Print this pagePetroleum Migration History in the Terra Nova Area, Jeanne d'Arc Basin, Offshore Newfoundland: Evidence from Fluid Inclusions
HUANG, Z., M. A. WILLIAMSON, C. YANG, H. QING, O. Y., and D. L. STASIUK
The diagenetic history, composition of diagenetic fluids, the role of major faults and the time of diagenetic events and oil migration in the Jeanne d'Arc Formation of the Terra Nova area, the Jeanne d'Arc Basin, were investigated using fluid inclusion data. Aqueous, CO[2]-rich and hydrocarbon fluid inclusions co-occur in the same fluid inclusion assemblages (FIAs). The homogenization temperatures (T[h]), which are interpreted to be reliable estimates of the entrapment temperatures (T[t]), of primary aqueous fluid inclusions in quartz overgrowth/cements range from 82 to 135 degrees C. Salinity varies in these inclusions from 0.17 to 12.86 wt.%, with an average entrapment pressure (P[t]) of 317 bars. T[h] variations among wells seem to be related to burial depth and especially the proximity to major faults. Where the Jeanne d'Arc formation was cut by fault(s) the T[h] are higher and show increased variations. A comparison of different habits of oils in their wavelength at the maximum intensity and RIG quotients suggested that the reservoirs were charged at least twice. The hydrocarbon inclusions that occur in the same FAIs with the aqueous fluid inclusions are of lower maturity than those in annealed fractured quartz and in late diagenetic clays. The crude oils show intermediate maturity between the two, suggesting mixture of oils. Decompacted burial curves indicate that the first charging event occurred at around 70 Ma, when the sandstones was under quartz overgrowth and cementation, and the second one happened at around 30 Ma.