SAGD低物性段分支参数优选及对提高采收率影响研究

Study on optimization of branch parameters of SAGD low physical property segment and its impact on enhanced oil recovery

在新疆克拉玛依油田超稠油油藏SAGD开发后期,受低物性段隔夹层影响,部分井蒸汽腔无法纵向扩展,注气驱替不充分导致产量下降。针对这一问题,可采用优化井型等措施来扩大主井筒两侧泄油面积进一步提高采收率。本文结合现场数据建立数值模型,采用方差分析法分析不同井型参数对产能的影响大小并采用控制变量法以采收率为评价指标优选出适合目标区块的最佳井型参数,顺序为分支长度、分支数量、分支角度、分支间距,井型参数为分支长度150m,分支数量3条,分支角度90°,分支间距150m。在原模型基础上对优化方案进行了模拟预测,结果表明:目标区块累计产油量增加6247.6t,采收率提高12.7%,含水率平均降低8%~12%,研究成果对分支井辅助SAGD低物性段提高采收率提供了理论指导。

In the late development of super-heavy oil reservoir SAGD in xinjiangkaramay oilfield,due to the influence of low-physical intercalation,some well steam Chambers could not expand longitudinally,and inadequate injection gas displacement led to a decline in production.In order to solve this problem,the optimized well type can be adopted to expand the drainage area on both sides of the main wellbore and other measures to further enhance the recovery.Numerical model is established in this paper,combining with the field data,using analysis of variance analysis of the influence of different well type parameters on the capacity and size control variable method is used to recovery for the selected evaluation indexes is suitable for the optimum parameters of the well type,target block order to branch,branch length,branch number and branch Angle spacing,well type parameter for the branch length of 150 m,branch number 3,branch Angle 90°,branch span of 150 m.On the basis of the original model,the optimization program is simulated and predicted.The results show that the cumulative oil production in the target block increases by 6247.6t,the recovery rate increases by 12.7%,and the water content decreases by 8%~12%on average.The results of this study provide theoretical guidance for improving the recovery of SAGD in the low physical zone assisted by branch Wells.