The thesis generally describes the principals of Well Control, Kick Causes, the connected Drilling Mode Kick Frequency and Kick Morphology. The different kick detection approaches (Classic Kick Detection [CKD], Early Kick Detection [EKD]) are described in detail based on kick indicators, utilized detection techniques and measurement technologies. Based on the acquired knowledge, Real-Time Kick Detection approach is proposed through a general overview of the working principles and interpretation of the involved parameters and circumstances. A description on the physics of ultrasound (wave characteristics, propagation, attenuation, effects of pressure and temperature), ultrasonic sensing (sensing principals, transducers, operation modes) and description about the specific device (Ultrasonic Test Package [UTP]), which has been partly utilized and modified to conduct kick detection experiments, is also provided. This includes its components (Ultrasonic Sensor Package and Artificial Wellbore) and characteristics (hardware and software, data acquisition and interpretation). Ultrasonic Sensor Package (USP) is assessed for Real-Time Kick Detection purpose through experiments. Assessment is carried out by experiments with water and drilling mud (at ambient conditions) both, with and without gas injection. Results and evaluation is categorized by experiment goals: smallest distance between transducers, effect of liquid movement on captured data and effect of gas injection on data pattern. Evaluation of results show that kick detection is possible by the current setup as deviations from established data patterns can be categorized into flow movement and gas influx caused deviations.