Open AccessDevelopment of a Methodological Approach to Identifying Petrophysical Types of Complicated Carbonate Rocks According to Laboratory Core Studies
Author(s) -
Aleksandr V. Raznicyn,
I.S. Putilov
Publication year - 2021
Publication title -
nedropolʹzovanie
Language(s) - English
Resource type - Journals
eISSN - 2687-1513
pISSN - 2712-8008
DOI - 10.15593/2712-8008/2021.3.2
Subject(s) - petrophysics , geology , carbonate , characterisation of pore space in soil , carbonate rock , permeability (electromagnetism) , thin section , mineralogy , porosity , petrology , geochemistry , geotechnical engineering , chemistry , sedimentary rock , biochemistry , organic chemistry , membrane
Petrophysical typification of productive hydrocarbon deposits is one of the main stages of building a petrophysical model of a reservoir. For carbonate reservoirs characterized by a heterogeneous complex structure of the void space, the problem of identifying petrotypes is very relevant. An extensive literature review of existing methods of petrophysical typification showed that the most well-known and widely used of them were based on simple theoretical models of the structure of the void space of rocks, which did not allow a full description of complex carbonate deposits. Moreover, the petrotypes identified on the basis of these methods did not agree with the results of microdescription of thin sections. A new methodological approach to the identification of petrophysical types of complex carbonate rocks was proposed, based on the integration of the results of standard (determination of the absolute gas permeability and open porosity coefficients) and special (nuclear magnetic resonance studies) core studies and data obtained in the lithological description of thin sections. The developed approach took into account the main petrophysical properties of rocks that characterize its reservoir potential, as well as the structural features of the void space and the influence of secondary transformations. The proposed methodological approach was applied to distinguish petrophysical types in the section of the Assel-Sakmara deposits of the Yareyuskoye field: six petrotypes were identified and described in detail, combined into four zones (zone of development of healed fracturing, zone of development of leaching, zone of development of leaching and open fracturing, zone of development open fracturing), for each of them, individual dependences of the absolute gas permeability coefficient on the open porosity coefficient and the Leverett J-function on the water saturation coefficient were constructed. The information obtained would allow a differentiated approach to geological and hydrodynamic modeling of a hydrocarbon reservoir.