Case Studies

Below are examples of interesting projects we have successfully carried out in recent years

UK Exploration Well

North Sea - UK

 

Well Drilled in the UK North Sea for Azinor Catalyst

WELL OPERATORSHIP

  • Zephyr assisted Azinor Catalyst in becoming a fully qualified UK Well Operator
  • Assisted in establishing Well Standards and Procedures
  • Assisted in Re-developing their Management System

 

Planning Summary

  • Zephyr assisted with providing the Drilling Department for Operator (Azinor Catalyst)
  • Casing Design with Stresscheck
  • Basis of Design
  • Bridging Document with Drilling Contractor (Diamond Offshore)
  • Development of the EIA
  • ER planning with Azinor Catalyst and Diamond Offshore
  • Rig acceptance with ADC

 

Operations Summary

  • Supervision of drilling operations
  • Rig mobilised from stack in Invergordon
  • Well drilled for under $10MM including mob/demob
  • Daily Cost $200k

 

Challenges

  • Taking rig from stack

 

Outcome

  • Well drilled on budget
  • Excellent HSES performance

Black Sea Exploration

Black Sea - Romania

 

Design, Planning and Execution with Romanian Jack-up

Planning Summary

  • Casing Design using Stresscheck
  • Basis of Design
  • Bridging Document with GSP Drilling Contractor
  • Oil Spill Plan with OSRL
  • ER Planning with RPS
  • Rig upgrade and acceptance with Lloyds Moduspec
  • Rig at water depth limit 88m

 

Operations Summary

  • Supervision of drilling operations
  • S shaped directional well with WBM to 3200m
  • Daily costs $250k
  • Overall well cost $29mm

 

Challenges

  • Rig at maximum water depth limit
  • Slot rig (no cantilever)
  • Limited deck space – run production casing off supply vessel
  • Rig power reliability
  • Rig prime mover reliability
  • Shale stability issues
  • Bulk chemical supply
  • Conductor tensioning
  • Lack of logistics infrastructure

Iranian Well Re-instatement

Persian Gulf - Iran

 

Completed March 2016 (Before sanctions came into place)

 

Recovery of 8 Wells Damaged by an Oil Tanker Colliding with the Platform

Planning Summary

  • Assist Petro Paydar Iran with recovery of 8 damaged wells
  • Oil tanker collided with platform and destroyed it with severe damage to wells
  • 1 live well with gas to Xmas Tree
  • 8 wells predrilled - all wellheads and casings bent over to 40m below sea level
  • Assist salvage contractor to recover damaged conductors and casing
  • Design and fabricate casing caps to be installed over cut casings - facilitate pumping cement into uncemented annuli
  • Plan for well re-entry via Xmas tree using divers
  • Contingency relief well planning
  • Plans for plugging wells and making safe for repair and tie back to new platform
  • Tie back plan for wells – from undamaged casings close to seabed

 

Operations Summary

  • Using salvage barge with diver assist - hook up to damaged wells and install plugs
  • Enable opening of SSSV
  • Establish injection to well
  • Bullhead cement to well for successful kill
  • Make wells safe for suspension

 

Outcome

  • Successful well kill and suspension

Tanzania Campaign

Tanzania - Eastern Africa

 

Completed January 2016

 

3 Well Onshore Campaign – Land Rig

Planning Summary

  • Casing Design with Stresscheck
  • Basis of Design
  • Bridging Document with Sakson (Drilling Contractor)
  • Development of the EIA
  • ER planning with Dodsal (Operator)
  • Rig acceptance with ADC

 

Operations Summary

  • Supervision of drilling operations
  • 3 wells – deepest 4000m
  • Remote operations- wildcat exploration
  • Daily Cost $120k

 

Challenges

  • Rig and Third-Party Equipment mobilisation and importation
  • Hard rock drilling
  • Limited bit selection when formations not as prognosis
  • Lack of 3rd party support
  • Lack of logistics infrastructure

Montara Blowout

Timor Sea - Western Australia

 

Well Kill after the Montara Oil Spill

Planning Summary

  • Assist Seadrill (rig Contractor) with relief well planning for blowout on West Atlas jack-up rig over Montara platform.
  • Blowout occurred during tie back to platform and re-entry of suspended well. Rig evacuated
  • Discussions with PPTEP for relief well planning and dynamic well kill
  • Flow modelling with Add Energy of Norway
  • Well Control planning with ALERT of Singapore

 

Operations Summary

  • Drill directional relief well with West Triton jack-up rig
  • Penetrate production casing in blow out well at 5th attempt
  • 2 attempts at dynamic kill via relief with different mud weights
  • Flow of gas into well higher then estimated - unsuccessful first attempt at kill

 

Outcome

  • Successful well kill at 2nd attempt
  • Rig and platform salvage
  • Court proceedings
  • Changes to Australian legislation on well/re-entry consents

Expert Witness

East Africa

 

Well Cost Review for a Court Case Dispute

Overview

  • Arrangement made between 2 Oil Companies for farm in and cost split on land operation
  • Well drilled significantly over budget - at 3 times estimated cost
  • Operator used rig contractor owned by a subsidiary

 

Operations Summary

  • Disagreement on part of farminee on share of cost - in view of high well cost
  • Review case made against operator for poor performance by farminee
  • Review well costs
  • Review choice of rig and mob/demob arrangements

 

Outcome

  • Assist legal reps of Operator prepare defence case

Case Studies

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Black Sea Exploration

Montara Blowout

Expert Witness

UK Exploration Well