HEF has decades of experience drawing structural interpretations from dipmeter data to answer some of the most important questions you might have about your reservoir’s architecture: the orientation and sense of motion on fault and fold systems, and identifying angular unconformities. Applying correlation analysis methods forged in the structurally complex Canadian Rocky Mountain foreland fold and thrust belt, our consulting geologists are experienced in using dip data of any vintage to generate meaningful and useful structural cross-sections which, when linked with fracture data, can predict the location of curved and fractured bedding away from the borehole to help explain your well’s results, making it possible to plan your next step, be it an off-set, side-track or completion as-is.
Compressional and transpressional structures, often the most stunning in terms of bed geometry, can be the most frustrating to image well with seismic and near-impossible to properly identify and understand using conventional petrophysics. Common features include shattered and overturned structured bedding, structural duplexes, thrust and reverse faults and folds of multiple scales and sense of vergence, and complex bedding structures which become extremely challenging to identify. HEF can answer your geology questions about whether your well landed on the back-limb or fore-limb, or, if you missed your reservoir target altogether, where it would be and how to get there.
Extensional and transtensional structures tend to be more subtle at the borehole scale than compressional ones. The challenge here often lies in identifying subtle structural changes, identifying angular unconformities and isolating structural bedding from cross-bedding and soft-sediment deformation that is common to rift and passive margin geology settings. The fault structures can be visible directly in the image log as a zone of breccia or inferred from missing section or from fault drag features.
Horizontal wells present unique challenges for structural interpretation. Wellbores can dip in and out of bedding, and bedding can dip in and out of the wellbore due to changes in plunge, minor folds and position on the structure. Very subtle changes in bedding shape can seem larger and more significant than they actually are in true scales because of how stretched a particular bedding feature may be, while significant features like tear faults can be missed by inexperienced interpreters, who might not notice the subtle breaks in the bedding, especially as fracture intensity increases.
TST and Stratigraphic Bed Penetration
To help you better understand your structurally complex dip data, HEF provides a variety of visualization tools for understanding how wellbores cut through bedding. True Stratigraphic Thickness (TST) plots are used to undo bed “stretching” due to steep bedding and borehole deviations. This allows you to compare gamma ray repeats and correlation of geological sections from faulted and folded wells to offsetting wells with undeformed bedding.
Bed Penetration plots are used in horizontal wells to show the stratigraphic position within a formation. They also indicate the rate the wellbore is going up-section or down-section within the formation.
I wholeheartedly recommend HEF to anyone working on structure plays, naturally fractured reservoirs or the geomechanical datasets associated with Unconventional because they can be counted upon to provide a reliable and neutral third-party assessment of what are often incomplete and complex datasets.
HEF is unique because they have the depth and breadth of experience in a specialization many geoscientists encounter only infrequently. They are able to help clients visualize and communicate their interpretation with the confidence to challenge results.
Approachable, with highest professional standards and integrity, you can expect a quick turnaround and 24 hour on-call support to make sound recommendations to your team and avoid costly errors. Working with HEF on many different projects and in a variety of countries over the past 17 years has been extremely rewarding!
-Catherine Huff, P. Geo.