双基双凝水泥浆体系固井

CEMENTING TECHNIQUE WITH BI-BASE & BI-SETTING CEMENT SLURRY SYSTEM

青海油田的花土沟、狮子沟、七个泉等区块 ,地层压力系数低 ,在钻井过程中常发生不同程度地钻井液漏失、封固不合格 ,进而造成产层失效等。针对三区块的地质特征 ,通过对以往完成井声幅值进行仔细分析 ,并根据大量试验 ,对原有水泥浆体系配方进行改进 ,研究总结出用双基双凝 (上部易漏层段采用泡沫水泥浆加缓凝剂 ,下部主力油层段用常规水泥浆加速凝剂 )水泥浆体系固井技术。经过 18口井的现场应用 ,解决了以往固井施工中出现的问题。固井质量合格率 10 0 %、优质率 77.8%。

The formation pore pressure coefficient is very low in such blocks as Huatugou, Shizigou and Qigequan in Qinghai Oilfield, and lost circulations of different degrees, poor isolations and sometimes as worse as production zone abandonment take place during drilling. According to the geological characteristics of the three blocks, and by careful analyzing of the acoustic amplitude data of the completed well in this area, the conventional cement slurry system is modified based on many experiments. A novel cementing technique of using bi-base and bi-setting cement slurry system is developed, i.e., in the upper lost circulation interval, foam cement slurry is used with retardant, while conventional cement slurry with accelerator is used in the lower production zone. This technique has been field used in 18 wells, and remarkable improvement in cementing quality has been obtained.