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The Voyage Home

October 30, 2019

Petcinemetary - Podbean

 

This article is the last of a three part series.  Part 1: The Circle of Life (in the Canadian Oil Patch) can be found here.  Part 2: You're Going to Need a Bigger Boat can be found here.

 

If you have read this far, you probably either agree that the path towards more employment in the oil patch requires innovative thinking by Startups and Juniors to unlock plays such as the Upper Mannville Heavy Oil play or you find them humourous in some way.

 

If it is the former, this post will review some of the tools at your disposal to pursue the required innovation.

 

It is a common complaint of old duffers like myself that geoscientists have been so immersed in resource plays - learning about Higher Pressure Deep Basins, pyncometric flows, that Brittleness is not a thing and other critical inputs to those plays - that they have not been exposed to the requirements for assessing a more conventional play such as the Upper Mannville.  This background is important because as we discussed in Part 2, it was Old School geological grunt work that led to these discoveries.  So the following is a very short precis of what to consider.  And remember that Enlighten has innovative ways to offer help at each step along the way.

 

Stratigraphy/Sedimentology

 

The Upper Mannville is a very stratigraphically complex interval.  This is a bad news / good news situation.  Bad news in that you can't expect to parachute into a new area and quickly develop a coherent understanding of the stratigraphy.  Good news in that numerous researchers have picked up the gauntlet and written some excellent articles on the subject.  Some have even progressed from the peer reviewed to general interest publications.  But there is a caveat.  If an early mover in the play has given a talk on the play and included a map such as the one shown below, they probably have that area locked down.

 

 

Petrophysics

 

A key benefit of a detailed stratigraphic model for whichever interval you are considering is the ability to build a detailed mineralogical model for each facies.  This in turn will allow for a much better petrophysical interpretation.  Pay in the Upper Mannville is often typified by subtle resistivity differences.  Take all steps necessary to avoid drilling wet sands!  (Often referred to as suitcase sands, because if you drill too many of those you will be told to pack your bags.)

 

Hydrodynamics

 

The Spirit River, close cousin of the Upper Mannville Heavy Oil section, kick-started modern hydrodynamics with the recognition of Deep Basin trapping.  Since then we have often tended to associate the Upper Mannville with a Deep Basin.  While the Upper Mannville Heavy Oil trend is extensive, it is difficult to consider this as a Deep Basin style trap consistent with the accepted model for this trap type proposed by Burnie et al., 2008.  Evidence of gas as the continuous phase has not been demonstrated, and trapping is more likely due to sub-regional capillary variations than a continuous hydrocarbon column.

 

Developing an understanding of the trapping mechanism will quite possibly be one of the exciting innovations to arise from exploring in this play.

 

In the meantime, there are a lot of useful hydrodynamic applications.  As examples, predicting phase contacts and, given the fluid density variations and structural trends, tilted oil/water contact evaluations could be considered.

 

Geothermics

 

Oil viscosity varies exponentially with temperature.  As described by Darcy's Law, oil viscosity has implications for oil production rate and for understanding the relative permeability of oil to water.

 

I began blogging on the implications of temperature on the producibility from this play in August of 2018.  As the play developed, I was able to post some preliminary observations on the relationship between Geothermics and production as part of a talk for the Geothermal Division of the CSPG (Watson, 2019).  When the geothermal gradient and isotherm mapping takes care to understand the average surface temperature and temperature data quality, variations in production become apparent.

 

Recent work has focused on mapping techniques to allow the prediction of oil viscosity at reservoir conditions.  This is expected to be a very useful screening tool for this play.

 

Summary

 

Solid old timey geological prospecting combined with high resolution stratigraphy, hydrodynamics and geothermics can help unlock this play for intrepid Juniors and Startups. 

 

 

The scale of the available opportunity is so large and diverse that innovative methods are required to produce client focused and timely results.  Operators are, in addition, living through capital constrained times.  For this reason, Enlighten is able to provide assistance on an a la' carte basis (i.e. a client defined region and stratigraphic interval).  Please be in touch with me at neil.watson@enlightengeoscience.com if you are interested in discussing this approach.

 

Thanks for reading!

 

References

 

Brownridge, S., 2018.  The Clearwater Formation at Marten Hills: A case study.  Geoconvention 2018.  Calgary, Alberta.

 

Burnie, S., Maini, B., Palmer, B. and Rakhit, K., 2008. Experimental and Empirical Observations Supporting a Capillary Model Involving Gas Generation, Migration, and Seal Leakage for the Origin and Occurrence of Regional Gasifers, in Cumella, S., Shanley, K. and Camp, W., 2008.  Understanding, Exploring, and Developing Tight-gas Sands.The American Association of Petroleum Geologists.

 

Watson, N., 2019. Construction and Applications of an Enhanced Geothermal Gradient Map of Alberta and British Columbia. CSPG Geothermal Division.  September 2019.  Calgary, Alberta.

 

Wellner, R., Varban, B., Roca, X., Flaum, J., Stewart, E. and Blum, M., 2018. Simple is better when it comes to sequence stratigraphy: The Clearwater Formation of the Mannville Group reinterpreted using a genetic body approach.  AAPG Explorer, February 2018.

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