针对油田开发过程中分段、分层压裂产能测试难题, 研究了基于分配型示踪剂监测和评价压裂效果的基本原理与配套工艺技术, 在压裂过程中注入不同种类的分配型示踪剂, 通过监测压裂返排液中示踪剂的浓度变化, 计算各段 (层) 示踪剂的产出量、返排液产液量和贡献率等参数, 确定油水产出剖面及裂缝信息, 进而分析和判断油气井分段 (层) 压裂效果。最后, 应用该技术监测和评价了长庆油田涧*井的压裂效果。研究结果表明:涧*井27个压裂段的54条示踪剂产出浓度曲线可分为四大类:抛物线形单尖峰曲线、抛物线形单宽峰曲线、抛物线形多峰曲线和无峰曲线;通过分配型示踪剂监测, 可以获得水平井分段产能贡献的直观结果。该技术可用于水平井多段压裂和直井多层压裂过程中地层水、压裂液、原油的产出动态监测, 有助于准确评价压裂效果、优化压裂方案、判断井间连通状况。
In order to address the difficulty of testing the segmented and layered fracturing productivity in the process of oilfield development, the basic principle of monitoring and evaluating the fracturing effects based on distribution tracer and the supporting process technology are researched, and different types of distribution tracers are injected during the fracturing process. According to the parameters such as the output of tracers, flowback liquid production, and contribution rate, the oil-water production profile and fracture information are determined, thus the segmented (layered) fracturing effect of oil and gas wells are analyzed and judged. Finally, this technology is applied to monitor and evaluate the fracturing effect of Jian* well in Changqing Oilfield. The research results show that the 54 tracer production concentration curves of 27 fracturing sections in Jian*Well can be divided into four categories: parabolic single sharp peak curve, parabolic single broad peak curve, parabolic multi-peak curve, and peakless curve. By monitoring distributive tracer, intuitive results of horizontal well' s segmented productivity contribution can be obtained. This technology can be used for dynamic monitoring of formation water, fracturing fluid, and crude oil production during segmented fracturing in horizontal wells and layered fracturing in vertical wells, conducive to accurately evaluating the effectiveness of fracturing, optimizing fracturing schemes and determining interwell connectivity.