核磁共振测井微弱信号DPSD提取算法研究

Research on DPSD arithmetic for extracting echoes in weak signals from NMR logging

针对核磁共振测井中采集到的核磁回波信号十分微弱的特点,提出一种微弱信号的提取处理算法(DPSD,相敏检波算法),详细分析了DPSD算法的特点以及数字DPSD算法的实现方法,并对DPSD算法的频谱进行详细分析,提出一种通过FPGA并行执行DPSD算法提高运算速度、增强数据运算时实型的设计。目前已经成功实现该数字DPSD并行回波数据处理算法,并在实际测井过程中得到了很好的应用效果。

As detecting signal in NMR echoes is rather weak,DPSD arithmetic was introduced to extract the weak signals from noise.In this paper,the characteristic of DPSD was introduced firstly.Then the frequency spectrum of DPSD was analyzed.Finally a way of parallel DPSD realized through FPGA was introduced to improve the process speed and realize real-time processing.As the result,it is successful to extract the weak echoes from signals from NMR（nuclear magnetic resonance） logging.And the arithmetic is commendably used in practical logging.