Over the last decades, drilling through fractured and unstable formations has proven to be challenging, specially in terms of wellbore instability. Stability of boreholes in these scenarios requires a careful consideration of in-situ stresses, rock strength, pore pressure, wellbore fluid pressure and drilling fluid characteristics. This issue is more critical and complex in fractured rocks, because of the need to consider more parameters than in other kinds of rocks. In fractured formations, fractures play an important role and rock wedges movement controls the instability. Also, fractures fillings are of paramount importance. In spite of this fact, there are only a few studies on stability of fractured rocks and their strengthening methods.

The present paper aims to provide insights into wellbore stabilization in fractured rocks. A broad literature review was conducted on existing formation strengthening methods and their effectiveness for fractured formations. The work concludes with some recommendations for these kinds of formations and proposed topics for additional research and development.