油田管道不定衰减水声信号的仿真分析

Simulation and Analysis on Uncertain Attenuation Property of Underwater Acoustic Signal for Oil Field Pipe

研究管道水声信号的识别问题,油田管道声信道存在着不定衰减性特征,这种衰减随着管道长度、环境的不同而存在差异,传统的信号识别方法多是根据稳定的信号特征建立模型,很难对这种存在不定衰减特征的信号进行建模,进而造成识别的困难。提出了一种基于声学射线理论的油田注水井管道的声信道模型建立方法。结合声学射线理论知识和油田的现场实验数据,研究注水管道中的声传播特性,分析注水井的水声信道特征,分析由注水井油管的固体声传播媒介和井内流体———水的流体声传播媒介构成的声信道的物理环境,计算声波在这种信道环境下的传播规律,保证识别的准确。实验和仿真结果验证了水声信号经过井口后,几乎衰减至零,利用水声发射换能器发射信号,在实验井和工作井内水声信号能在井口附近能收到信号,其中距离增加井下50m后,仅有耦合信号。识别效果较好。

The recognition of acoustic signal in oil pipe was researched, and there was uncertain attenuation prop- erty in acoustic communication channel for oil field pipe, and the property was different with the difference of length of pipeline and environment. Traditionally, the recognition model is established based on the stable signal feature. And it is difficult to establish the model with the uncertain attenuation property which resulted in difficult to recogni- tion. In the paper, an acoustic communication channel model establishment method was proposed based on the ray theory. According to the acoustic ray theory and the real collected data from the oil fields, the acoustic communication property of the pipes was researched, the underwater communication channel characteristics of the injection well were analyzed, and the physical environment of the acoustic communication channel was analyzed. The propagation regular of acoustic in this condition was computed for the precise recognition. Simulation result shows that the underwater a- coustic signal can reduce to zero on the mouth of the well, the underwater acoustic signal can be received on the well mouth and there is coupling signal 50m to the well. The research result shows good performance in signal recognition.