Unrecognized 'fracture caging' could make shale drilling safer and more profitable

摘要

Drilling operations around the globe have been riskier than even the experts realized. A new analytical stress function study has revealed that underbalanced wellbores may unintentionally enlarge as a result of concentric tension fractures, which may occur when drilling into over-pressured rocks. Numerical models confirmed the circumferential tension fractures grow exactly as predicted by the new analytical theory.