Drilling-fluid thermal expansion, wellbore ballooning, and formation kick are similar in terms of surface observations such as pit volume gain. Each of these events, however, is solved in different ways. Treating wellbore ballooning the same way as a kick likely will result in losing the current borehole after days or weeks of unsuccessful operations. In this study, pressure-while-drilling technologies are combined with software simulations to differentiate drilling-fluid thermal expansion, wellbore ballooning, and formation influx during riserless drilling operations.
Wellbore Events
Thermal Expansion. Because mud density is dependent on temperature and fluid compressibility, volume gains or losses because of thermal effects may be substantial, especially in high-pressure/high-temperature and deepwater wells.
