Flemish Pass Basin:Hydrocarbon Prospectivity and Potential Deep Water Development

Abstract

Abstract The Flemish Pass Basin, offshore Newfoundland, is located in 400 to 1,100 m of water east of the Grand Banks. It is separated from the Jeanne d'Arc Basin to the west by the Ridge Complex (Central Ridge). The Jeanne d'Arc Basin contains 14 hydrocarbon discoveries, notable among them are the Hibernia, Terra Nova, White Rose, and the Hebron oil fields. Three hydrocarbon discoveries have been made on the Ridge Complex. The Flemish Pass Basin has been explored by three wells and several seismic surveys. These data, which are available to the public through the Canada-Newfoundland Offshore Petroleum Board (C-NOPB), show Early Cretaceous sandstone development and Kimmeridgian age, mature source rocks. A number of large structural closures have also been mapped. In the past the Flemish Pass Basin attracted less exploration interest relative to the basins on the Grand Banks with which it shares a similar geologic and tectonic history. This may be due to the deeper water. This paper reviews the hydrocarbon resource potential of the Flemish Pass Basin and some of the challenges to future developments. Introduction The eastern Newfoundland offshore area is characterized by three prominent physiograhic features; the Grand Banks, the Flemish Pass and the Flemish Cap (Figure 1). The Grand Banks and the Flemish Cap are positive features with water depths generally less than 200 m. The Flemish Pass is a north northeast elongated bathymetric trough with water depths in excess of 1,100 m. It separates the Grand Banks to the west from the Flemish Cap to the east and provides a passage for numerous icebergs brought down by the Labrador current. The Flemish Pass Basin underlies the Flemish Pass bathymetric low. The Newfoundland Grand Banks are underlain by a number of northeast trending Mesozoic sedimentary basins. To date 18 significant hydrocarbon discoveries have been declared on the Grand Banks, 15 in the Jeanne d'Arc Basin and three on the Ridge Complex between the Jeanne d'Arc and the Flemish Pass basins. Hibernia, Terra Nova, White Rose, and Hebron constitute the four largest discoveries. Estimated at a 50% probability, the total discovered resources on the Grand Banks consist of 336 million m3 (2.1 billion barrels) of oil, 142 billion m3 (four trillion cubic feet) of gas, and 46 million m3 (290 million barrels) of natural gas liquids (Table 1)(1). FIGURE 1: Physiography and Mesozoic basins offshore eastern Newfoundland (after Keen et al., 1987). Most of the recent hydrocarbon exploration offshore eastern Newfoundland has been concentrated in the Jeanne d'Arc Basin and on the Ridge Complex. Relative to these areas the Flemish Pass Basin has been explored minimally due to its greater water depths and the presence of icebergs. The Flemish Pass Basin is covered by seismic data acquired between 1971 and 1999. The most useful publicly available data sets are the Esso data, primarily in the eastern and northern parts of the basin, and the Parex survey, that covers the western and southern parts (Figure 2). The data quality is fair but is sufficient only for gross structural and stratigraphic interpretations.