Gamma ray scattering measurements for density and lithology determination

Conference · Mon Feb 01 04:00:00 EST 1988 · IEEE Trans. Nucl. Sci.; (United States)

OSTI ID:7181726

Ellis, D V

A common approach to determining the in situ bulk density of subsurface formations is to use gamma ray scattering devices. These well logging tools consist of a source of gamma rays and multiple detectors, mounted in an assembly which is kept in mechanical contact with the borehole wall during the moving measurement. Compton scattering is exploited for formation density information while analysis of the photoelectric absorption of multiply-scattered gamma rays provides the average atomic number of the scattering formation. The parameters which control the device performance, constrained by operation in the borehole, are examined. A technique of combining measurements from several detectors allows estimation of bulk density over a range of environmental conditions. The photoelectric absorption measurement is reviewed to indicate its relationship to formation lithology type. Borehole factors which may compromise both measurements are related to tool design parameters and fundamental physical limitations.

• Research Organization: Schlumberger-Doll Research, Old Quarry Road, Ridgefield, CT (US)
• OSTI ID: 7181726
• Report Number(s): CONF-871006-
• Conference Information: Journal Name: IEEE Trans. Nucl. Sci.; (United States) Journal Volume: 35:1
• 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
DETECTION
ELECTROMAGNETIC RADIATION
EXPLORATION
GAMMA DETECTION
GAMMA LOGGING
GAMMA RADIATION
GEOLOGIC DEPOSITS
IONIZING RADIATIONS
LITHOLOGY
MEASURING INSTRUMENTS
MINERAL RESOURCES
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
RADIATION DETECTION
RADIATION DETECTORS
RADIATIONS
RADIOACTIVITY LOGGING
RESERVOIR ROCK
RESOURCES
SCATTERING
WELL LOGGING