有线传输式近钻头地质导向钻井系统应用

Application of Near-bit Geosteering Drilling System through Wire Transmission

在CGDS172NB近钻头地质导向钻井系统中,近钻头的地质参数和工程参数通过无线电磁短传方式传输至MWD系统。无线短传容易受井底复杂工况干扰,在有些地层介质的干扰下,信号衰减严重,导致信号传输失败。为了使MWD系统得到高质量的信号,采用有线传输的方式,通过在测传短节、下过渡接头、上过渡接头、螺杆马达、旁通阀总成之间建立有缆通道,研制出了有线传输式近钻头地质导向钻井系统。介绍了有线传输式测传马达的结构特征。实践证明,有线传输方式不仅节约成本,而且使信号传输更加稳定,抗干扰能力更强,可靠性更高。

Near-bit geological and engineering parameters are transmitted to MWD system through wireless electromagnetic short distance transmission in the CGDS172NB Near-bit Geosteering Drilling System. Wireless short distance transmission is easily interfered by downhole complicated conditions, signal is badly attenuated in some stratum and wireless transmission failed. In order to receive high quality signals for MWD system, wire transmission is used. The cable channel is established in the measuring sub, lower transition sub, upper transition sub,power section by and pass valve and near-bit Geosteering Drilling System through Wire Transmission is developed. This paper introduces the slructure of wire CAIMS （China Adjustable Instrumented Motor System）. It has been shown that wire transmission not only can cut down cost, but also have the advantages of more stable signal transmission, stronger anti-interference capability and higher reliability.