Reaction Kinetics Determined from Core Flooding and Steady State Principles for Stevns Klint and Kansas Chalk Injected with MgCl2 Brine at Reservoir Temperature

A novel methodology to determine reaction kinetics using core flooding and steady-state principles reveals that the dissolution of calcite and precipitation of magnesite in chalk reservoirs occur in a substitution-like manner, with calcium (Ca²⁺) production closely matching magnesium (Mg²⁺) loss. This approach, applied to Stevns Klint chalk from Denmark and Kansas chalk from the USA, demonstrates computationally efficient modeling that avoids complex spatial-temporal simulations. The study, conducted at reservoir temperatures of 100°C and 130°C, shows that injected MgCl₂ brine alters rock wettability and strength, with implications for oil recovery and reservoir management. By varying injection rates and using shut-in tests, the researchers accurately characterized reaction kinetics, providing insights into geochemical behavior under dynamic conditions.

Andersen, P. Ø., Korsnes, R. I., Olsen, A. T., & Bukkholm, E. (2022). Reaction Kinetics Determined from Core Flooding and Steady State Principles for Stevns Klint and Kansas Chalk Injected with MgCl2 Brine at Reservoir Temperature. SPE Improved Oil Recovery Conference. https://doi.org/10.2118/209380-ms