Information from a Downhole Dynamics Tool Provides Real-Time Answers for Optimization While Drilling 10,000 ft Laterals in the Middle Bakken Formation of the Williston Basin

Abstract

Economically exploiting the Bakken reservoir of the Williston Basin requires long horizontal wellbores through the drilling zones which continually change from sandstone to siltstone to shale with hard calcite cementation. Changes of formation within the drilling zone have caused numerous drilling challenges by creating dynamics issues, resulting in vibration problems and bit/bottom hole assembly deflections. These, in turn, result in high local doglegs that lead to a loss of drilling efficiency. Traditionally, a real-time downhole dynamics tool has been used occasionally within lower-cost drilling projects to accelerate learning about the downhole environment. This knowledge and real-time control of drilling parameters are essential. However, the value of these downhole tools may be underexploited, since they might not be considered economical for everyday use in the lower-cost drilling projects. Case history examples display the benefits due to the closer-to-the-bit steering control from bending moment and bending toolface data, and have made the use of this downhole dynamics tool a necessary choice. This paper will expand on the challenges encountered while drilling the long lateral sections in the Williston Basin, and show how the use of real-time downhole dynamics information helped optimize the drilling effort by saving time and increasing the percentage of successful one-run laterals. Furthermore, the paper expands on the practical use of the directional information from bending moment and bending toolface close to the bit thus allowing the directional driller to make better real-time decisions on whether a wellbore correction is really needed. The paper is supported with over 30 months of field examples and results.