Well of the Week – The Circle Game.
History never repeats itself, but it does often rhyme.
(attributed to) Mark Twain.
The first post in this series on the New Golden Age of Carbonates discusses how exploration is a cyclical process. Some fields, plays or even entire basins are deemed to be played out until fresh eyes, a new technical application or, more likely, a combination of the two discovers what was present in plain sight, and a new cycle of development takes place. This Petro Ninja – Enlighten Geoscience Well of the Week is an example of strong technical work repeatedly identifying opportunity in what may be thought of as a series of overlapping circles of exploration.
The decades of drilling that followed Leduc No. 1 (100/05-22-00-26W4/00) provided the data that allowed the identification of the Leduc – Woodbend Rex pool. This Mesozoic aged Upper Mannville deposit was recognized as one of the largest onshore North American discoveries in decades, an inspirational example of circling back to renew the field discovered back in 1947.
And now the wheel has turned full circle and the potential of the original Nisku discovery continues to be fully realized. A recent Top Well Report highlighted a well (100/07-20-051-26W4/00 ) which represents this discovery looping back to the initial pool itself.
The 7-20 horizontal has many interesting attributes. It is, with a horizontal reach of 4.3 km, exceptionally long and prolific. By October of 2021 it had already produced over 340,000 barrels of oil at a current rate of 913 bbls/d. It is my default assumption that drilling this complex a well requires detailed work by a collaborative team. But what do I know? Maybe they used sharks with frickin’ laser beams on their heads. Rather than presume, I reached out to Brian Fischer, VP Exploration and Development for Aspenleaf to see if I was missing some profound technique they had employed to capture this resource.
Brian was kind enough to respond and I have quoted him at length:
“For what it is worth, what we do is not rocket science, but we make sure we integrate all the data and information we can lay our hands on in a truly integrated fashion (earth science and engineering) and by doing our “homework” good opportunities arise. The Nisku formation in the Leduc Woodbend area is a complex system in which you need to understand the implications of structure, stratigraphy, sedimentology, diagenesis, natural water drive and historical water and gas injection and depletion to really grasp where the remaining opportunities lie. These vary laterally across the play area and although complex, are relatively predictive.” Sure beats laser beams. Brian also pointed out another well (100/01-25-050-27W4/00) drilled off of the same pad as 7-20 and other wells which demonstrates the repeatability of the play.
Now comes the part I find very instructive. The 7-20 and 1-25 wells were drilled within the defined boundaries of the Leduc Woodbend Pool. Not only that, but the hydrocarbon accumulation was also highlighted in the Atlas of the Western Canada Sedimentary Basin. The opportunity was in plain sight. As the saying goes; low hanging fruit can be very tasty.
Figure 1. After Switzer et al. (1994))
It is interesting to overlay the recent Aspenleaf drilling on an insert from this Atlas map. It shows that successful exploration does not have to rely on inventing a play from whole cloth. No doubt modern technologies helped make this well successful, but it illustrates the value in recognizing opportunities that present themselves from the groundwork our predecessors did in the past.
Figure 2. After Switzer et al. (1994) with Aspenleaf wells including 7-20 and 1-25.
Switzer, S. B., Holland, W. G., Christie, D. S., Graf, G. C., Hedinger, A. S., McAuley, R. J., Wierzbicki, R. A. and Packard, J. J. (1994): Devonian Woodbend-Winterburn Strata of the Western Canada Sedimentary Basin; in Geological Atlas of the Western Canada Sedimentary Basin, G.D. Mossop and I. Shetsen (comp.), Canadian Society of Petroleum Geologists and Alberta Research Council, URL https://ags.aer.ca/publications/chapter-12-devonian-woodbend-winterburn-strata.html, [01-01-2023].