胜利油田老油区CO2提高原油采收率及其地质埋存潜力评估

胜利油田经过近40年的开采,大部分油藏已进入开发中后期,注CO_2提高原油采收率(CO_2 EOR)及地质埋存技术应用前景广阔.以胜利油田老油区3个采油厂共183个油藏作为评估对象,依次从区域地质、CO_2埋存油藏筛选、CO_2EOR油藏筛选、增产油量及埋存潜力计算4个方面进行CO_2EOR及埋存潜力评估.评估结果表明,胜利油田老油区距离CO_2主要排放源近,具备CO_2埋存的地理和地质条件,共有41个油藏适合埋存,其中18个适合EOR,23个可作为废弃油藏直接埋存,期望总增产油量为999.72×10~4t,CO_2总埋存量为9 553.92×10~4t,整体可提高采收率5.76%.油藏的地质储量越大,CO_2埋存量和增产油量越大,越适合大规模的埋存工程.地质储量大的CO_2EOR油藏是将来CO_2埋存的首选场地.可用于埋存的(即将)废弃油藏数量多且地质储量大,在不久的将来很有可能成为CO_2埋存的主力油藏.图6表6参27

Assessment of CO2 EOR and its geo-storage potential in mature oil reservoirs, Shengli Oilfield, China

Most oil reservoirs in Shengli Oilfield have entered middle and late development stages after nearly 40-year production, and they are suitable for applying CO2 EOR and storage techniques. This study is aimed at assessing the potential of CO2 EOR and storage in 3 large oil fields in the region based on the data of 183 mature oil reservoirs. The assessments include regional geology assessment, storage site screening, reservoir screening for CO2 EOR, and EOR potential and storage capacity calculations. Many mature oil reservoirs are close to the main CO2 sources and have good geographical and geological conditions for CO2 storage. Of 41 reservoirs,18 are suitable both for EOR and storage and 23 suitable for storage as depleted oil reservoirs. The total EOR potential can be 999.72×104 t, and the CO2 storage can reach 9 553.92×104 t. The overall incremental oil recovery rate can be 5.76%. The greater OOIP the oil reservoir has, the greater potential of CO2 EOR and storage it will have, and the more suitable for large-scale storage projects it will be. Those oil reservoirs suitable for CO2 EOR with large OOIP will be the preferred sites for CO2 storage. Many nearly depleted oil reservoirs with large OOIP can be considered as main sites for CO2 storage in the near future.