基于物质的量平衡的气藏CO_(2)埋存潜力评估方法

A evaluation method of CO_(2) sequestration potential in gas reservoirs based on mole balance

枯竭气藏是进行CO_(2)埋存的有利场所之一,进行气藏CO_(2)埋存潜力评估至关重要。基于气藏生产和CO_(2)埋存采注过程中物质的量平衡原理,考虑气体偏差系数随着温度和压力的变化,依据气体状态方程,建立了气藏CO_(2)埋存潜力评估模型,分析了采出程度和气体偏差系数对气藏CO_(2)埋存量的影响。结果表明,采出程度和气体偏差系数越大,越有利于CO_(2)埋存。结合川中A区块L1井的实际参数进行了CO_(2)埋存潜力评估,考虑气体偏差系数随储层温度和压力变化预测的CO_(2)埋存量比传统物质平衡法计算的埋存量高27%。该方法对CO_(2)埋存潜力评价研究及埋存方案优化具有重要意义。

Depleted gas reservoirs are one of the favorable sites for underground CO_(2) sequestration,and it is vital to evaluate the CO_(2) sequestration potential of gas reservoirs.Based on the principle of mole balance in the gas recovery and CO_(2) sequestration,production and injection processes,the gas reservoir CO_(2) sequestration potential evaluation model was developed,which incorporates the gas state equation and the variation of gas deviation factor with temperature and pressure.With this model,the effects of the gas recovery efficiency and gas deviation factor on the CO_(2) sequestration capacity were analyzed.The results show that higher recovery efficiency and gas deviation factor are more favorable for CO_(2) sequestration.The CO_(2) sequestration potential evaluation for Well L1in block A,central Sichuan Basin,reveals that the CO_(2) sequestration capacity predicted by the presented method considering the variation of gas deviation factor with reservoir temperature and pressure is 27% higher than that estimated by the conventional material balance method.The presented method is valuable for CO_(2) sequestration potential evaluation and scheme optimization.