汶川地震断裂带科学钻探工程一号孔主断层的随钻流体响应特征

Responding Features of Fluids during Drilling of the Main Fracture Zone in WFSD-1 Hole

汶川地震断裂带科学钻探工程(WFSD)的主要研究目的是探讨龙门山断裂带深部断裂的物质属性。随钻实时流体分析作为井口流体实时监测手段,首次获得了龙门山断裂带随钻流体组分响应特征,在一号孔(WFSD-1)主断层上出现随钻流体多组分同时异常,且异常强度大。通过比较WFSD-1号孔主断层的钻探岩心岩性和随钻流体组分剖面,认为随钻流体组分的异常区间与主断层的区间保持一致,表明流体异常与断层的响应特征,主断层区间的流体异常为多组分的极值异常,强度与断层泥厚度成正比。这些钻探泥浆气体响应特征将为钻探工程、取心钻进提供第一时间支持。

The main goal of Wenchuan Earthquake Fault Scientific Drilling Project （WFSD） is to investigate the material property of deep fracture of Longmenshan fault zone. As the real-time monitoring means of fluids during drilling, the responding features of fluid components were obtained by the real-time fluid analysis for the first time, in which the anomalies of multi-components of fluids simultaneously appeared and the intensity of the anomaly was great. Through the lithologic comparison between the drilling core of the main fracture in WFSD-1 hole and the drilling profile of fluid components, the authors found that the range of fluid anomaly and that of the main fracture zone in drilling core are almost the same, and the anomaly intensity of the fluid positively varies with the thickness of fault gouge of the drilling hole. In addition, the multi-components of the fluid are extreme anomaly （maximum or minimum）, showing the same responding result as the fault gouge in the main fracture zone. These responding features of drilling mud gas would be very helpful for the whole drilling project and the timely collection of drilling core