超声井径随钻测井回波信号补偿方法与电路实现

Echo Signal Compensation Method and Circuit Realization in Ultrasonic Caliper Measurement While Drilling

超声波反射测井在大密度泥浆中随着距离的增加回波信号急剧衰减,使得无法准确提取回波到达时间。研究了超声波在泥浆中的衰减特性,提出了基于时变压控放大器的回波信号补偿方法,进行了基于AD8336芯片的时变压控放大器的电路设计与实现。实验结果表明,该方法能够有效地补偿超声波在泥浆中的衰减,对随钻超声井径测量具有重要的实用价值。

Ultrasonic reflection logging is an important logging method. But in large proportion of the mud, the ultrasonic echo amplitude has a sharp attenuation with the increase of the distance, so that it can＇t accurately extract echo arrival time. In order to solve this problem, this paper studies the attenuation characteristics of ultrasonic wave in the mud, we proposed the echo signal compensation method based on time-varying VGA, completed circuit design and implementation of time-varying VGA based on AD8336. The experimental results show that this method can effectively compensate the ultrasonic attenuation in the mud, and has important practical value for LWD ultrasonic caliper measurements.