METHOD FOR DETERMINING LITHOLOGIC COMPOSITION OF FROZEN ROCKS Russian patent published in 2011 - IPC G01V3/02 

FIELD: mining.

SUBSTANCE: at the profile points the current is supplied through a pair of feeding electrodes to the earth. Current value and potential difference between pair of receiving electrodes is measured. Feeding electrodes are moved with pitch equal to 1 m symmetrically relative to the centre to limit distance between feeding electrodes, which is determined by the specified investigation depth. As per measurement results the apparent specific resistance is calculated. As per data of apparent specific resistance the graph of its behaviour is built depending on half-spacings of feeding electrodes. Specific resistances of frozen beds are calculated as per apparent specific resistance graph. Percentage of clay in unit volume of rock is calculated as per data of specific resistances of frozen beds by the following formula: where ρ_clay - specific clay resistance, which in permafrost zone section is characterised as constant value which on average is equal to 100 ohm m, ρ_fb -specific resistance of frozen bed. Lithologic composition of sand-clay complex of frozen rocks is determined as per clay content.

EFFECT: reducing the cost of operations and improving informativity owing to determining lithologic composition of frozen rocks without any drilling data and using common data on geologic structure of investigation region.

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