Patent ID: 11933136
Assignee: SAUDI ARABIAN OIL COMPANY
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 0:
1. A method for mitigating lost circulation while drilling a well, the method comprising:
opening a port of a circulating sub, including:
dropping a ball into a drill pipe containing a downhole fluid, in which the port is defined in a wall of the drill pipe; and

seating the ball on an actuator slidably disposed concentrically within the drill pipe, in which seating the ball on the actuator causes motion of the actuator relative to the drill pipe to open the port; establishing circulation by pumping a lost circulation material slurry through the drill pipe, out of the port, and into an annulus of a wellbore exterior to the drill pipe, bypassing a bottom hole assembly comprising a drill bit;
in response to establishing circulation, closing the port of the circulating sub, including:
introducing a solvent different from the downhole fluid and the lost circulation material slurry into the drill pipe, in which a solubility of the ball in the solvent is greater than a solubility of the ball in the downhole fluid and the lost circulation material slurry; and
degrading the ball in the solvent, in which the degrading of the ball deactivates the circulating sub causing the port to close.