Another Trivial Note on the Silurian Formation -- North Dakota, USA

Another interesting well:

• 7566, IA/682, Hess, T.P. Riggs 15-31, spud in 1980; test date 2/4/1981; cum 858,98 bbls 7/11;

This well continues to produce (on a pump) although since December, 2010, it looks like it might have been shut in.

This was another Silurian formation well. I talked about Silurian wells back on July 17, 2011.

This Silurian well was spud back in 1980 and has been active for 30 years.

I find it amazing how these companies can tease the oil out of the formation when it looks like production is dropping:

1. 1981 time period -- note the horrendous decline rate, which is also seen in the Bakken:

SILURIAN	4-1981	30	9967	9883	800	18667	18667	0
SILURIAN	3-1981	31	14030	14094	769	26149	26149	0
SILURIAN	2-1981	28	16510	15725	840	25958	25958	0

2. 1983 time period -- for some reason, production was shut down for part of a couple months, and then brought back up, producing at similar levels when first spud:

SILURIAN	1-1984	30	14415	13895	1630	22221	22221	0
SILURIAN	12-1983	31	16016	15963	2216	26659	26659	0
SILURIAN	11-1983	17	7155	7118	1700	12405	12405	0
SILURIAN	10-1983	11	935	1081	397	2328	2328	0

3. 1991 time period -- now it's getting serious. But then they go back in and manage to get production back to very good levels; this well was now 10 years old:

SILURIAN	8-1991	29	5347	5574	1762	8960	8960	0
SILURIAN	7-1991	14	4811	4601	2031	7455	7455	0
SILURIAN	6-1991	0	0	0	0	35	35	0
SILURIAN	5-1991	0	0	0	0	44	44	0
SILURIAN	4-1991	0	0	0	0	13	13	0
SILURIAN	3-1991	0	0	0	0	10	10	0
SILURIAN	2-1991	2	56	217	0	32	32	0
SILURIAN	1-1991	10	106	0	0	54	54

4. This year -- are we finally going to see the well abandoned? Or will see yet another comeback?

SILURIAN	2-2011	0	0	0	0	275	275	0
SILURIAN	1-2011	1	62	62	1	58	58	0
SILURIAN	12-2010	28	273	265	785	608	608	0
SILURIAN	11-2010	30	391	370	922	757	757	0

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Another Silurian well in the neighborhood as the one above:

• 7571, 482, Hess, Reitsch NCT-2 4, Blue Buttes, t4/81; cum 997,798 bbls 8/14;

This well was spud in 1980; test date 4/3/81. and continues to produce, on a pump. This well has also celebrated its 30th birthday. Incredible.

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By the way, another spectacular well in the same neighborhood:

• 9057, 731, Hess, Riggs 10-31, Blue Buttes, Stonewall formation, t5/85; cum 808K 8/14;

This well was spud in 1981; test date 5/5/85. and continues to produce, on a pump. It targeted the Red River formation, which was DRY, and then targeted the Stonewall formation, which is still producing, on a pump. Again, incredible.

The Silurian Formation -- Idle Rambling -- For My Own Benefit -- Others May Enjoy It -- North Dakota, USA

Locator: 10010SILURIAN.

Like the Red Wing Creek wells, it is possible the Silurian formation is a relatively local phenomenon in North Dakota. More on that later, but for now, a look at some nice Silurian wells in the Charlson oil field. Some are still active, some are permanently abandoned.

• 10224, PA/1,560, Petro-Hunt, Devonian 10-1, vertical, AL, 614K (two formations) 2/15;
• 10498, 1,142, Phillip D. Armstrong, I. Thompson 8-34, vertical, abandoned, but Bakken in 1993 still flowing without pump; (two formations; Bakken still flowing); 198K 4/17; 202K 11/24; essentially producing nothing now, 11/24;
• 10499, PA/368, Berco Resources, LLC, Federal 17-32, vertical, abandoned, 414,862; still significant production when well shut down
• 11064, DRY -- Birdbear, Madison (abandoned), Silurian, Petro-Hunt, CMSU C-421
• 11194, PA/1,200, Petro-Hunt, Silurian 37-1, abandoned, 457,803; 12 years of production; stripper well level of production at end of production
• 11353, 711, Petro-Hunt, Silurian 39-1, vertical, still producing, cum 559K 4/17; cum 615K 11/24;
• 11853, PA/AB/869, XTO/Denbury Onshore, Silurian Unit 56-1, vertical, no production since 10/11, cum 354,168 10/11;
• 11897, 36 (not a typo), but the Madison, 312, Petro-Hunt, CMU B-108, vertical, still producing, cum 400K 4/17; cum 493K 11/24;
• 11948, PA/941, Prosper Energy, Prosper-Isaacson 1, vertical, abandoned, 196,553; abandoned after less than 3.5 years of production and still producing enough for a stripper well designation
• 12148, Dry -- but the Madison, PA/67 (not a typo), Petro-Hunt, CMSU A-421, vertical, last produced 1/13; cum 325,668 1/13;

No rhyme or reason to the wells I picked except for the fact they were in one small area in the Charlson that I could see quickly, and they were in the permit file range of 10,000 to 12,000, when there was activity in the Silurian. 

My hunch is that a lot of these wells were abandoned at a time when price of oil made them all not that economical, but with price of oil at $100, I wouldn't be surprised if we don't see some more vertical activity in these other formations.

With regard to the Silurian, from NDGS:

Oil is the most important hydrocarbon produced in the state, but oil was not discovered until 1951 when Amerada Hess Corporation completed the Clarence Iverson #1 on the Nesson anticline. Since then, oil exploration has been nearly continuous in the state. The discovery well was completed in the Silurian Interlake Formation but subsequent development on the anticline focused on the Mississippian Madison Group.

From that same link:

The upper Interlake Formation is productive along large structures (Fig. 15), but the controls on production are not well understood. Salt-plugged porosity degrades reservoir performance in some places whereas fracturing has enhanced performance in other areas. The middle Interlake Formation is productive in two fields in Stark County and the lower Interlake Formation produces from two porosity zones, informally named the Salsbury and the Putnam. These two porosity zones produce on major structures in North Dakota and production can be significant, like that at Stoneview Field on the Nesson anticline. Typically, oil with a significant volume of gas is produced from Interlake reservoirs.

The Charlson Field and Encore

Locator: 10010ENCORE. 

Updates

January 14, 2024: looking at three "almost identical" wells with regard to location and length:

• 18814, 1,754, Oasis/SM Energy/St Mary, Wilson 8-20H, 91k as of May, 2011; less than a year old, t10/10; cum 249K 10/16; cum 401K 11/23;
• 26374, 992, Oasis, Loraine Federal 1X-20H, t2/14; cum 414K 11/23;
• 26228, 1,097, Oasis, Wilson Federal 1X-20H, t2/14; cum 4544K 11/23;

Original Post

The Charlson field is one of the smaller fields in the Williston Basin, about 50 sections, not even two full townships in size. (Note: the most prolific ND well, to the best of my knowledge, is in the Charlson).

For being such a small field, there certainly is a lot of activity. Eight recent permits (in past three or four months) all in the Charlson:

• 18814, 1,754, SM Energy/St Mary, Wilson 8-20H, 91k as of May, 2011; less than a year old, t10/10; cum 249K 10/16; cum 401K 11/23;
  
• 18815, 853, SM Energy/St Mary, Norby 9-20H, 81k as of May, 2011; less than a year old; t10/10; cum 290K 10/16; cum 366K 11/23;
  
• 18816, 1,415, SM Energy/St Mary, Norby 16-20H, 66K as of May, 2011; one year old, t10/10; cum 243K 10/16; cum 329K 11/23;
  
• 19464, PNC, Denbury/Encore, Swenson 31-33SEH
• 19544, 1,032, XTO/Denbury/Encore, Gilbertson 34-26NEH, t6/11; cum 216K 10/16;
• 19545, PNC, Denbury/Encore, Gilberton 34-26NWH
• 19619, PNC, Denbury/Encore, Charlson 24-33H
• 19625,PNC, Denbury/Encore, Charlson 24-34H 

19625 will probably parallel Encore's #17113, a short lateral, PNC
19619 will probably parallel Encore's #17225, a short lateral, PNC

The Gilbertson wells are on the same pad, and will probably parallel Encore's #18703, 888; and, BR's #17356, 356.  Most of the wells in this area have been short laterals, although the BR well is a long lateral.

I'm eager to see the results of the Norby wells; these are three wells all in the same section, but all on different pads. As active as the Charlson has been in the past, and as small as the Charlson is, it is remarkable there has not been much activity in the immediate area of the Norby wells.

BR spudded 17356, a long lateral, back in 2008. It had a relatively unremarkable IP of 356 but as of May, 2011, has produced a cumulative 95,000 barrels of oil. It has probably paid for itself at the wellhead.

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Note the number of Encore wells, these coming after Encore had been bought by Denbury.  

The link takes you to a Wall Street Journal story that talks about further methods to extract oil from the Bakken. According to a Denbury spokesman:

... as a rough rule of thumb, about 15% to 30% of the oil in a reservoir can be extracted using the underground formation’s pressure. A water flood, essentially pumping in water to push out the oil, can get that figure up to 40%. A successful enhanced-oil recovery, or EOR, operation with carbon dioxide can get another 10% to 20%.

Saudi Arabia started using a water flood sometime during the past decade. DNR is looking to build a 200-mile carbon-dioxide pipeline in the Rockies. However, a report back in April, 2010, suggests that DNR has a cash-flow problem and this project remains in the planning stages.

I don't follow DNR closely enough to know where this project stands. DNR and Encore Energy Partners has scheduled an earnings call for November 4, 2010. It will be interesting to see if there is any update on this pipeline.