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IMO / STCW · Offshore Platform / Unit · Third Party Services (Geology)

Mud Logger / Wellsite Geologist

Also known as: Surface Logger · Drilling Data Analyst

Analyses cuttings and parameters to identify geological formations and risks.

Open in the explorer All Offshore Platform / Unit roles

What you need to perform it

Primary qualification

  • Degree in Geology, Geological Engineering or Geosciences, fluent in microscopy and cuttings description.
  • The surface-logging contractor's training programme (Geolog, Halliburton SDL — sector examples) on its cabin and software.
  • Offshore access: BOSIET/FOET with CA-EBS, offshore medical and H2S; A-VI/1 per flag.

Basic STCW

  • A-VI/1
  • OPITO BOSIET

Specific courses

  • Gas chromatography: background, connection and trip gas; calibrations
  • Abnormal-pressure detection: d-exponent, trends and influx indicators
  • Cuttings description, calcimetry and fluorescence
  • Cabin sensors: depth, SPP, torque, flow and pit levels

Indicative experience

Indicative: 6-18 months as trainee mud logger/sample catcher before solo shifts; promotion to data engineer/wellsite geologist comes with complete logged wells.

Observations

Third-party personnel embedded on the unit; reports functionally to the operator's wellsite geologist. Progression: mud logger → data engineer → wellsite geologist / pore-pressure specialist.

What this role does

DepartmentThird Party Services (Geology)
GroupWell Services / Third Party
Role typeGeological Technical Analyst
Reports toCompany Man
SupervisesNot applicable

The well's real-time geological eyes: analyses the cuttings coming up with the mud, watches the gas chromatograph at every connection, correlates lithology with the well programme and flags abnormal pressure trends. The logging cabin records every drilling parameter; an early call to the company man can pre-empt an influx.

Typical watches

  • 12 continuous hour guards

Key responsibilities

  • Analysis of rock cuttings to identify geological formations.
  • Detection of the presence of gas in sludge and cuttings.
  • Monitoring and recording of drilling parameters in real time.
  • Alerts about possible geological risks (H2S, high pressures, fragile formations).
  • Preparation of the lithological log (Mud Log) of the well.

Operational scope

  • Mud Logging Cabin (mobile unit on deck)
  • Cuttings laboratory
  • Real-time monitors

Profile reviewed by HydroAbyss (2026). Cited rules and timeframes are indicative: the final requirement is set by the flag State, the Administration and each company.