A novel wellbore strengthening method by using rotary jet while drilling

Lost circulation is one of the most common and costly problems in drilling operations. Improving the wellbore strengthening by plugging drilling induced fractures using rotary jet method is a novel and effective method to mitigate lost circulation. A stress analysis model based on elastic-plastic mechanics was established to reveal the wellbore strengthening mechanism of rotary jet plugging while drilling. The structure of rotary jet tool was proposed and mixture multiphase flow model was adopted to optimize the structure of the modulation unit of rotary jet. The field tests of engineering prototype were carried out in 8½″ interval of three wells. Satisfactory plugging results verify the effectiveness of rotary jet plugging and wellbore strengthening technology. •Wellbore strengthening mechanism of rotary jet was revealed based on an established stress model.•Applicable conditions of rotary jet plugging technology were proposed.•Engineering prototype of rotary jet tool is developed and tested in three wells.