Drilling with Casing Technology Eliminates Wiper Trips, Lost Circulation, Water Influx, and Wellbore Stability in Two Continuous Sections, Saving up to Five Days in Northern Bolivia

Abstract

This paper discusses the planning process, execution, and results of casing-while-drilling (CwD) operations in northern Bolivian fields that are historically plagued with problems of water influx, wellbore instability, lost-circulation, and severe bit wear. This paper will discuss why the selection of drillable casing bits is critical to ensuring successful drillout of the same type of polycrystalline diamond composite (PDC) casing bit. Formation drillability and suitability of well designs in targeted problematic fields, namely Yapacaní, Cobra, and Sirari, are also analyzed to ascertain whether CwD is a viable solution to tackle drilling challenges. A collection of conventional drilling data for six oil wells was provided for the analyses. At the end of the project, CwC technology successfully reduced operational time by 70% on average by improving drilling efficiency and mitigating drilling hazards.