用于双侧向测井仪的信号滤波电路设计

Design of signal filter circuit for dual laterolog tool

双侧向测井是地质钻井油气储量检测中的一种重要地球物理方法。为了增强双侧向测井仪的分层能力,设计了两种信号滤波电路,一种是巴特沃兹八阶带通滤波器电路,其特点是电路简单实用,高温高压环境下工作稳定,可用于检测深度大于2 000 m的石油钻井;另一种是以专用芯片LTC1068为核心的带通滤波器电路,其特点是可编程配置中心频率,灵活性好,可用于检测深度小于1 000 m的煤炭和矿产普查钻井。通过两种电路的现场测试效果图可以得出,两种滤波电路对10 mV~10 V的大、小信号都具有很好的滤波效果,电路实用性高,性能稳定。

Dual laterolog is an important geophysical method in the detection of oil and gas reserves in geological drilling. In order to enhance the layering ability of dual laterolog tool,two signal filter circuits are designed. One is Butterworth eighth order bandpass filter circuit,which is characterized by simple and practical circuit,stable operation under high temperature and high pressure environment,and can be used to detect oil drilling with depth greater than 2 000 meters. The other is the bandpass filter circuit with the special chip LTC1068 as the core. It is characterized by programmable configuration of center frequency and good flexibility. It can be used to detect coal and mineral exploration drilling with a depth of less than 1 000 meters. Through the field test results of the two circuits,it can be concluded that the two filter circuits have good filtering effect on large and small signals of 10 mV~10 V,high practicability and stable performance.