汶川科钻WFSD-3孔裂缝响应特征及识别方法

Fracture Identification and the Response Characteristics of Fracture in the Third Drilling Hole of WFSD Project

汶川科钻WFSD-3孔位于四川省绵竹市九龙镇境内,该孔测井资料齐全,钻遇裂缝种类丰富、特征明显,是研究裂隙识别方法和地应力场分布的理想对象。从成像测井出发,通过汶川科钻WFSD-3孔的测井资料研究常规测井识别和提取裂缝的方法,总结了不同种类的裂缝在成像测井中的响应特征,然后分析了对应深度处裂缝在常规测井的响应特征,再根据各参数对裂缝的敏感度优选出裂缝识别参数来构造判别函数进行裂缝自动识别。结果表明,声波测井AC、密度测井DEN、补偿中子测井CNL、微球形聚焦测井RMSL、三孔隙度比值RP、岩石结构指数m和地层因素比值FRP在裂缝处响应明显,其中,声波测井AC、密度测井DEN对低角裂缝尤为敏感,由它们构成的判别函数识别正确率为86.67%,具有较好的应用效果。

The borehole of WFSD-3, located in the town of Jiulong in Mianzhu city of Sichuan Province, has comprehensive data and a variety of fracture. Based on imaging logging, studies on the conventional logging methods of the identification of fractures through the WFSD-3 hole logging data. This paper sums up the response characteristics of fractures in imaging logging. Then it analyzes response characteristics of fractures of the conventional logging on the same depth. According to the sensitivity level of the various parameters for fractures identification, choose the more sensitive parameters for the further research of au tomatic identification. In the final analyzes the effect of this method. The results show that, these parame- ters like AC,DEN,CNL,RMSL ,RP, m and FRP have obvious response in fracture, especially AC and DEN are sensitive in low angle fracture. The discriminant function＇s recognition accuracy is 86. 67%, which is constituted by these parameters, yielding relatively satisfactory application results.