Bore tractor system

摘要: A tractor system for moving an item through a wellbore has been invented with central mandrel interconnected the item, first setting means about selectively and releasably anchoring in wellbore, having top, bottom, power thread therein, follower pin engaging to set against inner wall of bore. In one aspect, is bore at speed least 10 feet per minute. second on bore, spaced apart from means, therein retract communication thread,