CLAROM ACTIONS
- Competence groups -

CLAROM actions are carried out through four principal research axis, operated by competence groups. They are the principal places where CLAROM mission of exchanges is accomplished, around a common basis of knowledge on offshore structures.

Competence groups are followings :

• state of arts on a subject being not studied in France;
• seminar on subjects operated by one or several CLAROM members;
• prospective reflections on subject needing further works from CLAROM members.

Competence groups as proposal sources:

Reflections on former points will guide competence groups to propose precise actions to be launched by CLAROM in their fields of intervention:

• state of the arts financed by tickets;
• launch of R&D projects to be supported by the CEP&M or the European Union, or by JIPs;
• participation of CLAROM to international actions (common seminars, participation to existing JIPs…);
• revision or writing of practical guides;
• training actions.

The Marine Geotechnics group focuses on the following technical areas:

• seafloor characterization and survey down to 600 m depth below the mudline,
• platform foundation engineering,
• anchor and suction caissons design,
• pipe-soil interaction.

A major objective of the current research projects is to integrate local geotechnical measurements with continuous seismic data (high to very high resolution) to improve the extrapolation of soil data around geotechnical boreholes.

Particular attention is given to deep to very deep offshore conditions, where geohazards (slope failures, mud volcanoes, shallow gas, shallow water flow, …) can threat exploration drilling and subsequent field development activities.

> Leaders

The fields of interest of the Hydrodynamic and Meteocean competence group are:

• hydrodynamic behaviour of structures in marine environment;
• marine environment (waves, wind, currents) better understanding.

Large variety of floating structures are studied : semi submersible, TLPs, Spars, FPSOs or even jackets or compliant towers, as well as their subsea connections: rigid or flexible risers, mooring lines.

In the Meteocean domain the recent projects have been mainly oriented toward a better description of design waves for the offshore structures.

In the Hydrodynamic domain the non linear behaviour of offshore structures under the action of waves has been studied: damping of slow drift motion, springing and ringing, free surface elevation. These works are carried out from the theoretical, numerical and experimental points of view, in order to optimise the different approaches, and to obtain design tools and methods.

Studies running at present time are about:

• freak waves and rogue waves;
• definition of design waves (HOUDIM)
• change in wave conditions near the shore (ECOMAC)
• dynamic behaviour of riser systems under the effect of VIV induced by wave and currents (HYDLINES)
• prediction of roll at resonance and mooring efforts on production barges.

> Leaders

The competence group Materials and Structures focused on structures behaviour and innovative concepts. Structures that are considered are designed for the offshore exploration and production:

• Floating structures for which the experience return is accessible as well as new concepts for the different geographical zones;
• Structures fixed on sea bead: new concept studies, prolongation of life of existing structures on mature oilfield, structures for arctic environment;
• Risers and moorings systems;
• Equipment on sea bed such as new hydrocarbons processing systems.

Effects of mechanical loadings on structures, as well as potential of new materials are also studied:

• Use of new materials and new applications of traditional materials: high strength steel, thermal insulating materials, composite materials, synthetic cables, high performance concrete;
• Material behaviour with or without protection systems: mechanical strength, corrosion, fire, impacts;
• Advances in materials technologies and assembling methods;
• New structural concepts;
• Structure behaviour under mechanical and thermal loads (static and dynamic) or exceptional ones (impact, explosion, fire), the different models;
• Inspection, maintenance, and repair;
• Probabilistic approach of structural integrity.

> Leaders

The competence group ‘Flow assurance’ is the last created of the CLAROM groups. The concept of ‘Flow Assurance’ is in fact quite new and has appeared as a consequence of the deep offshore production conditions.

Deep offshore oil and gas production needs several specific constraints to be taken in account:

• Inaccessibility: technological risks, components qualification, specific installation and maintenance methods, costs and duration of interventions, needs of modular systems, installation lifetime
• Operating conditions: network of high productivity wells, preponderance of the hydrostatic pressure, high level of headlosses, low temperatures
• Hydraulic and thermal: multiphase gas/oil/water/solids flow, needs for minimal flow-rates, thermal management of the flow and of the physic chemistry phenomenon
• Well maturation: water flow increasing needing large water treatment, decrease of reservoir’s pressure
• Hydrostatic pressure at the sea bottom: thickness of materials, water tightness
• Long length: satellite and marginal fields.

All these parameters show the multiplicity of disciplines involved in the ‘Flow Assurance’. Although principal activity is focused on following items:

• Modeling of permanent or transient regimes (shut down, restart, severe slugging, terrain slugging)
• Thermal insulation of riser systems
• PVT data and physical properties of fluids
• Physic and chemistry of hydrocarbons mixtures (hydrates, wax, asphaltens)
• Corrosion, erosion, and production control;
• Well bore modeling (cross-flow, coning, incoming water…)

Although the discipline is new, the market needs answers and innovative technologies urgently, for deep and ultra deep offshore oilfields are developed. This implies that Flow Assurance main research axes are oriented on the theory and on the development of design tools or technological products.

> Leaders