Well of the Week – This is the end (of the Carboniferous and maybe something else)
This Petro Ninja – Enlighten Geoscience Well of the Week serves as examples of both fascinating geology and the reason for the swing to resource plays.
The collapse of the Peace River Arch (PRA), which began soon after the Devonian and continued intermittently throughout the Mississippian, really got going towards the end of the Paleozoic. This process was elegantly laid out in the landmark paper by Barclay et al. (1990); Dynamic casting and growth faulting: Dawson Creek Graben Complex, Carboniferous–Permian Peace River Embayment, Western Canada. The block model of the Dawson Creek Graben Complex is often cited as a visually instructive method of displaying the concept of the collapse of the PRA.
Barclay et al. (1990)
And while this diagram is appealing, it was the detailed stratigraphic cross sections (such as Figure 8d, shown below) that had an impact on a much younger me. It provided an epiphany as to a method to understand the effects of contemporaneous structuring and sedimentation patterns. With this conceptual framework it was possible to map out a series of tectonic valleys and the depositional trends of the targeted thick estuarine point bars. Once you have that figured out you can find an amazing well such as 100/06-30-081-10W6/00 which produced just a snick less than 45 bcf of gas. If you can land your well at the updip edge of the sand along a fault block, that is. Not an easy task, even with 3D seismic.
Barclay et al. (1990)
A successful Kiskatinaw well is a beautiful thing. But it is an exemplar of the reasons for the subsequent transition to resource plays. Big wells like the basal Kiskatinaw are not repeatable at the scale needed to attract major companies. Small companies can’t survive the 1-in-10 chance of success. If home run plays like the Kiskatinaw can’t sustain an industry, other facets will have to be exploited, such as exploiting low permeability reservoirs using horizontal multi-stage fractured, notwithstanding the considerable expense.
Log display created with data courtesy of Petro Ninja
There is a saying that necessity is the mother of invention. Which leads to a couple of questions. What if a different method of developing resources had been available? Was the need to move beyond the lower quality “conventional” plays the mother that resulted in MSFHs or would that technology have developed notwithstanding the lack of an apparent need?
J.E. Barclay, F.F. Krause, R.I. Campbell, J. Utting; Dynamic casting and growth faulting: Dawson Creek Graben Complex, Carboniferous–Permian Peace River Embayment, Western Canada. Bulletin of Canadian Petroleum Geology 1990; 38A (1): 115–145. doi: https://doi.org/10.35767/gscpgbull.38a.1.115