Milling the casing to expose the rock face is the first step before setting a rock-to-rock cement plug. This plug creates a permanent hydraulic seal that conforms to natural formation bedding and irregular surfaces, mitigates gas migration, and can be confirmed with a pressure test.
The blades are what makes this cutting and milling tool special: cut-out blades create a window in the casing, then the milling blades mill the casing to expose more of the rock face.
P&A operations are meant to permanently seal and isolate the wellbore. The Endura DSSM exposes the rock face so you can set a rock-to-rock cement plug and create that permanent barrier.
After milling is complete, the operator performs a clean-out run, then sets and inflates a packer across the milled interval. Next, the operator runs cementing tools to place cement on top of the packer. The resulting hydraulic seal conforms to natural bedding, mitigates gas migration, and eliminates channeling. Seal integrity can be confirmed with a pressure test.
In an offshore gas well, top-up cement between the 9 5/8- and 13 3/8-in. casing strings prevented the operator from cutting and pulling 9 5/8-in. casing. The Weatherford team used a conventional section mill to mill a window of the 9 5/8-in. casing in one trip. Then the team passed the Endura section mill through the 9 5/8-in. casing, milled a window in the 13 3/8-in. casing, and exposed a 98-ft (30-m) section of open hole for cementing. The operation took 147 hours, saving 118 hours—or 4.9 days—compared to the conventional P&A approach.
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Our Endura dual-string section mill creates a rock-to-rock hydraulic barrier—for the tightest seal in the industry. To learn how Weatherford P&A services and technologies can save time and reduce risk, please leave your contact information and one of our P&A experts will be in touch.