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井下与地面之间的双向通讯通道是构成地面与井下闭环控制不可缺少的一环．从井下向地面的通讯通道已由ＭＷＤ完成，而从地面向井下的通讯通道，目前还没有成熟的产品．在分析现有的下行通道及钻井实况的基础上，确定利用钻杆振动作为信息载体．信源编码确定为：若钻杆静止６０ｓ，视信源信号为“０”，若钻杆钻进６０ｓ，视信源信号为“１”．对信源进行组合，信息的编码由两部分组成，同步码元＋信息码元．针对编码系统，解码系统安装在钻头以上约２ｍ处，钻井时与钻杆一起旋转，它包括振动传感器，解码电路与解码软件．振动传感器将钻杆振动与静止的不同状况反映到解码电路的输入端，解码电路具有一定的学习能力，配合解码软件可完成解码功能．另外，对解码电路的参数选择及解码软件设计流程给予充分说明．并介绍了系统的模拟实验装置及试验结果
Downhole and ground between the two-way communication channel is composed of ground and underground closed-loop control an indispensable part. The communication channel from the downhole to the ground has been completed by the MWD, while the communication channel from the ground to the downhole, there is no mature product. Based on the analysis of the existing down-channel and drilling conditions, the use of drill pipe vibration as the information carrier was determined. The source code is determined as follows: If the drill pipe is stationary 60s, depending on the signal source signal is “0”, if the drill pipe drilling 60s, depending on the source signal is “1”. The combination of sources, the information encoded by the two parts, the synchronization symbol + information symbols. For coding systems, the decoding system is mounted approximately 2 m above the drill bit and rotates with the drill pipe while drilling, which includes the vibration sensor, decoding circuit and decoding software. The vibration sensor reflects the vibration and static state of the drill pipe to the input end of the decoding circuit. The decoding circuit has certain learning ability and can cooperate with the decoding software to complete the decoding function. In addition, the decoding circuit parameter selection and decoding software design process to give full explanation. And introduced the system simulation experimental device and test results