岩屑长石砂岩与CO_2流体在水热条件下的相互作用

LITHIC FELDSPATHIC SANDSTONE AND CO_2 UNDER HYDROTHERMAL FLUID INTERACTION

选用水+CO2+砂岩体系于高压釜中在不同温度下(100℃,150℃,200℃)进行反应,运用偏光显微镜、扫面电镜观察、X射线衍射分析和紫外分光光度计等技术手段来研究CO2流体活动对储层物性的改造。结果表明储层砂岩在CO2流体作用下,发生溶蚀溶解形成次生孔隙,溶蚀主要发生在低能位和晶格缺陷位置。同时生成了次生沉淀物,包括水铝矿和粘土矿物,其中水铝矿不稳定。这一研究对火山岩侵入区碎屑岩储层评价和二氧化碳地质储存的数值模拟研究具有重要意义。

Experiment of water＋ CO2 4-sandstone system in the autoclave reaction was conduc-ted at different temperatures （100 ℃, 150 ℃, 200 ℃ ）. Polarized light microscopy, technical means of the sweep surface electron microscopy, X-ray diffraction analysis and UV spectrophotometer were used to study the effect of CO2 fluid transformation activities on the reservoir properties. Secondary porosity develops in the reservoir sandstones duo to the dissolution resulted from dis-solved CO2 fluid. Dissolution occurs mainly in the position of low energy and lattice defects. Mean-while, secondary precipitation materials form, including clay minerals and unstable. This study is of great significance on the Numerical simulation and evaluation of geological storage of carbon di-oxide clastic reservoirs.