高含水后期凝胶调剖技术探讨与展望

Discussion and Prospect of Gel Profile Control Technique in Late High Water Cut Period

水井调剖是非均质油藏控水稳油、提高水驱效率的重要技术手段。近年来,大庆油田多数区块已进入高含水或特高含水开采后期,油藏不同区域吸水比例失衡矛盾日益突出。调剖理论的滞后制约了调剖技术大范围的推广应用,探索适用于大庆油田的调剖技术、确保调剖措施成功率并大面积推广成为当前凝胶调剖的发展方向。目前深部调剖技术主要采用凝胶型调剖剂进行高渗透层的封堵,凝胶类型及性能的选择成为措施成功与否的关键。从理论模型出发,分析了油藏中任意两点间的压降,确定了凝胶在油藏不同位置的剪切黏度,通过两者结合得到了油藏不同区域封堵对凝胶型调剖剂强度的要求,实现了油藏不同部位对凝胶强度要求的可预测性,为调剖方案和调剖剂选择提供了技术指导。通过凝胶应用性能的分析,认为高含水后期弱凝胶深度调剖技术具有广阔的应用前景。

Profile control for water wells is an important technology to enhance water flooding efficiency, control water cut and make oil production stable in heterogeneous reservoir.In recent years,most blocks in Daqing oilfield have entered into late high or extra-high water cut production period,water absorption contra- dictions in various regions of oil reservoirs have become increasingly prominent.Immature profile control theory restricts large-scale application of the profile control technique.Profile control technique suitable for Daqing oilfield is studied to ensure its successful ratio and will be the development direction of present gel profile control through large-scale application.Present in-depth profile control technique mainly adopts gel for the high permeability formation plugging,and the gel type and performance choose become the key to the success of the measure.Based on theoretical model,pressure drop between any two points in the oil reservoir is ana- lyzed and the shear viscosity of the gel at various positions of the oil reservoir is determined.Then various strength of gel profile control agent for various regions of oil reservoir is known,which makes the prediction on the gel strength requirement available and provides the technical guidance for the selection of profile con- trol plan and profile control agent.Through the analysis of gel application performance,it suggests that weak gel in-depth profile control technique in late high water cut period has a broad application prospect.