Three Forks vs Sanish Discusson: Very Esoteric

Since I suspect a lot of folks don't read all the comments, I'm going to post a comment here as it was sent into me.

It has to do with a posting regarding the evolving definition of the Three Forks / Sanish formation.

I've talked about the Three Forks / Sanish nomenclature several different places on the blog, and I won't link them again. One can find them by checking out the "Geology" tab at the top or the  sidebar at the right.

Here's the comment sent into me regarding the Sanish nomenclature, a posting which I very much appreciated:

This was my original post:

"During the "Bakken boom," there seems to be confusion with "Three Forks Sanish." Early on, that was how it was referred to: the "Three Forks Sanish." Over time, the "Sanish" was dropped, and it was simply "Three Forks." But on file reports, especially Whiting file reports, one sees "Sanish" standing alone. According to the "Petroleum Geology of North Dakota's Williston Basin (linked above also), "Sanish" was another name for the Bakken formation (Table 1, 1977). Further down in the article, it states that the Three Forks overlies the Birdbear formation; and, in turn, the Three Forks overlies the Bakken. (So, there is still a bit of confusion between the geologists and the NDIC administrative nomenclature.) According to the report at the link, the "Sanish" is an "informal unit," Sanish sandstone which overlies the Sanish itself. "

Here was what a reader sent into me (and again, I appreciate it):

If there was confusion it has been cleared up. The Sanish or Sanish Sand to some geologists is a member of the Three Forks formation and I think there are something like 7 or 8 members now (increased because of the increase in well data and core). The Sanish represents a lateral change in the depositional environment which I think was sea to beach or near shore, but I don't remember off hand. Last year there was a thesis from Colorado school of mines published on the Three Forks, but it has been awhile since I read it.

I think the NDIC fixed the wording of the post regarding the bakken and three forks with respect to each-other now reads:

"The Bakken Formation conformably overlies the Three Forks Formation in the basin center, and unconformably...

I will eventually write a geology section for thebakkenformation, but I haven't had time to work on the site at all lately.

This was how I responded to that comment:

1. With 7 or 8 members, the "Sanish" potentially becomes more confusing.

2. It appears that there is still differences in how producers classify things; how NDIC administratively classifies things; and how to update past logs (which I don't think will happen).

3. Whiting consistently calls it the Sanish (at least that's what I see), and CLR consistently refers to it as the Three Forks. The company geologists may disagree with me but that's my perception and among laymen, I probably follow this discussion as much as anyone. In my mind, I have a good feeling for what's going on (even if I'm wrong, I have my own "picture").

4. The problem I have is how to explain this in a 30-second soundbite to newbies before their eyes glaze over.

5. My own site has evolved over the past two years, and it might be smart of me to delete some of the old posts which might confuse things.

6. Please write to correct me when I make glaring errors on the geology. We all learn that way. I accept that kind of criticism very well. Other criticism, maybe not so well. Smile.

By the way, for those interested, there is a nice collection of articles/internet sources on the Bakken at this link: Discovery GeoServices Corporation.