The Key to Successfully Applying Today's Lost Circulation Solutions

Abstract

Abstract Though strengthening boreholes with particulate treated mud has achieved tremendous success in the past year, the theory behind the process still has not been widely accepted. Rock mechanics analysis and laboratory data review are performed in this paper to illustrate deepened understanding on some key points that are controversial. Algorithms have been developed and demonstrated for obtaining critical parameters in designing such jobs for improving hoop stress, by which a wellbore can be strengthened while drilling. Discussion of mechanisms and case histories has led to the development of systems that are designed to improve wellbore-pressure containment (WPC) by improving least principal stress. These systems are designed to function independent of formation permeability, unlike high fluid-loss and high solid-content squeeze pills. This method is normally applied when long fractures exist and when lost circulation has occurred. Since the first approach is proactive and the latter remedial or corrective, combining the two approaches can create synergy for borehole strengthening. A computer-aided design (CAD) process is also demonstrated for better use of available information in designing a deformable, viscous, and cohesive (DVC) system.