井下无线节流器控制信号编解码方法研究

Research on Codec Method of Downhole Wireless Throttle Control Signal

为改进当前天然气井中大量使用的节流器,提出了一种从地面无线控制的智能型井下节流器,并分析了信号的解码方法。首先根据压力脉冲的特点制订合适的编码方式;然后参考气井管道内压力的动态规律,定性分析蜀南气矿某气井的产量与井下压力的关系,从而将信号解码问题转化为产量的估计问题,并使用对参数变化鲁棒性强的自适应神经模糊推理系统(ANFIS)来解决;最后用气井的生产数据仿真验证解码思路。结果表明,该方法可准确、有效地解码压力波信号。

A smart throttle device that can wirelessly control downhole throttle from the ground is proposed,while signal decoding method is analyzed carefully in this paper.First,an effective encoding format is developed based on the form of pressure pulse.Then,referring to the variation law of pressure in gas well,relationships between gas well production and downhole pressure of a gas well in the Shunan gas mine are analyzed.Then the problem of decoding pressure pulse signals is transformed into a parameter estimation problem about gas well production. As know,the adaptive neural fuzzy inference system (ANFIS) has advantage of robustness to parameter changes,so it is applied to solve that parameter estimation problem.Finally,the production data of the gas well are used to simulate and verify the decoding idea.