Flashback: Williston Basin Petroleum Systems As Understood In 2000

Note: in a long note like this there will be formatting errors, typographical, and factual errors. Go to linked source if this is important to you.

I assume that I saw this paper years ago, and it's even possible I read some of it. LOL.

But now that I understand the Bakken a whole lot better and in light of Lynn Helms' recent comments, it is time to go through this article a lot more closely.

The author is Daniel M. Jarvie. The manuscript was submitted for publication in February, 2000. As a reminder, the North Dakota Bakken boom began seven years later. The North Dakota Bakken boom was preceded by a smaller, perhaps unnoticed by most, the eastern Montana Bakken boom, which began in 2000, about the same time this manuscript was submitted.

Jarvie gave his mailing address as Humble Geochemical Services, Humble, TX.

For newbies:

• 2000: a mini-Montana Bakken boom had just begun
• 2007: the North Dakota Bakken boom began

The Abstract

The lead sentence in the abstract is remarkable. It begins:

The Williston Basin has often been used as a model for petroleum exploration and production in basins around the world ...

Other data points from the abstract:

• carbonate source rocks in the Madison Group were overlooked for many years
• Jarvie came up with conclusions based on geochemical analysis of dead oils from 16 producing horizons (remember: Lynn Helms suggested 17 oil-producing horizons)
• the oils from these 16 horizons can be distinctly typed and correlated

His analysis would further elucidate the dominant Madison Group petroleum system in the Williston Basin, while also elucidating secondary petroleum systems including the Duperow, Red River, and Bakken-Lodgepole systems as well as other minor systems

• Madison Group:
• carbonate source rocks
• enriched in 6-carbon ring light hydrocarbons, toluene and methylcyclohexane
• while this 6-ring preference is generally thought to be indicative of terrestrially sourced oils, these oils are definitively derived from carbonate or marly shale source rocks
• Bakken oils:
• enriched in 5-carbon ring light hydrocarbons such as the alkylated cyclopentanes, which appears characteristic of a clay-rich, marine shale source
• Red River oils:
• enriched in normal paraffins and exhibit characteristic Ordovician-sources (G. prisca) oil fingerprints
• other unique petroleum systems:
• Duperow
• Winnipegosis
• Deadwood
• the single Spearfish oil groups with Madison oils
• Nisku oils are principally grouped with Bakken oils  
• Interlake oils are principally grouped with Red River oils

Introduction

The Williston Basin: an intracratonic, sag type Paleozoic basin, located on the western shelf of the North American Craton

Intracratonic basins are the classic type of sedimentary basin. Notable examples include the Williston, Michigan and Illinois basins of North America, the Maranhao basin of Brazil, and the Murzuk and Kufra. 

From Dr Abbas Mansour on sedimentary basins: The Williston basin is the classic example of an intracratonic basin. It contains some three kilometres of rocks of all periods from Cambrian to Tertiary, with notable gaps only in the Permian and Triassic. Sedimentation spanned a range of environments including fluvial and marine sands, reefal carbonates, evaporites and subwave- base pelagic muds. Deep-sea, turbidite and deltaic fades, igneous activity and shallow syndepositional faulting are all absent.

Prescient comment: "the impact of a new play can be dramatic"

Bakken-sourced Lodgepole oils had one year production rates accounting for 10% of the production totals in 1996 alone; this play was described by Lever and Anderson (1984) about 10 years prior to the major Lodgepole discovery in Stark County, ND

Lodgepole oils had one year production rates accounting for 10% of the production totals in 1996 alone 
 
Madison Group reservoirs account for 61% (750 million bbls of oil) of North Dakota's Williston Basin historical oil production (remember, this paper was published back in 2000)

Little attention has been given the source of Duperow oils even though Duperow reservoirs are the second highest producing horizon, exceeding Red River Foundation by about a percentage point

Combined Madison Group, Duperow, and Red River reservoirs account for over 80% of North Dakota's oil productioon

Bakken reservoirs account for 3.2% of production (remember, this paper was published back in 2000)

Oil typing and petroleum systems analysis in the Williston Basin were first published by Williams (1974) and Dow (1974) who detailed 3 petroleum systems as the Tyler, Bakken-Madison, and Winnipeg-Red Riverusing sterane biomarkers Grantham and Wakefield (1988) suggested that an effective source rock was present in the Mission Canyon Formation

Osadetz (1992) suggested and confirmed (1995) a Lodgepole source for Madison oils 

Price and LeFever (1995) described a "dysfunctionalism" in the hypothesized Bakken-Madison petroleum system based on quite different saturate and aromatic gas chromatographic data between the Bakken and Madison Group oils 

• using C7 light hydrocarbon data, Madison, Bakken, and Red River oils were typed and characterized as separate oil families (Jarvie, 1997, Obermajer, 1999)
• further correlation of an organic-rich Mission Canyon carbonate source source to various Madison oils was achieved using light hydrocarbons and biomarkers (Jarvie and Walker, 1997)  
• they also demonstrated the presence of organic-rich intervals throughout the Madison Group including 3 organic-rich Mission Canyon horizons (up to 14% TOC) in the Denielson #1 well in Sheridan County, MT 
• on the other hand, based on same criteria, they correlated the Lodgepole mound oil in the Conoco Kuntz well in Stark County, ND, to the underlying Bakken Formation, although organic rich False Bakken rocks have nearly identical fingerprints 
• while Osadetz (1992) suggest a Lodgepole source as opposed to Mission Canyon source (Jarvie and Walker, 1997) for Madison Group oils, there is, in part, some discrepancy over nomenclature
• for example, in Osadetz and Snowdon (1995), the Tilston Member is shown to be in the Lodgepole Formation, wherease in the US, the Tilston Member is placed in the lower Mission Canyon Formation (multiple studies, 1966, 1987)
• in addition, other intervals in the Mission Canyon Formation have high source potential such as the Richey Shale and other markers

The Madison

EXPERIMENTAL APPROACH FOR OIL TYPING

OBJECTIVES OF STUDY

Samples -- see linked source
Results -- see linked source

Prospective Williston Source Rocks

Madison Group oils: the thickness of these prospective source units range from 50 ft thick on the fringe of the basin to 200 - 300 ft thick in the central part of the Williston Basa detailed study of Madison sources in the central part of the Williston Basin has not yet been completed

Quantitative Gas Chromatographic Fingerprints, Yields, and Ratios

• paper describes the Ordovician oil set 
• the Madison Group oils have very low pristane-to-phytane ratios; whereas typical Bakken oils have values greater than 1.00  
• these data indicate several segregated families of oils following distinctive maturation trends
• the Madison, Bakken, and Red River oils are inferred to be derived from different source rocks  
• certain oils group with these 3 main groups including the Spearfish with Madison oils, the 4 Lodgepole and 4 Nisku oils with Bakken oils, and Interlake and Winnipeg oils with Red River oils  
• the single Madison oil plotting with the Bakken-Lodgepole oils is the Northlustre Field oil in Valley County, MT and is likely a Bakken or mixed source oil 
• there are large differences in sulfur contents among the Madison oils with oils in the northeastern part of North Dakota (Burke, Renville, Ward, and Bottineau counties) having the highest values 
• in general, high sulfur oils have lower API gravities 

In summary:

• Spearfish-Madison Group
• Lodgepole-Bakken-Nisku Group
• Red River Groups
• Madison-Bakken mixes
• Madison-Red River mixes
• Bakken-Duperow mix oil

Long, long discussion of the various oils -- see linked source

Skip ahead to seals

SEALS

Interesting, interesting, interesting:

The lack of correlation of Madison oils with Bakken oils except in certain highly faulted locales demonstrates that seals are effective between the Bakken and Madison as well as other horizons.

But then this: wherever overpressuring occurs within the Bakken, it is effectively a pressure-sealed system

Benzing and Shook (1996) hypothesized that pressure seals form in the presence of interstitial gas and the Bakken has been shown to generate gas at low maturity.

In addition, an overpressured system has significantly increased storage capacity (Holm, 1998) enabling such a system to retain more of its generated products, which will either be expelled in the presence of fractures or further cracked to light hydrocarbons 

CONCLUSIONS

1. Madison oils are distinct from Bakken oils indicative of different sources. This is based on 6-ring preference in the C7 hydrocarbons shown by Madison oils which is evident in Madison source rocks as well as biomarker data, the latter of which demonstrates that Madison Group oils are derived from carbonate or marly shale source rocks

2. Mixing of Madison and Bakken oils does not appear to be extensive in the US Williston Basin (unlike int he Canadian Williston Basin where there is a continuum suggesting high input of Bakken oil into Madison reservoirs

3. A single Spearfish oil from McHenry County, ND, correlates with Madison Group oils

4.  Lodgepole mound, Bakken, and most of the Nisku oils studied are Bakken-sourced oils with the Lodgepole oils being lower maturity oils than typical Bakken-produced oils

5. Some Madison Group oils in this study are mixed Bakken-Madison sourced oils. These oils are form E. Poplar (Roosevelt County, MT) and McGregor Field (Williams County, ND). The McGregor oil may have some Duperwon input in lieu of, or in addition to, Madison input

6. Duperow and Winnipegois oils are different from each other and other oils, but show considerable variabilty perhaps due to mixing or commingling of production; it is likely that there are separate sources for these oils

7. Red River oils are rich in paraffins

8. see linked source

9. see linked source

10. A single Tyler oil is likely derived from a marly shale source within the Tyler or Heath formations; these oils have been shown to be quite variable, however

Note: marly shale --  Marl or marlstone is a calcium carbonate or lime-rich mud or mudstone which contains variable amounts of clays and silt. The dominant carbonate mineral in most marls is calcite, but other carbonate minerals such as aragonite, dolomite, and siderite may be present.