Alex Whyte - Rotech Subsea - Subsea UK

Company Overview
HSEQC
Locations
Welcome to Rotech
Controlled Flow Excavation
Equipment
Applications
Case Studies
Oil & Gas & Renewables
Transport
Clients

Reef Subsea Power & Umbilical
-Onshore and Offshore project and
engineering Management
-Installation of submarine cables and
umbilicals
-Trenching
-Remedial and Deburial Services
-Subsea Construction
Via Group companies:
ROV and Survey Services
Seabed Dredging.
Reef Subsea
Established in February 2010
A join venture between:
- GC Reiber Shipping, one of Europe’s premier offshore vessel operators
- HitecVision, leading energy sector private equity investor
Technocean
As part of the Reef Subsea Group,
Technocean provides a
comprehensive range of integrated
subsea services in the following key
areas:
IMR services, Light Marine
Construction, Subsea Intervention,
Trenching, Cable laying and burial
services, Survey & Positioning
services.
S3
•Offshore installation and construction
support services encompassing route
and site surveys
•IRM services
•Decommissioning services
•Precise positioning and survey services
for construction vessel and drilling rigs
Rotech & Scanmudring
Will now be able to offer its clients in
the Oil & Gas and Renewable
industries one of the world’s largest
capabilities in seabed dredging and
excavation services. This will range
from the precise seabed operations
of Scanmudring machines (mainly
Scanmachine and Scancrawler) to
the control/mass flow excavation
capabilities of Rotech Subsea
systems

ISO 18001: 2007
Occupational health and
safety management
HSEQC
Rotech Subsea have an Integrated management System (I.M.S) certified to:
OHSAS 14001:2004
Environmental management
BS EN ISO 9001:2008
Quality management systems
FPAL Accredited
(reference No. 10050953)

Locations
Houston
Texas
Aberdeen
UK
Mexico Dubai
Perth
Australia
Singapore

FACT:
Rotech Subsea are the ONLY company worldwide dedicated to
Controlled Flow Excavation with over 280 projects completed.

High Volume
Low Pressure
Non Contact
Controlled Flow Excavation
(operating on live pipelines &
energised cables)
Excavates all soil types / mud/
sand/ gravel/ rock dump through
to hard clays
Animation of T8000

Equipment
Tools Subsea
Control
Deployment Video Deck Layout Transport
Deployment Methods

Subsea Equipment Tools
All tools are operated using bio-degradable vegetable oil – environmentally friendly
T8000 T4000
R4HP Jetting Systems
Twin R2000

T8000
Height – 6m
Weight – 8 tonnes
Maximum Volume Output – 8,000 litres per sec
Maximum Flow Capacity – 9m per second
Recent Case Study

T4000
Height – 4m
Weight – 5 tonnes
Maximum Volume Output – 4000 litres per sec
Recent Case Study

Twin R2000
Height – 2.6m
Width – 4m
(skid can be adapted for pipes)
Weight – 3.5 mt
Shallow waters
Shore Approach
Recent Case Study

R4HP
Height – 4.5 m
Weight – 6.5 mt
Jetting speed of 8 m/s
Jet Flow rate of 3 m3/s
Jet power of 120hp
2 x T4000 Impellers encased in a single body.
Ideal for access into confined spaces.
Recent Case Study

Jetting Systems
All tools are operated using bio-degradable vegetable oil – environmentally friendly
Augmented Jets
TwinR2
Harder Soils
Twin R2 Central Jets (Video Footage)

Real Time Sonar
Remote Control/Instantaneous Flow
Controlled by Team Leader/Supervisor
Subsea Control
Rotech Staff – All highly experienced full-time staff
Reason Sonar Seabat 9001 - Full Survey Package
T4000
Trenching 10” pipeline
3.5m depth
Trench width approx 10m at top
NCS Survey
(SVS Monitoring System)
Cable loops on Greater Gabbard
-Shows tools ability to excavate on
curved lay down area

Deployment Methods
Vessel/ Crawler/ A Frame/ Drill String Bow Roller (below)
Deployed from the winch of the cable lay ship to pre-sweep for cable installation at the rear

Deployment Video Footage
T8000 DEPLOYMENT T8000 RECOVERY T4000 CLUMP WEIGHT DEPLOYMENT
Operations/rigging:
Two deck-mounted tuggers fore and aft of the deployment location for sonar orientation
(most effective in depths up to 60 mtrs). 60 mtrs + a clump weight system can be used.

Deck Layout & Spread
Deck Space required – typically 10m x 10m Operates from jack ups, barges, & variety of DP vessels
Generic Image

Operational Depths - Extensions
Cutting Depths Extensions
Deepest depth cut : 21m
“Tetra” in Q4 2009
To keep head above seabed,
extensions are placed on tool
reducing spoil intake
2 x 3m extensions

Operational Depths
Shallow Waters - Super low draft (sld) Deep Water Power Pack
Adapted from the current Twin R2000
Operates in shallow waters from 1.4m
Electro-Hydraulic power pack: 3000m
Spec sheet

Harder Soils
Jetting Ring Augmented Jet Twin R2000
High pressure jet ring breaks soils for CFE
Adapted for T4 & T8
Cutting strength up to 200kPa
T8 power pack drives the two jetting units
while the T4 pump drives the Twin R2000 motors
Cutting Strengths 200kPa+
Operates in shallow waters from 1.6m

De-burial & IRM
Applications
CFE is extremely quick to expose pipe or cable for:
Seabed Preparation
Pipeline lowering/Crossings
Decommissioning/Salvage
Rock Dump
Pre-sweeping & Freespan Correction
Operational Depths & Extensions
Pipeline & Cable Trenching
Additional Services – Harder Soils

Repair
Maintenance
Inspection
Abandonment
Recovery
Tie-ins
No divers needed / Safe non contact
We need a good indication of where the pipe
(for example) is, in some cases, we would
cross trench to find pipe direction
Once identified/located, we give information
to DPO’s to keep on line and we start deburial
De-burial & IRM:
CFE is extremely quick to expose pipe or cable for:
Here Rotech worked in 100m water depth.
We removed rock armour in preparation for IRM
work. We re-opened the trench of 3m depth.
Cal-Dive Video
Case Study

- Cleared 2m layers of sand from cap rock
- Removed area (30m x 15m x 2m)
- At 8 locations
Seabed Preparation
East Timor, Jacket Installation
- Allowing jacket legs to be fixed directly to cap rock.
Case Study

Pipeline Lowering & Crossings
CFE Safe Option as Non Contact
Lower the live pipelines & cables in
Alternative to Supports
Less vessel requirement
No diver intervention
Experience gained from projects:
Saudi Arabia – Global Industries
Lowered over 70 pipelines
Original plan was to install supports.
Our lowering rate was 3-5 pipes per day.
Saved client money/time on construction.
Safer with no diver installation.
Pipelines left un-exposed
Case Study

Decommissioning &
Salvage
GOM – Hurricanes
Case Study

Rock Dump Removal
Molikpaq Platform – Sakhalon
Case Study
Typical size and scale of rock dump we can move
Our CFE method is ideal for moving large amounts of rock dump
The client here was installing new pipelines into the platform
Primary method for moving the rock dump was a mechanical grab, concerns were raised regarding damage to existing pipelines
We cleared channels through the rock dump for new pipeline and the grab was not required, we worked from the rock dump vessel
From this project in 2005 we have returned to work here for a number of times for Sakhalin Energy

Pre-Sweeping
& Freespan Corrections
Animations of Freespan Correction
showing before and after footage
Case Study

Firstly trial the area for tool settings/ true kPa
Confirm location with sonar
Pipeline and Cable Trenching
CFE (Non contact) –
Safe method compared to ploughs or sleds
(cause damage with contact)
Power the tool to trench the desired depth
Vessel moves along the pipeline
Transition down to depth specified
Case Study

Oil & Gas
T4 – Subsea 7/Centrica
Twin R2 - Visser & Smit
Hanab
Case Studies
Rotech Subsea…
Latest
Developments
R4HP – Reel Group
/ Invergordon
Renewables
T8 – Red 7 Marine/Fluor
Twin R2 - VSMC

Equipment Transportation

Clients
Want to know more?
Rotech Subsea Ltd
Rotech House
Whitemyres Avenue
Aberdeen
AB16 6HQ
Scotland, UK
iain.buchan@rotech.co.uk
alex.whyte@rotech.co.uk

T8000
Bahamas
CalDive International Inc - Feb 2011
45 – 90 feet depth
Rotechs T8000 mas flow excavation spread was mobilized on board the CalDive pipe lay barge Lonestar.
The work scope was to trench in 10 pipelines offshore the Bahamas.
10 pipelines had been laid in close proximity to each other and the minimum requirement was trenching
them level with seabed. The pipeline details were as follows:
4 x 30” (35” OD)
4 x 24” (28” OD) – one of these had a 4” piggy back line
2 x 14” (16 ½” OD)
Pipeline & Cable Trenching
CalDive International Inc : Bahamas
A total length of approximately 2300 feet of each pipeline was to be trenched.
All 10 pipleines were trenched to specification in 36 1/1 operational hours. An overall progress rate of 3.2m/min
Rotechs “NON-CONTACT” method was ideal in this situation, where a sled or plough could not be used.
CalDive Lonestar Rotechs T8 Equipment
spread on deck
Sonar image showing T8 trenching
3 pipelines simultaneously
Site Images

T4000
Valhall Field Norway - Q2- 2010
75 meters water depth
Vessel: Geosund 52
De-Burial
Subsea 7 Norway/ BP : Valhall Field, Norway
The workscope was to debury designated areas of the 20” concrete coated EKO pipeline to allow access
for a concrete removal manipulator during this re development program.
It was imperative that there was no over excavation creating any freespan.
Rotech firstly cut a perpendicular trench across the designated pipeline area to find that was was buried
at 1.1mtr T.O.P Deburial of the pipeline also required additional 1 mtr clearance below the pipeline for the
concrete removal manipulator access and also to allow safe diver access.
We recommended a 3 mtr trench excavated over a length of 25 mtrs would be sufficient
The T4000 prepared the required area for Subsea 7 to carry out and complete their re development workscope
for BP within the time frame without incident and to clients satisfaction.
Site Images

T8000
West Delta 117, Gulf of Mexico - Aug–Dec 2010
202 feet water depth
Vessel: Adams Vision
Decommissioning
Anglo Suisse Offshore Partners: West Delta 117,Gulf of
Mexico
A platform was knocked over during a gulf of Mexico hurricane. Rotech was contracted to excavate
around 11 bent conductors as part of the decommissioning process.
Rotech’s T8000 excavated an area around the conductor bay to give safe diver access to straight pipe
on the conductors, allowing them to be cut and capped.
The platform and 11 conductors were protruding above the mudline. The structure and debris sitting above
the seabed around the conductors were removed before the T8000 spread and personnel were mobilized
on board the vessel. The final excavation was 44 feet deep and at seabed level was 230feet diameter.
Total excavation time for the T8000 was 277 hours.
Total running time for the equipment including deployment, recovery, positioning and survey was 372 hours.
Site Images

T8000
Gulf of Cambay, West Coast of India - March 2007
20 – 40m water depth
A new 20” gas pipeline was being laid as part of the Tapti Field development.
Part of the route had large sand waves, which had to be removed or lowered to prevent the pipeline
from having serious free spans. Rotech subsea were contracted to lower the sand waves ain order
to facilitate the new installation.
We had to create a 10m wide lay corridor at the base of the sand waves prior to the installation of the pipeline.
There were 19 sand waves, ranging from 3 to 6m in height, 80 to 280m in length, Rotech equipment and crew
were mobilized ion board the REM Fortress. Conditions were challenging, with up to 5 knots and a 5m tidal range.
The sample 3-D image shows the trench that was cut through on particular area.
The lay corridors were cut through the sand waves in a total excavation time of 320 hours,
averaging one sand wave every 17 hours.
Oil & Gas
BG India : Sandwave Pre-sweeping - Gulf of Cambay, West Coast of
India
Site Images

T4000 c/w Jetting Ring
Caspian Sea, Turkmenistan - March-April 2010
60 meters water depth
Clays up to 100kPa Shear Strength
Rotech Subsea USA LLC was contracted to excavate 3 holes to facilitate the setting of a Jack-Up’s spud cans safely.
A Jack-Up had been in place beside the MDP-A Platform in 2007. A new Jack-Up was to be placed in approximately
the same position, but to do so without stabilising the seabed could be dangerous. The existing holes were around
4 – 5m deep and the possibility was that the rig legs could migrate to these existing holes when jacking up. Petronas
asked Rotech Subsea Ltd to excavate three holes approximately 28m diameter x 5m deep in the location where the
latest rig would be placed.
Oil & Gas
Jack-Up Installation - Seabed Preparation : Turkmenistan, Caspian
Sea
Rotech mobilised a T4000 Mass Flow Excavation tool with auxiliary jetting ring and associated pumping spread onto
the DP vessel Marzhan in Turkmenbashi, Turkmenistan.
Grid patterns were set up on the vessel navigation screen over the required spud can locations and 3 holes with
dimensions 28m x 4.5 to 5.3m depth were completed. Total excavation time for the first (Port Leg) hole was 41 hours.
With the vessel and crew becoming used to the unusual application, the Bow Leg hole was completed in 28 hours with
the Starboard one taking only 22 hours excavation time.
Site Images

R4HP
Invergordon Docks, Inverness - April 2011
10 - 16 meters water depth
Unspecified Mud / Silt
Rotech Subsea were contracted to clear mud from spud cans off the Galaxy II Jack Up Rig
The tool was positioned inside the leg of the rig and lowered by tuggers to sea level where the
umbilical was fed out form the quayside and attached by Reel rope access personnel.
Divers were deployed to position tool using slings and chains prior to excavation.
In order for the R4HP to clear the angled surface of the can, a chain ratchet block was used
by the divers to pull the bottom of the tool and create a slight angle. The spud can was completely
cleared in 11/2 shifts. The 2nd spud can was also a complete success.
Total excavation time was 20 hours.
Latest Developments
Spud Can Maintenance : Reel Group - Invergordon
Reel Group were very impressed with the capabilities of the tool, its size and manoeuvrability
and the possibility of having different nozzle and/or configuration.
Site Images

T4000
North Sea, UK Sector - March 2011
60 meters water depth
1” – 5” Rock Dump
MV Seven Pelican
Oil & Gas
The 122mm Eris umbilical had been damaged and Rotech Subsea Ltd
was asked to uncover 1200m of it to facilitate and repair. The cable was
covered by 1m of rock-dump in a water depth of 60m.
The T4000 excavation spread was trucked to Peterhead, NE Scotland,
for mobilization on the MV Seven Pelican. Within 7 hours, the kit was
sea fastened on deck and a wet test was conducted just outside the harbour.
A total length of 1268m of cable was fully exposed in 15 hours excavation time,
with deployment and recovery taking around 20 minutes each way.
Referee; Neil Haigh (Centrica Upstream Energy)
SubSea7 / Centrica : Eris Umbilical Deburial & Repair : North
Sea
“the equipment provided performed exactly as had been stated and in fact outperformed what had been expected. I will definitely recommend Rotech services”
Site Images

Twin R2000LD
Netherlands - May 2011
3 - 15 meters water depth
Sand and Soft Clay
Rotech Subsea Ltd were asked to assist in the NorNed cable repair project, offshore Netherlands.
A 300m length of the 217mm x 136mm HVDC cable needed uncovered, to allow the client to lift it on board
the Fetsy-L(top right) and repair it.
The cable was covered in 1m – 1.5m of sand and soft clay, in water depths ranging from approximately 2m to 8m.
Rotechs Twin R2000LD Controlled Flow Excavation tool was set up and tested on board the Fetsy-L within 6 hours
of arrival.
The 300m length of cable was uncovered to specification in 1 ½ hours excavation time.
The non-contact method of excavation produced by the TwinR2000LD was ideal for this project, with no chance
of damaging the cable.
Oil & Gas
Visser & Smit Hanab : NorNed Cable Repair - Netherlands
Site Images

T8000 c/w Ancillary Jetting Ring
North Sea, UK & Dutch Sectors - Q1- Q2, 2011
50 meters water depth
Renewables
MMT/ABB : Post Trenching of Britned Cables : Southern North Sea
Medium to very hard soils, clay & sand waves
Rotech Rotech Subsea were contracted by MMT to carry out post lay excavation works on the BritNed
interconnector cables, SNS to the required burial depths of 2m
After stringent testing over a section of BritNed cable our T8000 was contracted and deployed from the Olympic Zeuss
to excavate 2 x bundled power cable sections to complete their post lay rectification work. With the size of the workscope
to be completed within given window MMT contracted a second vessel (Stril Explorer) with an identical T8000 spread
to carry out operations from the shallower Dutch sector end of the BritNed work scope to meet with the Zeus coming in
from the UK end of the cable. Soils varied from soft sand to over 100kpa sheer strength.
The jetting ring was only active when we encountered heavy clay to assist with breaking through the surface.
52km of BritNed cable was successfully lowered to the required protection depths of 2m. The workscope was
carried out to specification without incident, safely and the integrity of the Britned cable was never endangered.
Site Images

T8000
Oil & Gas
Pipeline Crossings Persian Gulf
Live Pipeline & Cable Lowering for New Pipeline Installation
Global Industries Ltd for Saudi Aramco/Kuwaiti Oil JV
Saudi Arabia - September 2007 - Duration: 3 weeks
Up to 35 meters water depth
A new pipeline was being laid in the Persian Gulf as part of the Khafji Field Development. Rotech Subsea were contracted
to lower existing pipelines and cables in order to facilitate the new installation.
Scope of Work
The existing infrastructure comprised of 59 no. 4” cables and pipelines of various sizes up to 10” diameter. Rotech were
required to transition these down to 1m cover at the crossing point. The Client would then sandbag these crossing points
and install the new pipeline.
The Rotech equipment and crew were mobilized on board the vessel REM Fortress in Sharjah, UAE. The equipment was set up and tested prior to sailing to
Saudi Arabia. Due to the non-contact method of excavation employed by the Rotech tools, the trenching of the live pipelines was completed with no risk to the
pipeline integrity. The instant controllability of the T8000 allowed our Supervisors to create transitions down to the specified depth and back out.
The 59 crossings were lowered to specification in 65 operational hours. Total time on board was approximately 3 weeks.
Rotech saved the Client significant cost and time compared to alternatives such as installing supports on the seabed for the new pipeline.
Referee - Michael Empey : Global Industries Ltd.

Renewables
Red 7/ Fluor : Post Trenching of Power Cables & J Tube Entry
T8000 c/w Ancillary Jetting Ring
around Monopiles, Greater Gabbard
Greater Gabbard Field, Southern North Sea - Q2 – Q4 2010
10 – 30 meters water depth
Medium to very hard soils & clay
Rotech Subsea was contracted by Red 7 to carry out post lay excavation work of power cables
in Greater Gabbard Field, Southern North Sea
T8000 deployed from Bourbon Enterprise to excavate cable sections and cable loops to complete post lay
rectification work along with J Tube entry around base of monopiles.
Some soils in excess of 100 kPa sheer strength so we included our ancillary ring which allowed us to excavate in
excess of 200 kPa. Once the rings had cut through the heavy clay surface the T8 completed the task on its own.
The power and controllability of this tool along with out full time professional and competent team ensured a safe
and successful outcome.
The clients criteria and specifications were met without incident and the cables integrity was never in question.
The post lay rectification work was carried out safely and successfully to allow Red 7 to complete their required
work scopes for their client
Site Images

Renewables
VSMC / BV : Walney Wind Farm Cable Trenching : Irish Sea
Twin R200 c/w Auxillary Jets
Walney Wind Farm, Irish Sea - December 2010
4 - 12 meters water depth
Dense Sand conditions
Rotech Subsea were contracted to trench 900, of an 8” cable to a minimum 3m below seabed level. An alternative
method of trenching had previously been used, but damaged the cable. Rotech’s NON-CONTACT Controlled flow
Excavation system was therefore ideal for this application.
Prior to commencing the Client requested a trial to show what effect the high pressure jets from the winR200
would have on the nylon cover of the cable. This was carried out on the deck, as the two photos on the right
show the trial in progress and the minimal erosion of the cable cover respectively. The client stated that they
would have expected more damage to occur during the lay process and was more than satisfied with the results.
The 900m length of cable was trenched to a depth greater than 3m below seabed in only 36 hours.
Rotech were then requested a trial trench be excavated in an area where a plough had previously failed to get to
the required depth. Again the Twin R2000 proved its worth, achieving a trench of 1m depth in a single pass.
A sample of the clay was taken and analysed by a Torvane Tester, the shear strength of the sample being 70kPa.
Site Images

Twin R2000 : Harder Soils
*Twin R2000 with props directed towards
each other at a 22 degree angle with high
pressure jets to cut through harder soils
*This joined the flows form the 2 props
directly over the cable to reach the trench
depth but also limit the width of the trench
*Trench 2 m wide and 1.74m deep
The hard rocks were removed using the
control flow of the Twin R2 excavator and
the clay area was cut up using the jets.
Then the CF removed them from the
trenching area.
CF alone would not have managed to dig
into the clay areas.
Some materials that were recovered
during final part of the excavation

T4 Spread
KEY
3
4
Deck Layout & Spread
1
1 – Hose Reel – 2.1m x 2.1 x 2.2 x 5.6Te
2 – HPU – 3.9m x 1.9 x 2.0 x 4.8Te
3 – Spares Container - 6.1m x 2.4 x 2.6 x 8Te
4 – T4000 – 3.8m x 1.9 x 2.5 x 5.5Te
5 – Overboard Chute for Hoses
5
2
T8 Spread
KEY
4
3
1
2
1 – Hose Reel – 3.0m x 3.0 x 3.0 x 12.5Te
2 – HPU – 6.1m x 2.4 x 2.6 x 14.5Te
3 – Spares Container - 6.1m x 2.4 x 2.6 x 8Te
4 – T8000 – 5.9m x 2.1 x 3.2 x 8Te
5 – Overboard Chute for Hoses
5

Underwater Power Pack (UPP)
The Rotech Underwater Power Pack (UPP) replaces the usual topside
diesel-powered hydraulic pump with an electrically driven hydraulic pump
sited with the tool, to permit operation in much deeper water than is
possible with the standard arrangement.
The system is designed to operate to a depth of around 3,000m,
depending on the handling system and umbilical.
APPLICATIONS
♦ Pipeline/Cable Trenching
♦ Decommissioning & Abandonment Excavation
♦ Free Span Rectification
♦ Inspection, Repair & Maintenance Excavation
♦ Pre-Sweeping/Seabed Preparation