Variations in extent, distribution and impact of dolomitization on reservoir quality of Upper Cretaceous foreland-basin carbonates, Abu Dhabi, United Arab Emirates

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F23%3A73622760" target="_blank" >RIV/61989592:15310/23:73622760 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0264817223002635" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0264817223002635</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.marpetgeo.2023.106357" target="_blank" >10.1016/j.marpetgeo.2023.106357</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Variations in extent, distribution and impact of dolomitization on reservoir quality of Upper Cretaceous foreland-basin carbonates, Abu Dhabi, United Arab Emirates

Popis výsledku v původním jazyce

Petrography, petrophysics, and geochemistry of an Upper Cretaceous, foreland-basin carbonate reservoir, Abu Dhabi, United Arab Emirates, are used to constrain the spatio-temporal variations in the extent of dolomitization and its impact on reservoir quality. Dolomitization in highstand systems tracts (HST) is attributed to repeated tidal and evaporative pumping as well as seepage reflux of penesaline brines during restriction of the platform due to 4th and 5th order cycles of relative sea-level fall and particularly below parasequence boundaries. This interpretation is supported by the presence of rare poikilotopic gypsum cement and scattered laths and micronodules of calcitized gypsum in the dolomitized peritidal dolostones. Dolomitization along bioturbation sites, which is most common in the transgressive systems tracts (TST), is attributed to the development of suitable localized geochemical conditions (e.g., microbial sulfate reduction and related increase in carbonate alkalinity). Porosity and permeability of the dolostones are strongly controlled by depositional textures of precursor limestones and by subsequent diagenetic evolution. Dolomitization of mudstones, wackestones and matrix-rich packstones has resulted in the formation of micropore-dominated microcrystalline dolostones whereas dolomitization of the shoal grainstones resulted in the formation of coarse-crystalline dolostones with abundant wellconnected intercrystalline and moldic macropores. Mesogenetic alterations of the dolostones, which are attributed to the flow of hot basinal brines along steep faults, include dolomite cementation and, subsequently, dissolution and calcitization of dolomite (dedolomitization) and calcite cementation. The lack of systematic differences in porosity and permeability of dolostones between the oil and water-saturated dolostones suggest that most diagenesis occurred prior to completion of oil emplacement and/or reflect the shallow maximum burial depths of the formation (around 1.3 km). This study demonstrates that variations in the distribution and extent of dolomitization within a sequence stratigraphic context across an oilfield should be considered as primary control on the spatio-temporal reservoir lithology and heterogeneity in carbonate successions.

Název v anglickém jazyce

Variations in extent, distribution and impact of dolomitization on reservoir quality of Upper Cretaceous foreland-basin carbonates, Abu Dhabi, United Arab Emirates

Popis výsledku anglicky

Petrography, petrophysics, and geochemistry of an Upper Cretaceous, foreland-basin carbonate reservoir, Abu Dhabi, United Arab Emirates, are used to constrain the spatio-temporal variations in the extent of dolomitization and its impact on reservoir quality. Dolomitization in highstand systems tracts (HST) is attributed to repeated tidal and evaporative pumping as well as seepage reflux of penesaline brines during restriction of the platform due to 4th and 5th order cycles of relative sea-level fall and particularly below parasequence boundaries. This interpretation is supported by the presence of rare poikilotopic gypsum cement and scattered laths and micronodules of calcitized gypsum in the dolomitized peritidal dolostones. Dolomitization along bioturbation sites, which is most common in the transgressive systems tracts (TST), is attributed to the development of suitable localized geochemical conditions (e.g., microbial sulfate reduction and related increase in carbonate alkalinity). Porosity and permeability of the dolostones are strongly controlled by depositional textures of precursor limestones and by subsequent diagenetic evolution. Dolomitization of mudstones, wackestones and matrix-rich packstones has resulted in the formation of micropore-dominated microcrystalline dolostones whereas dolomitization of the shoal grainstones resulted in the formation of coarse-crystalline dolostones with abundant wellconnected intercrystalline and moldic macropores. Mesogenetic alterations of the dolostones, which are attributed to the flow of hot basinal brines along steep faults, include dolomite cementation and, subsequently, dissolution and calcitization of dolomite (dedolomitization) and calcite cementation. The lack of systematic differences in porosity and permeability of dolostones between the oil and water-saturated dolostones suggest that most diagenesis occurred prior to completion of oil emplacement and/or reflect the shallow maximum burial depths of the formation (around 1.3 km). This study demonstrates that variations in the distribution and extent of dolomitization within a sequence stratigraphic context across an oilfield should be considered as primary control on the spatio-temporal reservoir lithology and heterogeneity in carbonate successions.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

N - Vyzkumna aktivita podporovana z neverejnych zdroju

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

MARINE AND PETROLEUM GEOLOGY

ISSN

0264-8172

e-ISSN

1873-4073

Svazek periodika

155

Číslo periodika v rámci svazku

SEP

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

24

Strana od-do

"106357-1"-"106357-24"

Kód UT WoS článku

001017661300001

EID výsledku v databázi Scopus

2-s2.0-85161703620