In a learning process of using turbodrilling and hybrid bits in Field A, a technical feasibility study was performed by the operator and service companies involved to analyze the viability of executing this new well whilst creating new products to optimize drilling performance in the complex Cretaceous formations. The study had two basic objectives: increasing the rate of penetration (ROP) and reducing the numbers of runs to complete the section.
The Well-3 was planned to drill through three high-compressive-strength, high-temperature Cretaceous formations composed of 30% chert using a 6⅝-in steerable turbodrill. To meet the drilling goals, a newly designed diamond-impregnated bit was used to achieve directional efficiency and to reduce shock and vibrations typically seen in this interval.
The turbodrilling system completed the interval in a single run, achieving both directional and durability objectives by drilling 287 m in 94 hours at an average ROP of 3.05 m/h, overcoming the drilling challenges and high chert content.
This paper will describe the methodology and engineering approach highlighting the most-critical parts of the design, execution, and evaluation phases that were key factors in achieving the objectives and minimizing all the associated risks.