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Case Study: Precise Bottomhole Pressure Maintained with Automated Mud Rollover

i-balance control system provided precise constant bottomhole pressure while displacing between drilling fluid systems before and after tripping

Challenge: Maintain constant bottomhole pressure while displacing between statically underbalanced and overbalanced drilling fluid systems used for drilling and tripping on narrow margin well.

Solution: Use i-balance control system to perform dynamic pore pressure fingerprinting to verify overbalanced mud weight and use automated mud rollover to follow displacement pressure schedule developed by @balance managed pressure and underbalanced drilling services with VIRTUAL HYDRAULICS ECD and ESD management software and monitored with PRESSPRO RT real-time downhole performance measurement software.

Result: Successfully completed 6 displacements between drilling fluids maintaining bottomhole pressure within a window of ± 0.11 ppg [±87 psi].

A customer in the North Sea was drilling an exploration HPHT well with a predicted narrow mudweight window (0.92 ppg/0.11 sg) with large uncertainties on the pore pressure prediction. The customer decided to drill the hole section with a statically underbalanced drilling fluid and use managed pressure drilling to keep the well overbalanced at all times. This approach required displacing the well between lighter underbalanced drilling fluids used for drilling and a heavier overbalanced drilling fluid to maintain well control while tripping.


Download: Precise Bottomhole Pressure Maintained with Automated Mud Rollover (0.28 MB PDF)

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