Identification and control methods for ballooning effect types during drilling

Abstract:

The ballooning effect is a common and complex flow phenomenon during drilling， characterized by periodic loss and backflow of drilling fluid. It is often confused with well influx and poses a significant threat to well control safety. Based on a systematic review of relevant studies， this paper categorizes the formation ballooning effect into four types—borehole elastic deformation， drilling fluid expansion-contraction， fracture-induced breathing， and permeability-induced breathing—and analyzes their triggering mechanisms， identification characteristics， and applicable conditions. For identification， typical methods such as Pressure While Drilling （PWD）， resistivity logging， decision tree analysis， and event tree analysis are reviewed， and their adaptability to different mechanisms is assessed. In terms of control， strategies including managed pressure drilling， continuous circulation systems， and drilling fluid parameter optimization are summarized， and their effectiveness across different breathing types is discussed. This study aims to establish a systematic cognitive framework for understanding the ballooning effect， providing theoretical support and practical guidance for accurate identification and scientific response under complex downhole conditions.