Porosity reduction in sandstones induced by mechanical compaction: Cathodoluminescence evaluation

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

OSTI ID:5802781

Hathon, L A; Houseknecht, D W ^[1]

---

1. Univ. of Missouri, Columbia (United States)

Cathodoluminescence (CL) petrography has been instrumental in documenting the importance of chemical compaction (pressure solution) to porosity reduction in sandstones. Comparatively little work has been focused on the role of mechanical compaction, although this process is probably more pervasive. Brittle failure of quartz grains has been largely overlooked as a compaction mechanism because fractures are commonly healed by quartz cement that is not visible unless CL petrography is utilized. Grain boundary extension fractures form at grain contacts in response to overburden stress and are not related to tectonic stress. They result in extension of detrital quartz fragments into intergranular space, causing reduction of bulk volume, intergranular porosity, and total effective porosity. Samples of quartzose sandstones from sedimentary basins of diverse geologic history have been examined using CL petrography. This survey documents significant reduction of intergranular volumes by mechanical compaction to values as low as 20% in sandstones that have undergone little or no chemical compaction. Factors favoring the incidence of mechanical compaction induced by brittle failure include rapid burial, high temperatures, coarse grain size, and the absence of diagenetically early cements. This reconnaissance work suggests that mechanical compaction associated with brittle failure of quartz grains is more important than commonly thought, and emphasizes the need for CL petrography to be integrated into routine analysis of sandstone reservoir quality.

• OSTI ID: 5802781
• Report Number(s): CONF-910403-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
NATURAL GAS DEPOSITS
RESERVOIR ROCK
PETROLEUM DEPOSITS
QUARTZ
CATHODOLUMINESCENCE
DIAGENESIS
POROSITY
COMPACTING
CRACK PROPAGATION
FRACTURE MECHANICS
GRAIN BOUNDARIES
GRAIN GROWTH
MICROSTRUCTURE
PETROGRAPHY
ROCK MECHANICS
SANDSTONES
CRYSTAL STRUCTURE
GEOLOGIC DEPOSITS
LUMINESCENCE
MECHANICS
MINERAL RESOURCES
MINERALS
OXIDE MINERALS
RESOURCES
ROCKS
SEDIMENTARY ROCKS
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration