Downward energized motion jars

Abstract

An apparatus for dislodging stuck tools downhole, which includes a tool body; a mandrel moveable within the tool body; a spring member for allowing the mandrel to move with jarring force within the tool body when actuated; actuating fluid allowing the mandrel to travel a portion of the distance in a controlled manner, and at a predetermined point, accelerate its travel to provide a jarring force against the tool body; wherein the actuating fluid includes a first and second volumes of fluid through which a portion of the mandrel travels; the first volume providing controlled travel, and the second volume allowing accelerated travel of the mandrel.

1 . An apparatus for dislodging stuck tools downhole, comprising: 
 a. a tool body;    b. a mandrel moveable within the tool body;    c. spring means defining a compressible force as the mandrel is moved to a first cocked position;    d. means for moving the mandrel downward relative to the tool body within a controlled time frame allowing an operator time to slack off placing compression in drill string, so that at a point in its travel, the mandrel is able to accelerate its travel, and assisted by the spring means, to provide a jarring force against the tool body.    
     
     
         2 . The apparatus in    claim 1   , wherein the means for moving the mandrel downward relative to the tool body comprises first and second volumes of fluid through which a portion of the mandrel travels; the first volume providing controlled travel, and the second volume allowing accelerated travel of the mandrel.  
     
     
         3 . The apparatus in    claim 1   , wherein the mandrel further comprises a hammer portion which makes jarring contact with the upper end of the tool body.  
     
     
         4 . The apparatus in    claim 1   , further comprising a one-way valve for allowing rapid pulling of the mandrel upward in order to cock the tool into the jarring mode.  
     
     
         5 . The apparatus in    claim 2   , wherein the first volume defines a reduced travel space for controlling the speed of travel of the mandrel.  
     
     
         6 . The apparatus in    claim 2   , wherein the second volume defines an enlarge travel space for allowing rapid movement of the mandrel to provide a jarring contact.  
     
     
         7 . The apparatus in    claim 1   , wherein the spring means further comprises a coiled spring or a compressible gas or fluid medium within the apparatus.  
     
     
         8 . An apparatus for dislodging stuck tools downhole, comprising: 
 a. a tool body;    b. a mandrel moveable upward within the tool body;    c. spring means compressible as the mandrel moves upward relative to the tool body;    d. means for moving the mandrel downward relative to the tool body within a controlled time frame allowing an operator time to slack off placing compression in the drill string;    e. the spring means providing a means to accelerate the downward travel of the mandrel at a predetermined point in its downward travel to effect a downward jar to dislodge the stuck object.    
     
     
         9 . The apparatus in    claim 8   , further comprising first and second volumes of fluid through which a portion of the mandrel travels; the first volume providing controlled travel, and the second volume allowing accelerated travel of the mandrel.  
     
     
         10 . A method of dislodging stuck tools downhole, comprising the following steps: 
 a. providing a self-contained body section, having a mandrel moveable relative to the body section, the lower end of the body engaged to drill string below and an upper end of the mandrel portion attached to the drill string above the body portion;    b. pulling upward on the mandrel portion to a first cocked position;    c. providing a spring means defining a compressible force within the body section as the mandrel is pulled upward;    d. releasing the mandrel to travel in a controlled downward movement so that an operator is allowed to slack off putting compression in the drill string; then    e. accelerating the downward travel of the mandrel by the compressed spring means so that a hammer portion of the mandrel imparts a striking force to the upper end of the body section.