基于总线技术的井下流量采集传输系统设计

Collecting and Transmitting Downhole Flow RateBased on 485 Bus Communication

摘要:

文章介绍了一种井下流量采集传输系统设计和实现方案。针对油田分层注水井需要实时监测每层油层注水量以及压力温度等参数,设计了基于文丘里流量计原理和485总线通信的井下流量采集传输系统,该井下流量采集传输系统实时采集文丘里流量计入口和出口处压力差,根据测量压力差及文丘里管尺寸,通过能量守恒定律--伯努力方程和流动连续性方程计算实时流量,并对时间进行积分计算出总流量,通过485总线实时将流量等参数上传至地面测控计算机,具有参数上传实时性强、流量采集精度高、抗干扰能力强、尺寸小等特点。实验结果表明,井下流量采集传输系统满足注水井流量等参数实时监测的要求。

Abstract:

This article introduced a monitoring system, which used to collect and transmit downhole flow rate. Typical separating injection well needs to monitor injected water volume of each oil layer and measure parameters such as pressure and temperature. This monitoring system is designed based on principle of the venture meter and 485 bus communication. It by way of monitoring pressure difference in between inlet and outlet of the venturi meter, with measured pressure difference and tube size of the venturi meter, applied energy equation (Bernoulli Equation and continuity equation) to calculate the real time flow and time integral algorithm to calculate the total flow. Then data will be send to surface measuring and controlling computer. This system has benefits such as real time data sending, high accuracy data collection, anti-interference ability, compact-sized. The experimental results showed that this system satisfies the requirements of measuring real time downhole parameters such as flow rate within injection well.