摘要
CO2捕集与埋存可实现大气中CO2的有效降低,但成本高昂,而处于特定温度压力范围的气藏可保证超临界CO2的稳定埋存,是其理想的埋存靶场。研究认为:气藏中所储存的具有开发潜力的天然气会挤占超临界CO2的地层空间,影响其稳定埋存;选择适合的超临界CO2稳定埋存深度,在埋存的同时利用CO2驱替开采天然气,有利于CO2埋存并降低成本;在向气藏注入CO2提高天然气采收率的过程中,CO2驱替地层天然气的过程是"混相驱替"。根据PY干气藏温度、压力条件,在CO2与天然气混合体系PVT相态特性实验测试基础上,运用状态方程模拟方法,分析了3种不同流体带特别是超临界CO2天然气过渡带的偏差系数、地下体积比、密度、黏度的变化,明确了利用气藏实施超临界CO2稳定埋存与注CO2提高天然气采收率相互配套的必要性和可行性,并据此给出PY气藏在实施注入CO2提高天然气采收率技术时,超临界CO2可行的注入深度和采气压力范围。
The capture and sequestration of CO2 can effectively reduce the amount of CO2 in the atmosphere,but it involves a high cost.A gas reservoir within a specific range of temperature and pressure will be an ideal space for the CO2 sequestration,which can ensure the sequestration stability of supercritical CO2.Some researchers suggest that natural gas with development potential in the reservoir might occupy the space for supercritical CO2,which will badly affect the stability and sequestration of CO2.A proper sequestration depth and the application of gas displacement by CO2 for natural gas development can favor the CO2 sequestration and reduce costs.During the process of CO2 injection,the natural gas displacement by CO2 is 'miscible displacement'.According to the temperature and pressure conditions of the PY dry gas reservoir,and based on the laboratory test of the PVT phase behavior for the mixed CO2 and natural gas system,this paper analyzes the changes of deviation factor of three kinds of fluid zones,especially the supercritical CO2 gas transitional zone,as well as the changes of underground volume ratio,density and viscosity.The paper makes clear the necessity and feasibility of CO2 sequestration in reservoirs and CO2 injection for the improvement of gas recovery.It accordingly recommends the feasible injection depth of supercritical CO2 and the practical gas production pressure range for enhancing the recovery of the PY gas reservoir.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2012年第5期39-42,102,共4页
Natural Gas Industry
基金
国家自然科学基金"考虑CO2在地层水中溶解度动态变化的高含CO2天然气相行为研究"(编号:51174169/E0403)
