Comparing Production by Formation in the Williston Basin -- The Bakken, North Dakota, USA

Update

Earlier this week I posted the note below but did not identify the formations. I was interested in folks looking at the data first, noting that wells in some formations are averaging one million barrels of production over 20 years, and others are struggling to get to 150,000 barrels over 20 years. Of course, with the Bakken, the jury is still out. Bakken wells are getting to 150,000 barrels in about three to four years, often sooner, but we don't know what the total cumulative average will be 20 - 30 years from now.

I have updated the post below to show the formations.

I don't know the difference between the Lodgepole and the Lodgepole/Bakken, but my hunch is that the "Lodgepole" refers to the reefs down around Dickinson, where the Lodgepole/Bakken refers to the more classical formation which lies continuously above the three Bakken formations. Based on some new wells coming in, I think that will be sorted out in the next six months, if not sooner.

Original Post  
Oil was discovered in North Dakota in 1951. Oil has been produced from not less than 36 formations -- 36 formations -- in North Dakota, in the Williston Basin.

Statistics have been kept from the beginning. The crude (no pun intended) table below shows the total amount of oil produced from a given formation (first column), the total number of wells drilled into that specific formation (second column in bold), and the average amount of oil, so far, produced by each well targeting that formation, dividing first column by second column (in bold red).

Later, I will identify the formations.  First, I want folks to look at the data, and ask some questions.

One cannot compare formations, unfortunately, directly with each other in all cases, because the first column is the total accumulated production since oil has been produced from that formation -- some formations have been producing oil continuously since 1951. Other formations are fairly new (such as the Bakken, and especially the Three Forks) and have not been producing for as many years. However, I think I will be able to say with a certain amount of confidence that one can compare two formations.

Bakken (mostly middle Bakken):   204,716,740               2341                    87,448

Bakken/Three Forks):                   659,678                           12                   54,973

Lodgepole:                                  56,901,337                      49               1,161,251

Lodgepole/Bakken:                       5,883                                 1                      5,883

Madison:                                       914,789,572                5505                 166,174

Red River:                                     105,475,181                  696                 151,544

Red River B:                                  123,988,984                   542                 228,761

Red River and RR B:                      229,464,165                 1238                 194,603

The first thing one notices is that the third formation down is in a league of its own: over 1 million bbls/oil/well since 1951. The fifth, sixth, seventh, and eighth formations have been producing oil since oil was discovered in 1951. Obviously not quite true, because only one well was producing oil in 1951 (the Clarence Iverson well). However, based on the little information I have, or can remember, the amount of oil produced by the fifth, sixth, seventh, and eighth, formations has accumulated over the last 20 years or so. Same with the formation "# 3."
 
Formation # 3: > 1 million barrels/well since 1951; these wells are still active and still highly productive.
Formation # 6: > about 200,000 barrels/well since 1951; many of these wells produced for 20 - 30 years but if older than 20 years have become stripper wells.