断裂导水对哈南油田注采的影响及开发对策

通过哈南油田岩芯裂缝古地磁定向,确定了裂缝发育方向.鉴定了121块微裂缝薄片,分析了微裂缝与大裂缝关系.作了一个井组的示踪剂实验,检测裂缝与断层导水形式.在此基础上,分析了前人的地震、钻井断层解释,以及动态资料,认为哈南油田阿尔善油藏断裂系统是NE向断层(包括裂缝)与NW向裂缝组成的一组共轭断裂系统.发现断裂系统导水严重,断裂发育区水进速度约为0～100m/d.断层面导水、断层对接导水致使注采层系混乱,形成上层注下层采或下层注上层采的非同层注采局面.同时部分油井憋压过高,部分油井暴性水淹.针对油田断裂系统特征,提出了应对措施:导水断层附近注水井井距加大;在断层面充水情况下,断层附近注水井适当减少注入量或采用脉冲式注水;针对层系之间串水现象,调整开发层系.

EFFECTS OF WATERCONDUCTION OF FAULTS ON WATERFLOODING AND DEVELOPMENT COUNTERMEASURES IN HANAN OILFIELD

The directions of fractures in Hanan Olifield are determined by paleomagnetic method.121 micro-fracture slices are identified to analyze the relationship between micro-and macro-fractures.The tracer experiment of a well group is done to detect the water transmission fractures and faults.Based on the data of seism,drilling interpetation in faults and the performance data,a conclusion is drawn that in the fault system of Aershan Reservoir,NE strike faults and NW strike fractures are conjugated.The transmissibility of the fault system is so serious that the inflow rate in fault-developed areas is 40-100 m/d.The effects of tansmissibility resulted in the confusion of the injection-production layers,thus forming injection-production in different layers.On the same time,some production wells are of high pressure and flooded.According to the characteristics of the fault system,corresponding contermeasure is put forward.