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Case Study : “It Can’t be Drilled”

Case Study : “It Can’t be Drilled”
Merlin ERD

Case Study : “It Can’t be Drilled”

Client:  Mid-sized independent operator

Project: In an accelerated time-frame, Merlin were asked to support this client and work with them to plan and drill an “edge of the envelope” ERD well from a jack-up rig over a fixed installation in shallow water. The well is designed to produce a small outlying reservoir discovered with an exploration well only months before, and is beyond the step-out of any wells drilled in the field. Initial analysis suggests “It can’t be drilled” due to economic limitations and mechanical loads.

Merlin ERD TVD Vs Stepout

Challenges: Hole cleaning in 6000m section of 12-1/4” interval at 84°, ROP and hole condition management to make well economic (maximise ROP and avoid hole related NPT), 9-5/8” casing run (flotation), small target size (beyond standard survey tool accuracy).

Merlin ERD Solution: Fit-for-purpose engineering design and focused monitoring of operations.

(1)Engineering: Use of extensive offset data to develop a robust well design with loads (T&D, Hydraulics) within rig and down-hole limitations.  Target design and survey program developed to allow small target to be intersected, 9-5/8” casing flotation plan with adequate contingencies.

(2)Operations Monitoring: Apply fit-for-purpose practices to manage hole cleaning while maximising ROP, real-time monitoring of drilling and casing running operations to optimise performance.



Merlin ERD added value supporting the client to:Drill the “un-drillable”

  • Well drilled and completed in 29 days with cost below AFE
  • 580,000 bbls of reserves added.
  • 6000m of 12-1/4” hole drilled at high ROP’s with no hole problems and 9-5/8” floated casing run to bottom.
  • No lost BHAs or hole instability.
  • Record well for the client.