振动波井下通讯技术

Vibration wave downhole communication technique

为了克服传统井下通讯方法的不足,提出一种振动波井下通讯技术,开发了振动波井下通讯系统,进行了现场试验,并将该技术应用于分层注水。理论和实验研究表明,油套管振动波传输呈通阻带交替分布,据此制定了多基频传输策略,采用开关键控调制和曼彻斯特编码方式对振动信号进行处理,将控制信息加载到振动波。研发了振动信号发生系统,实现电能到振动波能量的可控转换。研发了振动波接收解码系统,以微振加速度传感器作为信号拾取元件。设计了振动波井下远程传输测试系统,并进行了井下通讯现场试验,验证了振动波井下通讯技术的可行性以及通讯系统的准确性和可靠性,得到了套管振动波信号的衰减特性。该技术已成功应用于分层注水,在井筒控制领域有广阔的应用前景。

To overcome the disadvantages of traditional downhole communication methods, a vibration wave downhole communication technique is proposed, and a vibration wave downhole communication system is developed. This technique has been verified by field test and is applied to separated layer water injection. It is shown by theoretical and test research that transmission of the vibration wave through tubing and casing appears as the alternate distribution of pass-band and stop-band. According to that, a multi-baseband transmission strategy is formulated. The on-off keying modulation and Manchester encoding scheme are used to load the control information into the vibration wave. A generation system of vibration signals is developed to realize the controllable conversion from electric energy into vibration wave energy. A receiving and decoding system of vibration waves, which uses a micro-vibration acceleration sensor as the signal pickup element, is developed too. A test system for vibration wave downhole remote transmission is designed and applied to field test. The feasibility of the technique and the accuracy and reliability of communication system are verified and the attenuation characteristics of casing vibration wave signals are obtained. This technique has been applied to separated layer water injection successfully with wide application prospect in wellbore control field.