Circuit for monitoring well kick at deepwater drilling mud line

Abstract

The invention relates to a circuit for monitoring well kick at a deepwater drilling mud line. The circuit comprises an ultrasonic transceiving module connected with an ultrasonic sensor, and a measurement and control module which is connected with the transceiving module through an interface circuit and communicates with an upper host position, and is characterized in that: the ultrasonic transceiving module comprises a transceiving circuit, a passage switch and a power circuit; a microprocessor is arranged in the transceiving circuit, and generates an electric pulse driving signal with a certain frequency, a certain pulse width and a certain output power to excite the ultrasonic sensor; the measurement and control module comprises an amplifying circuit, a filtering circuit, an automatic gain control circuit, an analog-to-digital converter, a voltage conversion circuit and a digital signal processor which are connected with one another according to an input and output sequence; and the output end of the digital signal processor is connected with a digital-to-analog conversion circuit and a voltage regulation circuit sequentially. The circuit is arranged by the measurement of a Doppler effect, and can measure flows of a seabed marine riser and an annular drilling column in real time so as to immediately determine underground overflow situations.

Description

technical field [0001] The invention relates to the measurement of the instantaneous flow rate of the annular space between the riser and the drill pipe in deep water drilling, in particular to a circuit for monitoring well kick at the mud line of deep water drilling. Background technique [0002] During the drilling process, when the formation pore pressure is greater than the bottom hole pressure, the formation fluid will invade the well, and then overflow and kick will occur. If the well kick continues to develop, it will become a blowout. Early monitoring of well kick is a key to deepwater well control. If it is discovered later, it will bring serious safety problems. [0003] For offshore deepwater drilling, there is a long riser section, and a drill string is arranged inside the riser, and it is possible to judge whether a well kick occurs by monitoring the instantaneous flow rate in the annulus between the riser and the drill string, so as to make on-site decisions fo...

AI Technical Summary

Problems solved by technology

The measurement principle is to rely on the momentum of the drilling fluid at the outlet to change the position of the target body, and rely on the sensor to transmit the signal to measure the flow rate. The change response is relatively sensitive, and the measurement results can basically reflect the abnormal change of the drilling fluid outlet flow rate. Lag, not conducive to early detection of well kick

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