Compositional and Diagenetic Evolution of a Siltstone, with Implications for Reservoir Quality; an Example from the Lower Triassic Montney Formation in western Canada
| Autor: | Vincent Crombez, Sébastien Rohais, Tristan Euzen, Matthew Power, Chris DeBhur, David L. Bish, Nicholas B. Harris, Korhan Ayranci, Rick Chalaturnyk, Federico F. Krause, Noga Vaisblat |
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| Přispěvatelé: | University of Alberta, King Fahd University of Petroleum and Minerals (KFUPM), Vidence Inc., University of Calgary, Indiana State University, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), IFP Canada, IFP Energies nouvelles (IFPEN) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
010504 meteorology & atmospheric sciences
Stratigraphy Dolomite Geochemistry [SDU.STU]Sciences of the Universe [physics]/Earth Sciences engineering.material 010502 geochemistry & geophysics Oceanography 01 natural sciences Diagenesis Petrography chemistry.chemical_compound CementCompaction Siltstone 0105 earth and related environmental sciences Anhydrite Geology Authigenic Grain size Montney Geophysics chemistry Illite [SDE]Environmental Sciences engineering Economic Geology Organic matter Pressure solution Porosity |
| Zdroj: | Marine and Petroleum Geology Marine and Petroleum Geology, Elsevier, 2021, 129, pp.105066. ⟨10.1016/j.marpetgeo.2021.105066⟩ |
| ISSN: | 0264-8172 |
| Popis: | International audience; Diagenetic models for silt-rich mudstone (siltstone) are less advanced than those for sandstone and clay-rich mudstone. In addition, the influences of diagenetic processes on reservoir quality in siltstone formations are poorly understood. Here we examine the roles of depositional facies, detrital composition, and diagenetic processes in the compositional evolution and reservoir quality of the Lower Triassic Montney Formation, a prominent siltstone-dominated reservoir in western Canada with very large reserves of oil, gas-liquids and natural gas. We applied advanced, high-resolution petrographic methods including SEM (SE, BSE, EDX and SEM-CL), XRD, and QEMSCAN technologies, as well as He-pycnometry on samples from 17 different locations within the basin that represent a range of depths and thermal maturities. Cross-cutting and overgrowth relationships and volumes of authigenic phases demonstrate massive precipitation of quartz, feldspar, dolomite, calcite and anhydrite cements at shallow burial depths, leading to compositional homogeneity among different lithofacies. We propose that the precipitation of large volumes of cement resulted from high fluid flux through the formation at shallow depth, possibly driven by reflux of concentrated seawater in nearshore saltpans. Siltstones preserve relatively high porosity and permeability at shallow burial depths, differing from clay-rich mudstones. In contrast to sandstones, deep burial diagenesis played a relatively minor role in the compositional evolution of the Montney Formation siltstone and is expressed in the form of pressure solution and minor amounts of fibrous illite precipitation. |
| Databáze: | OpenAIRE |
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