基于套管气监测数据的CO_2运移特征研究

Study on CO_2 Migration Features Based on Casing Gas Monitoring Data

乔家洼油田开展了CO_2捕集、利用和埋存(CCUS)示范工程,研究注入地层中的CO_2运移规律,对评价示范工程CO_2驱油和埋存效果具有重要意义。示范区对套管气中CO_2浓度进行了监测,对监测数据进行分析,提出了CO_2前缘突破采油井时刻的确定方法;将CO_2浓度监测曲线划分为4个典型阶段,分别为未突破段、突破段、窜流段和注入调整段;CO_2浓度监测数据显示北东-南西方向为CO_2优势运移方向,和数据模拟研究结果相同。分析套管气中CO_2浓度能在一定程度上明确CO_2在地层中的运移特征。

A demonstration project about Carbon Capture Use and Storage （CCUS） was conducted in Qiaojiawa oil field. The COz migration features have significances on effectiveness evaluation for sweep and storage. The CO2 concentration in casing gas was monitored. A method was proposed about the time of the breakthrough for CO2 flooding frontier based on monitoring data. The monitoring curve of CO2 concentration was divided four typical sta- ges, such as not breakthrough stage, breakthrough stage, channeling stage and flooding adjust stage. The dominant migration direction of CO2 is northeast to southwest,which has the same result with numerical simulation. The CO2 migration features can be studied by analyzing casing gas monitoring data.