RU2010116907A

RU2010116907A - METHOD OF PETROPHYSICAL STUDIES OF LARGE DIAMETER ROCK SAMPLES IN FIELD CONDITIONS

Info

Publication number: RU2010116907A
Application number: RU2010116907/28A
Authority: RU
Inventors: Игорь Яковлевич Кононенко (RU); Игорь Яковлевич Кононенко; Яков Львович Белорай (RU); Яков Львович Белорай
Original assignee: Игорь Яковлевич Кононенко (RU); Игорь Яковлевич Кононенко
Priority date: 2010-04-29
Filing date: 2010-04-29
Publication date: 2011-11-27
Also published as: RU2453831C2

Abstract

1. Способ ЯМР исследований полноразмерных образцов горных пород большого диаметра с естественной насыщенностью в полевых условиях, включающий помещение исследуемого образца в катушку индуктивности, создание намагниченности, обусловленной магнитными моментами ядер водорода порового флюида породы, путем пропускания тока поляризации через катушку, возбуждение измеряемых сигналов свободной прецессии этой намагниченности в магнитном поле Земли, накопление результатов измерений и определение параметров сигналов, отличающийся тем, что, с целью повышения точности измерений, выбирают оптимальную величину приемной полосы частот из условия ΔF≥2/0,14πТ2min *, где Т2min * - наименьшее значение постоянной времени затухания измеряемых сигналов СП, осуществляют цифровую регистрацию волновых форм измеряемых сигналов и выполняют обработку полученной информации в частотной области после оптимальной цифровой фильтрации, для каждого из накапливаемых сигналов порового флюида исследуемого образца породы осуществляют фазовый сдвиг, приводящий фазу сигнала к начальной фазе первого из накапливаемых сигналов, причем величину фазового сдвига определяют путем измерения фазы и частоты сигнала от дополнительно помещаемого в катушку индуктивности образца перфторированного масла и умножения фазового сдвига сигналов от перфторированного масла на отношение величин гиромагнитных отношений ядер фтора и водорода. ! 2. Способ ЯМР исследований по п.1, отличающийся тем, что необходимое для накопления количество повторных измерений определяется исходя из заранее заданной допустимой относительной погрешности измерений ε и измерен� 1. NMR method for studying full-sized large-diameter rock samples with natural saturation in the field, including placing the test sample in an inductor, creating magnetization due to magnetic moments of hydrogen nuclei of the pore rock fluid, by passing a polarization current through the coil, exciting the measured free precession signals this magnetization in the magnetic field of the Earth, the accumulation of measurement results and determination of signal parameters, characterized in that, in order to improve the accuracy of measurements, choose the optimal value of the receiving frequency band from the condition ΔF≥2 / 0.14πТ2min *, where T2min * is the smallest value of the decay time constant of the measured signals of the SP, digitally register the waveforms of the measured signals and process the received information in the frequency domain after optimal digital filtering, for each of the accumulated signals of the pore fluid of the test rock sample, a phase shift is carried out, leading the signal phase to the initial phase of the first of the signals being accumulated, and the magnitude of the phase shift is determined by measuring the phase and frequency of the signal from the perfluorinated oil sample additionally placed in the inductance coil and multiplying the phase shift of the signals from the perfluorinated oil by the ratio of the gyromagnetic ratios of the fluorine and hydrogen nuclei. ! 2. The NMR research method according to claim 1, characterized in that the number of repeated measurements required for accumulation is determined based on a predetermined allowable relative measurement error ε and measured

Claims

1. NMR method for studying full-sized large-diameter rock samples with natural saturation in the field, including placing the test sample in an inductor, creating magnetization due to magnetic moments of hydrogen nuclei of the pore rock fluid, by passing a polarization current through the coil, exciting the measured free precession signals this magnetization in the magnetic field of the Earth, the accumulation of measurement results and determination of signal parameters, characterized in that, in order to increase the measurement accuracy, the optimum value is selected receiving frequency band from the condition ΔF≥2 / 0,14πT _2min ^*, where T _2min ^* - the smallest value of the time constant of damping of the measured SP signals is performed digitally recording waveforms measured signals and perform processing information received in the frequency domain after optimal digital filtering, for each of the accumulated signals of the pore fluid of the test rock sample, a phase shift is carried out, leading the signal phase to the initial phase of the first aplivaemyh signals, the amount of phase shift is determined by measuring the phase and frequency of the signal from the additional coil placed in the sample and multiplying the perfluorinated oil phase shift signals from the perfluorinated oil at the ratio of the gyromagnetic ratios of the nuclei of hydrogen and fluorine.

2. The NMR research method according to claim 1, characterized in that the number of repeated measurements required for accumulation is determined based on a predetermined allowable relative measurement error ε and measured in the first measurement cycle of the free fluid index ISF ₁ according to the formula