Direct hydrocarbon indications from fluid contacts - stop calling them 'flatspots'!
So called 'flatspots' rarely have the appearance of flatness, even at proven gas and oil fields and on seismic data that has been converted to depth using best-practice methods. The appearance of fluid contacts on seismic reflection data is influenced by several controls, most notably, flu...
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ftzenodo:oai:zenodo.org:7955930 2024-09-15T18:32:58+00:00 Direct hydrocarbon indications from fluid contacts - stop calling them 'flatspots'! Jarrod Dunne James Parsons 2023-03-15 https://doi.org/10.5281/zenodo.7955930 eng eng Zenodo https://zenodo.org/communities/aseg_extended_abstracts_2023 https://doi.org/10.5281/zenodo.7955929 https://doi.org/10.5281/zenodo.7955930 oai:zenodo.org:7955930 info:eu-repo/semantics/openAccess Creative Commons Attribution Non Commercial No Derivatives 4.0 International https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode Australian Society of Exploration Geophysicists Extended Abstracts, Volume 2023, 4th Australasian Exploration Geoscience Conference, Brisbane, 2023, (2023-03-15) AEGC, Australasian Exploration Geoscience Conference, Brisbane, Australia, 15-17 March 2023 DHI flatspot quantitative interpretation AvO info:eu-repo/semantics/conferencePaper 2023 ftzenodo https://doi.org/10.5281/zenodo.795593010.5281/zenodo.7955929 2024-07-27T06:10:26Z So called 'flatspots' rarely have the appearance of flatness, even at proven gas and oil fields and on seismic data that has been converted to depth using best-practice methods. The appearance of fluid contacts on seismic reflection data is influenced by several controls, most notably, fluid type; burial depth; saturation; and the size of the 'flatspot' anomaly compared to the imaging velocity resolution. Many cases of non-flatness are caused by lateral velocity variation in the overburden. Often the structural form of the trap itself is the cause. Non-flat seismic hydrocarbon contacts are seen at shallow gas hazards in Sakhalin, Russia; at oil fields in the Santos Basin, Brazil; and at 'gas on oil' accumulations in the Browse Basin, Australia. So, it appears that non-flat 'flatspots' are ubiquitous, suggesting an urgent name change is needed for this form of DHI. The interpretation of DHIs is aided by a new 2D synthetic modelling method that characterizes the time-depth behaviour of a field or prospect simultaneously with its amplitude response. The software interactively models seismic cross-sections using rock physics or seismic velocities to compute AvO synthetics at significant layer boundaries. Hydrocarbon porefill effects can be modelled using Gassmann fluid substitution to modify the elastic properties within the proposed trap. DHIs are thus characterized at (1) the top of the trap; (2) the base of the trap (if base sealed); and (3) at the contacts between different fluid types, such as a gas/water contact; oil/water contact; or gas/oil contact. We propose a more representative terminology, referring to DHIs as either top reservoir indicators; base reservoir indicators or contact indicators, thus removing the rarely met implication that 'flatspots' ought to appear flat on a depth converted seismic section. Open-Access Online Publication: May 22, 2023 Conference Object Sakhalin Zenodo |
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DHI flatspot quantitative interpretation AvO |
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DHI flatspot quantitative interpretation AvO Jarrod Dunne James Parsons Direct hydrocarbon indications from fluid contacts - stop calling them 'flatspots'! |
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DHI flatspot quantitative interpretation AvO |
description |
So called 'flatspots' rarely have the appearance of flatness, even at proven gas and oil fields and on seismic data that has been converted to depth using best-practice methods. The appearance of fluid contacts on seismic reflection data is influenced by several controls, most notably, fluid type; burial depth; saturation; and the size of the 'flatspot' anomaly compared to the imaging velocity resolution. Many cases of non-flatness are caused by lateral velocity variation in the overburden. Often the structural form of the trap itself is the cause. Non-flat seismic hydrocarbon contacts are seen at shallow gas hazards in Sakhalin, Russia; at oil fields in the Santos Basin, Brazil; and at 'gas on oil' accumulations in the Browse Basin, Australia. So, it appears that non-flat 'flatspots' are ubiquitous, suggesting an urgent name change is needed for this form of DHI. The interpretation of DHIs is aided by a new 2D synthetic modelling method that characterizes the time-depth behaviour of a field or prospect simultaneously with its amplitude response. The software interactively models seismic cross-sections using rock physics or seismic velocities to compute AvO synthetics at significant layer boundaries. Hydrocarbon porefill effects can be modelled using Gassmann fluid substitution to modify the elastic properties within the proposed trap. DHIs are thus characterized at (1) the top of the trap; (2) the base of the trap (if base sealed); and (3) at the contacts between different fluid types, such as a gas/water contact; oil/water contact; or gas/oil contact. We propose a more representative terminology, referring to DHIs as either top reservoir indicators; base reservoir indicators or contact indicators, thus removing the rarely met implication that 'flatspots' ought to appear flat on a depth converted seismic section. Open-Access Online Publication: May 22, 2023 |
format |
Conference Object |
author |
Jarrod Dunne James Parsons |
author_facet |
Jarrod Dunne James Parsons |
author_sort |
Jarrod Dunne |
title |
Direct hydrocarbon indications from fluid contacts - stop calling them 'flatspots'! |
title_short |
Direct hydrocarbon indications from fluid contacts - stop calling them 'flatspots'! |
title_full |
Direct hydrocarbon indications from fluid contacts - stop calling them 'flatspots'! |
title_fullStr |
Direct hydrocarbon indications from fluid contacts - stop calling them 'flatspots'! |
title_full_unstemmed |
Direct hydrocarbon indications from fluid contacts - stop calling them 'flatspots'! |
title_sort |
direct hydrocarbon indications from fluid contacts - stop calling them 'flatspots'! |
publisher |
Zenodo |
publishDate |
2023 |
url |
https://doi.org/10.5281/zenodo.7955930 |
genre |
Sakhalin |
genre_facet |
Sakhalin |
op_source |
Australian Society of Exploration Geophysicists Extended Abstracts, Volume 2023, 4th Australasian Exploration Geoscience Conference, Brisbane, 2023, (2023-03-15) AEGC, Australasian Exploration Geoscience Conference, Brisbane, Australia, 15-17 March 2023 |
op_relation |
https://zenodo.org/communities/aseg_extended_abstracts_2023 https://doi.org/10.5281/zenodo.7955929 https://doi.org/10.5281/zenodo.7955930 oai:zenodo.org:7955930 |
op_rights |
info:eu-repo/semantics/openAccess Creative Commons Attribution Non Commercial No Derivatives 4.0 International https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode |
op_doi |
https://doi.org/10.5281/zenodo.795593010.5281/zenodo.7955929 |
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1810474726375555072 |