摘要
结合储层CO_(2)埋存技术,自主搭建了地层温度压力条件下CO_(2)埋存实验装置,开展了多介质辅助CO_(2)埋存实验研究。研究结果表明,乙醇-KOH体系能够有效进行CO_(2)矿化埋存,其中96%乙醇+3 g KOH 500 mL溶液捕集CO_(2)能力最强,是最佳的CO_(2)矿化埋存溶液配比。经CO_(2)矿化埋存后,低渗透岩心孔隙度平均降低7.07%,孔隙度变化率与孔隙度呈正相关关系,渗透率平均降低16.01%。因此,96%乙醇+3 g KOH能够加速CO_(2)在储层中的CO_(2)沉淀过程,缩短CO_(2)在储层中的矿化埋存时间。该研究可重复性、准确性和可扩展性较强,能够激发学生自主设计实验的积极性及创新意识,培养学生的独立思考能力,有利于学生将理论知识与实际工程问题相结合,实现科研能力与创新能力的相互促进。
[Objective]Carbon dioxide(CO_(2))displacement and storage are the most viable technologies for achieving carbon neutralization and enhancing low-permeability reservoir recovery.The current research focused on the evaluation of CO_(2) storage capacity and mechanism under different geological conditions but ignored the problem of CO_(2) storage time being too long.When CO_(2) was injected into the stratum for geological burial,it mainly existed in the form of geological structure burial in the initial stage of injection(within several decades),and the safety was relatively low.In the middle stage of injection(within 100 years),it changed from geological structure burial to bound storage and gradually to dissolved storage,and the safety was relatively good at this time.In the later stage of injection(thousands of years),the storage forms were mainly dissolved storage and mineralized storage,and the safety was the highest.Therefore,through laboratory experiments,studying how to improve CO_(2) mineralization and storage speed and shorten the CO_(2) storage time using chemical agents is of great significance.[Methods]Based on the actual CO_(2) storage technology in reservoirs,a CO_(2) storage experimental device under formation temperature and pressure conditions was independently built,and multimedia-assisted CO_(2) storage experimental research was conducted.The precipitation of potassium carbonate through the utilization of the ethanol+KOH solution system enabled CO_(2) capture and carbonization.The reaction process in the solution system was affected by the ethanol concentration,resulting in different CO_(2) carbonization amounts with the change in the ethanol concentration.Simultaneously,the precipitation-generated potassium-based acid salt could undergo a reaction with water to facilitate ethanol regeneration.This paper utilized experimental methods to investigate the CO_(2) capture efficiency of the ethanol+KOH system,real-time monitoring of ethanol content in the solution,and identification of the optimal ethanol concentration for the formation temperature.The solution was supplemented with KOH,followed by the utilization of regenerated ethanol from the solution’s carbonization reaction for subsequent carbonization,enabling the determination of the maximum CO_(2) capture capacity of the ethanol+KOH system.The CO_(2) burial experiment was conducted using a high-temperature and high-pressure core displacement device after injecting the ethanol+KOH solution.The characteristics of CO_(2) mineralization under different permeability/porosity conditions were discussed.[Results]The research results indicated that the 96%ethanol+3-g KOH solution demonstrated effective CO_(2) capture,resulting in an average precipitation of 4.56 g per capture.Simultaneously,following the saturation of the core with the 96%ethanol+3-g KOH solution,CO_(2) injection was conducted to induce sediment formation,resulting in a reduction in core permeability of approximately 16.01%.After CO_(2) mineralization and burial,the average porosity of the low-permeability core decreased by 7.07%,and the porosity change rate was positively correlated with porosity.The results of the CO_(2) storage experiment indicated that after the action of the 96%ethanol+3-g KOH solution,CO_(2) could be effectively captured in the form of precipitates in the reservoir,with the largest degree of capture in medium to large pores.Compared with formation water,the composite solution studied in this paper can improve the CO_(2) storage efficiency by 30%.The 96%ethanol+3-g KOH solution can accelerate the CO_(2) precipitation process in the reservoir and shorten the mineralization and storage time of CO_(2) in the reservoir.[Conclusions]This study proposed a new method to increase CO_(2) storage capacity by injecting a KOH+ethanol solution into a formation to improve CO_(2) mineralization and storage efficiency.Moreover,it realized the effective integration of the chemical industry and petroleum engineering disciplines and provided a new research approach for carbon peaking and carbon neutrality.
作者
王文东
王程伟
任慈
孙庆豪
苏玉亮
李蕾
WANG Wendong;WANG Chengwei;REN Ci;SUN Qinghao;SU Yuliang;LI Lei(Key Laboratory of Unconventional Oil&Gas Development,Ministry of Education,School of Petroleum Engineering,China University of Petroleum(East China),Qingdao 266580,China;Shanghai Branch of CNOOC(China)Co.,Ltd.,Shanghai 200030,China)
出处
《实验技术与管理》
CAS
北大核心
2024年第1期130-135,共6页
Experimental Technology and Management
基金
山东省研究生教育质量提升计划项目(SDYKC21026)
山东省本科教学改革项目(Z2021015,M2022284)
山东省研究生教学改革项目(SDYJG21017)
中国石油大学(华东)教学改革重点项目(CZ2022004)。
