Estimation of thermal neutron cross sections from potassium, uranium, and thorium concentrations for rock samples

Conference · Wed Jan 01 04:00:00 EST 1992 · Transactions of the American Nuclear Society; (United States)

OSTI ID:6942070

Loskiewicz, J; Swakon, J ^[1]

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1. Institute of Nuclear Physics, Krakow (Poland)

The thermal neutron absorption cross section [Sigma][sub a] is an important parameter for correcting the response of porosity gauges or dual-detector logging tools. It is well known that the formation porosity determines the amount of fluid (oil or water) filling the rocks. This is used to evaluate the hydrocarbon potential of the oil field. The thermal neutron absorption cross section is difficult to measure. At laboratory scale and on samples it may be measured by several methods. It is thought that the increase in [Sigma][sub a] value is due to effects of strong absorbers such as boron and rare earth elements that may be present in small amounts in the formation matrix. But their measurement is even more complicated and costly than the measurement of the thermal neutron absorption cross section. This paper discusses ways to find easily measured quantities that are correlated with the strongly neutron-absorbing elements.

• OSTI ID: 6942070
• Report Number(s): CONF-921102--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (United States) Journal Volume: 66
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200 -- Petroleum-- Reserves
Geology
& Exploration
663000* -- Nuclear Physics-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDES
ALKALI METALS
BARYONS
CROSS SECTIONS
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
GEOLOGIC DEPOSITS
HADRONS
MATERIALS
MEASURING INSTRUMENTS
MEASURING METHODS
METALS
MINERAL RESOURCES
NEUTRON ABSORBERS
NEUTRONS
NUCLEAR POISONS
NUCLEONS
OIL FIELDS
PETROLEUM DEPOSITS
POROSIMETERS
POROSITY
POTASSIUM
REACTOR MATERIALS
RESOURCES
ROCKS
THERMAL NEUTRONS
THORIUM
URANIUM
WELL LOGGING