US Patent 9933293 Speed-of-sound independent fluid level measurement apparatus and method of use

A system and method for determining the depth to the top surface of a fluid contained in a hydrocarbon well generates a pressure pulse which travels down the casing to the fluid and receives a returning pressure pulse. The system and method may measure the decay rate or pulse width of the returning pressure pulse and not necessarily require the measurement of the time between the emission of the pressure pulse and the detection of the return pulse to ascertain the depth to the fluid.