胭脂红示踪剂在评价压裂液返排中的应用

针对川西地区SF气田近期部分水平井压后返排率和测试产量较低的问题,采用胭脂红示踪剂来评价压裂液返排情况。将胭脂红定量加入到水平井某一分段的压裂液中,通过检测返排液中胭脂红的含量来评价返排率。针对返排液中的杂质影响测量准确性的问题,建立简便可靠的比色卡法来判断返排液中的胭脂红浓度。在SF气田应用了4口水平井,定量描述了2口井的返排情况,定性判断另外2口井示踪压裂段液体并未返排。应用结果表明,胭脂红作为示踪剂能够定性/定量评价示踪段的返排情况,为水平井的压裂设计提供重要的理论依据。

Carmine tracer for evaluating flowback of fracturing fluid

Aiming at the problems such as low flowback rate,low gas production,etc.in some horizontal wells of SF Gasfield in western Sichuan,carmine tracer was used to evaluate the flowback of fracturing fluid.A certain amount of car-mine was added into fracturing fluid.And then the flowback rate was calculated by detecting the content of carmine in flow-back fluid.For impurity in the fracturing fluid affecting the measurement accuracy,a simple and reliable colorimetric meth-od was established to determine the carmine content.The process was applied in 4 wells.The fluid flowback in two wells was described quantitatively,and the unflowback in the other two well was qualitatively determined.The application results indicated that the carmine tracer can be used to evaluate the flowback of fracturing fluid qualitatively and quantitatively, thus this can provide an important theoretical basis for the fracturing design of horizontal wells.