deep water seabed intervention - iploca · deep water seabed intervention jan vlak – operations...

1

Deep Water Seabed InterventionJan Vlak – Operations Manager

Van Oord Offshore Offshore and EPC Contractors

2

Subsea Rock Installation

Rock installation in deep and shallow water o Pre lay support for subsea pipelines, cables and

structureso Post lay support for the stabilization of subsea

pipelines and cableso Scour protection around structureso Ballasting

Equipment o Flexible Fall Pipe Vessels (FFPV)

For deep water installation up to 1500 meters o Side Stone Dumping Vessels (SSDV)

For shallow water installation to 30 meters

Offshore and EPC Contractors

3

Offshore and EPC Contractors

4

Deep water seabed intervention using excavation techniquesHow deep?Two projects: 1. Nothern Scarp Australia – 625m / 657m2. Polarled, Norway – 115m / 375m

Offshore and EPC Contractors

5

Northern Scarp Australia Scope of WorkPreparation of the Jansz Field pipeline route

ClientChevron Australia Pty Ltd

LocationAustralia, Gorgon/Jansz Field

Offshore and EPC Contractors

6

Northern Scarp Australia

Offshore and EPC Contractors

7

Northern Scarp Australia

Profile of the northern scarp crossing project

Offshore and EPC Contractors

8 m to be removed

-/- 657 m !!

8

Northern Scarp AustraliaSoil conditionso CPT = 2.5 – 3.5 MPa.o Hard Silt o Su = 80 – 200 kPa

Offshore and EPC Contractors

9

Northern Scarp Australia

Primary approach: o Flexible Fall Pipe Vessel Tertneso Equipped with FPROVo And High Pressure Jetting Device (Clay Cutter)

Offshore and EPC Contractors

10

Northern scarp Australia

Key elements of the Primary Approacho Pumps at deck levelo Composite coiled tubing in combination with Fall Pipe ROVo Higher accuracy of controlling excavation tools (Fall Pipe ROV)o Back up / alternative tool – Clamshell Grabo Option to install rock

Offshore and EPC Contractors

11

Northern Scarp Australia

Primary approach: o Unfortunately, the “hose” failed.

Offshore and EPC Contractors

And then????

12

Offshore and EPC Contractors

13

Northern Scarp Australia

Primary approach:

o Flexible Fall Pipe Vessel Tertneso Equipped with FPROVo And High Pressure Jetting Device (Clay Cutter)

Alternative approach: o Clamshell Grab or

Deepwater Excavation System (DES)

Offshore and EPC Contractors

14

Northern Scarp project

Plan B – Deep Excavation System

Offshore and EPC Contractors

15

Northern Scarp project

Plan B – Deep Excavation System (movie)

Offshore and EPC Contractors

16

Northern scarp Australia

Offshore and EPC Contractors

17

Northern scarp Australia

Project progress

Offshore and EPC Contractors

18

Northern scarp Australia

As built main trench

Offshore and EPC Contractors

19

Northern scarp Australia

Client satisfaction

“I would like to express my gratitude and admiration for the crew of the Tertnes that has done all the hard work.

It has been a bit of a difficult start, but with the grab as an add-on to the FPROV all of you have once again demonstrated the outstanding ability and agility of Van Oord and Tertnes to achieve the extraordinary.”

Offshore and EPC Contractors

20

Polarled Norway

Scope of WorkRemoval of high peaks on the Polarled Route by FFVP Tertnes in deep excavation mode at 115 – 375 m waterdepth

ClientStatoil

Location50 locations along the Polarled pipeline route Norway

Offshore and EPC Contractors

21

Polarled Norway

Offshore and EPC Contractors

To be removed

22

Polarled Norway

10,000 m3 of excavation saves 350,000 m3 of rock

Offshore and EPC Contractors

23

Polarled Norway

Soil conditionso Soft Clayo Su = 10 – 50 kPao Risk of some Hard Clay

and Cobbles/Boulders

Offshore and EPC Contractors

24

Polarled NorwayCorals

Offshore and EPC Contractors

25

Polarled Norway

Dedicated disposal area’s

Offshore and EPC Contractors

26

Polarled Norway

Offshore and EPC Contractors

27

Polarled Norway

Offshore and EPC Contractors

28

Polarled Norway

Offshore and EPC Contractors

29

Polarled Norway

Location

Offshore and EPC Contractors

30

DEEP EXCAVATION SYSTEM (DES)

Conclusions o Two projects have been very successfully executedo Two very happy clientso Combination of Grab with FPROV gives good positioning controlo Good control of deposited materialo Grab Excavation System gives very limited turbidity (Coral)o Van Oord has a patent on Deep Excavation System.

Offshore and EPC Contractors