CAJ | 학술논문

为了研究盐水层孔隙结构特性对CO_2注入过程的影响,采用对数正态分布的随机分布孔隙率表征地下盐水层的非均质孔隙特性,引入与盐水层中局部温度和局部压力相适应的CO_2密度和黏度,建立了超临界CO_2-盐水体系的两相流驱替过程数学模型.通过数值模拟研究了超临界CO_2注入的过程参数和盐水层特性对CO_2注入特性和盐水层中饱和度分布的影响.研究表明:CO_2的注入压力主要与盐水层的深度和盐水层的体积平均孔隙率有关,而受盐水层孔隙率分布的影响较小;盐水层的孔隙率分布特性对CO_2饱和度分布影响非常显著;在盐水层总容积相同的条件下,深层盐水层的CO_2存储容量比浅层盐水层的小,且注入压力大;在CO_2封存过程中,应选择合适的注入速率,最大限度地提高盐水层封存容量的利用率.本文的计算方法和分析结果为超临界CO_2的地下封存过程和注入后的评估方法等提供了计算方法和理论依据.
위료연구염수층공극결구특성대CO_2주입과정적영향,채용대수정태분포적수궤분포공극솔표정지하염수층적비균질공극특성,인입여염수층중국부온도화국부압력상괄응적CO_2밀도화점도,건립료초림계CO_2-염수체계적량상류구체과정수학모형.통과수치모의연구료초림계CO_2주입적과정삼수화염수층특성대CO_2주입특성화염수층중포화도분포적영향.연구표명:CO_2적주입압력주요여염수층적심도화염수층적체적평균공극솔유관,이수염수층공극솔분포적영향교소;염수층적공극솔분포특성대CO_2포화도분포영향비상현저;재염수층총용적상동적조건하,심층염수층적CO_2존저용량비천층염수층적소,차주입압력대;재CO_2봉존과정중,응선택합괄적주입속솔,최대한도지제고염수층봉존용량적이용솔.본문적계산방법화분석결과위초림계CO_2적지하봉존과정화주입후적평고방법등제공료계산방법화이론의거.
In order to have in-depth understanding of the influences of heterogeneous porous structure inside saline aquifers during carbon dioxide injection,a two-phase flow mathematical model was proposed to describe the imbibition process of the supercritical carbon dioxide-brine system,in which a lognormal distribution of porosity was introduced to represent heterogeneity of porous saline aquifers.The model also featured the imbibition process at varying densities and viscosities of supercritical carbon dioxide that were correlated to local pressure and temperature of saline aquifers.Numerical simulations were conducted to investigate the influences of process parameters during injection and characteristics of saline aquifers on injecting behavior and saturation distributions of supercritical carbon dioxide in the saline aquifers.The results showed that injection pressure was dependent on the depths and volumetric average porosities of saline aquifers.It was less affected by the porosity distribution of the saline aquifer.However,the saturation distributions of supercritical carbon dioxide in saline aquifers were strongly affected by the porosity distribution.When the total volumes of saline aquifers were identical,the storage capacity of a deep saline aquifer was less than that of a shallow aquifer,whereas the injection pressure in the former case was larger than that in the latter case.For the purpose of maximizing the storage efficiency,an appropriate injection rate needed to be chosen during carbon dioxide injection.The proposed method would provide an insight into carbon dioxide sequestration in saline aquifers,and it would also be a tool for evaluating the consequence of injection.