便携式岩屑声波录井系统研制与测试

Development and Testing of a Portable Acoustic Logging System on Cuttings

  • 摘要: 为了在钻井过程中实时测量所钻地层的声波速度,在研究岩屑声波录井方法的基础上,研制了高精度的便携式岩屑声波录井系统。设计岩屑声波录井系统时,采用了具有脉冲发生器和示波器功能的一体化电路,并研制了能够快速读取、存储波形数据的软件示波器;采用了超声波透射法,通过超声波探头发射1 MHz频率的超声波,测量声波穿过岩屑样品的纵波速度和横波速度。对该系统进行了实验室比对和实钻井偶极子声波测井比对测试,结果表明,声波速度测量精度大于98.0%、岩屑声波和电缆声波数据一致性大于80.0%。利用该系统不仅可以随钻监测地层异常压力,还可以实时评价岩石的脆性、可压性、可钻性和井壁稳定性。

     

    Abstract: In order to measure the real-time acoustic velocity in the formation while drilling, a portable acoustic logging system on cuttings with high precision was developed based on the research of acoustic logging on cuttings. In the design of this logging system, integrated circuit of pulse generator and oscilloscope was adopted. In addition, software functioning as oscilloscope that could quickly read and store waveform data was studied for this system. By using the ultrasonic transmission method, an ultrasonic probe was used to emit ultrasonic waves with 1 MHz frequency to measure the P-wave velocity and S-wave velocity of the acoustic wave passing through cuttings samples. Results comparisons were conducted on both the laboratory test and the dipole acoustic logging in actual drilling. The results showed that the accuracy of acoustic velocity measurement was more than 98.0%, and the consistency of acoustic logging data of cuttings and wireline acoustic data was greater than 80.0%. This system could not only be used to monitor abnormal formation pressure while drilling, but also to evaluate rock brittleness, compressibility, drillability and wellbore stability in real time.

     

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