|Titre||Effect of sediment source on source rock hydrocarbon potential: an example from the Kimmeridgian and Tithonian-aged source rocks of the central ridge, off-shore Newfoundland, Canada|
|Auteur||Gordon, J B; Sanei, H; Ardakani, O H; Pedersen, P K|
|Source||Marine and Petroleum Geology vol. 127, 104965, 2021 p. 1-18, https://doi.org/10.1016/j.marpetgeo.2021.104965|
|Séries alt.||Ressources naturelles Canada, Contribution externe 20200776|
|Document||publication en série|
|Media||papier; en ligne; numérique|
|Province||Terre-Neuve-et-Labrador; Région extracotière|
|Lat/Long OENS|| -55.0000 -45.0000 46.0000 45.0000|
|Sujets||Jurassique supérieur; Kimméridgien; Tithonien; ressources pétrolières; capacité de production d'hydrocarbures; hydrocarbures; roches mères; géochimie organique; maturation thermique; pétrologie du
sediment; analyses pétrographiques; sediments; origine; kérogène; milieu sédimentaire; puits d'exploration; géologie du substratum rocheux; lithologie; roches sédimentaires; macéraux; combustibles fossiles; géochimie; sédimentologie; géologie marine;
Sciences et technologie; Nature et environnement; Phanérozoïque; Mésozoïque; Jurassique|
|Illustrations||cartes de localisation; coupes lithologiques; diagrammes stratigraphiques; tableaux; graphiques; photomicrographies; diagrammes ternaires; histogrammes|
|Diffusé||2021 02 17|
|Résumé||(disponible en anglais seulement)|
This study presents an integrated approach using organic geochemistry and incident-light organic petrographic microscopy techniques to characterize kerogen
type, hydrocarbon potential, thermal maturity, and the effect depositional environment has on five wells from Upper-Jurassic Kimmeridgian and Tithonian-aged source rock intervals in the Central Ridge area offshore Newfoundland, Canada. The results
show that hydrocarbon potential in these organic-rich marine mudrocks is mainly dependent on depositional environment and present-day burial depth of the sediments. Oscillations and transitions between (i) rocks with dominant allochthonous organic
matter (OM) (including primary/reworked vitrinite and inertinite macerals) representing high influence by continental sediments (e.g., deltaic and littoral depositional environment) and (ii) rocks with dominant autochthonous OM (fluorescing
liptinites such as alginite and their degraded remains) indicating more distal, productive marine continental shelf depositional environment. The latter is of main interest to this study as it is the only rock type that has the capability to generate
oil while the former has very little contribution to oil generation potential due to the abundance of hydrogen-poor organic matter. The secondary maceral, solid bitumen, occurs within the mature section in the deeper part of the basin. Measured %VRo
on vitrinite macerals ranges from 0.62 to 0.82% on four of the five wells studied indicating early oil window to oil window thermal maturity due to the mixing of the organic matter types mentioned above. Integrating Fluorescent Red/Green (R/ G)
quotient measurements from high intensity fluorescing alginite range from 0.77 to 0.86. Conversion of these values to %VRo equivalent range 0.58-0.66% indicates that thermal maturity has not yet reached the primary oil generation window. Vitrinite
reflectance equivalent derived from solid bitumen (%BRo) in the deepest buried well ranges 1.10-1.16% indicating wet gas thermal maturity.
|Sommaire||(Résumé en langage clair et simple, non publié et disponible en anglais seulement)|
This study investigates rocks from five wells in the Central Ridge area offshore Newfoundland, Canada. The
researchers want to understand the type of material, potential for hydrocarbons, how hot it got over time, and the influence of the environment where these rocks formed.
They found that the rocks' ability to produce oil is mainly determined by the
environment where they were deposited and how deep they are buried now. Some rocks contain organic matter from continental sediments and have little potential for oil generation. Others, with organic matter from a marine continental shelf
environment, have the ability to generate oil.
The researchers used techniques like organic geochemistry and microscopy to analyze these rocks. They also measured the thermal maturity, which tells us how hot these rocks got over time.
findings reveal that most of these rocks are in the early stages of oil generation. However, one of the wells showed signs of having reached the wet gas thermal maturity stage.
Understanding the characteristics and potential of these rocks is
crucial for the oil and gas industry, as it helps in identifying areas with the most significant oil-producing potential.