Exploration of the Carson, Bonnition, and Salar Basins — An Integrated Seep Hunting and Geochemical Sampling Approach Reduces Uncertainty and Increases Scientific Knowledge in Frontier Basins

Abstract

Hydrocarbon-rich fluids seep through the seafloor in many regions of the world. When the hydrocarbons derive from reservoirs, then there is much information to be gained for frontier oil and gas exploration, thereby making seep hunting and sampling a very effective method to reduce exploration risk and cost.

Newfoundland and Labrador, although best known for the Jeanne d’Arc and Flemish Pass basins, are surrounded by nearly two dozen underexplored basins. In anticipation of Newfoundland and Labrador’s 2019 licensing round, Fugro, AGI, and Nalcor Oil and Gas collaborated to complete a seep exploration and geochemical campaign to help exploration and production companies to evaluate lease options.

This campaign focuses on the Carson, Bonnition, and Salar Basins, offshore Eastern Canada, located ~350 km SE of St. John’s and ~100 km SSE of existing major oil fields, Hebron, Hibernia, Terra Nova, and White Rose. The campaign consisted of two phases - a geophysical survey acquiring multibeam echosounder (MBES) data (bathymetry, seafloor backscatter, and water column imaging) with sub-bottom profiler (SBP) data over ~18,880 sq km in 88 m to 3,708 m depths. About 239 core targets identified through rigorous geological interpretation of integrated MBES, SBP, and seismic datasets by experienced geoscientists guided a geochemical sampling and heat flow phase that consisted of precision ultra short baseline (USBL) coring on interpreted seep-related targets within the Carson, Bonnition, and Salar Basins. High-quality thermal data (water column temperature, shallow subsurface thermal gradient and sediment conductivity, and seafloor heat flow) were acquired at ten stations within the survey region. Ninety-nine cores were described and sampled for both shipboard and shore-based analysis of hydrocarbon geochemistry. Geoscientists on the vessel analyze headspace gas and perform total scanning fluorescence analysis of solvent extracts. Core targets were refined using these near real-time results from the shipboard geochemistry. Data acquired and interpreted during the seep hunting and geochemical campaign provides new geological insight into the commercial petroleum assessment of the Carson, Bonnition, and Salar Basins. This talk will discuss preliminary results of this study and how the use of an integrated approach to seep hunting is an effective hydrocarbon exploration tool for reducing uncertainty and increasing scientific knowledge in a deepwater frontier basin.

AAPG Datapages/Search and Discovery Article #90350 © 2019 AAPG Annual Convention and Exhibition, San Antonio, Texas, May 19-22, 2019