Resistivity of reservoir sandstones and organic rich shales on the Barents Shelf: Implications for interpreting CSEM data

Marine controlled source electromagnetic (CSEM) data have been utilized in the past decade during petroleum exploration of the Barents Shelf, particularly for de-risking the highly porous sandstone reservoirs of the Upper Triassic to Middle Jurassic Realgrunnen Subgroup. In this contribution we comp...

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Published in:Geoscience Frontiers
Main Authors: Senger, Kim, Birchall, Thomas, Betlem, Peter, Ogata, Kei, Ohm, Sverre Ekrene, Olaussen, Snorre, Paulsen, Renate Strugstad
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier Ltd. 2020
Subjects:
Online Access:https://hdl.handle.net/11250/2827271
https://doi.org/10.1016/j.gsf.2020.08.007
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author Senger, Kim
Birchall, Thomas
Betlem, Peter
Ogata, Kei
Ohm, Sverre Ekrene
Olaussen, Snorre
Paulsen, Renate Strugstad
author_facet Senger, Kim
Birchall, Thomas
Betlem, Peter
Ogata, Kei
Ohm, Sverre Ekrene
Olaussen, Snorre
Paulsen, Renate Strugstad
author_sort Senger, Kim
collection University of Stavanger: UiS Brage
container_issue 6
container_start_page 101063
container_title Geoscience Frontiers
container_volume 12
description Marine controlled source electromagnetic (CSEM) data have been utilized in the past decade during petroleum exploration of the Barents Shelf, particularly for de-risking the highly porous sandstone reservoirs of the Upper Triassic to Middle Jurassic Realgrunnen Subgroup. In this contribution we compare the resistivity response from CSEM data to resistivity from wireline logs in both water- and hydrocarbon-bearing wells. We show that there is a very good match between these types of data, particularly when reservoirs are shallow. CSEM data, however, only provide information on the subsurface resistivity. Careful, geology-driven interpretation of CSEM data is required to maximize the impact on exploration success. This is particularly important when quantifying the relative resistivity contribution of high-saturation hydrocarbon-bearing sandstone and that of the overlying cap rock. In the presented case the cap rock comprises predominantly organic rich Upper Jurassic–Early Cretaceous shales of the Hekkingen Formation (i.e. a regional source rock). The resistivity response of the reservoir and its cap rock become merged in CSEM data due to the transverse resistance equivalence principle. As a result of this, it is imperative to understand both the relative contributions from reservoir and cap rock, and the geological significance of any lateral resistivity variation in each of the units. In this contribution, we quantify the resistivity of organic rich mudstone, i.e. source rock, and reservoir sandstones, using 131 exploration boreholes from the Barents Shelf. The highest resistivity (>10,000 Ωm) is evident in the hydrocarbon-bearing Realgrunnen Subgroup which is reported from 48 boreholes, 43 of which are used for this study. Pay zone resistivity is primarily controlled by reservoir quality (i.e. porosity and shale fraction) and fluid phase (i.e. gas, oil and water saturation). In the investigated wells, the shale dominated Hekkingen Formation exhibits enhanced resistivity compared to the background (i.e. the ...
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geographic Barents Sea
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op_doi https://doi.org/10.1016/j.gsf.2020.08.007
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https://doi.org/10.1016/j.gsf.2020.08.007
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spelling ftunivstavanger:oai:uis.brage.unit.no:11250/2827271 2025-06-08T14:00:47+00:00 Resistivity of reservoir sandstones and organic rich shales on the Barents Shelf: Implications for interpreting CSEM data Senger, Kim Birchall, Thomas Betlem, Peter Ogata, Kei Ohm, Sverre Ekrene Olaussen, Snorre Paulsen, Renate Strugstad Barents sea 2020-09-26T17:58:58Z application/pdf https://hdl.handle.net/11250/2827271 https://doi.org/10.1016/j.gsf.2020.08.007 eng eng Elsevier Ltd. Norges forskningsråd: 228107 Norges forskningsråd: 257579 https://hdl.handle.net/11250/2827271 https://doi.org/10.1016/j.gsf.2020.08.007 cristin:1833784 Attribution-NonCommercial-NoDerivatives 4.0 Internasjonal http://creativecommons.org/licenses/by-nc-nd/4.0/deed.no © 2020 ChinaUniversity of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. 1-17 12 Geoscience Frontiers 6 petroleumsgeologi Barentshylla VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Mineralogi petrologi geokjemi: 462 VDP::Teknologi: 500::Berg‑ og petroleumsfag: 510::Geoteknikk: 513 Peer reviewed Journal article 2020 ftunivstavanger https://doi.org/10.1016/j.gsf.2020.08.007 2025-05-16T03:36:58Z Marine controlled source electromagnetic (CSEM) data have been utilized in the past decade during petroleum exploration of the Barents Shelf, particularly for de-risking the highly porous sandstone reservoirs of the Upper Triassic to Middle Jurassic Realgrunnen Subgroup. In this contribution we compare the resistivity response from CSEM data to resistivity from wireline logs in both water- and hydrocarbon-bearing wells. We show that there is a very good match between these types of data, particularly when reservoirs are shallow. CSEM data, however, only provide information on the subsurface resistivity. Careful, geology-driven interpretation of CSEM data is required to maximize the impact on exploration success. This is particularly important when quantifying the relative resistivity contribution of high-saturation hydrocarbon-bearing sandstone and that of the overlying cap rock. In the presented case the cap rock comprises predominantly organic rich Upper Jurassic–Early Cretaceous shales of the Hekkingen Formation (i.e. a regional source rock). The resistivity response of the reservoir and its cap rock become merged in CSEM data due to the transverse resistance equivalence principle. As a result of this, it is imperative to understand both the relative contributions from reservoir and cap rock, and the geological significance of any lateral resistivity variation in each of the units. In this contribution, we quantify the resistivity of organic rich mudstone, i.e. source rock, and reservoir sandstones, using 131 exploration boreholes from the Barents Shelf. The highest resistivity (>10,000 Ωm) is evident in the hydrocarbon-bearing Realgrunnen Subgroup which is reported from 48 boreholes, 43 of which are used for this study. Pay zone resistivity is primarily controlled by reservoir quality (i.e. porosity and shale fraction) and fluid phase (i.e. gas, oil and water saturation). In the investigated wells, the shale dominated Hekkingen Formation exhibits enhanced resistivity compared to the background (i.e. the ... Article in Journal/Newspaper Barents Sea University of Stavanger: UiS Brage Barents Sea Hekkingen ENVELOPE(17.832,17.832,69.597,69.597) Geoscience Frontiers 12 6 101063
spellingShingle petroleumsgeologi
Barentshylla
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Mineralogi
petrologi
geokjemi: 462
VDP::Teknologi: 500::Berg‑ og petroleumsfag: 510::Geoteknikk: 513
Senger, Kim
Birchall, Thomas
Betlem, Peter
Ogata, Kei
Ohm, Sverre Ekrene
Olaussen, Snorre
Paulsen, Renate Strugstad
Resistivity of reservoir sandstones and organic rich shales on the Barents Shelf: Implications for interpreting CSEM data
title Resistivity of reservoir sandstones and organic rich shales on the Barents Shelf: Implications for interpreting CSEM data
title_full Resistivity of reservoir sandstones and organic rich shales on the Barents Shelf: Implications for interpreting CSEM data
title_fullStr Resistivity of reservoir sandstones and organic rich shales on the Barents Shelf: Implications for interpreting CSEM data
title_full_unstemmed Resistivity of reservoir sandstones and organic rich shales on the Barents Shelf: Implications for interpreting CSEM data
title_short Resistivity of reservoir sandstones and organic rich shales on the Barents Shelf: Implications for interpreting CSEM data
title_sort resistivity of reservoir sandstones and organic rich shales on the barents shelf: implications for interpreting csem data
topic petroleumsgeologi
Barentshylla
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Mineralogi
petrologi
geokjemi: 462
VDP::Teknologi: 500::Berg‑ og petroleumsfag: 510::Geoteknikk: 513
topic_facet petroleumsgeologi
Barentshylla
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Mineralogi
petrologi
geokjemi: 462
VDP::Teknologi: 500::Berg‑ og petroleumsfag: 510::Geoteknikk: 513
url https://hdl.handle.net/11250/2827271
https://doi.org/10.1016/j.gsf.2020.08.007