This paper will describe the improvement made to the reamer cutter blocks to enhance its durability and optimize the Pre-salt Well Construction
Currently, most of the Brazilian's Pre-Salt wells have the last phase built-in 12.25in. In some situations, it is necessary to drill oil wells in a giant offshore field wells with five phases, enlarging the third phase from 18.125in to 22in. The high abrasiveness encountered at this phase increased the number of runs needed to drill it and, consequently, time and costs that encouraged the development of solutions.
This work relates what has been observed during the last years about reaming difficulties, specifically, in the enlargement from 18.125in to 22in when facing abrasive formations. Petrobras specialists analyzed these events and concluded the matrix of the reamer's cutter blocks was wearing faster and losing the capacity to hold the PDC cutters. The hole enlargement company, that Petrobras works for nowadays, developed a process that increased the resistance of the cutter blocks by increasing the hardness of the surface material prior to the brazing of the cutters. Then, Petrobras has had the opportunity to use both modified and common cutter blocks in a challenging operation to compare their durability and the results were completely satisfactory. The modified cutter blocks had much less wearing on the same formations. Based on this operation, we can conclude this process is validated since improved the reamer cutter blocks quality and its lifetime.
This paper can serve as a guide to reduce operations costs and to optimize well construction when there are concrete possibilities to enlarge abrasive formations.