微量物质示踪剂对页岩油水平井压后排液诊断技术

Diagnostic technology of trace substance tracer for backflow liquid after fracturing in shale oil horizontal well

为分析页岩油水平井、直井压裂施工后各层段返排产液情况,评价压裂效果,合成了20种微量物质示踪剂系列产品。施工时在每一段入井压裂液中加入一种示踪剂,通过检测不同时段返排液中各种示踪剂的种类及含量,判定各层是否出液及出液顺序;通过分析计算得出各层返排液量及产液剖面,形成页岩油压裂返排示踪诊断技术。该系列产品经室内实验评价,检出限均在80 mg/m3以内,可同时检测,灵敏度高,互无干扰,且与压裂液配伍性好。现场用于页岩油水平井吉岩油X井20段压裂,压后累计测试119 d,获取各层段产液顺序、启动时间及产液量,落实了该井的产液剖面。该技术可为同区块后续压裂工艺参数的精确优化提供技术支撑。

To analyze the backflow production of shale oil horizontal wells and vertical wells after fracturing,and evaluate the fracturing effect,20 types of trace substance tracer products were synthesized.During the operation,one tracer is added into the fracturing fluid of each section.By detecting the types and contents of various tracers in the backflow fluid of different sections at different times,it is determined whether the fluid is discharged from each layer and its sequence;Through analysis and calculation,the flowback fluid volume and production profile of each layer are obtained,thus forming the tracing diagnosis technology of shale oil fracturing flowback.The detection limits of these products are all within 80 mg/m3,which can be detected at the same time with high sensitivity,no interference and good compatibility with fracturing fluid.It was used for fracturing in 20 section of Well Jiyanyou X,a horizontal well of shale oil.The cumulative test time after fracturing was 119 days.The fluid production sequence,start-up time and fluid production of each section were obtained,and the fluid production profile of the well was determined.This technology can provide technical support for accurate optimization of subsequent fracturing process parameters in the same block.