11-3/4 SET® OpenHole Liners Provide Simple, Effective Hole Isolation for an Offshore, Platform Based, Batch Drilling Campaign in the Middle East
The operator required a simple and effective system to isolate an unstable shale section while drilling the 12-1/4” section below the 13-3/8” casing shoe. The optimized well path increased the inclination through the unstable shale section increasing the length and exposure time that the shale is open. Increasing the mud weight effectively supports the shale but now requires a casing point below as the formation cannot be drilled effectively with the higher mud weight.
A solution was required which would allow the shale to be isolated in a timely manner and provide the pass through required to run 9-5/8” casing with a coupled connection. The solution also could not add any wellhead requirements as the slot size of the platform was already fixed.
The planned well architecture required the 11-3/4” SET liner to be run in a 12-1/4” x 14-1/2” open hole section. A total of 4 sections were batched drilled and the 11-3/4” SET liners were run, cemented and expanded in each wellbore to isolate the unstable shale.
The 11-3/4” 47lb/ft SET OpenHole liner allows the shale section to be isolated in one run as the liner is installed, cemented and expanded in one continuous operation with a top seal anchoring the liner to the 13-3/8” casing. As the SET system is run as a liner, no additional BOP or well head equipment is required. The post expanded ID allows a standard 9-5/8” coupling to pass through allowing the operator to run existing 9-5/8” casing to the planned casing point without issues.
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