He said that's an easily reversible process once the weather passes: Purge the seawater out, pull the packer out and reinsert the drillstring to begin drilling again.
Drillers also use sensors to detect particularly promising rock intervals within the formation, and are able to move the drillstring up or down, left or right as they drill through the horizontal section to target those intervals.
Allen said that in preparation for the storm, crews had pulled the drillstring out, put a plug known as a "packer" in the casing pipe and filled the riser with seawater so the pipe would be stable.