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Greg Semways

Independent Consultant


Greg has worked in many different basinal settings and plays, contributing to reservoir, source and seal characterisation projects in conventional and unconventional, clastic and carbonate reservoirs. He has gained over 25 years of experience in the various exploration projects in the O&G industry. He is currently an independent consultant for Robertson UK Ltd.

Greg has combined experience in field, consulting, and training with the following background in:
• Practical & Consulting – Greg was with Badley Ahston and Associates, UK), where he work on a wide range of reservoir problems, from exploration to production for clients such as BP, Shell, Amerada Hess, PDO, etc. Moreover, being an independent consultant he has also been involved with various field projects as well as development of training programs internationally.
• Training Delivery – He has been in training, mentoring and development, with experience in creation and presentation of classroom and field-based industry courses including: Basin Analysis, Play Fairway Analysis, Prospect Evaluation, Sequence Stratigraphy, Carbonate and Clastic Reservoir Geology, Reservoir Quality Analysis, Reservoir Modeling, Wireline Log Interpretation for Geologists, Formation Evaluation, Field Development Planning, and Project Management.


• Geological Project Scoping: Scoping of multidisciplinary reservoir geology projects aimed at deriving the best possible solution from a diverse range of available analytical techniques. Integrating sedimentological and petrographical analysis with petrophysics (including NMR core and log analysis), SCAL and CCA, borehole image analysis, chemo and biostratigraphy, organic and inorganic chemistry.
• Sedimentology and Structural Geology: Prediction of depositional environments and geometries, and permeability architectures in the subsurface, by comparison with subsurface and outcrop analogues. Evaluation of fracture population orientations based on oriented core measurements and borehole images. Palaeocurrent analysis from oriented core and borehole images.
• Petrographical & Reservoir Quality Analysis: modal and grain size determinations and thin-section description of clastics and carbonates. Equipped with mobile petrological microscope and digital camera system, enabling petrographical analysis anywhere. Determination of the geological controls on reservoir quality and subsequent prediction of porosity and permeability, based on integration of diverse datasets (sedimentological, petrographical, CCA, SCAL, BHI, NMR, conventional logs etc).
• Diagenetic Studies: Determination of paragenetic sequences and diagenetic histories based on integrated interpretation of a range of inorganic geochemical techniques, including fluid inclusions, stable isotopes, cathodoluminescence, SEM, XRD, including integration with burial histories and source-rock maturation histories.
• Petrel Mapping and Geocellular Modelling: Structural models, volumetrics, well-log upscaling, gridding, facies and petrophysical modelling. Bringing 20+ years of reservoir description to bear in the construction of geologically robust subsurface models.