This paper presents the results and lessons learned to improve the performance while drilling the 36-in tophole sections in the Culzean field field HPHT development. Seven 36-in sections were drilled in a batch sequence with less than four days between wells. This presented a challenge in quickly identifying operational and equipment changes necessary to improve performance in each subsequent well. The first well was drilled with no operational issues; however, the rate of penetration (ROP) was lower than had been expected for this area. Borehole inclination increased in the following two wells and required significant reaming to reduce the inclination observed. Damage was also observed to the 26-in × 36-in Hole Opener, suspected to be due to the additional reaming work. As the reaming impacted operational efficiency and equipment, a re-design of the bottomhole assembly (BHA) was initiated. To maintain verticality without the need to backream a 17.5-in Rotary Steerable System (RSS) was added between the 17.5-in Bit and the 26-in × 36-in staged Hole Opener on the fourth well. The RSS system was then used in this configuration for the remaining three wells, resulting in a 24% improvement in drilling performance over the baseline well.