Simultaneous thermal neutron decay time and porosity logging system

Patent · Tue May 01 04:00:00 EDT 1979

OSTI ID:5829782

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

A simultaneous pulsed neutron porosity and thermal neutron capture cross section logging system is provided for radiological well logging of subsurface earth formations. A logging tool provided with a 14 MeV pulsed neutron source, an epithermal neutron detector, and a combination gamma ray and fast neutron detector is moved through a borehole. Repetitive bursts of neutrons irradiate the earth formations; and, during the bursts, the fast neutron and epithermal neutron populations are sampled. During the interval between bursts the thermal neutron capture gamma ray population is sampled in two or more time intervals. The fast and epithermal neutron population measurements are combined to provide a measurement of formation porosity phi. The capture gamma ray measurements are combined to provide a simultaneous determination of the thermal neutron capture cross section ..sigma...

• Assignee: Texaco Inc.
• Patent Number(s): US 4152590
• OSTI ID: 5829782
• Country of Publication: United States
• Language: English

Related Subjects

440400* -- Well Logging Instrumentation
47 OTHER INSTRUMENTATION
BARYONS
CAPTURE
CROSS SECTIONS
DETECTION
ELEMENTARY PARTICLES
EQUIPMENT
FAST NEUTRONS
FERMIONS
GAMMA DETECTION
HADRONS
IRRADIATION
NEUTRON DETECTION
NEUTRON LOGGING
NEUTRONS
NUCLEONS
POROSITY
PULSED IRRADIATION
RADIATION DETECTION
RADIOACTIVITY LOGGING
THERMAL NEUTRONS
WELL LOGGING