Study of corrosion mechanism of dawsonite led by CO_(2)partial pressure  

作　　者：Fulai LI Hao DIAO Wenkuan MA Maozhen WANG 

机构地区：[1]Shandong Provincial Key Laboratory of Deep Oil and Gas,School of Geosciences,China University of Petroleum(East China),Qingdao 266580,China [2]Laboratory for Marine Mineral Resources,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266071,China [3]Bohai Oilfield Research Institute,Tianjin Branch of CNOOC China Limited,Tianjin 300452,China

出　　处：《Frontiers of Earth Science》2022年第2期465-482,共18页地球科学前沿（英文版）

基　　金：The authors thank the editors and two anonymous reviewers for their careful check and helpful comments and modification of the manuscript.This study is financially supported by the National Natural Science Foundation of China(Grants Nos.42072130 and 41872152).

摘　　要：The stability of dawsonite is an important factor affecting the feasibility evaluation of CO_(2)geological storage.In this paper,a series of experiments on the interaction of CO_(2)-water-dawsonite-bearing sandstone were carried out under different CO_(2)pressures.Considering the dissolution morphology and element composition of dawsonite after the experiment and the fluid evolution in equilibrium with dawsonite,the corrosion mechanism of dawsonite led by CO_(2)partial pressure was discussed.The CO_(2)fugacity of the vapor phase in the system was calculated using the Peng-Robinson equation of state combined with the van der Waals 1-fluid mixing rule.The experimental results indicated that the thermodynamic stability of dawsonite increased with the increase of CO_(2)partial pressure and decreased with the increase of temperature.The temperature at which dawsonite dissolution occurred was higher at higher f_(CO_(2)).There were two different ways to reduce dawsonite’s stability:the transformation of constituent elements and crystal structure damage.Dawsonite undergoes component element transformation and crystal structure damage under different CO_(2)pressures with certain temperature limits.Based on the comparison of the corrosion temperature of dawsonite,three corrosion evolution models of dawsonite under low,medium,and high CO_(2)pressures were summarized.Under conditions of medium and low CO_(2)pressure,as the temperature continued to increase and exceeded its stability limit,the dawsonite crystal structure was corroded first.Then the constituent elements of dawsonite dissolved,and the transformation of dawsonite to gibbsite began.At high CO_(2)pressure,the constituent elements of dawsonite dissolved first with the increase of temperature,forming gibbsite,followed by the corrosion of crystalline structure.

关 键 词：dawsonite stability CO_(2)-water-rock interaction corrosion mechanism CO_(2)geological storage 

分 类 号：P59[天文地球—地球化学]