Secondary ferroan dolomite rhombs in oil reservoirs, Chadra Sands, Gialo field, Libya

Journal Article · Wed Mar 01 00:00:00 EST 1978 · Am. Assoc. Pet. Geol. Bull.; (United States)

OSTI ID:7070132

Al-Shaieb, Z; Shelton, J W

Oil-productive, Oligocene Chadra sands in Gialo field, Libya, at depths of 600 to 750 m contain small dolomite rhombs. The rhombs are present as single crystals on detrital grains and as nonmosaic aggregates in pore space. The dolomite is calcium-rich and contains up to 10% iron but not measurable sodium or strontium. Total dissolved solids of produced interstitial water from the Chadra sand range from about 4,500 to 10,000 ppM. Introduction of fresh (meteoric) water into the Chadra sands, which were deposited in shallow-marine (shelf) environment, was responsible for formation of the dolomite rhombs. Iron in the dolomite rhombs was derived from alteration of galuconite.

• Research Organization: Oklahoma State Univ., Stillwater
• OSTI ID: 7070132
• Journal Information: Am. Assoc. Pet. Geol. Bull.; (United States), Vol. 62:3
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
LIBYA
OIL FIELDS
GEOLOGIC STRUCTURES
DEPTH
DIAGENESIS
DOLOMITE
MATURATION
OIL SANDS
TERTIARY PERIOD
AFRICA
ALKALINE EARTH METAL COMPOUNDS
BITUMINOUS MATERIALS
CARBON COMPOUNDS
CARBONACEOUS MATERIALS
CARBONATE ROCKS
CARBONATES
CENOZOIC ERA
DIMENSIONS
ENERGY SOURCES
FOSSIL FUELS
FUELS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MINERALS
OXYGEN COMPOUNDS
PETROLEUM DEPOSITS
RESERVOIR ROCK
RESOURCES
ROCKS
020200* - Petroleum- Reserves
Geology
& Exploration