过钻杆存储式交叉偶极子阵列声波测井仪的设计及应用

Design and Application of a Through-drillpipe Memory Cross-dipole Array Acoustic Logging Tool

中国存储式声波测井仪多采用单极子技术,主要为储层评价提供地层孔隙度等参数。对软地层的测量中该仪器无法提取出横波信号,测量精度不高。这类仪器的应用范围仅限于单一的各向同性地层,对于复杂多变各向异性的地层应用效果差。研制了一种外径为60 mm的过钻杆存储式交叉偶极子阵列声波测井仪,包括硬件电路设计、软件设计以及数据压缩算法的设计,并通过实验确定了小直径的单极、偶极及斯通利波发射换能器的发射控制频率。现场测井资料表明,该仪器能够测量地层纵波、横波及斯通利波,识别地层各向异性大小和方位,可用于页岩气井等复杂水平井的过钻杆存储式测井施工作业。

Monopole technology is widely used in domestic memory acoustic logging tools for evaluating formation porosity and other parameters.For soft formation,this technology is ineffective because it can not record S-wave signals,and the measurement accuracy is not high.In addition,it is only applicable to isotropic media,but less effective for complicated anisotropic media.A through-drillpipe memory cross-dipole array acoustic logging tool is developed.The tool with a diameter of 60 mm include hardware circuit,software and data compression algorithm.And the frequency of small diameter monopoles,dipoles and Stoneley wave transducers has been determined by experiments.Field logging data show that the tool can measure P-wave,S-wave and Stoneley wave,and identify formation anisotropic degree and azimuth.It is useful for through-drillpipe memory logging operation in shale gas horizontal wells.