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Geoinformatika 2018; 4(68) : 44-52

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SOFTWARE PACKAGE FOR MODELING PETROPHYSICAL PROPERTIES OF COMPLEX RESERVOIRS

VirshyloI. I.1, Khalimendik V.2,

1 Kyiv National Taras Shevchenko University, Institute of Geology, 90 Vasylkivska str., Kyiv, 03022, Ukraine, e–mail: ivirshylo@gmail.com
2 Kyiv National  Taras Shevchenko University,  Institute of Geology, 90 Vasylkivska str., Kyiv, 03022, Ukraine, e–mail: valera-h92@yandex.ru

Purpose. The unconventional reservoirs of oil and gas deposits searching are a priority way in the oil and gas industry at the present stage of development.
The elastic properties of complex reservoirs of oil and gas studying, as well as obtaining a quantitative assessment of the structure of the void space of rocks of oil and gas complexes (cracks, cavities, granules) has considerable relevance.
The study presented in the paper is based on the results of the works conducted at the Department of Geophysics Kyiv National Taras Shevchenko University for the last 35 years. These works focused on the the development of methods for mathematical modeling of complex acoustic characteristics of the reservoir rocks. According to the studies, the structure of reservoir rock can be represented in the form of a rigid matrix, which is full range of voids approximated by spheroids rotating with different formats of α= a/c (where a and c are a fixed and a rotatable axis of the spheroid).
Methodology. The paper presents the results of the investigation of models of complex reservoir rocks oil and gas having the same volume of the hollow space. The acoustic properties vary considerably depending on the ratio of different types of voids and the total porosity of the rocks. The studied models obtained by the author’s utilities “SDI” working on the basis of systemic principles and methods of mechanics of stochastic inhomogeneous medium and implementing the algorithm of iterating models with different concentration of voids formats.
Findings. The obtained results illustrate the dependence of the distribution of velocity of propagation of longitudinal elastic waves (Vp) from the format of voids and porosity.
So the results of modeling established that the transition from the model with 100% concentration of the cavernous component (format) in the voids to the model with 100% of the pore, causes a slight linear increase of Vp. And the introduction to the model rolling into the microcracks format and of the format of microcracks causes sharply intensive exponential decrease of Vp value.
The increase of porosity (φ) produces the effect of an increase in the gap between Vp models with different concentration of voids formats. It is noted that with increasing values of φ increase of brought effect in terms of previous values of φ logarithmically slows down.
Implications. The developed instrument  makes it possible to facilitate the study of complex reservoir rocks by accelerating and increasing the number of results obtained in modeling their elastic and acoustic properties depending on the types of voids.

 

Keywords: acoustic properties, different types of pores, pore aspect ratio.

 

The full text of papers

 

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