快速均匀启动技术改善蒸汽辅助重力泄油预热效果

摘要

预热效果对蒸汽辅助重力泄油(SAGD)开发井组的见产速度和生产效果均有直接影响,研究高效的预热方式对提高SAGD开发效果有重要意义.以现场快速均匀启动试验为例,采用数值模拟方法揭示了快速均匀启动技术的高压扩容机理,并优化了快速均匀启动操作压力.研究结果表明:通过在注采井间形成高孔隙度、高渗透率和高含水带,可以加速蒸汽与岩石之间的热对流,从而实现双水平井井间快速均匀热连通;快速均匀启动存在最佳操作压力,该压力与油藏地应力及岩石变形特征相关.进一步结合现场生产动态数据,分析了快速均匀启动技术的实施效果.分析结果表明,实施快速均匀启动井组的预热天数明显减少,预热阶段节省了蒸汽注入量,转生产后早期生产效果有显著提高,对指导稠油油藏SAGD高效开发具有重要意义.%Preheating phase of steam assisted gravity drainage (SAGD)has direct effect on its early production response and corresponding performance in heavy oil reservoirs.Therefore,it is important to develop an effective method to improve SAGD performance.A pilot test of the fast and uniform start-up enhancement technology (FUSE) was taken as a case study.The high pressure dilation mechanism of the FUSE was revealed and its related operating pressure was optimized by using numerical simulation method.The results show that a zone with high porosity,high permeability and high water cut was formed between the injector and producer,and the heat convection between steam and reservoir rocks was enhanced,and thus the heat exchange rate and thermal connectivity between double horizontal wells were improved.There was an optimal operating pressure for the FUSE and it was closely related to the in-situ stress and the rock deformation characteristics.Field production data was applied to analyze the performance of the FUSE.The result presents that the number of days for preheating and the steam consumption in the preheating phase are reduced significantly,and the SAGD performance in the early production stage is improved obviously.It has important guiding significance for the realization of efficient SAGD development.