Published: 10/01/2019
Published: 10/01/2019
BP wanted the highest possible ROP while drilling 12 1/4-in vertical intervals from shoe-to-shoe in single runs. The series of wells are in Oklahoma, through a formation that includes soft shale interbedded with sandstone and limestone.
Previous bit runs used 12 1/4-in matrix PDC bits to successfully drill the interval in a single run, but it was thought that there could be an opportunity to further improve ROP by modifying the bit design.
Steel-bodied bits enable bit-body geometries more favorable to better evacuate cuttings from the bit face. But conventional steel-bodied bits are prone to erosion, so bit balling occurs by positioning the nozzles to direct the hydraulic energy away from the cutting structure. Smith Bits, a Schlumberger company, solved this with the introduction of Aegis armor cladding. The advanced strips of shielding protect blade faces on steel-bodied bits, enabling Smith Bits to design steel bits with taller blades and an increased junk-slot area.
Two new-built steel-bodied bits with Aegis cladding were run in 8 different wells, for a total of 8 bit runs. BP was able to drill the respective intervals from shoe-to-shoe in a single run. ROP with bits shielded by Aegis armor cladding increased by an average of 36%, compared with direct offset runs of matrix PDC bits. This enabled BP to save an estimated 179 hours of drilling time across the 8 runs.
By replacing a matrix bit with a modified steel-bodied bit shielded with Aegis armor cladding, BP made significant gains in drilling performance. The 12 1/4-in vertical interval in each of 8 wells was drilled shoe-to-shoe in a single run. ROP increased by an average of 36% compared with direct offset runs of matrix PDC bits, saving an estimated 179 hours of drilling time across the 8 runs.
