Patent attributes
Embodiments of the disclosure provide an unfoldable device for controlling lost circulation in a target lost circulation zone in a borehole. The unfoldable device includes a sheet, a backbone, and a shell. The sheet has an unfolded state and a folded state. The backbone reinforces the sheet. The backbone includes a shape-memory material having an original state and a deformed state. The shell encapsulates the sheet in the folded state and the backbone in the deformed state. In some embodiments, the shell includes a degradable polymer that degrades in the borehole upon contact with a drilling fluid such that the sheet transitions to the unfolded state and the backbone transitions to the original state. The sheet in the unfolded state accumulates on a borehole wall at least partially covering an entrance to a macrochannel of the target lost circulation zone.