Well of the Week – The Once and Future King
The start of a New Year is a good time to begin a Petro Ninja – Enlighten Geoscience Well of the Week series on the resurgence of a lithologic succession that used to dominate the western Canadian oil and gas industry. There are several ongoing examples of how carbonate reservoirs are resuming their prominence in our imaginations.
At this point it is important to note that, as illustrated by the AER Table of Formations, the Paleozoic of the WCSB is dominated by carbonate rocks (limestones and dolomites) while the Mesozoic is primarily clastics (sands and shales). After Leduc No. 1 launched the post-WWII Canadian oil and gas industry almost all energy was focused on carbonates. Following the Leduc discovery, a spate of drilling looking to replicate this historic well occurred targeting the Paleozoic. This activity represented the “Golden Age” of carbonate exploration.
After AER (2019)
And the Golden Age continued from 1947 until the mid-1980s. It might be hard for geologists who cut their teeth on concepts such as steam chambers, pycnometric flow, frac stages and horizontal reach to realize just how intense this focus was. As an example, Gulf Canada held three in-house courses on the subject (imaginatively named Carbonates I, II and III) as part of the journey to being an properly trained geologist. The last course was a helicopter supported tour of hard to access outcrops (We all miss those days as well as the Turks and Caicos trips). And in the pre-Google era, the company assigned Hans Speelman, a carbonates expert, the task of collating a binder of the “must know” abstracts on carbonate reefs.
A photograph of the author’s copy of the Bibliography of Published Reef Studies.
But the first iteration of carbonate research died out soon after this opus was published. As did the interest in ossicles, hydrothermal dolomitization and bank margin facies models. It was time for the never-ending industry cycles to focus on clastic plays.
But the wheel has fully turned and there are new carbonate stories to be told. You cannot discuss lithium without mentioning the Leduc. There are compelling discoveries being made throughout the Paleozoic section. And while Pore Space Resources is the au courant term, that is really just a buzzword for reefs. You can’t talk abut thick regionally extensive porous formations without mentioning rocks that fizz. These are just a few of the topics to discuss in the series on the New Golden Age of Carbonates.
Reference
Alberta Energy Regulator, 2019. Alberta Table of Formations. https://static.ags.aer.ca/files/document/INF/Table_of_Formations_2019.pdf [accessed 2023-01-01].