塔河油田缝洞型碳酸盐岩油藏水驱开发特征及改善对策

Waterflooding characteristics and improvement measures of fracture-cavity carbonate reservoirs in Tahe Oilfield

以塔河油田缝洞型碳酸盐岩油藏注水开发实践为基础,综合应用地质、地球物理、示踪剂测试、生产动态等资料,对其水驱开发特征进行了系统研究,建立了低效水驱模式,并针对性提出了改善水驱技术对策。研究结果表明,缝洞型碳酸盐岩油藏水驱开发呈现三大特征:①受效方向单一;②注水利用率低;③注水失效的主要原因为底水水侵。主要存在低水驱控制型、低水驱动用型、低洗油效率型3大类10亚类低效水驱模式。改善水驱开发效果的对策包括:①围绕连通缝洞体(或缝洞群)构建(或完善)注采关系,通过完善井网、改善连通等提高水驱控制程度;②通过调驱、注采参数优化、改变水驱方向、变强度注水等提高水驱动用程度;③通过改善岩石及油水界面性质提高水驱洗油效率;④通过提高生产井井底压力、封堵水侵通道、降低底水能量等方式抑制底水。同时,还要综合利用多种技术手段提高油藏描述精度,提高技术实施有效率。

Based on the waterflooding development practice of fracture-cavity carbonate reservoirs in Tahe Oilfield,this pa⁃per systematically study waterflooding characteristics with geology,geophysics,tracer test,and production performance da⁃ta.In addition,the paper constructs low-efficiency waterflooding modes and puts forward technical measures to improve wa⁃terflooding technologies.The research results show that the waterflooding fracture-cavity carbonate reservoirs have three characteristics:the single response direction,the low utilization factor of water injection and the most waterflooding failure due to bottom water invasion;and there are three main types and 10 subtypes of the low-efficiency waterflooding modes in⁃cluding the low the percentage of reserves on hold under waterflooding,the low the percentage of producing reserves under waterflooding,and the low displacement efficiency.The measures to improve the waterflooding development are as follows:First,the percentage of reserves on hold under waterflooding could be increased by improving the well pattern,and connec⁃tivity based on constructing(or improving)the injection and production relationships around the connected fracture-cavity bodies(or groups).Second,the percentage of producing reserves under waterflooding can be improved by profile control and flooding,optimizing the injection and production parameters,changing waterflooding direction,and changing water in⁃jection intensity.Third,the oil displacement efficiency can be enhanced by improving the properties of the rock and oil-wa⁃ter interface.Finally,the bottom water can be inhibited by improving the bottom hole pressure,blocking the water invasion channel,and reducing bottom water energy.At the same time,the various technologies should be comprehensively used to strengthen the accuracy of reservoir description and the efficiency of technology implementation.