Hibernia Sandstone Formation

In the Lower Cretaceous (Berriasian-Albian) Hibernia to Avalon/Ben Nevis formations, which contain the main reservoir levels of the Hibernia Field (the 200 m thick Hibernia Sandstone and the 150 m thick Catalina Member of the Whiterose Formation, as well as the up to 800 m thick Avalon/Ben Nevis Sandstone), the shift to elastic-dominated marginal-marine and marine sedimentation occurred, as rifting continued in the Grand Banks region. Most of the detrital material was derived from elevated areas to the west (Bonavista Platform Figs 1 and 3) and southwest (Avalon Uplift Jansa Wade, 1975) of the Jeanne d Arc basin, but also from uplifted and... 

Secondary porosity development as the main contributor to the present reservoir porosity in Hibernia Field is closely related to the former presence of early calcite cements. The fraction of total porosity which is secondary increases with depth, from 20% in Avalon/Ben Nevis Sandstone (Hauterivian-Albian), to 60% in Catalina Sandstone (Lower Hauterivian), and to >80% in Hibernia Formation (Berriasian to Mid-Valanginian). In the Avalon/Ben Nevis Sandstone the formation of secondary porosity may have been caused by meteoric water influx. In the deeper reservoirs it was caused by acidic pore fluids generated by organic-matter maturation. The present average geothermal gradient of 26°C/km suggests that the most deeply buried sandstone reservoirs in Hibernia (Tithonian Jeanne d Arc Formation) did not experience temperatures in excess of 130°C. 

Brown, D.M., McAlpine, K.D. Yole, R.W. (1989) Sedimentology and sandstone diagenesis of Hibernia Formation in Hibernia Oil Field, Grand Banks of Newfoundland. Bull. Am. Ass. Petrol. Geol., 73, 557-575. 

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