Patent Number: 8,820,398

Title: Down hole tool with adjustable fluid viscosity

Abstract: A down hole tool includes a tool body, a fluid cavity, a magnetorheological fluid disposed in the fluid cavity, and an electrical control unit in communication with the MR fluid. The electrical control unit is configured to adjust a viscosity of the MR fluid by varying a magnetic field.

Inventors: Lee; Arley G. (Katy, TX)

Assignee: Smith International, Inc.

International Classification: E21B 10/32 (20060101); E21B 31/113 (20060101)

Expiration Date: 9/02/12018