While wellbore strengthening techniques have been proven successful in strengthening weak permeable zones to achieve higher fracture gradients, the extent of their effectiveness is variable. This paper discusses an integrated approach where Managed Pressure Drilling (MPD) is incorporated and designed in conjunction with wellbore strengthening strategies to drill wells with formation strength below borehole stability requirements, thus allowing fail-safe outcomes from depleted drilling and completion operations, ultimately reducing the consequence of failure, and simplifying recovery efforts.

There are two main benefits of incorporating MPD. First, MPD enables a reduction in the required drilling margin, and this in turn prevents an over-reliance on the effectiveness of wellbore strengthening strategies. Second, MPD provides the ability to reduce downhole pressure, reducing the consequences of unexpected loss circulation events. Mud weight selection was carefully engineered with several factors taken into consideration, including shale inhibition, impact on completion operations, and consequence of MPD system failure.

Eight hole sections across four deep-water subsea wells were initially designed to be drilled with wellbore strengthening strategies alone, however, a loss circulation event led to challenging remediation and recovery efforts. Upon incorporating this MPD design, while seven other hole sections were drilled successfully without any loss circulation events, one hole section encountered loss circulation, and this design allowed an instant reduction in surface back pressure to stop the losses, effectively "failing safely". Four lower completion operations were also successfully executed with this design incorporated.

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