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Oil located in deep offshore reserves now account for around 30% of the conventional resources that remain to be found worldwide. Accessing them, which means coping with the deepwater conditions, rough seas and sometimes isolated reserves with complex fluids, is of central importance to our energy future. With its experience in deep offshore operations and its ongoing innovation strategy, the Exploration & Production branch at TotalEnergies, a pioneer and one of the leaders in this field, is able to tackle the daily challenges related to producing this oil from reserves found in very deep waters.

TotalEnergies A Pioneer and Leader in Deep Offshore

Imaging, characterizing and simulating flows from new deepwater reserves

Evaluating new deepwater reserve resources and related uncertainties is complex but vital for the dimensioning of future production facilities. New reserves are being discovered in increasingly deep waters with new geological characteristics (for example, post-salt carbonates). The key elements for estimating the reserves and optimizing surface facilities are:

  • seismic imaging of these reserves,
  • an understanding of the dynamic heterogeneities of these new fields,
  • an optimization of the number of wells and of recovery techniques.

Reducing the costs of deep offshore project development and operation

D’ici peu, toutes les opérations de production et de traitement par grande profondeur d’eau seront installées au fond de la mer.

The biggest savings have been achieved via efforts to optimize and reduce drilling time as well as new operational strategies based on automation, standardization and even industrialization of subsea equipment and industrial synergies where possible.

Some technologies, having now reached a high level of maturity, allow us to safely envision standardizing a number of designs and items of equipment that can bring technical costs and execution time down.

Implementing new subsea solutions will be another way to cut costs, as has already been demonstrated with the subsea separation rolled out in a world’s first on Pazflor (Angola) in 2011. The innovation reduced the overall cost of this huge-scale development by 7%. Over the longer term, the new, entirely subsea architecture concept Deep Export Production Treatment Hub (DEPTH®) will make it financially feasible to access reserves that are too far from coasts or too small   to justify floating production units. On the seabed, this fully integrated subsea plant will safely handle all the treatment operations necessary for extracting products ready for refining and exporting to land via subsea tie-backs that are several hundreds of kilometers long.

To meet the electricity requirements generated by this massive use of subsea processing, TotalEnergies is working to develop breakthrough technology for subsea electricity transportation and distribution, with three main goals:

  • improving the energy efficiency of its developments
  • increasing the distance that AC electricity can be transported
  • acquiring electrical equipment that can withstand the enormous pressure of deep waters

Access to deep offshore satellite reservoirs

Some DEPTH® technology bricks that will be available in the shorter term will enable us to substantially cut the costs of developing these peripheral reserves, which most often represent 20 to 200 million barrels.

We anticipate substantial savings in various areas, such as water injection with the Subsea Process and Injection Gear for Seawater (SPRINGS®) project, the first subsea sulfate removal and treated seawater injection unit, which has already been successfully tested in deep waters. By making it possible to eliminate a surface-connected high-pressure water injection line, its roll-out will significantly reduce the costs of developing satellite reserves located over 50 kilometers from a floating production storage and offloading (FPSO) unit.

Another example, our new subsea chemical product storage and injection concept, meets this same objective. It is one of the innovations designed to meet the challenge of all-electric subsea production systems that make it possible to stop using umbilicals containing hydraulic fluid and chemical product lines. Envisioned in the design studies for the next satellite reserve developments, the local chemical product storage and injection solution will make it possible to cut costs up to 35%.

Facilitated oil transportation

LedaFlow®, a new multiphase flow simulation code, is one of the technological levers necessary for making qualitative leaps forwards for managing flow assurance in the context of increasing depths and lengthening subsea lines.

Improved modelling of the fluid dynamics, making more reliable and accurate calculations possible, now give it a clear competitive advantage in the area of simulating unstable flow regimes. Its performance, which has been improving continuously thanks to increased R&D efforts, will make it an essential tool for optimizing the design and economy of production and transport lines.

The ongoing development of simulation tools, together with detailed analysis of the kinetic aspects of our fluids’ hydrate formation, made it possible to introduce the NADAH approach (New Approach of Design Against Hydrates). This allows us to relax design constraints for subsea production line thermal insulation and therefore to lower the cost of subsea networks by operating in zones, thermodynamically favorable to hydrate formation.

Asset integrity guaranteed by new subsea technologies

Un AUV Total pour l’inspection des pipelines deep offshore d’ici 2017.

New subsea technologies for inspection, monitoring, maintenance and repair should emerge to guarantee the integrity of TotalEnergies’s mature fields and the operability of our facilities over time, all at an optimal cost. An autonomous underwater vehicule (AUV) for acoustic and visual inspection of pipelines was the first example of this, enabling optimized and much less costly inspection campaigns. In the mid-term, the goal is to have a multifunctional resident AUV that can be kept underwater for several months and used in the facilities at any time.

The design of new risers for ultra-deep offshore operations

The emergence of new exploration targets at depths of 3,000 meters or more requires us to expand the operational windows of existing technologies and deliver breakthrough technologies for drilling, developing and producing in a cost-effective way at these depths. Today, risers are one of the most critical links in the ultra-deep offshore chain, for drilling and production alike. Composite materials lighter than steel will be indispensable for this so that beyond a certain length, these pipelines can bear their own weight. To secure a reliable solution in an optimal timeframe and ensure that the offering is diversified, TotalEnergies is investing in the qualification of innovative solutions in partnership with several manufacturers.

Reducing greenhouse gas emissions linked to the production of our fields

Lowering the greenhouse gas emissions of our deep offshore assets is a major part of our goal of achieving carbon neutrality by 2050. To this end, and at the request of our affiliates, we are launching studies related to all deepwater aspects:

  • optimizing the number of wells and factors involved in field recovery
  • a strategy for halting flaring and consumption of fuel gas
  • energy efficiency assessments for our deep offshore facilities
  • replacing and optimizing topside equipment
  • studies for concepts routing a supply of electricity from land
  • studies for capturing and storing CO2 in the fields, where possible

We also share our experience and expertise with operators of deep offshore assets that we partner with, to ensure that these assets follow the right path for our operated assets.

Deepwater’s contribution to our emissions-reduction goals is key and, together with reducing the costs of our developments, is a major priority.

16 Mt CO2eq in 2020

Deep Offshore: an approach based on ongoing innovation

Recognized by the profession as a pioneer and historic inventor in deep offshore operations, TotalEnergies began innovating with subsea technologies in the late 1960s. Since that time, this trailblazing attitude has continued, allowing TotalEnergies to accompany its conquest of deep waters with major industrial milestones and new industrial standards.

  • TotalEnergies began its deep offshore operations with the commissioning of its first FPSO, Girassol, in Angola - Exploration & Production - Angola
    TotalEnergies began its deep offshore operations with the commissioning of its first FPSO, Girassol, in Angola.
  • Dalia Angola
    TotalEnergies possesses high-level expertise in FPSO design and managing on-board safety. Dalia in Angola.
  • Pour gagner en flexibilité opérationnelle, l’organisation des topsides évolue tout au long de la vie du champ. Akpo, au Nigeria 
    To improve operational flexibility, the topsides structure changes throughout the lifetime of the field. Akpo in Nigeria.
  • Constructing an FPSO requires considerable expertise in managing large projects. Pazflor in Angola.
    Constructing an FPSO requires considerable expertise in managing large projects. Pazflor in Angola.
  • CLOV Angola
    Building an FPSO takes approximately ten million work hours over two years. Clov in Angola.

Past innovations

  • 1967: First underwater production well, constructed at a depth of 40 m and 1,200 m from a host platform (Anguille Marine, Gabon).
  • 1976: First subsea production station with three production wells on a template, and first step in subsea robotics for wellhead maintenance (Grondin Northeast, Gabon).
  • 1983: Frigg Northeast, the first subsea gas project in the North Sea, operated from six subsea wells controlled remotely from the Frigg platform located 18 km away (Norway).
  • 1987: Frigg East, the world’s first subsea project, developed, maintained and operated without divers and opening the way to deep sea operations (Norway).
  • 2001: Girassol, the largest development to date at a depth of 1,400 m (Angola). Its riser towers, a technological first, is one of the many innovations that earned it an award at the 2003 Offshore Technology Conference (OTC) (Angola).
  • 2002: Canyon Express, the deepest development to date (2,250 m), producing three gas fields simultaneously in the Gulf of Mexico (US).
  • 2003: First tension leg platform installed at a depth of 800 m, with surface wellheads in the Gulf of Mexico (US).
  • 2007: 20-km tieback constructed at a depth of 1,400 m to connect Rosa to the FPSO unit Girassol, a technological first for a field of this size and at such a depth (Angola).
  • 2008: K5F, the first subsea project in the world to use electrically-activated wellheads. A world first was achieved in 2016 with the start-up of a new, entirely electric subsea well (Netherlands).
  • 2008-2012: World’s first industrial polymer injection pilot for deep offshore enhanced oil recovery (EOR) on the Dalia field (Angola).
  • 2011: Pazflor, the world’s first development deploying subsea systems activating production combining gas/liquid separation and next generation pumps in several fields, distinguished with an award at the 2013 OTC (Angola). 
  • 2012: A pilot of electrical trace heated pipe-in-pipe (ETH-PiP), an innovative technology for heating subsea pipelines, is launched on the Islay field in the North Sea (UK).
  • 2014: SPRINGS® tested at a depth of 500 m, confirming the excellent performance of this subsea device for treating seawater (Republic of the Congo).
  • 2015: Laggan-Tormore, the first subsea-to-shore development (West of Shetland) of two isolated reserves whose gas is exported to shore via a 143 km subsea tieback. It was distinguished with an award at the 2016 International Petroleum Technology Conference (IPTC) (UK).
  • 2016: First subsea high boost multiphase pump, developing a power of 3.5 MW, on Moho Phase 1b, a complementary development to the Alima brownfield (Republic of the Congo).
  • 2018: Total’s first use of a development plan based on a hybrid loop on the Kaombo project (Angola).

TotalEnergies: a Leading Deep Offshore Operator

Today, deep offshore accounts for nearly half of TotalEnergies’s production and represents close to 70% of its exploration goals for the 2018-2021 period.

Global deep offshore production between 2000 and 2035

Global deep offshore production between 2000 and 2035.


Deep offshore: an expanding strategic activity

TotalEnergies’s developments, which are focused mainly in the Gulf of Guinea, have made it the leading deep offshore operator in West Africa in terms of production. However, the scope of its operations in this area is now expanding significantly thanks to new mining permits in eastern and southern Africa, as well as Asia and the Americas, the latter becoming an area of significant activity for TotalEnergies with Brazil, the Gulf of Mexico and most recently Surinam.


TotalEnergies’s Angola Exploration-Production subsidiary demonstrated the Company’s capacity for innovation by developing Block 17 and then Block 32, at the same time proving its cutting-edge operational expertise. This takes the form of a total production maintained at nearly 600,000 barrels per day and competitive operation costs of around $5 per barrel thanks to logistics synergies and, more broadly, operational ones implemented in this very prolific block.

Block 17 and 32: cutting-edge operational expertise

  • 9,000 square kilometers
  • 27 discoveries
  • 6 FPSO units commissioned in 18 years (Girassol, Dalia, Pazflor, CLOV & Kaombo Norte and Sul)

Priority on managing risks specific to deep offshore operations

Performance and profitability requirements remain subject to the absolute priority of managing every risk, in particular the specific risks inherent to deepwater operations.

Controlling oil eruptions

After the blow-out of a competitor’s exploration well in the Gulf of Mexico, TotalEnergies collaborated with other industry players to develop new technologies and equipment (leak capture and well confinement) to be able to respond to a major accident of this type as quickly as possible. Confinement measures adapted to its subsea production wells in the Gulf of Guinea have also been developed internally and an entity dedicated entirely to introducing emergency responses has been created in the Deepwater & Subsea product line.

In November 2013, TotalEnergies also carried out a wide-ranging exercise in Angola to prepare to react optimally to a major marine pollution incident. In March 2019, to test this response in as realistic conditions as possible, TotalEnergies held another large-scale exercise in which it rolled out the first capping system in Africa. With the success of these exercises, TotalEnergies increased its ability to respond to marine pollution incidents and has shared what it learned in the oil industry as a whole.

Système de réponse d’urgence sur les puits subsea (SERS) – images fournies par OneSubsea

Subsea Emergency Response System (SERS) project – images courtesy of OneSubsea

Fighting marine pollution effectively

The development of Spill Watch, an internally developed operational chain devoted to monitoring and forecasting oil slick drifts, made it possible to make a qualitative leap forwards in the reliability and accuracy of drift forecasts.

Subsea monitoring

Involved in a vast program aimed at qualifying new subsea spill detection technology, TotalEnergies has also designed an observatory for real-time monitoring of subsea geological incidents.