Method and apparatus for pulsed neutron capture measurement of borehole conditions and formation hydrogen index

Patent · Tue Nov 25 04:00:00 EST 1986

OSTI ID:7054525

Smith, Jr, H D

A method is described for measuring the thermal neutron decay time of materials in an about a well borehole, comprising: (a) generating, in the well borehole, a relatively short duration discrete burst of fast neutrons which are rapidly moderated by interaction with nuclei of materials in the borehole and surrounding earth formations and slowed down to thermal energy. This creates a thermal neutron population in the borehole and surrounding earth formations, (b) detecting, in the borehole, radiations representative of the thermal neutron population in the borehole and surrounding earth formations, in at least two time intervals subsequent to the burst of fast neutrons. At least two time intervals are chosen to maximize the borehole component radiations relative to the formation component, and at least two count signals representative of the thermal neutron population during the at least two time intervals are generated, and (c) combining the count signals from the at least two borehole count maximizing time intervals according to a predetermined relationship to provide a measurement indicator representative of the thermal neutron decay time of the borehole medium.

• Assignee: Halliburton Co., Duncan, OK
• Patent Number(s): US 4625111
• OSTI ID: 7054525
• 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
BARYON REACTIONS
BARYONS
BOREHOLES
CAPTURE
CAVITIES
DECAY
ELEMENTARY PARTICLES
ELEMENTS
FAST NEUTRONS
FERMIONS
GEOLOGIC DEPOSITS
HADRON REACTIONS
HADRONS
HYDROGEN
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NEUTRON LOGGING
NEUTRON REACTIONS
NEUTRONS
NONMETALS
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
NUCLEONS
PETROLEUM DEPOSITS
PULSED NEUTRON TECHNIQUES
RADIOACTIVITY LOGGING
RESOURCES
SIGNALS
THERMAL NEUTRONS
TIME MEASUREMENT
WELL LOGGING