Scotian Basin Petroleum and Source Rocks (an explorationist s perspective) David E. Brown Senior Advisor, Geology Canada-Nova Scotia Offshore Petroleum Board 21 January 2014 1
PREVIOUS RESEARCH Since early 1970s to today (~40 years) 207 wells; good sample and analysis datasets SR and petroleum identification and characterization Industry (companies, consultants) and government (GSC) Significant research, publications and reports by Mukhapadhyay, Snowdon, Fowler, Obermajer, Avery, Issler, Powell, Robertson Research, GeoMark, Industry, etc. New data, compilations and interpretations PFA 2011 2
SOURCE ROCKS Major Late Jurassic Tithonian (~J150) Carbonate-deltaic transition MFS Up. Mic Mac and Lr. Missisauga Fms. Type IIA/IIB-III kerogen TOC 2-3%, up to 7% Oil and gas Early Jurassic Pleinsbachian Toarcian (N/A) Shallow near-normal to limited restricted marine carbonates, marls and shales Mohican and Iroquois Fms. equivalents Not penetrated (indirect evidence) Modelled Type I oil-prone (OETR 2011) Dominantly oil, minor gas
Minor Early Cretaceous Aptian (K125 K113) Intra-deltaic MFS Naskapi Mb. (Logan Canyon Fm.) TOC 1-2% Type III kerogen Dominantly gas, minor oil Early Cretaceous Berriasian - Valanginian (~K147 / K137) Multiple intra-deltaic MFS marine shales Lower Missisauga Fm. TOC 1-2% Type III kerogen Dominantly gas Middle Jurassic Callovian (J163) MFS marine shale Misaine Mb. (Abenaki Fm.) TOC 2% (1 sample) Type II/III kerogen Greater development / potential in deep water? Dominantly gas, minor oil
Potential Late Triassic Carnian Rhaetian (~J200) Lacustrine to restricted marine shales Eurydice Fm. and equivalents Not penetrated Subsalt; generally deeply buried Probable Type I kerogen, oil-prone Not modelled in PFA Dominantly oil?
3 Powell and Snowdon (1979) 3 Mukhopadhyay et al. (1995) 5 Illich et al. (1999) 3 Fowler & Obermajer (2001) HC LIQUIDS - FAMILIES & GROUPS How closely are they related? Are there any significant differences? Have all oils / condensates been analyzed? What are the gaps? Can they be addressed? Require integration and normalization? 7
LIQUIDS FAMILIES 8 Revised and updated by Mukhopadhyay (original in Mukhopadhyay, GSC OF Report 3284, 1995). Used with permission.
SR HC LIQUIDS CORRELATIONS Mixed Oils / Families E.g. Cohasset, Panuke, Balmoral, Penobscot, etc. High gravity oils API 47-55 Several oil families in same and adjacent fields / pools Multiple sources? Mixing? Multi-phase maturation / migration? Relationship to tectonic / diagenetic episodes? 9
B-90 SS-2 F-99 SS-4 10 Revised and updated by Mukhopadhyay (original in Mukhopadhyay, GSC OF Report 3284, 1995). Used with permission.
SR HC LIQUIDS CORRELATIONS Enigmatic shows in old wells E.g. Mic Mac, Wyandot, Erie Medium gravity oils API 38 No modern analyses Oil samples lost (not in CNSOPB collection) Samples in industry / GSC-C archives? Source rocks unknown Oils found at shallow depths Maturation: reservoir < oil SR E. Jurassic / L. Triassic SR? 11
13 Early Jurassic Isochron: Iroquois, Mic Mac & Scatarie Fms.
ION-GXT 1800 14
VISION Hydrocarbon & Source Rock Atlas Compilation, integration and interpretation of existing and new analysis and data SR identities, distribution, characteristics, maturation HC families, characteristics, compositions Photograph images (cores, thin and polished sections) Depositional environments Thickness, isopach, structure, maturation, CRS maps Cross sections, well data Comprehensive data appendices and references Searchable 16
WAY FORWARD 17 Systematic comparative review of existing analyses Industry, government, academic Determination of useful data CNSOPB, GSC, literature Identification of data and knowledge gaps Samples, analyses, intervals, formations, basins Collection of new liquid / SR sample data Extracts, cuttings, cores, sediments Search for missing / better preserved HC liquids (industry, GSC-C) Undertaking new analyses and studies GC-MS / -IRMS, APT, carbon isotope, biomarkers, diamondoids Polished and thin sections TOC, kerogens, HI, OI, Rock Eval, maturation Depositional facies, environments, distribution Influence of salt and overpressure Burial / thermal history modelling (Temis, BasinMod, APT) Integration of vintage and new data / analyses / interpretations Creation of new Bible wells
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