (CNEEC)/ Merloni TermoSanitari (MTS Group)

Project period 2002

Location Dai Shan Province, South China Sea


Trench Details 3 km, up to 2.9 metres to TOP

Water depth 2 – 27 metres

Soil strength Sand and Clay From 3 – 50 kPa

Vessel names Yang Gang Bo 16

Comments

This project took place in very severe and turbid coastal sea conditions interrupted by typhoons with high prevailing currents of up to 7.2 knots across an estuary. Trenching operations were conducted from a shallow drafted moored barge operated by CNEEC. The majority of the work was conducted in currents speeds of approximately 3.5 knots with the pipeline in a full production at 2000 psi operating pressure.

SeaVator & V Jet Assembly (Parallel Orientation)


Union Plaza

1 Union Wynd

Aberdeen

AB10 1SL, UK

Tel: +44 1224 629280

[email protected]

www.agr.com

SEABED INTERVENTION

Project name PTT 3rd Pipeline Trenching Project


Operator PTT

Client Hyundai

Project period March to November 2006

Location Thailand


Trench length Several discrete sections of pipeline trenching along a total pipeline length of 90 km

Water depth 40m

Soil strength Clay soils with strengths from 5 kPa to 300 kPa.

Vessel names MV Sartu Santabong

Comments

Generally the upper 1.5m of seabed consisted of sand and gravely silts in some areas and 1 to 50 kPa clays in other areas. For such soils the SeaVator with 1,200hp V Jets was used. In order to carry out the job efficiently a SeaVator with 4,500hp V Jets was also used areas possessing higher soil strengths to achieve the required excavation depth.

SeaVator & Multi – Jet Assembly


Union Plaza

1 Union Wynd

Aberdeen

AB10 1SL, UK

Tel: +44 1224 629280

[email protected]

www.agr.com

SEABED INTERVENTION

Project name LGTS Green Stream Project

Equipment used SeaVator; V Jets (both 600 and 1,200 hp versions); Dual SeaBat 9002 sonar

Operator Agip

Client Saipem / Sonsub

Project period September 2003 to July 2004

Location Libya and Sicily


Trench length Total of 30 km in section lengths of 3km to 7km trench depth various; 14km to 1.5m; 6km to 3.5m; other areas to 4.0 and 5.0m trench depths

Water depth 4.5 - 55 metres

Soil strength Loose sand; dense sand; weak sand stone & clays up to 37 kPa

Vessel names MV Polar Prince; MV Sentinel; MV Skandi Inspector

Comments

This project required a wide range of different trench depths in a variety of soil conditions. In addition the SeaVator & V-Jet systems were used to excavate areas up to 0.5 km in length and 5 metres deep to allow inspection and repairs to the pipeline and to bury boulders and debris under the pipeline. The SeaVator (using tilt beam) was also used to backfill sections of trench.

SeaVator & V – Jet Assembly (Perpendicular Orientation)


Union Plaza

1 Union Wynd

Aberdeen

AB10 1SL, UK

Tel: +44 1224 629280

[email protected]

www.agr.com

SEABED INTERVENTION

Project name Giovanna field IRM


Operator ENI

Client Saipem/Sonsub

Project period February/March 2008

Location Adriatic Sea

Excavation Depth Down to 3m below seabed

Water depth 42m – 80m

Soil Strengths Loose sands, natural backfill, some stiff clays

Vessel name Texas Horizon

Comments SeaVator was used to debury a variety of pipelines for inspection/repair work. V-jets were deployed to dig some areas of stiff clays to allow access to the underside of trenched pipelines.

SeaVator & V Jet Assembly (Perpendicular Orientation)


Union Plaza

1 Union Wynd

Aberdeen

AB10 1SL, UK

Tel: +44 1224 629280

[email protected]

www.agr.com

SEABED INTERVENTION

Project name Ormen Lange Southern Field Extension Route Preparation Project

Equipment used ClayCutter X; AquaDrive SeaVator

Client StatoilHydro

Project period July 2008

Location Offshore Norway

Trench Width 5m

Trench Length 1500m

Water Depth 870m

Soil Strength Clay from 15 kPa to 440 kPa Shear Strength

Vessel name Island Valiant

Comments

ClayCutter X was mobilised in conjunction with AGR’s new build trenching pumps to prepare the seabed around the Ormen Lange field. In total 3,400 m3 of clay was excavated at rates of up to 500 m3/hr. The excavation was split between 10 separate sites of varying complexity and soil strength. Overall the project was completed in 17 days, compared with an initial prognosis of 32 days for 1975 m3. All of the equipment performed flawlessly and the project was completed without any harm to personnel or the environment.

Pre-Excavation 3D DTM Post-Excavation 3D DTM


Union Plaza

1 Union Wynd

Aberdeen

AB10 1SL, UK

Tel: +44 1224 629280

[email protected]

www.agr.com

SEABED INTERVENTION

Project name Black Tip Pre-Lay & Post-Lay Intervention Project


Client Saipem

Project period September 2008 to February 2009

Location Darwin, Northern Australia

Pipeline Diameter 18” & 12” Pipelines

Water depth 70m

Vessel name Miclyn Endurance

Comments

The SeaVator scope of work included pre-pipelay sweeping of sand waves and post-pipelay freespan correction. The upper 1.5m of seabed consisted of sand and gravelly silts in some areas and 1 to 50 kPa clays in other areas. For such soils the SeaVator with 1,200hp V Jets was used.

Pre-Excavation 3D DTM* Post-Excavation 3D DTM*

*Images produced by Fugro for AGR


Union Plaza

1 Union Wynd

Aberdeen

AB10 1SL, UK

Tel: +44 1224 629280

[email protected]

www.agr.com

SEABED INTERVENTION

Project name Trans Gas Indonesia Pipeline Repair Project

Equipment used SeaVator 60 bar Monojet ; Dual SeaBat 9002 Sonar

Operator TGI

Client Global Industries

Project period February/March 2009

Location Offshore Sumatra, Indonesia

Excavation depth 2m below seabed

Trench length Variable

Water depth 50m

Soil strength Loose sands, clays up to 100 kPa

Vessel name Sanko Angel

Comments

SeaVator was used to excavate boxes around a pipeline to enable access for clamps prior to a hot tap. Soils were expected to range up to 100 kPa so a high pressure pump and extended central jet were employed to cut these stiff clays. Once on location the soils ranged up to 395 kPa, beyond the capability of the equipment, but soils up to 100 kPa were excavated successfully – well beyond the usual operating limits for mass flow equipment.

SeaVator & Mono – Jet Assembly


Union Plaza

1 Union Wynd

Aberdeen

AB10 1SL, UK

Tel: +44 1224 629280

[email protected]

www.agr.com

SEABED INTERVENTION

Project name Ekofisk Cessation Project

Equipment used AGR Disc Pump Dredge System

Operator ConocoPhillips

Client Heerema Marine Contractors

Project period June-August 2009

Location Norwegian North Sea


Water depth 50m

Soil strength Loose sands, grout bags, general platform debris

Vessel name Thialf

Comments

Excavation of loose sands and general debris from around platform risers and piles prior to cutting. The work was performed using AGR’s unique CTS high-flow area pumps as the distance required for discharge of the spoil was greater than could be achieved using traditional ejector pumps. The equipment coped well with a very challenging range of platform debris which included cable trays, gloves, grout bags amongst other detritus. The work was performed under the AGR frame agreement with HMC.

CTS pump skid and LARS in position on the Thialf


Union Plaza

1 Union Wynd

Aberdeen

AB10 1SL, UK

Tel: +44 1224 629280

[email protected]

www.agr.com

SEABED INTERVENTION

Project name Baltic Beta Spud Can Excavation

Equipment used AGR Disc Pump Dredge System

Operator PetroBaltic

Client PetroBaltic

Project period June-August 2010; May 2011-March 2012

Location Baltic Sea


Water depth 80m

Soil strength Clays to 180 kPa, small boulders, grout bags, general platform debris

Vessel name Granit

Comments

Excavation of clays and debris from around jackup legs & spud cans to allow access for dive inspection. Combination of AGR Disc pump and high pressure jetting system gave good progress even in soils much stiffer than prognosed. Work continued on the other legs in 2011.

ROV arm and dredge pump suction head in action


Union Plaza

1 Union Wynd

Aberdeen

AB10 1SL, UK

Tel: +44 1224 629280

[email protected]

www.agr.com

SEABED INTERVENTION

Project name North Scarp Excavation

Equipment used ClayCutter X with Coiled Tubing and Fall Pipe ROV

Operator Chevron

Client Van Oord

Project period July 2010-May 2011

Location NW Shelf Australia


Water depth 650m

Soil strength Overconsolidated carbonate silts to 180 kPa

Vessel name Tertnes

Comments

An entirely new deployment system was devised for this ClayCutter X job. The workscope involved excavating around 4,000 m3 of soil from a subsea scarp feature to enable the export pipeline to be laid in the most direct route. Due to the high variation between the top & bottom of the excavation area (80m) a system utilising composite coiled tubing for water transport and a heavily modified fall pipe ROV was designed, built & tested. The system gave excellent results in terms of ease of deployment, low pressure losses through the conduit and accuracy of positioning of the ClayCutter X.


Union Plaza

1 Union Wynd

Aberdeen

AB10 1SL, UK

Tel: +44 1224 629280

[email protected]

www.agr.com

SEABED INTERVENTION

Project name Ormen Lange Mid North Extension

Equipment used ClayCutter X deployed on drillpipe

Operator Shell

Client Shell

Project period February 2011-October 2011

Location Offshore Norway

Excavation depth Up to 9m below seabed

Water depth 900-930m

Soil strength Clays from 15 to 440 kPa

Vessel name Island Valiant

Comments

A return to the Ormen Lange field saw a substantially greater workscope compared to the 2008 campaign. In all 42 separate sites were excavated, giving a total volume of excavated soil of 25,000m3. The largest single site required 4,698m3 of soils to be removed and the deepest seabed penetration was 9m. The project was completed with minimal mechanical downtime and without serious HSE incidents.

Documents

12-6-5 AGR Seabed Intervention Track Record seabed Intervention Ltd Union Plaza 1 Union Wynd Aberdeen AB10 1SL, UK Tel: +44 1224 629280 [email protected] SEABED INTERVENTION