Predicting carbonate mineral precipitation/dissolution events during progressive diagenesis of clastic rocks

Conference · Fri Mar 01 04:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:7171077

Surdam, R C; MacGowan, D B; Dunn, T L ^[1]; Moraes, M ^[2]

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1. Univ. of Wyoming, Laramie (United States)
2. Petrobras (Brazil)

There is an observable, regular progression of early and late carbonate cements that is separated by carbonate mineral dissolution in many sandstones during progressive burial and diagenesis. The distribution of early cements is a function of incipient hydration of framework grains, sulfate reduction, and bacterial methanogenesis. These early cements typically precipitate from the sediment water interace to burial depths corresponding to about 80C. The distribution of late carbonate cements is a function of the relationship of organic acid anions, aluminosilicate reactions and CO{sub 2} in formation waters. Elevated PCO{sub 2} in a fluid where the pH is buffered by organic acid anions or aluminosilicates results in precipitation of a late carbonate cement (typically ferroan); these late carbonate cements generally form over the temperature interval of 100-130C. The late and early carbonate cement events are separated in time by a period of carbonate mineral dissolution or nonprecipitation. This dissolution is related to the increase in concentration of carboxylic acid anions resulting from the thermocatalytic cracking of oxygen-bearing functional groups from kerogen and/or redox reactions involving kerogen. Examples of the importance of early carbonate cementation/decementation to hydrocarbon reservoirs include the Campos basin of Brazil and the U.S. Gulf Coast. An example of late carbonate cementation/decementation includes the Norphlet Formation. This observed sequence of cementation and decementation can be modeled, and the modeling results can be used to predict enhanced porosity in the subsurface.

• OSTI ID: 7171077
• Report Number(s): CONF-910403--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 75:3
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000 -- Geosciences
BRAZIL
BUILDING MATERIALS
CARBONATE MINERALS
CEMENTS
CHEMICAL REACTION KINETICS
CHEMISTRY
DEVELOPED COUNTRIES
DEVELOPING COUNTRIES
DIAGENESIS
DISSOLUTION
GEOCHEMISTRY
GEOLOGIC DEPOSITS
GROUND WATER
HYDROGEN COMPOUNDS
INTERSTITIAL WATER
KINETICS
LATIN AMERICA
MATERIALS
MINERAL RESOURCES
MINERALIZATION
MINERALS
NATURAL GAS DEPOSITS
NORTH AMERICA
OXYGEN COMPOUNDS
PARTIAL PRESSURE
PETROLEUM DEPOSITS
PH VALUE
PRECIPITATION
REACTION KINETICS
RESERVOIR ROCK
RESOURCES
ROCK-FLUID INTERACTIONS
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
SEPARATION PROCESSES
SOUTH AMERICA
US GULF COAST
USA
WATER
WATER CHEMISTRY