Source rock potential of the Bakken shales in the Williston Basin, North Dakota and Montana

The lower and upper Bakken shales are world class source rocks in the Williston Basin, sourcing reservoirs in the Bakken, upper Three Forks, and lower Lodgepole formations, which comprise the economically significant Bakken Petroleum System (BPS). Lower and upper Bakken shales exhibit a wide range in TOC contents, and the kerogen type present in Bakken shale is primarily Type II. Lower and upper Bakken shales also exhibit vertical recurrent patterns in each shale section. Vanadium and Nickel elements are strongly sensitive to the paleoredox conditions of the depositional setting. The location of maximum flooding surface was identified near the top contact of the lower and upper Bakken shales, where the most enrichment of V and Ni occurs. Oil-generation kinetics were also experimentally derived by the method of hydrous pyrolysis from the immature upper Bakken shale samples. After the whole series of HP experiments, the kinetics (E[subscript a] and A[subscript 0]) of upper Bakken composite sample are summarized as follow: (E[subscript a]= 55.17 kcal/mole and A[subscript 0]= 3.89x10[superscript 27]m.y.[superscript -1]) for unadjusted kinetics and (E[subscript a]= 53.79 kcal/mole and A[subscript 0]= 1.25x10[superscript 27]m.y.[superscript -1]) for adjusted kinetics. After modeling, the adjusted HP kinetics from this study were recommended to apply to the Bakken shales in other areas of the Williston Basin for the estimation of the extent of oil generation. A systematic increase in PI and Tmax and a significant reduction in HI, TOC, and residual kerogen contents with increasing experiment temperatures (thermal maturity) were also observed for both unextracted and extracted rocks. The west-east cross-section through the Parshall Field indicate that Bakken shales in the Parshall area are immature with very minimal extent of oil generation, but significant amount of oil resources are discovered in this area. So, most of the produced oil was probably migrated from deeper areas, because just west to the Parshall/Sanish area, there are much more mature Bakken shales generating and expelling significant amounts of oil, which short laterally migrated to the Parshall Field. It is suggested that the maturity should be the primary control on oil generation and expulsion.

Name thesis:degree_name

Doctor of Philosophy (Ph.D.)

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Geology and Geological Engineering

Grantor dc:publisher

Colorado School of Mines. Arthur Lakes Library

Year dc:date.issued

2014

Author dc:creator

• Jin, Hui

Advisor dc:contributor.advisor

• Sonnenberg, Stephen A.

Committee members dc:contributor.committeemember

• Sarg, J. F. (J. Frederick)
• Curtis, John B.
• Prasad, Manika
• LeFever, Julie A.

• kerogen
• Bakken shales
• kinetics
• TOC
• Parshall field
• maximum flooding surface

Statement dc:rights

• Copyright of the original work is retained by the author.

Language dc:language.iso

eng, English

Identifier

T 7417

OAI identifier oai:identifier

oai:repository.mines.edu:11124/293