Integrated geophysical and petrophysical characterization of Upper Jurassic carbonate reservoirs from Penobscot field, Nova Scotia: a case study

Abstract

In the recent past, an integrated analysis of predicted petrophysical properties along with acoustic impedance has emerged as an effective means of characterizing reservoirs. Model-based inversion method was applied to precisely estimate acoustic impedance (correlation: 87.9% & error: 414 m/s*g/cm³), while the multi-layer perceptron algorithm was applied to predict gamma-ray (correlation: 90.5% & error: ~ 2.5API), neutron porosity (correlation: 92.3% & error: ~ 0.01) and effective porosity (correlation: 85.8% & error: ~ 0.01) from post-stack 3D seismic data. We analyzed the entire Abenaki Formation into four parts, i.e., the Scatarie, Baccaro, Misaine shale and Artimon Members. These members have been characterized by combining the P-Imp, GR, NPHI, and PHIE responses. Well-based cross-plot study suggests that the high P-Imp, low GR and low NPHI indicate carbonate facies. In contrast, low impedance, high GR and high NPHI values indicate the shale facies from the Abenaki Formation. P-Imp, GR, and NPHI values fall in the intermediate range for the sand facies. The attribute stratal slice maps indicate the dominance of carbonate facies within the Scatarie, Baccaro, and Artimon Members, while shale facies dominate within the Misaine shale Member in the Penobscot field. The carbonate facies' hydrocarbon potentiality within different members was also accessed based on PHIE responses. The Artimon, Baccaro and Scatarie Members observed several high porosity (10–20%) zones. The current study also advocates that the integrated analysis using multi-attributes certainly minimizes the risk associated with facies discrimination in reservoir characterization for hydrocarbon exploration. Other potential prospective zones could be probed to chase the lead from well L-30 in the study area for further exploration-related works.