Improvement of In-situ CO2 generation technology with compensation of chemicals concentration technological losses

Abstract

The paper is about the enhanced oil recovery technology, based on in-situ carbon dioxide generation, after stoichiometric reaction between gas releasing chemical agent and gas producing one. Two ways of technology improvement are considered: for more uniform in-situ CO2 generation and for more safety when chemicals injection. Both ways require sufficient increase of buffer water, which divides reactive chemicals. Larger buffer water volumes, when being mixed with chemicals water solutions, sufficiently drop down chemical concentration. It also decreases CO2 concentration in water solution. Finally, chemicals and CO2 concentrations, for in- situ generation, decrease. To prevent such decrease, it is necessary to adjust, increase chemicals concentration, when preparing chemical water solution, so to consider further dilution in buffer water and to ensure required stoichiometric concentration in reservoir conditions. Increase of chemicals concentration can be also from decrease of chemicals solutions volumes. Quantitative estimates are given for increase of buffer water volumes, for impact of such increase on decrease of initial chemicals concentrations and decrease of CO2 concentration, in water solutions, as well. Working formulas are provided for calculations on buffer water volumes, adjusted, increased concentrations and decrease volumes of chemicals water solutions, at their preparation stage.