Marine riser unit system, well drilling system and method for well drilling system

A marine riser unit system comprises a marine riser unit part provided with a channel and including a first ultrasonic module for sending a first ultrasonic signal to obtain first ultrasonic data anda second ultrasonic module for sending a second ultrasonic signal to obtain second ultrasonic data, and a processing module for receiving the first ultrasonic data and the second ultrasonic data and obtaining first information and second information, wherein the wave beam direction of the first ultrasonic signal is perpendicular to the axis of a channel, the wave beam direction of the second ultrasonic signal inclines with respect to the axis of the channel. The invention also provides a well drilling system and a method for the well drilling system. 种隔水管单元系统，其包括：隔水管单元部件，其具有通道，并包含用于发送第超声信号来获得第超声数据的第超声模块以及用于发送第二超声信号来获得第二超声数据的第二超声模块，其中，所述第超声信号的波束方向垂直于所述通道的轴线，所述第二超声信号的波束方向倾斜于所述通道的所述轴线；及处理模块，用于接收所述第超声数据和所述第二超声数据，并获得第信息和第二信息。还描述了种钻井系统和用于钻井系统的方法。