Entry Senior

Wellsite Geologist

Courtesy of CNRL

About This Career

Wellsite Geologists supervise every stage of the drilling process to extract oil and natural gas from deep underground. They study and analyze rocks from oil and gas wells in order to direct the drilling, and identify the rock formation into which they are drilling. They use specialized tests such as petrographic analysis, rock-cutting data, wireline data, core samples and other measures to accomplish this work. Wellsite Geologists document results from drilling activities, analyze and evaluate this information in order to inform the Development/Reservoir Geologist about the status of drilling activities.  The Wellsite Geologist is responsible for executing a drilling plan, provided by the Development/Reservoir Geologist, and making real time decisions. 

Education: A post-secondary degree in geology is typically required. However, a post-secondary diploma from a technical institute or a graduate degree in chemistry, geochemistry, physics or geophysics may be another route into this occupation.

Employment: This occupation is found in onshore and offshore environments and is typically employed in exploration and production, oil sands and oil and gas services sectors of the oil and gas industry.

Example titles: Operations Geologist, Petrologist, Logging Geologist

Work Activities
Analyzing Data or Information
Performing reservoir analysis for consolidation, grain size, roundness, porosity and cementation.
Performing hydrocarbons analysis and interpretation for stain, visual cut; surface florescence, cut florescence and percentage of HOT occluding porosity.
Communicating with Persons Outside Organization
Advising the logging company of program revisions and timing.
Informing and advising on measurements, program requirements and revisions while drilling and mud logging.
Advising on changes needed in the well plan.
Interfacing with the hiring company's geologist(s).
Communicating with Supervisors, Peers or Subordinates
Communicating with the Rig Supervisor on geological risks and casing point tallies.
Documenting/Recording Information
Documenting sample data and information.
Providing a final operations report and interpreted log.
Evaluating Information
Evaluating and describing geological samples.
Selecting the casing point based on data such as isopachs, changes in drilling parameters and samples.
Selecting the core point based on data such as isopachs, changes in drilling parameters and samples.
Identifying formation and fluid marker picks.
Revising marker and target projections.
Identifying wellbore landings and target adjustments to drill data in horizontal wells.
Identifying forward projections and apparent thickness corrections in horizontal wells.
Identifying geological faults.
Getting Information
Collecting wellsite reference data, such as correlation/offset logs, maps, etc.
Performing Administrative Activities
Preparing daily reports, files and interpreted data for the operating company's representatives and partners.
Quality Assurance
Ensuring sample quality control.
Observing the acquisition of a full logging suite to ensure quality of logging data.
Attention to Detail
Quality Control Analysis
Critical Thinking
Active Listening
Career Path
  • The following are examples of progressive or lateral career paths associated with this occupation:
  • Petroleum Geologist
  • Area Geologist
  • Manager
Related Careers
Working Conditions
  • Field 2
    Field Visits
  • Office
    Office Based
  • Steeringwheel
    Driving Required
  • Road
    Remote Locations
  • Industrial excavator
    Active Machinery
  • Arrow
    Shift Work
Transferable Sectors
  • Forestry and logging
  • Professional, scientific and technical services
  • Mining and quarrying
Job Details

Job Category

Geosciences Professionals


Exploration and production

Oil and gas services

Oil sands



Qualifications + Experience


  • Post-secondary degree


  • Standard and emergency first aid
  • Workplace Hazardous Materials Information System (WHMIS)
  • H2S Alive


  • Having a Professional Geologist designation, while not strictly required in every jurisdiction, is preferred and/or required by many organizations. Licenses are issued by provincial jurisdictions and may provide interprovincial mobility.
  • Unlicensed Geologists may be required to work under the supervision of a licensed Geologist.