声频谱测井仪器的研制和野外实验

研制成功的声频谱测井仪器在井下发射和接收三种频率的声波信号，其中发射和接收20kHz声波信号的声系有一个发射和四个接收探头，源距为2．1～2．568m，间距为0．156m；发射和接收40kHz声波信号的声系由一个发射和两个接收探头组成，源距1．0—1．5m，间距0．5m；发射和接收10kHz声波信号的声系由一个发射和两个接收探头组成，源距为2．168—2．668m，间距0．5m．用三种不同的频率的声波进行测量记录目的是获得井壁径向深度不同处介质的声学信息，而且不同频率的声波信号在岩石中传播过程中频谱变化也是井壁岩层的可用声学信息．在井下的信息采集、数据传输、地面记录和监控全部由计算机控制．该仪器已经在大庆油田的三口井中成功的进行了野外实验．

Tool Development of Acoustic Spectrum Logging and Field Experiment

In the paper we introduce a new acoustic kHz, 40 kHz and 10 kHz. The acoustic sonde of 20 kHz is spectrum logging tool with three frequencies of 20 composed of one emission transducer and four reeeiving transducers, the spacing and the span are 2. 1m -2. 568m and 0. 156m, respectively. The acoustic sonde of 40 kHz consists of one emission and two receiving transducers, the spacing and the span are 1.0m - 1.5m and 0.5m, The acoustic sonde of 10 kHz has one emission transducer and two receiving transducers and the spacing and the span are 2. 168m -2.668m and 0.5m,respectively. The aim of the log tool with three acoustic frequencies is to obtain the formation＇s acoustic information of the different radial depth of investigation in the borehole. On the other hand, the change of the acoustic spectrum with different frequencies in the formation is useful. Data acquisition in the borehole, data transfer, ground record and monitoring of the tool are all controlled by a computer. The successful field experiments of three wells have been carried out in Daqing Oilfield.