Date of Award
Master of Science (MS)
Stephan H. Nordeng
With the continuous demand for fossil fuel and advancement in technology, the unconventional petroleum resources have come into limelight. The Devonian Three Forks Formation consisting of carbonate and clastic sediments is an unconventional oil accumulation
containing about 3.73 billion barrels of technically recoverable oil. However, understanding rock properties of the various lithofacies and fluid saturation is still challenging.
The petroleum prospectivity was evaluated by integrating organic maturity and hydrocarbon generation with porosity distribution and fluid saturation in the Ambrose field and adjacent fields. The organic maturity was done with a programmed pyrolysis analysis (Source
Rock Analyzer) using samples taken at 1ft intervals through the Lower Bakken Shale. Core samples from the Lower Bakken Shale and Three Forks Formation were prepared for NMR analysis by saturating with 300,000 ppm NaCl brine solution at 100 psi of compressed air for 50 days. Porosity analysis was acquired from Helium porosimeter and quality checked by NMR transverse relaxation (T2) analysis with Oxford Instruments GeoSpec2 core analyzer coupled with Green Imaging Technology software. Pore size distributions were determined using T2 cutoff values to partition total porosity measurements into micropores, mesopores and macropores.
Tmax from the programmed pyrolysis showed that the organic maturity between wells varies from immature to mature (427°C to 440°C). NMR relaxation time results showed saturation is proportional to distribution of pore size with mesopore and macropore contributing more to oil saturation while micropore contributes to water saturation.
Adeyilola, Adedoyin Suleman, "Comparing Source Rock Maturity With Pore Size Distribution And Fluid Saturation In The Bakken-Three Forks Petroleum System, Williston Basin, North Dakota" (2018). Theses and Dissertations. 2138.