Borehole compensated density logs corrected for naturally occurring gamma rays

Patent · Tue Jul 16 04:00:00 EDT 1985

OSTI ID:5961810

Arnold, D M

A method for measuring formation density is disclosed. It provides a corrected gamma gamma-type density log having a correction for the adverse effects of gamma radiation from thorium, uranium and potassium ore bodies. The adjacent formation is irradiated with gamma radiation preferably from a cesium (Cs/sup 137/) source which emits gamma radiation at 0.663 Mev. Two differently longitudinally spaced detectors are used, a short spaced detector and a long spaced detector. A gamma ray spectrum observed at one of the detectors is broken down into four energy windows across the spectrum and count rate signals are determined and corrected to separate the naturally occurring gamma radiation from the scattered gamma radiation. This information may then be combined with count rate information from the other detector, thereby yielding a compensated density log corrected from naturally occurring gamma rays.

• Assignee: Halliburton Company
• Patent Number(s): US 4529877
• OSTI ID: 5961810
• 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
ACTINIDES
ALKALI METAL ISOTOPES
ALKALI METALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BULK DENSITY
CESIUM 137
CESIUM ISOTOPES
DENSITY
DESIGN
DETECTION
ELEMENTS
EQUIPMENT
GAMMA DETECTION
GAMMA SOURCES
GAMMA-GAMMA LOGGING
ISOTOPES
MEASURING INSTRUMENTS
METALS
NATURAL GAS WELLS
NUCLEI
ODD-EVEN NUCLEI
OIL WELLS
PHYSICAL PROPERTIES
POTASSIUM
RADIATION DETECTION
RADIATION DETECTORS
RADIATION SOURCES
RADIOACTIVITY LOGGING
RADIOISOTOPES
RESERVOIR ROCK
SCATTERING
THORIUM
URANIUM
WELL LOGGING
WELL LOGGING EQUIPMENT
WELLS
YEARS LIVING RADIOISOTOPES