核磁共振测井仪软硬脉冲时序设计与应用

Design and Application of Softhard Pulse Timing for NMR Logging Tools

为改善核磁共振测井仪泥质束缚水测量效果,基于软硬脉冲原理,建立软硬脉冲型调幅信号模型,设计一种软硬脉冲时序。基于Microsemi Libero SoC v11.8软件开发平台,采用Verilog语言实现仪器软硬脉冲型调幅数据模块和载波数据模块;借助软件开发平台上的Modelsim仿真模块进行功能仿真。软硬脉冲时序设计程序,功能仿真满足核磁共振测井仪工作要求。经测井对比分析,软硬脉冲时序测量的泥质束缚水孔隙度重复性优于硬脉冲型时序。软硬脉冲时序能够有效改善泥质束缚水孔隙度测量效果。

A soft-hard pulse model for signal amplitude modulation is established,and a soft-hard pulse timing is designed to improve the measurement of mud bound water by NMR logging tools.On the Microsemi Libero SoC v11.8(a software platform),there equips with a soft-hard pulse amplitude-modulating module and a wave-carrying module based on the Verilog language;and the Modelsim module is used for data simulation.The program of soft-hard pulse timing and the functional simulation meet the requirements of NMR logging tools.Logging comparison and analysis proves that the porosity repeatability of mud bound water measured by the soft-hard pulse timing is better than that by hard pulse timing.The soft-hard pulse timing can effectively improve the measurement of the porosity of mud bound water.