CO2—水—岩作用对二氧化碳地质储存砂岩储层的改造机制研究

The development of Carbone Capture，Utilization and Storage（CCUS for short）is an important effective measure for controlling greenhouse gas emissions in the reality of China's energy structure which is dominated by coal. Injection tests and time lapse seismic monitorings on Shenhua Group CO2 Capture and Storage Demonstration Project in Erdos of Inner Mongolia showed that with the increases of injected CO2, inspiratory pressure in the sandstone reservoirs decreased from 6.19MPa in 2011 to 5.38MPa now, and Liujiagou Formation became optimal reservoir instead of Shiqianfeng Formation. Based on this, the study intends to take the core of Liujiagou Formation and Shiqianfeng Formation sandstone as the research object. Carry out CO2 - water - rock interaction experiments in high temperature and pressure reactor，and study the geochemical behavior of the rock in the supercritical CO2 - water system at different temperature and pressure conditions. Compare the difference of rock physical properties, mineral composition, ratio surface area and the reaction fluid components before and after experiments, analysis of the dissolved and mineralization reaction of rock under the experimental conditions, clarify the mechanism of sandstone mineral dissolution and precipitation during the CO2 -water - rock interaction processes ，and discuss the main controlling factors of mineral trapping CO2 ability in sandstone reservorirs. Take the lab experiments and engineering inject tests into the comparative study, research CO2 can be injected at core scale and reservoir scale, enhance the understanding of CO2 geological storage mechanism in deep saline aquifers of sandstone reservoirs, so as to guide the implementation of similar projects.

发展二氧化碳捕获、利用和储存是有效控制温室气体排放一项重要措施。内蒙古鄂尔多斯二氧化碳地质储存示范工程监测表明，各砂岩储层中，随着二氧化碳注入量增加，储层启动吸气压力由2011年的6.19MPa降为5.38MPa,且刘家沟组取代石千峰组，成为示范工程二氧化碳可灌注性最优储层。本研究拟以工程前期采取的刘家沟组和石千峰组砂岩岩心为研究对象，进行CO2—咸水—岩石相互作用实验，研究其在不同温度压力条件在超临界CO2—咸水体系中所发生的地球化学行为。通过实验前后岩石物理特性、矿物成分、比表面积及反应流体组分的变化，分析岩石在实验条件下溶解和矿化反应，阐明CO2—咸水—岩石相互作用过程中砂岩矿物的溶解和沉淀机制，探讨储层砂岩矿物CO2圈闭能力主控因素；开展室内试验与工程注入对比研究，研究岩心尺度和储层尺度的二氧化碳可注入性，提升砂岩储层深部咸水含水层二氧化碳地质储存机理认识，从而指导类似工程的实施。

发展二氧化碳捕获、利用和储存（Carbone Capture，Utilization and Storage，简称CCUS），是有效控制温室气体排放的一项重要措施。本项目以神华鄂尔多斯深部咸水含水层二氧化碳地质储存示范工程前期采取的刘家沟组、石千峰组、山西组砂岩岩心为研究对象，开展了CO2—咸水—岩石相互作用实验，研究了不同温度压力条件在超临界CO2—咸水体系中所发生的地球化学行为，分析了岩石在实验条件下溶解和矿化反应，阐述了CO2—咸水—岩石相互作用过程中砂岩矿物的溶解和沉淀机制，探讨储层砂岩矿物CO2圈闭能力主控因素，研究了岩心尺度和储层尺度的二氧化碳可注入性，提升砂岩储层深部咸水含水层二氧化碳地质储存机理认识，为国内深部咸水层二氧化碳地质储存以及二氧化碳驱水与封存工程实施提供了理论基础。.