Petroleum System Insights of Newfoundland and Labrador From Fluid Inclusions
The Canadian Province of Newfoundland and Labrador is emerging as a major oil player on the international oil and gas stage. The primary exploration focus in the past has been within the proven reservoirs and shallow waters of the Jeanne d'Arc Basin, but in recent years, large seismic 2D and 3D seismic programs, novel geological concepts are aiming for new oil and gas reserve along the Newfoundland and Labrador continental margin, extended now from proven basins to less explored or unexplored areas. All these basins are part of a widespread interconnected network of rift basins that formed during the Mesozoic continual break-up and Atlantic Ocean opening and contain world quality reservoir and source rocks. Trapped fluids occur within matrix cements, fracture fill, and discontinuous, organic-matter-related nanopores within liquids-rich unconventional plays. Such “fluid inclusions” are isolated during natural processes and record certain chemical and physical conditions attending the generation, migration, and entrapment of the original fluid. By studying these encapsulations with a combination of unique and classical techniques, explorationists can reduce risk associated with identifying and exploiting productive reservoirs. Automated Fluid inclusion stratigraphy (FIS), a high-throughput process that macerates approximately 0.5 gm of rock material in a vacuum system and analyzes the liberated volatiles species by direct quadrupole mass spectrometry. The process generates a depth record of C1-C13 organic species, and inorganic compounds, with individual sample analytical times of less than 1 minute. Combined with classical fluid inclusion optical work (petrography and microthermometry) can provide evidence for multiple pulses of migration or generation, including a free gas phase. Over 20 wells were studied. Microseeps were detected in wells at Flemish, Orphan, and Labrador Shelf. Possible deeper thermal alternation with temperatures near 140-150 C is observed in Cretaceous and Jurassic where deeply buried. Hydrocarbon migration evidences were documented in Margaree A-49, a dry hole drilled in the Orphan Basin. Paleo-oil column are recorded in Cretaceous (Kyle L-11) and Jurassic (Panther P-52) with measured API gravities generally at 27-46. These examples illustrate the potential for using fluid inclusions to address regional exploration risk in areas with limited well control.
AAPG Datapages/Search and Discovery Article #90350 © 2019 AAPG Annual Convention and Exhibition, San Antonio, Texas, May 19-22, 2019