Case Study: a large North Sea drilling service provider achieves precise bottomhole pressure control with SLB i-balance

Precise Bottomhole Pressure Maintained with Automated Mud Rollover

SLB worked with a large North Sea drilling service provider drilling an exploration HPHT well with a very narrow mud-weight window and significant pore pressure uncertainty. The customer needed to keep bottomhole pressure constant while switching between underbalanced and overbalanced drilling fluids during drilling and tripping on a narrow-margin well.

SLB used the i-balance control system, along with dynamic pore pressure fingerprinting, VIRTUAL HYDRAULICS ECD and ESD management software, and PRESSPRO RT real-time downhole performance measurement software to manage the mud rollover and maintain pressure. The operation successfully completed six displacements between drilling fluids while keeping bottomhole pressure within ±0.11 ppg, or ±87 psi, demonstrating precise pressure control throughout the transitions.