MECHANICALLY LOCKING HYDRAULIC JAR AND METHOD

A mechanically locking hydraulic jar device includes an outer sleeve, an inner sleeve partially disposed in an inner bore of the outer sleeve, and a mechanical lock engaging the outer sleeve and the inner sleeve in a default position to axially secure the inner sleeve to the outer sleeve. Activation of the hydraulic jar disables the mechanical lock to allow axial movement of the inner sleeve relative to the outer sleeve, which generates an impact force when the inner sleeve reaches an activated position. The hydraulic jar device also includes an upward block and a downward block configured to limit the upward and downward axial movement, respectively, of the inner sleeve relative to the outer sleeve when the mechanical lock is disabled.