Fate of injected CO2 in the Wilcox Group, Louisiana, Gulf Coast Basin: Chemical and isotopic tracers of microbial-brine-rock-CO2 interactions

Jenna L. Shelton, Jennifer McIntosh, Peter D. Warwick, Amelia Lee Zhi Yi

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

The "2800' sandstone" of the Olla oil field is an oil and gas-producing reservoir in a coal-bearing interval of the Paleocene-Eocene Wilcox Group in north-central Louisiana, USA. In the 1980s, this producing unit was flooded with CO2 in an enhanced oil recovery (EOR) project, leaving ~30% of the injected CO2 in the 2800' sandstone post-injection. This study utilizes isotopic and geochemical tracers from co-produced natural gas, oil and brine to determine the fate of the injected CO2, including the possibility of enhanced microbial conversion of CO2 to CH4 via methanogenesis. Stable carbon isotopes of CO2, CH4 and DIC, together with mol% CO2 show that 4 out of 17 wells sampled in the 2800' sandstone are still producing injected CO2. The dominant fate of the injected CO2 appears to be dissolution in formation fluids and gas-phase trapping. There is some isotopic and geochemical evidence for enhanced microbial methanogenesis in 2 samples; however, the CO2 spread unevenly throughout the reservoir, and thus cannot explain the elevated indicators for methanogenesis observed across the entire field. Vertical migration out of the target 2800' sandstone reservoir is also apparent in 3 samples located stratigraphically above the target sand. Reservoirs comparable to the 2800' sandstone, located along a 90-km transect, were also sampled to investigate regional trends in gas composition, brine chemistry and microbial activity. Microbial methane, likely sourced from biodegradation of organic substrates within the formation, was found in all oil fields sampled, while indicators of methanogenesis (e.g. high alkalinity, δ13C-CO2 and δ13C-DIC values) and oxidation of propane were greatest in the Olla Field, likely due to its more ideal environmental conditions (i.e. suitable range of pH, temperature, salinity, sulfate and iron concentrations).

Original languageEnglish (US)
Pages (from-to)155-169
Number of pages15
JournalApplied Geochemistry
Volume51
DOIs
StatePublished - 2014

Fingerprint

Sandstone
brine
Coastal zones
methanogenesis
tracer
Rocks
sandstone
coast
Dacarbazine
basin
rock
Gases
Oil fields
oil field
Oils
Bearings (structural)
gas
Carbon Isotopes
Propane
Petroleum reservoirs

ASJC Scopus subject areas

  • Environmental Chemistry
  • Pollution
  • Geochemistry and Petrology

Cite this

Fate of injected CO2 in the Wilcox Group, Louisiana, Gulf Coast Basin : Chemical and isotopic tracers of microbial-brine-rock-CO2 interactions. / Shelton, Jenna L.; McIntosh, Jennifer; Warwick, Peter D.; Yi, Amelia Lee Zhi.

In: Applied Geochemistry, Vol. 51, 2014, p. 155-169.

Research output: Contribution to journalArticle

@article{a91effa063b44174afc6da1a5989a652,
title = "Fate of injected CO2 in the Wilcox Group, Louisiana, Gulf Coast Basin: Chemical and isotopic tracers of microbial-brine-rock-CO2 interactions",
abstract = "The {"}2800' sandstone{"} of the Olla oil field is an oil and gas-producing reservoir in a coal-bearing interval of the Paleocene-Eocene Wilcox Group in north-central Louisiana, USA. In the 1980s, this producing unit was flooded with CO2 in an enhanced oil recovery (EOR) project, leaving ~30{\%} of the injected CO2 in the 2800' sandstone post-injection. This study utilizes isotopic and geochemical tracers from co-produced natural gas, oil and brine to determine the fate of the injected CO2, including the possibility of enhanced microbial conversion of CO2 to CH4 via methanogenesis. Stable carbon isotopes of CO2, CH4 and DIC, together with mol{\%} CO2 show that 4 out of 17 wells sampled in the 2800' sandstone are still producing injected CO2. The dominant fate of the injected CO2 appears to be dissolution in formation fluids and gas-phase trapping. There is some isotopic and geochemical evidence for enhanced microbial methanogenesis in 2 samples; however, the CO2 spread unevenly throughout the reservoir, and thus cannot explain the elevated indicators for methanogenesis observed across the entire field. Vertical migration out of the target 2800' sandstone reservoir is also apparent in 3 samples located stratigraphically above the target sand. Reservoirs comparable to the 2800' sandstone, located along a 90-km transect, were also sampled to investigate regional trends in gas composition, brine chemistry and microbial activity. Microbial methane, likely sourced from biodegradation of organic substrates within the formation, was found in all oil fields sampled, while indicators of methanogenesis (e.g. high alkalinity, δ13C-CO2 and δ13C-DIC values) and oxidation of propane were greatest in the Olla Field, likely due to its more ideal environmental conditions (i.e. suitable range of pH, temperature, salinity, sulfate and iron concentrations).",
author = "Shelton, {Jenna L.} and Jennifer McIntosh and Warwick, {Peter D.} and Yi, {Amelia Lee Zhi}",
year = "2014",
doi = "10.1016/j.apgeochem.2014.09.015",
language = "English (US)",
volume = "51",
pages = "155--169",
journal = "Applied Geochemistry",
issn = "0883-2927",
publisher = "Elsevier Limited",

}

TY - JOUR

T1 - Fate of injected CO2 in the Wilcox Group, Louisiana, Gulf Coast Basin

T2 - Chemical and isotopic tracers of microbial-brine-rock-CO2 interactions

AU - Shelton, Jenna L.

AU - McIntosh, Jennifer

AU - Warwick, Peter D.

AU - Yi, Amelia Lee Zhi

PY - 2014

Y1 - 2014

N2 - The "2800' sandstone" of the Olla oil field is an oil and gas-producing reservoir in a coal-bearing interval of the Paleocene-Eocene Wilcox Group in north-central Louisiana, USA. In the 1980s, this producing unit was flooded with CO2 in an enhanced oil recovery (EOR) project, leaving ~30% of the injected CO2 in the 2800' sandstone post-injection. This study utilizes isotopic and geochemical tracers from co-produced natural gas, oil and brine to determine the fate of the injected CO2, including the possibility of enhanced microbial conversion of CO2 to CH4 via methanogenesis. Stable carbon isotopes of CO2, CH4 and DIC, together with mol% CO2 show that 4 out of 17 wells sampled in the 2800' sandstone are still producing injected CO2. The dominant fate of the injected CO2 appears to be dissolution in formation fluids and gas-phase trapping. There is some isotopic and geochemical evidence for enhanced microbial methanogenesis in 2 samples; however, the CO2 spread unevenly throughout the reservoir, and thus cannot explain the elevated indicators for methanogenesis observed across the entire field. Vertical migration out of the target 2800' sandstone reservoir is also apparent in 3 samples located stratigraphically above the target sand. Reservoirs comparable to the 2800' sandstone, located along a 90-km transect, were also sampled to investigate regional trends in gas composition, brine chemistry and microbial activity. Microbial methane, likely sourced from biodegradation of organic substrates within the formation, was found in all oil fields sampled, while indicators of methanogenesis (e.g. high alkalinity, δ13C-CO2 and δ13C-DIC values) and oxidation of propane were greatest in the Olla Field, likely due to its more ideal environmental conditions (i.e. suitable range of pH, temperature, salinity, sulfate and iron concentrations).

AB - The "2800' sandstone" of the Olla oil field is an oil and gas-producing reservoir in a coal-bearing interval of the Paleocene-Eocene Wilcox Group in north-central Louisiana, USA. In the 1980s, this producing unit was flooded with CO2 in an enhanced oil recovery (EOR) project, leaving ~30% of the injected CO2 in the 2800' sandstone post-injection. This study utilizes isotopic and geochemical tracers from co-produced natural gas, oil and brine to determine the fate of the injected CO2, including the possibility of enhanced microbial conversion of CO2 to CH4 via methanogenesis. Stable carbon isotopes of CO2, CH4 and DIC, together with mol% CO2 show that 4 out of 17 wells sampled in the 2800' sandstone are still producing injected CO2. The dominant fate of the injected CO2 appears to be dissolution in formation fluids and gas-phase trapping. There is some isotopic and geochemical evidence for enhanced microbial methanogenesis in 2 samples; however, the CO2 spread unevenly throughout the reservoir, and thus cannot explain the elevated indicators for methanogenesis observed across the entire field. Vertical migration out of the target 2800' sandstone reservoir is also apparent in 3 samples located stratigraphically above the target sand. Reservoirs comparable to the 2800' sandstone, located along a 90-km transect, were also sampled to investigate regional trends in gas composition, brine chemistry and microbial activity. Microbial methane, likely sourced from biodegradation of organic substrates within the formation, was found in all oil fields sampled, while indicators of methanogenesis (e.g. high alkalinity, δ13C-CO2 and δ13C-DIC values) and oxidation of propane were greatest in the Olla Field, likely due to its more ideal environmental conditions (i.e. suitable range of pH, temperature, salinity, sulfate and iron concentrations).

UR - http://www.scopus.com/inward/record.url?scp=84908574628&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84908574628&partnerID=8YFLogxK

U2 - 10.1016/j.apgeochem.2014.09.015

DO - 10.1016/j.apgeochem.2014.09.015

M3 - Article

AN - SCOPUS:84908574628

VL - 51

SP - 155

EP - 169

JO - Applied Geochemistry

JF - Applied Geochemistry

SN - 0883-2927

ER -