基于气-砂两相流振动信号特征分析的砂粒检测
Vibration Signal Characteristics Analysis for Sand Detection in Gas-Sand Two-Phase Flow

气-固两相流中固相信息的实时检测广泛应用于工业中的各个方面, 特别是天然气开采过程中面临的出砂监测问题．为了丰富现有固相颗粒监测方法和技术, 本文通过分析气-砂两相流流动撞击管壁激励的振动信号特征, 开展气井出砂实时监测室内研究．本文利用加速度传感器感受砂粒撞击管壁的一次信号, 随后通过信号调理、采集并转化为所需出砂信息．通过设计室内实验, 对不同流速下的气流信号、不同携砂流速下的气-砂两相流信号、不同出砂率下的气-砂两相流信号进行时-频特征分析, 结果表明14.0～18.0 kHz频段内气流信号幅值波动稳定且幅值较小, 该频段为气井出砂监测的特征频段．进一步增加砂流量率, 发现特征频段内的振动能量随含砂率的增加而增加, 进一步验证了该出砂特征频段的有效性, 并建立了气体流速与振动能量关系数学模型．本研究方法为后续较复杂的水-砂两相流、气-砂多相流流体中的固相检测研究奠定了良好的基础．
Real-time detection of solid-phase information in gas-solid two-phase flow is widely used in industry，especially in sand production monitoring problems faced in natural gas exploitation. In order to enrich existing solid-phase particle monitoring methods and technologies，sand production of gas well in laboratory has been studied by analyzing the vibration signal characteristics of the gas-sand two-phase flow when the sand impinges on the pipe wall. The accelerometer was used to acquire the sand signals which then were converted to the sand production information by signal acquisition and conditioning. In this test，the time-frequency characteristics of vibration signals were analyzed under the condition of different velocities of gas flow，different sand-carrying velocities of gas-sand two-phase flow and different sand rates of gas-sand two-phase flow. The results show that the amplitudes of gas flow signals are steady within 14.0―18.0 kHz，which is the characteristic frequency band of sand production monitoring for gas well. With the increase of sand flow rate，the vibration energy also increases within the sand characteristic frequency band. Furthermore，the results verify the validity of the sand characteristic frequency band，and the relationship between the gas flow velocity and vibration energy is established. This research method lays a good foundation for the follow-up research on solid phase detection in the more complex water-sand two-phase flow and gas-sand multiphase flow