A system for monitoring an annular fluid level may include a floating element disposed on a surface of a drilling fluid within an annulus of the well, during mud cap drilling operations. The system may also include an antenna disposed above the floating element. The antenna may be configured to transmit a first signal to the floating element, and to receive a second signal from the floating element in response to the first signal. The system may also include a processor configured to determine a time value that measures a time between a transmittal, by the antenna, of the first signal and a receipt, by the antenna, of the second signal. The processor may also determine a state of a drilling fluid level within the annulus based on the time value, and update a drilling program for the well based on the state of the drilling fluid level.

A humidifier includes a pedestal, a water tank, a float, and a detection device. The water tank is detachably mounted on a top of the pedestal. The float is on the water tank and movable relative to the water tank. The detection device is on the pedestal and configured to detect a position of the float in a preset space of the humidifier. In the preset space, the position of the float indicates whether the water tank is separated from the pedestal and whether the water tank is short of water.

A system for monitoring an annular fluid level may include a floating element disposed on a surface of a drilling fluid within an annulus of the well, during mud cap drilling operations. The system may also include an antenna disposed above the floating element. The antenna may be configured to transmit a first signal to the floating element, and to receive a second signal from the floating element in response to the first signal. The system may also include a processor configured to determine a time value that measures a time between a transmittal, by the antenna, of the first signal and a receipt, by the antenna, of the second signal. The processor may also determine a state of a drilling fluid level within the annulus based on the time value, and update a drilling program for the well based on the state of the drilling fluid level.

A humidifier includes a pedestal, a water tank, a float, and a detection device. The water tank is detachably mounted on a top of the pedestal. The float is on the water tank and movable relative to the water tank. The detection device is on the pedestal and configured to detect a position of the float in a preset space of the humidifier. In the preset space, the position of the float indicates whether the water tank is separated from the pedestal and whether the water tank is short of water.