Earth formation pulsed neutron porosity logging system utilizing epithermal neutron and inelastic scattering gamma ray detectors

Patent · Tue Oct 24 04:00:00 EDT 1978

OSTI ID:6512382

Smith, Jr, H D; Smith, M P; Schultz, W E

An improved pulsed neutron porosity logging system is provided in the present invention. A logging tool provided with a 14 MeV pulsed neutron source, an epithermal neutron detector and an inelastic scattering gamma ray detector is moved through a borehole. The detection of inelastic gamma rays provides a measure of the fast neutron population in the vicinity of the detector. repetitive bursts of neutrons irradiate the earth formation and, during the busts, inelastic gamma rays representative of the fast neutron population is sampled. During the interval between bursts the epithermal neutron population is sampled along with background gamma radiation due to lingering thermal neutrons. the fast and epithermal neutron population measurements are combined to provide a measurement of formation porosity.

• Assignee: Texaco Inc.
• Patent Number(s): US 4122339
• OSTI ID: 6512382
• 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
440400* -- Well Logging Instrumentation
47 OTHER INSTRUMENTATION
BARYONS
BOREHOLES
CAVITIES
DESIGN
DETECTION
ELEMENTARY PARTICLES
ENERGY RANGE
EPITHERMAL NEUTRONS
FERMIONS
GAMMA DETECTION
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
HADRONS
HYDROCARBONS
INELASTIC SCATTERING
MEASURING INSTRUMENTS
MEV RANGE
MEV RANGE 10-100
NATURAL GAS DEPOSITS
NEUTRON DETECTORS
NEUTRON LOGGING
NEUTRON SOURCES
NEUTRON-GAMMA LOGGING
NEUTRONS
NUCLEONS
ORGANIC COMPOUNDS
PARTICLE SOURCES
PETROLEUM DEPOSITS
POROSITY
PULSED NEUTRON TECHNIQUES
RADIATION DETECTION
RADIATION DETECTORS
RADIATION SOURCES
RADIOACTIVITY LOGGING
RESOURCES
ROCKS
SCATTERING
WELL LOGGING