Systems and methods for monitoring annular fluid level

A method comprising:

• determine a time value that measures a time between a transmittal, by an antenna disposed above a floating element within an annulus of a well, of a first signal and a receipt, by the antenna, of a second signal from the floating element disposed on a surface of a drilling fluid within the annulus;
• determining a state of a drilling fluid level within the annulus via:
• accessing a return time threshold value from a database record;
• determining that the time value exceeds the return time threshold value;
• and
• determine that the drilling fluid level is below a drilling fluid threshold value, based on the determining that the time value exceeds the return time threshold value, and
• updating a drilling program for the well based on the state of the drilling fluid level.

A system comprising:

• a floating element disposed on a surface of a drilling fluid within an annulus of a well, during mud cap drilling operations;
• an antenna disposed above the floating element and attached to a rotary table of the well via an extension element that extends downward into the annulus of the well, the antenna being configured to:
• transmit a first signal to the floating element, and
• receive a second signal from the floating element in response to the first signal;
• and
• 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,
• determine a state of a drilling fluid level within the annulus based on the time value, update a drilling program for the well based on the state of the drilling fluid level.