基于ADIS16228的井下振动分析仪设计

Downhole vibration analyzer design based on ADIS16228

为避免钻井时钻具共振引起的钻具失效事故,设计了一种基于微机电系统（MEMS）差动式变极距电容传感器的井下振动分析仪。该仪器可以测量井下钻柱的纵向、横向、扭转振动,并对采样数据进行快速傅里叶变换（FFT）分析,可以设定振动报警阈值并具有节电休眠功能。测量得到的数据保存在本地磁阻存储器中供起钻后回放诊断分析。一旦发生钻柱共振事件,报警信息可以通过泥浆脉冲发生器实时传送到地面方便调整钻井参数以消除共振,同时报警时的FFT数据也能保存起来。该井下振动分析仪结构简单、具有较高可靠性。

A downhole vibration analyzer based on MEMS differential capacitive displacement sensor was designed to avoid failure in drilling engineering caused by drill string resonance.This instrument can survey drill string vibrations including longitudinal vibration,lateral vibration and twisting vibration,process FFT analysis to captured data,configure alarm trigger levels and power down itself at idle time.Captured FFT data was stored in local MRAM used to diagnose vibration conditions after pulling out.Once a resonance accident was happened,a triggered alarm message was sent to surface immediately by mud pulse generator in order to handle accident by adjusting drilling parameters and alarm FFT data was stored locally at same time.This downhole vibration analyzer has simpler structure and higher reliability.