Measurement of formation porosity using fast neutron spectroscopy

Patent · Tue Aug 12 04:00:00 EDT 1986

OSTI ID:5303197

Smith, Jr, H D

A method is described for determining the porosity of earth formations in the vicinity of a well borehole, comprising: (a) irradiating the earth formations in the vicinity of the well borehole with a source of fast neutrons, (b) detecting an energy spectrum of the fast neutrons at a single spaced distance from the neutron source in the borehole and generating a plurality of energy related pulse height spectral signals representative thereof, and (c) deriving from the fast neutron spectral signals a measurement signal functionally related to the porosity of the earth formations in the vicinity of the borehole by forming a ratio of the signals representing the count rates observed in a first pulse height range of the observed fast neutron energy spectrum to those signals representing the count rates observed in a second pulse height range thereof.

• Assignee: Halliburton Co., Duncan, OK
• Patent Number(s): US 4605854
• OSTI ID: 5303197
• 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
BARYONS
BOREHOLES
CAVITIES
COUNTING RATES
DISTANCE
ELEMENTARY PARTICLES
FAST NEUTRONS
FERMIONS
GEOLOGIC DEPOSITS
HADRONS
IRRADIATION
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NEUTRON LOGGING
NEUTRON SOURCES
NEUTRON SPECTROSCOPY
NEUTRONS
NUCLEONS
PARTICLE SOURCES
PETROLEUM DEPOSITS
POROSITY
PULSES
RADIATION SOURCES
RADIOACTIVITY LOGGING
RESOURCES
SIGNALS
SPECTROSCOPY
WELL LOGGING