About NeerS Engineering - offshore structural engineering

About Us

Welcome to NeerS Engineering

We are an offshore structural engineering company for unique structures, focusing on projects where the safe operation and efficiency requires in-depth detailed analysis combined with creative design. Our high quality service and expertise have made us a preferred outsourcing destination for a world class provider of drilling equipment for the high-efficieny drilling market.

Benefit

We are delivering structural solutions for the client’s benefit, providing a reduced overall cost of the specific project.Applying the relevant codes for each specific project and minimizing the neccesarry changes on client’s application/structure – thus reinforcing the weak points – to achieve optimized load capacity. The high level offshore structural engineering solutions provide longer lifetime, furthermore the operational conditions become significantly safer.

Reliable Partner

Most of the services outsourced are related to design services around patented products, therefore we treat our client's intellectual property confidentially. NeerS Engineering works with clients in the long term; this has resulted in 80% of our business coming from repeat clients and acknowledgement for significant contribution to the bottom line of their products and brands. The key factor to the success of our Engineering outsourcing services is domain expertise and good engineering judgment in the field of offshore structural engineering.

Location

Our company is located in Europe, harmonizing projects with the aid of Internet, thus we can deliver offshore structural engineering services to clients based anywhere on the globe.

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Engineering Services

Offshore Structural Engineering Services

Load level evaluation

Gathering all project information and examining the possible operational and parked sequences to achieve realistic load combinations.

Detailed structural calculation

All details are checked for the governing forces both by hand calculations and beam/FE modeling for maximum reliability.

Reinforcement

Load level for critical parts are again controlled together with client to ensure only necessarry changes addressed. Reinforcement solutions provided and negotiated with client to reach optimum solution.

Documentation

A design manual is compiled for external supervision (DNV, ABS …etc) and archive purposes.

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Case

Case

Riser Spider Skid

We have calculated the critical live load on structure for several positions – to achieve realistic loading.

Bucket - Riser Spider Skid - offshore structural engineeringBucket Animation - Offshore Structural Engineering

The complex structure of derrick top has been modelled in detail, with several hinges, trusses and springed supports.

Bucket2 - offshore structuralBucket Animation2 - offshore structural engineering

This showed several critical points, -which due to the strict dimensional limitations-, had to be examined in depth. We have checked the plastic capacity of the multispan vertical rails, and have found these parts to be satisfactory. Nevertheless some parts had to be reinforced, but in a limited number and region.

Lower Guiding Arm

When checking a Lower Guiding Arm, we have looked at the possible loading scenarios, and the results of a possible equipment failure. We have found that the previously used design loads are low, and the environmental loads could cause the LGA fold back (as the cylinders switch off at an overloaded case). This in turn would have resulted in a potential loss a Drill-pipe bottom guideance. The control cabin was nearby, therefore we had to take action, and re-design this equipment.

Lower Guiding Arm Calculation

The telescopic arm of a Lower Guiding Arm had sliding pad connections between the inner and outer box section. Due to serviceablity – the pads were in the middle of the webs, thus creating a large hole on the box and furthermore severe bending moments. We have checked this situation both with hand calculation and FE modeling. As a result – both the main section and the details have been reinforced.

Lower Guiding Arm Back - AnimationLower Guiding Arm AnimationLower Guiding Arm - Back

Ask for more details about Lower Guiding Arm

Lockfinger

The full setback conditions (loading) have been significantly increased for general DP/DC Fingerboard lockfingers. Nevertheless the original size and geometry had to be kept as close as possible in the new design.

Lockfinger

Checking each part and consulting with equipment designer, resulted in a very different optimized shape. The corners had to be rounded, to avoid large peak stresses in this region. Finally a casted element, was the solution.

Offshore Structural Design - Lockfinger Stresses 1

Gantry Crane

The design of several Gantry Crane was checked: first evaluating the possible loading scenarios and finding the governing situations. The main beam model of the crane was checked in several positions.

Gantry Cane

Also the main SWL (safe working load) was applied in the most realistic way. The sling arrangement was taken into account.

Gantry Crane - Winch Forces

All details have been checked, and some found to be critical. These have been reinforced and have found a possible solution together with the project designer.

More on Bridge Crane and Gantry Crane design

Drillfloor Manipulator Arm

The Drillfloor Manipulator Arm is placed on the drillfloor. There is a pedestal between drillfloor and DFMA. A slewing frame/gear is fixed on the pedestal, which is able to move rotate.

Drillfloor Manipulator Arm

 

Support conditions are allways significant element of analysis, as these can alter final results greatly.

 

Drillfloor Manipulator Arm
Connection between slewing frame and pedestal in reality

 

Our first results showed, peak stresses mainly at the slewing frame supports. At these points the connection between slewing frame and pedestal was modelled with a vertical beam (bolt). The pedestal was modelled with a 1250mm*1250mm 750mm long vertical beam which were connected to the bolts by non-structural beams

Drillfloor Manipulator Arm - Peak stresses
Drillfloor Manipulator Arm

Connection between slewing frame and pedestal in 1st model

 

We tried to avoid unnecessary changes of a finished design, therefore we looked at the displacements. We have found that these were not reliable (16mm) hence we have changed support conditions by defining supports at bolt ends.  At bolt-beam top (at slewing plate) we have added horizontal supports to take shear forces, and on bottom we allowed all possible forces due to slewing frame and pedestal connection. Also we used the exact bolt length. To get real displacement at bolt end we definied a spring (acting in bolt axis) modeling the pedestal capability to take vertical force.

 

Drillfloor Manipulator - acceptable stresses
Drillfloor Manipulator

Connection between slewing frame and pedestal in 2nd model

 

Thanks to all these changes, the stresses have been reduced at the critical points, while we have kept the bolt end's displacement within reasonable range. Finally we did not need to ask for any changes of this detail.

Ask for more details about Drillfloor Manipulator Arm

Guide Dolly

The Guide Dolly is designed to keep the DDM assembly in center well position while travelling up and down the derrick (tripping) and to transfer the torque of the DDM (drilling) into the derrick structure.
A new service loop bracket was added to this design at bottom horizontal beam of the Dolly. This bracket is holding all cables (electricity, mud).

  dolly new bracket Guide Dolly - New bracket added  

 

We have checked the whole dolly and this new detail, and have found that the dolly is OK, but this new bracket is highly overstressed:

guide dolly handcalc

Due to the complexity of the detail, we have also checked it with a Finite Element model. Hot spot areas also find at stiffeners connecting in unfavourable way.

Max Von Mis Original

We have proposed a simple solution, whereas the bracket was lowered, to achieve a direct contact to existing RHS profile, thus avoiding unwanted extra stresses. Furthermore, several stiffeners have been lengthened, to avoid high forces in middle of RHS.

Max Von Mis Reinforced Model

Max Von Mis – Reinforced model

Ask for more details about Guide Dolly

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Projects

Projects

Oil Industry Projects Drilling equipment for Conventional and RamRig (semi submersibles oil platforms)

Aker Solutions
as a subcontractor of Aker MH (=Maritime Hydraulics) (Kristiansand)

We have finished over 150 offshore structural engineering projects for our client on a large number of rigs.

Rig names – we were involved:

  • Petrorig-1,2,3
  • Seadrill-8,9,10
  • Transocean
  • AkerH6a,H6b
  • Sevan
  • MPF
  • West E Drill
  • West Eminence
  • West Navigator
  • West Aquarius
  • West Future II
  • Ben Loyal
  • Ocean Vanguard
  • Songa Venus
  • Songa Dee
  • Songa Neptune
  • Songa Explorer
  • Frigstad
  • Snorre A
  • Snorre B
  • Thunderhorse
  • Petroserv
  • CNOOC
  • TMT-1,2
  • Oseberg East
  • Grupo R
  • Pride North America
  • Pride Brazil
  • Pride Carlos Walter
  • Bideford Dolphin
  • Odebrectht 1
  • Carolina


Project types – we have made several of:

  • Riser Fingerboard
  • DP_DC Fingerboard
  • Adjustable Casing Fingerboard
  • Bellyboard
  • Gantry Crane
  • Rathole
  • Riser Spider Skid
  • Tail in Arm
  • Casing Feeding Machine
  • Riser Chute
  • Riser Gantry Crane
  • Standbuilder Arm
  • Lower Guiding Arm
  • Underhull Guide
  • Casing Building Arm
  • Tubular Chute
  • Tail in Machine
  • X-mas tree guide
  • BOP Trolley
  • Upper Racking Arm
  • Intermediate Racking Arm
  • Through Moonpool Guide
  • Monkey Hand
  • Bridge Crane
  • Riser Tensioner
  • BOP Seafastening device
  • Drill String Compensator
  • DAT Trip Saver
  • PDPH
  • DDM Test Tower
  • Riser Inspection Pedestal
  • Overhull Extension Guide
  • Production Tree Tansporter
  • BOP Stack up Guide
  • VPH Test Tower


  • Rig name:
    • Project:

  • Frigstad
    • Tubular Transfer Arm
  • Frigstad
    • Tail In Machine
  • West Future II
    • Lifting Yokes
  • Frigstad
    • TFM
  • Sevan
    • Casing Feeding Machine
  • Sevan
    • Bellyboard
  • MPF
    • Bellyboard
  • Sevan
    • X-mas tree guide
  • CNOOC
    • Aluminium walkways
  • STANDARD
    • Upper Racking Arm
  • TMT
    • Fingerboard DP/DC
  • TMT
    • Adjustable Casing
      Fingerboard
  • TMT
    • Bellyboard
  • Valhall
    • Tubular Feeding Machine
  • Petrorig 1
    • BOP Trolley
  • Frigstad
    • Riser Fingerboard
  • Pride Rio
    • Fingerboard DP/DC
  • TMT
    • Riser Crane
  • Frigstad
    • TFM trolley-cradle
      extra beam
  • MPF
    • Through moonpool guide
  • MPFMPF
    • BOP landing structure
  • CNOOC
    • Trolley for
      Riser Guiding
  • TMT
    • Standbuilding Arm
  • TMT
    • Riser TFM
  • TMT
    • Pipe TFM
  • Pride
    North America
    • Lockfinger
  • Bideford Dolphin
    • Monkey Hand
  • Frigstad
    • Lower Guiding Arm
  • Frigstad
    • X-mas tree trolley
  • TMT
    • Riser Tensioner
  • AkerH6a
    • BOP Seafastening device
  • AkerH6a
    • Gantry Crane
  • SNORRE B
    • Fingerboard DP/DC
  • Pride
    North America
    • DC+2 DP Fingerboard
  • Pride
    North America
    • Lower Guiding Arm
  • Valhall
    • Fingerboard DP/DC
  • Petrorig 3
    • BOP Trolley
  • Pride Brazil
    • Fingerboard DP/DC
  • Pride
    Carlos Walter
    • Fingerboard DP/DC
  • Frigstad
    • Riser Handling Crane
  • CNOOC
    • Riser TFM -
      AFT CRADLE
  • Sevan
    • Drill string compensator
  • STANDARD
    • Intermediate Racking Arm
  • West E Drill
    • Riser Chute -
      increase trolley weight
  • Seadrill 8
    • Offline Casing
      Building Hoisting yoke
  • West E Drill
    • Tubular Chute -
      chute top connection
  • TMT-1
    • Lower Guiding Arm
  • TMT-1
    • Idler Sheave
  • TMT-2
    • Riser Tensioner
  • TMT-2
    • Idler Sheave
  • STANDARD
    • DDM1000 Test Tower
  • CNOOC
    • Riser Fingerboard
  • GrupoR
    • Riser TFM aft Cradle
  • West Alpha
    • TFM
  • West Alpha
    • Gantry Crane
  • Odebrecht 1
    • Bellyboard
  • Frigstad
    • Riser Spider Skid
  • STANDARD
    • Double DDM
      Test Tower
  • Odebrecht 1
    • Fingerboard DP/DC
  • AkerH6a
    • Tail In Arm
  • Odebrecht 1
    • Riser Feeding Machine -
      AFT CRADLE
  • Songa Dee
    • 220T BOP forklift
  • Frigstad
    • Riser Spider Skid
      rails modification
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Codes

Codes

European Codes

FEM – Rules for Heavy Lifting Appliances (loading, stress, fatigue calculation)

EuroCode1: Basis of design and actions on structures

EuroCode3: Design of Steel structures

Hungarian Codes

MSZ 15021 Építmények teherhordó szerkezeteinek erőtani tervezése (Design of load bearing structures of buildings)

MI-04.133-81 Méretezési irányelvek földrengési hatásokra (Design guidelines for earthquake/seismic impacts)

MSZ 15022 Vasbeton szerkezetek (Reinforced concrete structures)

MSZ 15023 Falazott szerkezetek (Masonry structures)

MSZ 15024 Acél szerkezetek (Steel structures)

MSZ 15025 Faszerkezetek (Wooden constructions)

Norvegian Codes

DNV – Det Norske Veritas Rules and Technical Notes

NS3479 – Prosjektering av bygningskonstruksjoner (Loading criterias for buildings)

NS3472 – Prosjektering av stalkonstruksjoner (Design of Steel structures)

American (US) Codes

ASCE – Design of Blast Resistant Buildings in Petrochemical Facilites

ANSI - NDS: National Design Specification for Wood Construction

TIA/EIA – Structural Standards for Steel Antenna Towers and Antenna Supporting Structures

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