Method for jarring with a downhole pulling tool

The present invention generally relates to an apparatus and method of jarring with an overpull generator. In one aspect, a method of dislodging an object stuck in a wellbore is provided. The method includes the step of running an assembly into the wellbore on a conveyance member and attaching the assembly to the object, wherein the assembly comprises an overpull generator and a delay force release device. The method also includes the step of generating an overpull force in the wellbore by selectively activating the overpull generator. Additionally, the method includes the step of applying an impact force to the object by activating the delay force release device and releasing the generated overpull force, thereby dislodging the object stuck in the wellbore. In a further aspect, an assembly for dislodging an object stuck in a wellbore is provided. In yet a further aspect, an overpull generator for use in generating an overpull force in a wellbore is provided. 2$ /7< >7 o >7 2$ >7/> K 2$ >7 2$ >7 >7 2$7 ~K Cl oK/S 0 /7< / 7 4(1