The article considers the peculiarities of the material (chemical and mineral composition) and their influence on the nuclear-physical characteristics (effective atomic number, atomic mass, photoelectric absorption index and macroscopic capture section of thermal neutrons) of the solid phase of rocks on the example of the volcanogenic-sedimentary sequence of the northeastern framing of the Krasnoleninsky arch in East Siberian region. The nuclear physical characteristics of the rocks of the studied object vary over a wide range. As the effective atomic number and atomic mass increase, the photoelectric absorption index and macroscopic capture section of thermal neutrons increase. The authors revealed positive correlations of the photoelectric absorption index and the macroscopic section of thermal neutron capture of the solid phase of rocks with the content of iron, magnesium, potassium, titanium oxides, as well as with the content of minerals – potassium feldspars, chlorite, and siderite. Negative correlations were revealed with the content of silicon, sodium oxides, also with the content of minerals – quartz and albite. It has been shown that the effective atomic number increases from acidic volcanites to medium, basic, ultramafic differences. Transformed by secondary processes volcanites are characterized by increased values of nuclear-physical characteristics, due to higher concentration of clay, carbonate minerals and secondary potassium feldspar. The need to take into account the influence of the material composition of the solid phase of rocks when interpreting neutron logging by thermal logs is shown. The prospects of using pulsed neutron and litho-density logs in the sections of volcanogenic deposits are shown in order to find intervals promising for testing.
References
1. Korovina T.A., Kropotova E.P., Romanov E.A., Shadrina S.V., Geologiya i neftenasyshchenie v porodakh triasa Rogozhnikovskogo LU. Regional’nye seysmologicheskie i metodicheskie predposylki uvelicheniya resursnoy bazy nefti, gaza i kondensata, povyshenie izvlekaemosti nefti v Zapadno-Sibirskoy neftegazonosnoy provintsii (Geology and oil saturation in the Triassic rocks of the Rogozhnikovsky license area. Regional seismological and methodological prerequisites for increasing the resource base of oil, gas and condensate, increasing oil recoverability in the West Siberian oil and gas province), Collected papers “Sostoyanie, tendentsii i problemy razvitiya neftegazovogo potentsiala Zapadnoy Sibiri” (The state, trends and problems of the development of oil and gas potential of Western Siberia), Proceedings of mezhdunarodnoy akademicheskoy konferentsii, Tyumen, 11-13 October 2006, Ekaterinburg: Format Publ., 2006, pp. 138–142.
2. Kropotova E.P., Korovina T.A., Romanov E.A., Fedortsov I.V., Sostoyanie izuchennosti i sovremennye vzglyady na stroenie, sostav i perspektivy doyurskikh otlozheniy zapadnoy chasti Surgutskogo rayona (Rogozhnikovskiy litsenzionnyy uchastok) (The state of knowledge and modern views on the structure, composition and prospects of pre-Jurassic deposits of the western part of the Surgut region (Rogozhnikovsky license area)),Proceedings of IX scientific and practical conference “Puti realizatsii neftegazovogo potentsiala KhMAO” (Ways of realization of oil and gas potential of KhMAO), Ekaterinburg: IzdatNaukaServis Publ., 2006, pp. 133–146.
3. Kropotova E.P., Korovina T.A., N Gil’manova.V., Shadrina S.V., Usloviya formirovaniya zalezhey uglevodorodov v doyurskikh otlozheniyakh na Rogozhnikovskom litsenzionnom uchastke (Conditions for the formation of hydrocarbon deposits in pre-Jurassic sediments at the Rogozhnikovsky license area), Proceedings of X scientific and practical conference “Puti realizatsii neftegazovogo potentsiala KhMAO” (Ways of realization of oil and gas potential of KhMAO), Khanty-Mansiysk 13–17 November 2007, Ekaterinburg: IzdatNaukaServis Publ., 2007, pp. 372–383.
4. Shadrina S.V., Kritskiy I.L., The formation of volcanogenic reservoir by hydrothermal fluid (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2012, no. 8, pp. 18–21.
5. Efimov V.A., The nuclear physics characteristic of volcanogenic rocks (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2006, no. 8, pp. 108–110.
6. Dobryden’ S.V., Increasing geological information of well logging in volcanogenic deposits (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2023, no. 6, pp. 24-28, DOI: http://doi.org/10.24887/0028-2448-2023-6-24-28
7. Filippov E.M., Prikladnaya yadernaya geofizika (Applied nuclear geophysics), Moscow: Publ of USSR AS, 1962, 580 p.
9. Srugoa P., Rubinstein P., Porosity and permeability in volcanic rocks: A case study on the Serie Tobifera, South Patagonia, Argentina, Journal of Volcanology and Geothermal Research, 2004, no. 132, pp. 31-43, DOI: http://doi.org/10.1016/S0377-0273(03)00419-0
8. Kondakov A.P., Efimov V.A., Dobryden’ S.V., Reservoirs identifying in the volcanogenic-sedimentary rocks of the northeast edge of Krasnoleninskiy arch based on logging, core study and well testing (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2020, no. 1, pp. 29-34, DOI: http://doi.org/10.24887/0028-2448-2020-1-29-34
10. Ladygin V.M., Frolova J.V., Rychagov S.N., The alteration of effusive rocks due to acidic leaching by shallow thermal waters, the Baranskii geothermal system, Iturup island, Journal of Volcanology and Seismology, 2014, no. 1, pp. 17-33, DOI: http://doi.org/10.1134/S0742046314010035
11. Frolova J.V., Chernov M.S., Sokolov V.N., Kuznetsov R.A., The influence of hydrothermal argillization on the physical and mechanical properties of tuffaceous rocks: a case study from the Upper Pauzhetsky thermal field, Kamchatka, Bulletin of Engineering Geology and the Environment, 2021, no. 2, pp. 1635-1651,
