油基泥浆电成像测井仪器微弱电流检测电路设计  

Design of the Weak Current Signal Detection Circuit for Oil-base Mud Electric Imaging Logging Tools

作　　者：张全文[1] 于增辉[1] 张志刚[1] 张延峰[1] 

机构地区：[1]中海油田服务股份有限公司,北京101149

出　　处：《石油管材与仪器》2017年第1期29-32,共4页Petroleum Tubular Goods & Instruments

基　　金：大型油气田及煤层气开发科技重大专项(三维声波;油基泥浆电成像;二维核磁成像测井技术与装备编号:2011ZX05020-005)

摘　　要：针对油基泥浆电成像测井仪器电流信号微弱、信号数量多、动态范围大的特点,设计了一种基于CPLD的微弱电流信号检测电路。结合微弱电流信号的特点主要讨论了低噪声流压转换电路的设计、放大滤波电路的设计及电路噪声的计算方法。设计中由CPLD实现模数转换电路的时序控制,电路最终完成26路信号有序的采集操作。实践表明,该电路能够稳定可靠地工作,达到了井下仪器信号采集的要求。The weak current signal detection circuit is designed based on CPLD with view to the problems of weak and wide dynamic range of the current signals for oil-base mud electric imaging togging tool. Combining the characteristics of a weak current signal flow, the design of low-noise voltage converter circuit, amplifying filtering cireuit and the calculation method of circuit noise are mainly discussed. The timing control of analog-digilal conversion circuit is realized by CPLD, the eireuit ultimately completes the orderly operation of 26-channel signals acquisition. The practice shows that the circuit can work stably and reliably, meet the requirements of downhole instrument signal acquisition.

关 键 词：微弱电流检测 电流电压转换 滤波电路 噪声计算 

分 类 号：P631.81[天文地球—地质矿产勘探]