探测裸眼井中裂缝的井眼成象仪

电测井工具是利用微电子、数字遥控系统及声传感技术的新一代测井仪，将其沿井身上提时，旋转传感器以脉冲反向模式扫描井身周围，接收井壁地层的反射声脉冲，并进行数据采集，经计算机软件处理使图象显示成黑、白和灰色，从而鉴定孔隙类型、层理特点及岩石特性参数，直接量化了井壁中裂缝和孔洞的面积。可用于井间对比以预测侧向和垂向的岩相变化，确认沉积环境、强化油层特性描述。并叙述了与伽马测井仪、六臂倾角测量仪等同时使用

The Borehole Imaging Tool for Detecting Well Bore Fractures

The CBIL instrument is a new generation of logging tool,using microelectronics,digital telemetry systems,and acoustic transducer technology. As the tool is pulled up the borehole,a rotating transducer operating in pulse echo mode is scanning the entire circumference of the well. The transducer sends a sound pulse to the borehole wall and receives the reflected acoustic pulse from that portion of the formation. For each sound pulse,two parameters are measured and recorded: the amplitude of the reflected acoustic peak and the travel time of the reflected acoustic signai. The transducer rotates 6 times per second,aquiring 250 amplitude and travel time samples per revolution. The CBIL data are recorded in the scanning mode for full coverage of type borehole wall. The logging speed is typically about 3m/min.An advanced postprocessing computer programme can generate well site plots in black,white and gray tone images. The images can identify porosity type,bedding characteristics,and petrophysical parameters.Besides that,the images can visually quantify the area of a borehole wall occupied by fractures and vugs.The images can be used in well-to-well comparisons for prediction of lateral and vertical facies changes,confirmation of the sedimentary environment,and reservoir characterizaiton. This paper also describes the examples of runing the CBIL,together with gamma ray spectral instruments and six-arm dipmeter tool,to detect the borehole geometry,thin beds,fracture and porosity.