Platform Conductor Analysis

Platform Conductor Analysis

Background

In the Oil & Gas Industry, Platform Conductor Analysis is necessary to verify the structural design of offshore wells. Assessment for the full history of the well is undertaken including:

  •  Installation
  • Production/Injection/Cold kill
  • Workover

The analysis covers a range of possible offshore installations, such as:

  •  Platform drilled wells
  •  Platform wells drilled from a jack-up
  •  Platform tie-backs wells
  • Jacket slot recovery wells
  • Exploration wells drilled from a jack-up (no platform)

Conductors are the main structural support of a well which see a range of complex loading. Carrying out an analysis helps to identify the individual loads for each phase in the life cycle of the well. Load evaluation is then used to optimise the conductor design. This provides for an efficient and cost-effective design for the operators. AS Mosley provides consultancy support to assist throughout the design process.

Causes of Loading

The cause of loading on the conductor comes from many sources spanning the life of the well, for example:

  •  Environmental loads (wave and current)
  •  Weight of internal casing
  •  Weight of surface equipment (e.g. wellhead, BOP etc.)
  •  Thermal loads (i.e. hot production and cold injection)
  •  Installation loads (i.e. misalignment loads for tieback wells)
  •  Annular pressure build-up
  •  Platform/jack-up dynamic movement

Data Analysis

Crucial data is taken from the assessment and used to determine the suitability of a conductor design. Typical categories considered during the design process are:

  •  Extreme storm structural assessment (conductor and connectors)
  •  Stability assessment (for each span)
  •  Jacket guide load assessment
  •  Span length optimisation
  •  Conductor guide centralisation
  •  Centraliser placement between casing strings
  •  Wellhead growth /squat under thermal loads
  •  Tension setting requirements (tieback strings and exploration jack-up drilling)
  •  Wave and VIV fatigue analysis

 

 

 

Key Projects

Some of the key platform conductor analysis projects AS Mosley has worked on are listed below:

Shell Jackdaw
Analysis of a High Pressure, High Temperature Platform Conductor with surface wellhead

ONGC Cluster 8
Platform tieback conductor analysis in the Mumbi Offshore Basin

BP Bruce
Platform drilled conductor along with a separate tie back conductor analysis

Petrofac Dana
Driving and drilling conductor analysis from a jack up with the conductors supported within a monopole platform

For more information, please contact us today.