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

Researchers have developed a novel methodology to determine reaction kinetics using coreflooding and steady-state principles, which efficiently characterizes chemical interactions in chalk reservoirs without requiring complex spatial modeling. The study, conducted on Stevns Klint (Denmark) and Kansas (USA) chalks at reservoir temperatures (100–130°C), demonstrated that Ca²⁺ ions were produced while Mg²⁺ ions were retained during injection with MgCl₂ brine, indicating calcite dissolution and magnesite precipitation. This substitution-like process was successfully modeled using a simple kinetic framework with three parameters, which accurately predicted chemical interactions in both oil-bearing chalk reservoirs and outcrop chalks. The methodology offers computational efficiency for reactive flow modeling, particularly for chemically sensitive reservoirs like those at UNESCO World Heritage Site Stevns Klint, where injected seawater can impact wettability and rock strength.

Andersen, P., Korsnes, R., Olsen, A., & Bukkholm, E. (2022). Reaction Kinetics Determined from Coreflooding and Steady-State Principles for Stevns Klint and Kansas Chalk Injected with MgCl2 Brine at Reservoir Temperature. SPE Journal, 27(06), 3406–3425. https://doi.org/10.2118/209380-pa