Challenging our readers on new thoughts and Ideas
By Ted Godo
Greetings, members, and I hope your 2025 new year is beginning well. I first want to thank Steve Naruk, a fellow HGS member and a colleague whom I worked with at Shell Oil. Steve writes an informative article in this Bulletin on deformation bands. Deformation bands in thick sandstone reservoirs are clearly at least baffles to flow and reservoir compartmentalization. My first experience, unlike Steve's broader knowledge, presented itself to me when we first discovered the Norphlet Appomattox field. To this day, it is not apparent if the deformation bands we found in wells at the structural crest seal the huge south flank oil column from the lesser column on the north flank. Without any apparent structural faults along parts of the crest, it can only be speculated if the reservoir fortuitously thins to a pinch-out ending permeability or whether only the presence of deformation bands that we know are present, seal these accumulations. So here is an invitation for anyone at Shell to write and update us!
Secondly, I want to thank another Shell colleague, L. Taras Bryndzia, for contributing an excellent technical article on the role of organic-rich source rocks (hydrocarbons) to cinnabar ore formation. Cinnabar is an elemental compound composed of mercury sulfide (HgS). While mercury, according to the USGS critical mineral list, is not currently on the list; however, some previous assessments have listed it as a potential critical mineral due to supply chain concerns and use in certain industries.
Lastly, I apologize for the length of the “feature article” – it doubles the length of past bulletin guidelines. The subject matter could have been broken into two parts, one in each month’s bulletin. However, I decided to” let it rip” in this one, so to speak, because I want to cover a few more subjects before the June issue. My excuse is simply a passion for asking questions, seeking colleagues challenging ideas, and, most importantly, serving our readers by offering or imparting some knowledge, observations, and mentoring for new geoscientists.
For example, the SAKARN section, as originally defined by Thierry Rivas in 2019, has been known and worked in the industry for 20 years since the first 3D surveys came out in the early 2000s. During various colleague meetings and interactions over the years, we found out that Anadarko, for example, referred to the Sakarn as the “Smackunder.” At Shell, we referred to it as the “Mystery section.” It has baffled me frankly that despite many oil companies that acquired leases with obvious objectives in the Sakarn, none was drilled. In addition, the fact that academia has not incorporated the potential for this older fill age of the sediments into the rifting models has also been surprising.
At Shell, we periodically discussed promoting the industry to petition the BOEM for a C.O.S.T. well 1 (Continental Offshore Stratigraphic Test) to drill this “mystery section” to see, for example, if there might be source rock (a first significant uncertainty) and second if there, are reservoirs. Indeed, there are structures with rock closures that are present. In fact, one prospect at Shell, whom we referred to as “Five Forks,” had similar major reflections to those of Appomattox.
Lastly, I encourage you to write your “letters to the editor” about any subject or challenge or correct things I may have misrepresented or gotten wrong. We are transparent and are happy to interact and publish your letters “as is”. So far in my term, we have only received one” letter to the editor,” it appeared in the September issue (2024) correcting an article from a 2002 Bulletin. Thank you, Robert Leslie, for your letter on this subject.
See you next month,
Ted Godo
Footnote:
(1)-A deep stratigraphic test, as defined in 30 CFR § 551.1, means, “drilling that involves the penetration into the sea bottom of more than 500 feet (152 meters).” These wells are sometimes known as Continental Offshore Stratigraphic Test (COST) wells and are drilled primarily to gather geological information. Examples of information collected would be core samples and geochemical and geophysical data. COST wells have been drilled offshore in the Atlantic, Pacific, and Alaska regions.
https://www.boem.gov/sites/default/files/uploadedFiles/BOEM/Oil_and_Gas_...