Radiant energy – Geological testing or irradiation – Well testing apparatus and methods
Patent
1989-12-20
1990-08-07
Berman, Jack I.
Radiant energy
Geological testing or irradiation
Well testing apparatus and methods
250264, 250269, G01V 510
Patent
active
049470400
ABSTRACT:
A borehole logging method for determining the porosity of a formation surrounding the borehole, comprising the steps of: irradiating the formation surrounding the borehole from a location within the borehole with a burst of neutrons, detecting at a near detector indications of the concentration of thermal neutrons following the burst of neutrons and generating near count rate signals as a function of time in response thereto, detecting at a far detector indications of the concentration of thermal neutrons following the burst of neutrons and generating far count rate signals as a function of time in response thereto, fitting a count rate model to the near count rate signals to determine a near impulse formation count rate amplitude, fitting a count rate model to said far count rate signals to determine a far impulse formation count rate amplitude, determining the ratio of the near and far count rate signals as a characteristic proportional to the porosity of the formation.
REFERENCES:
patent: 3509342 (1970-04-01), Dewan
patent: 3890501 (1975-06-01), Johnstone
patent: 4302669 (1981-11-01), Allen et al.
patent: 4394574 (1983-07-01), Grau et al.
patent: 4424444 (1984-01-01), Smith, Jr. et al.
Polyachenko, ISV Geophysics, "The Theory of Nonstationary Diffussion of Thermal Neutrons in a Two-Substance Infinite Medium with a Cylindrical Dividing Surface", 1964, pp. 532-547.
Rezvanov, Izv Earth Physics, "Results of Statistical Modelling of Problems of Pulsed Neutron-Neutron Logging with Epithermal Neutrons", 1970, pp. 105-110.
S. Locke, Private Communication, "A Refined Scale Factor Measurement for TDT Sondes", Jun. 29, 1972.
Choi et al., Nuclear Geophysics, "Monte Carlo Simulation of the Temporal and Spectral Responses of the Pulsed Neutron Logging Principle", vol. 1, No. 1, pp. 71-81, 1987.
Smith, Jr. et al., SPE 7432, "Computer Simulation of Two Nuclear Well Logging Methods", Houston, Tex., Oct., 1978.
Locke et al., SPWLA Sixteenth Annual Logging Symposium, "Computed Departure Curves for the Thermal Neutron Decay Time Log", Jun. 4-7, 1975.
Mahdavi Mehrzad
Sitaraman Shivakumar
Berman Jack I.
Garrana Henry N.
Schlumberger Technology Corporation
Wagret Frederic C.
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