Øyvind Johnsen – MSc - (co-founder of MTC and owner)

Name: 
Øyvind Johnsen
Mobil: 
+47 90821068
Fax: 
+47 66761531
email: 
Oyvind.Johnsen@mtc.no

Past Employment:

1996 - present Marine Technology Consulting AS

Dalia TLP; Kværner internal study - Client: Kværner Oil and Gas / BP (1998). Deep water study of small wellhead TLP for West Africa. The use of risers without heave compenstion was studied as well as the interaction between riser/tether dynamics and TLP in a coupled model.

Ship Motion Evaluation - Client: Petroleum Geo Services (1998). Evaluation of ship motions for different ships considered for drilling operations.

Umoe TLP - Client: Umoe Oil and Gas (1998). Performed hydrodynamic hull optimisation and tether sizing for a 4 column TLP. Performed tether fatigue analysis including the effects of springing (wave second order high frequency loading).

Workover Riser Analysis; Detail Engineering - Client: Seaflex / Kongsberg Offshore (1997/98). Performed riser analysis for operation in water depths ranging from 100 – 2000 m offshore Brazil. Standard drill pipe was used. The work included analysis of the different stages of installation-, operating- and disconnect conditions. Also performed fatigue analysis including vortex induced vibrations.

Shelf 5 Drilling Semi; Upgrade Engineering - Client: Kværner Oil and Gas / BP (1997). Performed mooring system analysis and design for operation in the Kaspian Sea, including :

wire/chain/taut leg comparison evaluation
mooring line installation analysis
establishing of environmental specification

Njord Flexi Riser Installation; Detail Engineering - Client: Coflexip Stena Offshore (1996/97). Performed installation analysis for the different types of flexible risers connected to the Njord semi. Also assisted in establishing procedures for the installation work.

1985 - 1996 Aker Engineering a.s, Senior Marine Engineer

Njord P45 Semi; Main Engineering - Client: Norsk Hydro (1995-1996). Had a general hydrodynamic support/resource function. Specifically performed analysis work related to:

kinematics of wave/structure interaction
analysis of mooring lines in time domain
interfaces with other disciplines related to global responses
model test correlation with special emphasis on airgap

Visund Production Ship; Conceptual Engineering - Client: Norsk Hydro (1995). Performed hull sizing and fairing. Performed analysis of global motion responses and generated wave and inertia induced sectional moments/shear forces for hull design (viscous effects and non-linear loads).

Norne Production Ship; Conceptual Engineering - Client: Statoil (1994). Similar to Visund above

Heidrun TLP; Conceptual-, Pre- and Main Engineering - Client: Conoco (1990-1993). Participated in hull and tether sizing in the conceptual phase. Responsible for the hydrodynamic hull models (diffraction/Morison) and the global motion response analyses for design. Correlated model test results with the hydrodynamic response models. Interfaced global responses with deck/hull/tether/foundation/component designers. Performed analysis of local wave/structure kinematics (from diffraction) and developed code for analysing sloshing in the ballast tanks.

Smørbukk Production Ship; Study - Client: Statoil (1991/1992). Performed motion simulation with mooring lines and dynamic positioning and analysis of global motion reponses. Developed new procedure and computer code for generating wave and inertia induced sectional moments/shear forces for hull design and compared with DnV.

Gulf of Mexico TLP in Deep Water; Study - Client: Chevron (1990). Responsible for hull- and tether sizing and all hydrodynamic analyses incl. global responses and loads to structural analysis. API rules and guidelines.

Gulf of Mexico H3.2; Conversion Study - Client: Mobile (1990). Performed mooring analysis and all hydrodynamic analyses incl. global responses and loads to structural analysis

Gulf of Mexico Ship; Conceptual Engineering (in Houston) - Client: Marathon Oil (1990). Performed mooring analysis and motion response analysis. API rules and guidelines.

Terra Nova Semi and Ship; Conceptual Engineering (Calgary location) - Client: Petro Canada) (1988). Performed design and analysis of the station keeping system and the turret as well as motion response analysis. Performed dynamic (time domain) analysis of the flexible risers and a loading buoy.

Snorre TLP; Conceptual-, Pre- and Main Engineering - Client: Saga Petroleum (1986-1989). Performed extensive work on hull and tether optimisation and sizing in the conceptual phase. Sensitivity analyses were performed to verify effect of uncertainties and variations on global responses and tether loads. Performed tether design analyses in terms of extreme load- and stress and fatigue computations. In pre- and detail engineering, performed global motion response analyses as well as tether design analyses (as above). Interfaced with deck/hull/tether/foundation/component designers in terms of global responses and local wave/structure kinematics. Performed various temporary stage evaluations; deck mating, vessel towing to site, TLP installation (two vessel coupled analysis including DP).

Snorre TLP Risers Study - Client: Saga Petroleum (1985). Performed time domain riser extreme stress analysis, spectral fatigue analysis and clearance checks.

Monopile Compliant Tower; Study - Client: Statoil (1985). Performed tower shape optimisation studies. Performed extreme stress analyses in time domain and fatigue analysis with evaluation of welding classes.

Minor Tasks:

Ship, Semi and TLP Design and Analysis - Clients: Internal Aker Engineering

D2 - diving support vessel

D6 - drilling vessel for ice-infested waters

PS series - early stage production floaters with and w/o storage

H3 series - modifications/conversions of existing drilling rigs

Stationkeeping Design and Analysis - Clients: Odfjell Drilling, Heerema, Maersk Drilling and internal Aker Engineering

Field specific mooring analyses for drilling and accommodation vessels for NMD approval. Complex laying patterns restricted by pipelines and other vessels.

Dynamic positioning analyses including capacity evaluation and DP simulations for pure DP vessels and combined mooring/DP systems.

Optimisation of composite wire/chain mooring systems for production semis.

Marine Operations

Responsible for the analytical work in evaluating various installation schemes for the Snorre TLP including simulation of tether tow, upending and docking.

Testing of computer software for jacket launch and installation.

Research Projects:

Motion analysis JIP (FPS2000) administered by NTNF to assess various methods for analysing motions response, with special emphasis on slowly varying motions and damping.

Wave drift damping JIP administered by DnV research to assess a version of the diffraction program Wamit which accounts for forward velocity.

Computer Programs:

Responsible for the continuous development and maintenance of :

Tencon - TLP hull and tether sizing tool
Seafloater - AEs main motion/tether response analysis tool
Developed various smaller codes, in the fields of :
wave kinematics
kinematics of wave/structures interaction based on diffracted waves
sloshing kinematics in large tanks
wave and inertia loadings on ships for structural design
interfaces between motion response programs and other applications; riser time/frequency domain analyses, mooring analysis

During the Heidrun project, introduced a rational method for organising analytical models into libraries to enable safe administration of the models used by many people and to enable efficient execution of large amount s of analysis. The procedure is executed by means of Script files under UNIX or command files under VMS.

Involved in shaping of internal procedures for Software Quality Assurance.

Computer Systems Management:
VAX System Manager in Aker Engineering Oslo and responsible for purchasing, setting up and maintaining local area VAX clusters for :

Heidrun Project (Oslo)
Aker Omega (Houston)
Terra Nova Project (Calgary)

Courses and Seminars:

Marine Hydrodynamic (Newmans book) Univ. of Oslo (2 semesters)

QA of Software Posteducation course at NTH

Probabilistic methods in Proban AE internal course

Positioning of semisubs and ships (multiple) NIF seminars