Modular testing facility for downhole sensor evaluation
Research output: Research › Master's Thesis
Real Time Kick Detection (RKD) technology is becoming more and more known to the oil and gas industry. Since 2009, 30 fatalities and more than 1500 injuries have occurred in well control incidents, declaring well control one of the most critical situations in the industry. Real Time Kick Detection can add value to the reduction of well control incidents, saving human lifes and cost reduction. The thesis generally describes the kick causes from geology and drilling perspective, Early Kick Detection (EKD) techniques and equipment, but also the principles of well control. Kick detection approaches are described based on kick indication and the necessary surface and downhole sensors equipment for the required measurements. Different well control procedures are described in detail for a successful shut in and killing operation of the well. The purpose of the thesis, is to conduct experiments to evaluate sensors for kick detection. Therefore an initial artificial well testing facility was designed and built in a way to recreate wellbore conditions (wellbore size, drill string, influx. etc.) but also to allow the installation of various type of sensors for Real Time Kick Detection and other experiments. Applying current technology and recent sensor development, an approach for Real Time Kick detection is presented based on evaluating capacitive sensors in the developed test stand. A detailed description of the working principle of capacitive sensors (capacitor, capacitance, dielectric constant and strength, etc.) as well as relevant limitations (noise and temperature) for their application is given. The results of this thesis are showing that the artificial well testing facility is capable of conducting gas and oil influx experiments as well as for testing different types of sensors for Real Time Kick Detection. Recommendations for further research is to test conductivity and analog capacitive sensors for detection of gas or oil kick, but also ultrasonic sensors to estimate downhole flow rates by cuttings velocity.