Fault Seal Analysis and Residual Saturation in the Migrant Structure, Offshore Nova Scotia: Implications for CCS

In this paper, we document immovable residual gas at Migrant using static and dynamic models based on 1996 3D seismic data, that we used to analyse the Migrant structure drilled by Mobil et al in 1977 (the 67th of 210 wells on the margin). We use a fault plane profile to illustrate cross-fault leak and “stair-stepping” with net upward gas migration at a crestal fault. By simulating methane influx at depth, we replicate residual gas and transition zone gas saturations up to 50% interpreted from logs. In addition, we briefly show similar examples from the Penobscot and Venture areas.