【摘要】 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更多还原

【Abstract】 The bi directional communication channel between down hole and surface is essential to down hole closed control system (DCLS). Measuring while Drilling (MWD) is a good channel from down hole to surface. and it has become an universal product in the world. But until now, there has not been a mature channel from surface to down hole. To meet the demand, a channel is put forward. In it, the vibration of drilling string is as an information carrier. The information is coded as “0” that drilling string has been resting for 60s, and “1” that the drilling string has been vibrating for 60s. The code of information source consists of synchronism codes and message codes. Decoding system is mounted on the drilling string about 2m from bit. It consists of vibration sensor, decoding circuit and decoding software. The sensor distinguishes the rotation from the rest of the string, and then feeds the signal into the decoding circuit. The circuit has learning ability to some extent, and it finishes decoding with the decoding software. The selection of the circuit parameters and the flow chart of the decoding software are given in the paper. Finally, the equipment for simulation experiment is introduced. And the simulated results are given.更多还原