Objectives
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To explore its production potential, reenter a well using managed pressure drilling (MPD) techniques. Previously, the well had been deemed undrillable using conventional drilling practices, and it had been plugged and abandoned.
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Mitigate well-control incidents and nonproductive time (NPT) while drilling through a total-loss zone to total depth (TD).
Our Approach
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Weatherford deployed the Microflux® control system (MFCS) to manage annular pressure and to provide early kick and loss detection. The MFCS incorporated the SeaShield® Model 7875 below-tension-ring, slim (BTR-S) rotating control device (RCD) to divert annular returns and to enable easy conversion between MPD and conventional drilling techniques. An MPD riser joint provided additional risk mitigation.
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Using the MFCS and BTR-S RCD, the team drilled the well to the depth at which the MFCS detected the total-loss zone.
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From the total-loss zone to TD, the team switched to floating mud cap drilling (FMCD), a technique that involved continuously injecting seawater—which serves as sacrificial drilling fluid—into the drillstring. This helped to lubricate the bit, dispose of drilled cuttings into loss zones, prevent reservoir fluid from migrating up the annulus, and maintain the highest possible riser-fluid levels despite losses. Using the FMCD technique with MPD equipment enabled drilling through the highly depleted formation to TD safely and efficiently.
•After just 4 days of drilling, the team reached a network of reservoirs with good-grade oil.
Value to Client
•Weatherford transformed an abandoned well into a potentially productive and valuable asset. Drilling safely and efficiently through a total-loss zone to access the reservoirs would have been extremely challenging without MPD equipment.
•The operation incurred zero NPT related to well-control incidents.
•Future wells in the field can be drilled using similar methods.