Title | Variation of porosity and permeability with diagenetic minerals in the Scotian Basin, offshore eastern Canada and its implications for reservoir quality |
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Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
Author | Zhang, Y; Pe-Piper, G; Piper, D J W |
Source | Geological Survey of Canada, Open File 7642, 2015, 459 pages, https://doi.org/10.4095/295067 Open Access |
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Year | 2015 |
Publisher | Natural Resources Canada |
Document | open file |
Lang. | English |
Media | on-line; digital |
File format | pdf |
Province | Eastern offshore region |
Area | Scotian Shelf; Scotian Basin; Sable Sub-basin; La Have platform; Abenaki Sub-basin; Orpheus Graben; Laurentian Sub-basin |
Lat/Long WENS | -64.0000 -57.0000 45.0000 43.0000 |
Subjects | igneous and metamorphic petrology; marine geology; sedimentology; porosity; permeability; sandstones; reservoirs; reservoir rocks; lithology; petrography; sedimentary petrology; detrital minerals;
albite; detritus; potassium; feldspar; plagioclase; diagenesis; Lower Cretaceous; scanning electron microscopy; electron microscope analyses; sedimentary facies; lithofacies; Peskowesk A-99 well; Louisbourg J-47 well; Kegeshook G-67 well; Cohasset
A-52 well; Dauntless D-35 well; Esperanto K-78 well; Glenelg E-58 well; Glenelg H-59 well; Glenelg N-49 well; Mic Mac J-77 well; Mohican I-100 well; Onondaga O-95 well; Panuke B-90 well; Sable Island C-67 well; Thebaud C-74 well; Thebaud I-93 well;
Thebaud-3 well; Venture B-52 well; Venture H-22 well; Wyandot E-53 well; Mesozoic; Cretaceous |
Illustrations | location maps; photomicrographs; plots; stratigraphic columns; tables |
Program | Offshore Geoscience |
Released | 2015 02 04 |
Abstract | The Scotian Basin is an under-explored offshore basin that has produced gas and minor oil from Jurassic-Cretaceous deltaic sandstones. Reservoir quality is an important exploration risk in the basin.
This study investigates whether there are systematic stratigraphic or geographic variations in diagenetic mineral assemblages that relate to reservoir permeability. Three data sets are used: a compilation of all available core-plug porosity and
permeability measurements (3271 in total), a subset of 577 corresponding to thin sections with lithofacies assignments, and a subset of 35 thin sections principally from reservoir sandstones, in which modal abundance of diagenetic minerals has been
determined by image analysis of scanning electron microscope backscattered electron images. Abundances above a threshold of ~ 4% diagenetic kaolinite, calcite and ankerite correlate inversely with permeability, but chlorite and possibly siderite
correlate positively. Diagenetic assemblages show no systematic variation with stratigraphy or geography, both of which may have variable detrital supply. Permeability shows the well-known variation with grain size and depth of burial, but after
correcting for these effects is greatest in estuarine channel and river-mouth turbidite sandstones. Local effects such as facies distribution, architecture of channel sandstones, fluid pathways related to complex salt tectonics, and the effects of
overpressure are more important than predictable basin-wide effects such as detrital supply, regional depositional lithofacies or sequence stratigraphy in controlling sandstone reservoir quality. |
Summary | (Plain Language Summary, not published) This study uses a quantitative assessment of cements that partially fill pores in sandstones that are oil and gas reservoirs to examine relationships
between such minerals and reservoir permeability. It contributes to a broader goal of assessing exploration risk associated with reservoir quality in the Scotian Basin. |
GEOSCAN ID | 295067 |
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