Applications of Underbalanced Fishbone Drilling for Improved Recovery and Reduced Carbon Footprint in Unconventional Plays

This paper provides a comprehensive review of Fishbone Drilling (FbD), a technique involving drilling multiple micro-holes in various directions from a primary vertical or deviated wellbore. FbD enhances hydrocarbon production in naturally fractured formations or in refracturing operations by connecting existing natural fractures. Further enhancement is possible when combined with underbalanced drilling using a coiled tubing rig, as it facilitates natural hydrocarbon flow from the reservoir to the wellbore.

The paper also discusses the design aspects of FbD, which include determining the number, length, distance, and sidetracking angle of the branches from the main borehole, as well as the development of efficient drill string components for FbD conditions. It explores the use of high-performance small diameter downhole motors and High Voltage Pulsed Discharge (HVPD) plasma shock waves for easier formation breakage. Additionally, the potential for integrating FbD with hydraulic fracturing to enhance production by creating a network of connected fractures is considered, comparing its technical and economic benefits and challenges.