Laboratory Study on Carbonate Rocks Characterization and Porosity Changes Due to Co2 Injection

Abstract

Enhanced oil recovery methods must be improved continuously to provide higher recovery factors for the new fields under development in a globally competing market. CO 2 injection processes in carbonate rocks involve reactions between acid brine and the rock. These interactions promote petrophysical changes in the rock structure due to calcite dissolution or precipitation. Lab experiments in saturated coquina samples were carried out to better understand the effects on porosity by CO 2 injection. X-ray Photoelectron Spectrometer (XPS) was used to analyze the surface chemistry of the rock sample for elemental composition measurement. X-Ray Micro-CT and Mercury Injection Capillary Pressure (MICP) were carried out to calculate mean porosity in the rock sample. X-Ray scans were run for each pore volume injected. The results show that dissolution should be considered when supercritical CO 2 is injected in the reservoir. This process has relevance for project design, risk analysis, economic evaluation and reservoir behavior forecast.

Imaging techniques as tool in the characterization of the impact of silica nanofluid in Indiana limestone

“…In order to obtain different pore morphologies, carbonate rocks are used in laboratory experiments for studies focused on the oil industry 13,14 . Combined digital image analysis techniques have been widely used for qualitative and quantitative analyses of formation damage 15 .…”

“…In order to obtain different pore morphologies, carbonate rocks are used in laboratory experiments for studies focused on the oil industry. 13,14 Combined digital image analysis techniques have been widely used for qualitative and quantitative analyses of formation damage. 15 More specifically, when using digital images to perform analyses associated with computational modeling with rock characterization information, often called digital core analysis or digital rock physics (DRP).…”