核磁共振测井信号调理与回波提取技术研究

Research of processing NMR signal and detecting echo signal

针对核磁共振激励发射信号CPMG序列的特点,采用一种微弱信号调理技术对核磁共振回波信号进行预处理以便于回波信号的提取,并提出了一种相敏检波算法以提取相应的微弱回波信号。信号接收调理电路设计采取了隔离板与前置放大板配合协调工作,以达到防止高压发射信号冲击和微弱信号调理的作用。目前已经利用该信号调理技术与DPSD算法成功提取出相应的核磁共振回波信号。

According to the characteristic of CPMG array,an approach of weak signal processing was adopted to preprocess NMR echo signals in order to pick up echo signal,and a kind of DPSD algorithm was also introduced to extract weak echo signal.Decoupler and pre-amplifier were used to avoid high-voltage impact and to process weak signal.Now the NMR echoes have been picked up successfully with the method of weak signal processing and DPSD.