A real time monitoring method for well-kick and lost circulation based on distributed fiber optic temperature measurement

Abstract

In the process of oil drilling, if the formation pressure does not match the pressure in the borehole, it may cause well-kick or lost circulation. The existing methods of mud level monitoring and micro-flow monitoring have some shortcomings. In these methods, information feedback is untimely and inaccurate. Well-kick or lost circulation position cannot be located in time. In order to monitor the well-kick and lost circulation situation more accurately and find the location of well-kick or lost circulation in time, the borehole temperature distribution models under well-kick and lost circulation conditions were established and solved. The distribution law of wellbore temperature when well-kick and lost circulation occur during drilling was analyzed. Based on the above research results, this work proposes a method for real-time monitoring of well-kick and lost circulation based on distributed optical fiber temperature measurement. This method compares and analyzes the real-time measured temperature with the theoretically calculated temperature, promptly determines whether well-kick or lost circulation has occurred, identifies the location of well-kick or lost circulation, and issues an alarm. This method effectively solves the problems of low monitoring accuracy and information delay, shortens the time required to search for the locations of well-kick or lost circulation, and has broad application prospects.