The Coupled Effect of Fines Mobilization and Salt Precipitation on CO2 Injectivity

Abstract

Abstract:In terms of storage capacity and containment efficiency, deep saline aquifers are among the best candidates for CO 2 storage. However, salt precipitation in the wellbore vicinity and fines mobilization ensued from in situ mineral dissolution could impair CO 2 injectivity and reduce the quality and capacity of deep saline reservoirs for CO 2 storage. The mechanisms of salt precipitation and its impact on CO 2 injectivity have been studied, but the effects of fines mobilization have not been properly investigated. We conducted core-flood experiments and theoretical studies to investigate the impact of fines mobilization on CO 2 injectivity, the relative contribution of fines mobilization and salt precipitation to injectivity impairment, and the coupled effect of salt precipitation and fines mobilization. We found that, mineral dissolution and transport effects could induce up to about 26% injectivity impairment. The findings also suggest that about 0.3 wt % particle concentration in the pore fluid could induce over twofold injectivity impairment compared to about 10 wt % of total dissolved salt in the formation water. Salt precipitation was also found to compound injectivity impairment induced by fines mobilization. The present study provides important insight, and could serve as a foundation to inspire further experimental and theoretical investigation into the effects of mineral dissolution and fines mobilization in the context of CO 2 injectivity.

The coupled effect of salt precipitation and fines mobilization on CO2 injectivity in sandstone

“…Preliminary theoretical studies conducted earlier to investigate the coupled impact of the fines mobilization and salt precipitation suggested that the entrapment of fines could compound CO 2 injectivity impairment induced by salt precipitation . In the present work, a dynamic core‐scale model was developed based on experimental observations and extended to investigate the coupled effect of the fines mobilization and salt precipitation on CO 2 injectivity.…”

“…The transportation of fines under CO 2 injection conditions involves the multiphase flow of supercritical CO 2 , formation brine, and the suspended particles. Mobilized fine particles could plug narrow pore channels and impair CO 2 injectivity . On the other hand, vaporization of formation brine by the injected supercritical CO 2 may precipitate salt into the pores .…”

Experimental study on dual benefits of improvement of CO2 enhanced oil recovery and its storage capacity for depleted carbonate oil reservoirs

“…Specifically, for composite core 1D, injectivity declines from 1.85 to 1.01, and for composite core 10D, it reduces from 0.68 to 0.07. The observed decrease in injectivity suggests varying degrees of core sample damage, likely attributed to a combination of mineral grain falloff, fine particle migration, which can block the pore throat of the pore system, and interactions within the seawater/sc-CO 2 /carbonate rock system (Sokama-Neuyam et al, 2017, Yusof et al, 2022. For the depleted oil reservoirs, the influence of the residual phases on injectivity can not be ignored in this study.…”

Assessment of Advanced Remediation Techniques for Enhanced CO2 Injectivity: Laboratory Investigations and Implications for Improved CO2 Flow in Saline Aquifers

“…While salt precipitation hinders CO 2 injectivity, the combination with fines migration under high CO 2 injection rates has a synergistic effect, significantly reducing formation permeability . In a typical CO 2 injection field, fines are detached and begin migrating with the carrier fluid during the injection process. , The CO 2 gas phase, influenced by flow rate and velocity, displaces and evaporates residual water within rock pores, thereby weakening the capillary forces that bind fine particles to the rock surface.…”