NUCLEAR LOGGING METHOD AND DEVICE FOR ITS REALIZATION Russian patent published in 2005 - IPC

FIELD: oil and gas industry.

SUBSTANCE: method includes irradiating rock in well with neutrons. Alpha particles coming from neutron target in direction, opposite to direction of movement of fast neutron from target, are registered. Well device is directed relatively to well in such a way, that cone of movement of fast neutrons was directed from the well in such a way, that plant, plotted through axis of well device, axis of pressing to well wall and cone axis was perpendicular to touching plane, plotted through touching line of well device and well wall. Angle between cone axis and well device axis of detector side lies within 10÷60 degrees. Amplitude spectrums of induced gamma radiation are registered in n time windows. Coordinate of position of non-resilient dispersion of fast neutron is calculated. On basis of it spectrums of gamma radiation of non-resilient dispersion from different well zones are marked. Device has well device, having neutron generator, alpha particles detector, positioned at certain space from well device axis and enabled serially with appropriate discriminating amplifier, gamma-quantum detector, enabled serially with appropriate amplifier, multi-channel amplitude analyzer, amplifier-discriminator of gamma-quantum channel, time analyzer of coincidence, selector. Well device has pressing to well wall, positioned in same plane with axis of well device and axis, connecting center of neutron generator target and alpha articles detector center.

EFFECT: higher precision.

2 cl, 5 dwg