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Reservoir and Source Rock Evaluation Services

Discover our services

Surface Logging Services

The cornerstone of our reservoir and source rock evaluation portfolio is our Surface Data Logging. The commitment to excellence, safety and continual improvement delivered through all of our specialist solutions is developed from this core function.

Our field personnel undergo rigorous classroom and in the field training. Our G-Rise program of continuous learning covers QHSE awareness, clearly defined technical competencies, field exposure, classroom analysis of events and interpretation of data to ensure our personnel reach the highest levels of competency. Through a series of self-training modules, practical and written examinations, career advancement from initial trainee through to advanced service specialist and all levels of technical proficiency are clearly defined.

Global technical support is available through our interactive knowledge base and support system – Leonardo.  This provides access to all available documentation, lessons learned and 24/7 contact with subject matter experts to rapidly resolve issues in even the remotest of locations.

Our equipment may be tailored, with wide ranging options available to meet all customer and statutory requirements.  Our cabins allow a modular approach with sensors and analytical equipment available for all forms of formation evaluation. This ability to add or remove specialist techniques allows us to provide high quality, relevant solutions through all phases of a drilling campaign, from exploration, appraisal and development through to workovers and abandonment. GEOLOG has provided Surface Logging in all working environments.

In addition to providing data, our analysts and interpreters are available to assist when required, ensuring reservoir characterization is possible in all situations.

  • Highly trained, competent field personnel
  • Dedicated technical support & management
  • Global presence
  • Wide range of easily implemented services available
& Solutions

Surface Logging performs a variety of functions in modern drilling operations, including monitoring for safety awareness, formation evaluation through cuttings and gas analysis and drilling performance. By ensuring the quality of the basic components, these requirements are not compromised. The latest technologies are available, including FID gas detection, digital photo-microscopy, sonic and radar sensors as examples.


Surface Logging has applications in conventional and numerous unconventional operations, including coal seam gas, geothermal and shale oil/gas. GEOLOG brings particular value when the wells being drilled have a variety of targets and analytical requirements, which may require the level of interpretation to be modified through a campaign. Our ability to implement more complex services when required provides our customers with the flexibility and knowledge that they can achieve their formation evaluation goals.

GEOLOG is consistently the best mudlogging service I have worked with

Drilling Superintendent, Exxon Mobil Guyana
Surface Logging



Basic Calculated Value


C1, C2, C3, iC4, nC4, iC5, nC5, He, CO2, H2S

Bh, Wh, OCQ, Normalization

Total Gas

Total Gas

Background Gas, Connection Gas, Trip Gas

Hazardous Gas

CO2, SO2, H2S, LEL



Depth, WOB, ROP, Overpull, MSE, DxC






Flow in, Displacements, Lag Time




Standpipe/Casing/Choke Pressure


Hydraulics/Kick & Kill

Flow in/Flow out

Flow in/Return flow

Delta Flow, Pump Efficiency

Pit Level

Pit Level

Pit Volume, Flowback, Mud Losses, Mud Gains

Mud Temperature

Fluid Temperature

Formation Pressure Trends

Mud Resistivity

Fluid Resistivity

Formation Pressure Trends

Mud Density

Fluid Density


Cuttings Evaluation

Lithology, Contamination

Chemical Tests

Cement Presence, Solvent Tests