Full-size core epoh at laboratory research of EOR technologies

Abstract

The article analyzes influence of core sample size on authenticity of data, obtained in laboratory simulation of reservoir stimulation technologies depending on reservoir type. It is found that in contrast to composite models, a full-size core reflects relationship of pore systems of complex reservoirs to the full extend. That allows making more correct conclusions about the effectiveness of technologies. In particular determination of adsorption and mechanical destruction of polymer compositions, strength of created water-proof barrier, dynamics of pressure during mixture injection etc. In order to improve authenticity of results obtained in laboratory simulation at the stage of selection of full-size core samples rock anisotropy, which is common for carbonate reservoirs and are usually connected to rocks fracture system, have to be taken into account. On the basis of ideas about improved efficiency of modeling technologies for enhanced oil recovery (EOR) for the conditions of complex carbonate reservoirs laboratory study is performed. The study used core samples with thermo reversible polymer composition МЕТКА, developed by the Institute of Petroleum Chemistry of Siberian Branch of the Russian Academy of Science. Use of a full-size core allowed evaluating the effectiveness of МЕТКА technology. The technology allowed to involve in the development low-permeability reservoirs and reservoirs that were not flooded. Study showed that results of standard-size core models are not informative to evaluate flooding efficiency. For the conditions of complex carbonate reservoirs due to low representation of standard samples the need to use core samples of maximal diameter is determined. Results obtained have practical importance in correct determination of parameters for EOR application during field development.

Keywords

• full-size core sample
• complex carbonate reservoir
• anisotropy
• oil recovery factor
• pilot project