Methods of Study of Reservoir Properties of Large Diameter Oriented Core of Complicated Carbonate Reservoirs

Effective study and exploration of complex carbonate structures are achievable providing quality core sampling and testing of representative core material with obtaining fullest possible information about structural and textural characteristics of reservoir rock cross-sections and about their petrophysical parameters. High anisotropy and spatial variability of complex carbonate structures properties result in decreased reliability of petrophysical parameters correlation curves while laboratory testing of standard core samples. However this can be nearly avoided by conducting tests on core samples of a large diameter (100 mm). The study presents methodological approaches of laboratory testing of complex carbonate structures reservoir characteristics anisotropy. The work gives results of analysis of the scale-factor (core sample size) influence on filtration characteristics of rock formations. The directional distribution of total gas permeability is shown by the results of laboratory experiments on full-size azimuthal-oriented core samples from Magovskoe field. Along with vertical anisotropy, lateral anisotropy has been experimentally evaluated using a specially selected collection of samples with complex structure of porous medium. The study presents a procedure for evaluation of azimuth-oriented core total gas permeability anisotropy along vertical and six lateral directions, which allows for a more complete description of pore system symmetry and determination of maximum filtration direction