Surface gamma-ray logs as a correlation tool between outcrop and subsurface: Application to the Silurian-Devonian of west Texas and southern New Mexico

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

OSTI ID:7031349

Colleary, W M ^[1]; Crafton, J W ^[2]

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1. Colorado School of Mines, Golden (United States)
2. Colorado School of Mines, Golden (United States) Gas Research Institute, Chicago, IL (United States)

Outcrop gamma-ray logs are an excellent tool for correlation between surface measured sections and subsurface well logs. The work presented here illustrates the utility of constructing such profiles and the applicability of this technique to carbonate sequences such as those of the Permian basin. Outcrop sections with gamma-ray profiles have been measured over the Silurian-Devonian section in three separate areas. These sections are located in the Sacramento Mountains of southern New Mexico, and the northern Franklin Mountains and Hueco Mountains of west Texas. A hand-held Scintrex Model BGS-4 Digital Scintillometer was used to measure surface gamma radiation while detailed stratigraphic sections were being measured and described. Data were collected at regularly spaced intervals along the section. The scintillometer detects natural radiation emitted by radioactive elements that occur in most clay minerals and generally are more abundant in shales than in sandstones or carbonates. The lithology of poorly exposed or covered units also may be inferred from surface gamma-ray profiles. Organic-rich black shales are particularly radioactive, as are condensed sections. The strength of this method does not lie in the absolute reading of gamma radiation. The value of this tool lies in recognizing patterns within each profile, directly relating these patterns to their associated facies, and correlating them with subsurface profiles.

• OSTI ID: 7031349
• Report Number(s): CONF-9204139-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 76:4; Conference: American Association of Petroleum Geologists (AAPG) Southwest section meeting, Midland, TX (United States), 21-24 Apr 1992; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
02 PETROLEUM
03 NATURAL GAS
CARBONATE ROCKS
NATURAL RADIOACTIVITY
PERMIAN BASIN
GAMMA LOGGING
STRATIGRAPHY
COMPARATIVE EVALUATIONS
CORRELATIONS
DEVONIAN PERIOD
EXPLORATORY WELLS
NATURAL GAS DEPOSITS
NEW MEXICO
PETROLEUM DEPOSITS
RESERVOIR ROCK
SILURIAN PERIOD
SOURCE ROCKS
TEXAS
DEVELOPED COUNTRIES
EVALUATION
FEDERAL REGION VI
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGY
MINERAL RESOURCES
NORTH AMERICA
PALEOZOIC ERA
RADIOACTIVITY
RADIOACTIVITY LOGGING
RESOURCES
ROCKS
SEDIMENTARY ROCKS
USA
WELL LOGGING
WELLS
580000* - Geosciences
020200 - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration