Organic matter in Delaware Mountain Group sediments - Geochemistry, source, and role in diagenetic alteration of reservoir sandstones

Conference · Wed Apr 01 04:00:00 EST 1992 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:6969530

Hays, P D; Tieh, T T ^[1]

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1. Texas A and M Univ., College Station (United States)

Rock-Eval pyrolysis data show that Delaware Mountain Group siltstone organic matter is oxygen-rich type II and type III kerogen, prone to generation of significant quantities of carboxylic acids and CO{sub 2} during thermal maturation. Rock-Eval T{sub max} data and various biomarker maturity indicators show that the organic matter is at a moderate stage of maturity, well within the oil generative phase. Petrologic study shows that the reservoir sandstones have experienced four major episodes of diagenetic alteration: (1) early cementation by carbonate, sulfate, and halite cements that partly arrested compaction and preserved significant intergranual volume during progressive burial; (2) extensive dissolution of cements and some detrital material to form voluminous secondary porosity; (3) extensive chlorite authigenesis, which dissected nearly half of the porosity into microporosity; (4) authigenesis of dolomite, feldspar, and Ti oxides during late diagenesis. Characterization of the organic geochemistry of Delaware Mountain Group siltstones and analysis of late authigenic products in the sandstones indicates that organic diagenesis controlled pore fluid chemical evolution within the sandstones and resulted in creation of secondary porosity there. Authigenic minerals in the sandstones exhibit isotopic and trace element content indicative of this organic influence.

• OSTI ID: 6969530
• Report Number(s): CONF-9204139--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 76:4
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
BIOLOGICAL MARKERS
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CARBONATE ROCKS
CHEMISTRY
DEVELOPED COUNTRIES
DIAGENESIS
FEDERAL REGION VI
GEOCHEMISTRY
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGY
KEROGEN
MATERIALS
MATTER
MATURATION
MINERAL RESOURCES
NEW MEXICO
NORTH AMERICA
ORGANIC MATTER
PETROLEUM DEPOSITS
PETROLOGY
POROSITY
RESERVOIR ROCK
RESOURCES
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
SILTSTONES
TEXAS
USA