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As part of The Tricontinental Group continual improvement process the groups subsea intervention operations and diving
assets as with construction and NDT activities will now be managed by our Port Harcourt Base devolving from our Lagos

Tricontinental has been created with the specific intent of providing the West African Oil & Gas Industry with a unique
integrated subsea and topside engineering and construction capability.  Tricontinental intends, as we progress, to provide
Survey and Positioning services independently or in support of ongoing diving and ROV projects.

Tricontinental overall capability is further enhanced by the provision of Field
Engineering Services and Drawing Office facilities. These facilities support TOSL Fabrication and Welding workshops at Port Harcourt. Welding procedures are qualified as per ASME IX. From March 2001 to date TOSL has fabricated and installed high- pressure production flowlines for Mobil Producing Nigeria in accordance with ASME B 31.3 with zero defects. TOSL also provides Offshore Maintenance, NDT and Construction Services to Mobil Producing Nigeria.

Base Equipment and Facility

The Tricontinental Base area which is leased from Atlantic Marine & Oilfield Services   Limited is situated at Damagix Yard,
Plot 312 PH / Aba Expressway, By Izzi Motors B/Stop, Port Harcourt, Rivers State and Warri Address ; Branch Office,
Natony Km 5, New Port Expressway, By Chevron, Warri, Delta State. It has an office complex and large expanse of land
for storage. There are standby generators for 24hrs lighting and an efficient water supply unit.

The Jetty is 78m in length with 21m width with strength of approximately 500 ton sqm. Currently, (At the time of writing) Noble Drilling has their Jack Up (MODU) Percy Johns alongside carrying out refurbishment and general maintenance works.  Tricontinental is involved in third party NDT inspection of sections of the pipework.

There is also a wasteland mooring section beside the jetty of approximately 100m and is fitted with pin pile moorings to which vessels can secure when the jetty facilities are not required by them.  The Jetty has substantial lighting with adequate work area.





The base has an industrial workshop which is 78m by 60m. This has the capabilities of handling major welding and fabrication works.There is also a smaller industrial workshop for industrial works.

Equipment at the base includes, but is not limited to the following:

  1. 2 nos of Crane (40T and 120T)
  2. 1 nos of Forklift (4T)
  3. 3 nos of Welding machines, Lincoln (2 electric &1 diesel)
  4. 1 nos of Compressor
  5. 3 set of Blasting equipment
  6. 1 set of heavy duty Pneumatic Jack (Vessel jack up)
  7. 2 fuel dumps (diesel & fuel)

Our Environmental, Health and Safety (EHS) performance has been exemplarily to dae. Tricontinental Oil Services Limited commitment to EHS issues and the welfare of our employees is central to our business philosophy.

Continual improvement of indigenous resources central to the business objectives of Tricontinental Oil Services Limited. As part of this process we have set up our operations base in Port Harcourt. 





Tricontinental primary Topside services include but are not limited too:

Field Engineering
Field Engineering Surveys have been carried out by TOSL experienced engineers at numerous offshore locations. Typical surveys include the design of new process piping routes in particular the hook-up of production flowlines from the xmas tree to the manifold. Surveys are undertaken using either manual or laser targeting techniques. The survey of platforms for the production and maintenance of as-built drawings is another area of expertise undertaken by TOSL

Detail Design
TOSL operates from state of the art Engineering Design and Drawing Office facilities at Port Harcourt. Our CAD department produces computer aided design engineering drawings from the information collated by our field engineers. Our highly skilled Nigerian CAD operators turn-around drawings in a timely manner without the need for overseas technical support.

TOSL actively supports the development of Nigerian procurement supplies and has an in-house local procurement unit. In addition The Tricontinental Group has established overseas procurement bases in London, United Kingdom, Houston, United States of America and South Africa for coordination of procurement activities with Client approved Vendors and manufacturers for materials and equipment and logistic activities through these offices.

Onshore Fabrication
Fabrications are undertaken to support our Subsea activities with pipe clamps, repair bracings and Subsea protection cages being an example.  In addition TOSL specialises in the fabrication of production flowlines and high pressure process pipework in carbon and exotic materials in accordance with ASME B 31.3





Coded Welding

Since March 2001 TOSL has recorded zero defects in welding of Mobil Producing Nigeria’s high pressure production flowlines. Weld Procedures have been qualified in accordance with ASME IX and witnessed and approved by Bureau Veritas in the United Kingdom. Welders are qualified in accordance with ASME IX and are routinely monitored during production welding to ensure compliance with the relevant approved Weld Procedure Specification (WPS). Small bore pipework in both carbon and stainless steels are welded using the Tungsten Inert Gas (TIG) welding process ensuring zero defects.

Inspection & Testing
All fabricated items are subject to material traceability when required and compliance with industry codes of practice. Prior to dispatch all fabricated items are dimensionally checked against the ‘Approved for Construction’ (AFC) drawings. SOSL also owns Pressure Testing Equipment rated to 10,000 PSI with time and temperature recorders. All Non Destructive Testing (NDT) requirements are undertaken by approved third party NDT contractors. The relevant inspection reports are collated forming part of the ‘Quality Package’ which proves compliance with the customer’s requirements.

Offshore Flowline Installation
TOSL has from March 2001 to date installed Crude Oil Production Flowlines and Gas Injection Lines for Mobil Producing Nigeria. All installations have been achieved without the need for offshore field-welds. This has significantly reduced the installation time ensuring that wells flow at the soonest opportunity. TOSL has engineered, fabricated and installed 6” x 1.25” WT high pressure Gas Injection Lines within six days from the xmas tree being stabbed in place by the drilling rig.

Offshore Maintenance & Construction
TOSL also undertakes general offshore Field Maintenance activities such as platform shutdown’s and valve change-outs, boat landing removal and replacement, process pipework re-routing as well as remedial platform repairs.

Continual improvement is central to the development of the Nigerian workforce of TOSL, in order to ensure that new technology and working practices are implemented into the workplace. .

Without question our indigenous workforce provides products and services of a quality equal to anywhere in the world.



The company is committed to providing adequate and frequent training to ensure personnel have the knowledge and expertise to execute their Health and Safety roles and responsibilities.

TOSL acknowledges the importance of ensuring the competence of its employees. Because of this it will satisfy industry standards to verify the competence of relevant personnel.  Where appropriate, personnel will be processed through Procedures and Standards to obtain qualification. The company will provide documented procedures for identifying the training needs for each discipline and a job description is prepared for each discipline.

Air Diving

TOSL has two (2) full specification air, and mixed gas surface supplied dive spreads.  The systems are housed in a 20 foot container containing the deck Decompression Chamber (DDC).  The DDC has a two diver capability, with O² Built in Breathing Systems (BIBS) facility both in the entrance lock and the main chamber.  All BIBS have overboard dump capability.   Mounted within the container is the three (3) diver control panel.  Most panels have a mixed gas capability and underwater video monitoring system.  The second container is eight by eight feet containing the compressor units.  These units are high and low pressure electric.  Also in the container is the high pressure hard plumbed, air banks for diver / chamber back up supply.  Both containers are air conditioned and come with their own IMCA specified diver deployment systems with two man dive baskets, man riding winches and clump weight system, and if so required a wet bell

The company utilizes a Computer Aided Inspection Reporting System (CAIRS) which is currently being used as the inspection reporting management tool for a number of subsea inspection, repair & maintenance contracts.



TOSL also operate direct satellite email communications at the company’s operations base located at Port Harcourt. This will allow for real-time project management and reporting on a global network.
TOSL has a full range of subsea inspection and construction equipment and spares consisting of but not limited too:

Construction Equipment

  1. HP Water Blasting Units.
  2. WACHS Cold Cutting Equipment.
  3. Hydratight Bolt Tensioning Equipment.
  4. Full Range of Rigging Equipment.
  5. Hydraulic Tools.
  6. Pneumatic Tools.
  7. Full Range of Air Lift Bags.
  8. Grouting Equipment.
  9. Pressure Testing Equipment.
  10. Water Pumps.
  11. Broco Cutting Equipment.
  12. Zodiacs.

    Inspection Equipment
    • Magnetic Particle Inspection (MPI) Equipment.
    • Cathodic Potential (CP) Meters.
    • Ultrasonic Wall Thickness (UT) Meters.
    • Flooded Member Detectors. (FMD)
    • Subsea Digital Cameras.
    • Eddy Current Systems.
    • Underwater Colour (SIT) Video Cameras.
    • Close up Weld Cameras.
    • Computer Aided Inspection Reporting Systems.



    Subsea Inspection

    TOSL conducts Detailed Underwater Inspections (DUI) for the Oil and Gas, Telecommunications and Maritime Industries.

    Oil and Gas
    TOSL has extensive experience in all aspects of underwater inspection for the Oil and Gas Industry.  These inspections range from General Visual Inspections by video to comprehensive detailed inspections of major Subsea Structures and associated appurtenances.  Further to this Classification Society Inspections are carried out on Vessels, Mobile Offshore Drilling Units (MODU’s) and FPSO’s in the field.


    The rapid expansion of the Telecommunications Industry has lead to a reciprocal expansion in the range of underwater services provided in this arena.  TOSL therefore provides a full range of Subsea support and maintenance services to this industry.  These Services include but are not limited to: cable inspection, burial/de-burial, maintenance, cable crossings, tension checks and cable protection services.

    Maritime - Shipping

    TOSL’s underwater participation in the Maritime Industry takes two distinct forms.  Namely, these are Shipping and Civil Engineering, The services conducted for these industries are Underwater Inspection, Underwater Construction and Underwater Maintenance.

    Shipping Inspection includes but is not limited to the following:



    Classification Society Inspections,
    Vessel hand-over Inspections,
    Post Cleaning,
    Non Destructive Testing,
    Cathodic Potential readings,
    Collision/Grounding Damage and Pre-salvage Inspections.

    Maritime – Civil Engineering

    Civil Engineering underwater inspection includes but is not limited to the following:

    Cathodic Protection surveys in the form of Impressed Current Anode Inspection, Cathodic/Anodic Protection Assessments and general Inspections and surveys for Jetties, Sea Ports and Seawalls, Intakes Refineries, Coastal Erosion Surveys etc.

    Inspection Personnel  

    Generally all of TOSL’s underwater inspection operations are carried out by certified Inspection Divers under the direction of an Underwater Inspection Coordinator and the Diving Supervisor.

    Our detailed underwater Inspection Manual outlines all procedures and methodologies for conducting underwater inspection and our inspection personnel hold the quality and accuracy of inspection data in the highest regard.

    The following qualifications are a standard requirement for the TOSL Inspection Personnel.

    Inspection Divers                       

    1. CSWIP 3.1u
    2. CSWIP 3.2u
    3. ASNT Level I, II & III
    4. Lloyds Register of Shipping Approved Diver Inspector (Visual)
    5. Lloyds Register of Shipping Approved Diver Inspector (MPI)
    6. CSWIP/Lloyds/PCN/ACFM Operators Qualification        




    ROV Inspectors                           -           CSWIP 3.3u – ROV Inspector

    Inspection Coordinators           -           CSWIP 3.4u – Underwater Inspection Controller






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       Current Projects


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