Decelerator device for ball activated downhole tools

Abstract

A decelerator device ( 210 ), or shock absorber, for slowing the speed of a moving ball ( 106 ) approaching a ball seat ( 104 ) anchored in a tool ( 102 ) in a pipe string ( 200 ) of a subterranean well ( 220 ). The decelerator device ( 210 ) has a ball passage ( 208 ), an entrance port ( 204 ) which directs the moving ball ( 106 ) from an open mouth ( 202 ) of the entrance port ( 204 ) to a drag-inducing throat ( 207 ) of the ball passage ( 208 ), and directs the moving ball ( 106 ) towards a ball seat ( 104 ). The body ( 214 ) of the decelerator device ( 210 ) is made of a deformable, solid-state yielding material that displaces away from a centerline ( 103 ) of the ball passage ( 208 ) as the moving ball ( 106 ) with a diameter ( 105 ) larger than the throat ( 207 ) passes through the decelerator device ( 210 ).

1 - 20 . (canceled) 
     
     
         21 . A decelerator device for slowing the speed of a moving sealing ball approaching a ball seat anchored in a pipe string of a subterranean well, the decelerator device comprising:
 a ball decelerating body having a ball passage therethrough;   the ball passage comprising a ball entrance port located at a top end of the body that directs a moving ball from an open mouth of the entrance port into a drag-inducing throat of the ball passage; and   at least a portion of the body comprising a deformable, solid-state yielding material that displaces away from a centerline of the ball passage as a ball larger than the throat of the ball passage passes therethrough.   
     
     
         22 . The decelerator device of  claim 21 , wherein the throat of the ball passage is cylindrical shaped. 
     
     
         23 . The decelerator device of  claim 21 , wherein the ball entrance port is frustoconical shaped. 
     
     
         24 . The decelerator device of  claim 21 , wherein the ball passage is funnel shaped. 
     
     
         25 . The decelerator device of  claim 21 , wherein the deformable, solid-state yielding material is plastically deformable under subterranean well conditions. 
     
     
         26 . The decelerator device of  claim 25 , wherein the body is annulus shaped about the throat of the ball passage. 
     
     
         27 . The decelerator device of  claim 26 , wherein the deformable, solid-state yielding material continuously extends across the annulus shaped portion of the body about the throat of the ball passage. 
     
     
         28 . The decelerator device of  claim 26 , wherein the deformable, solid-state yielding material contains voids therein, in the annulus shaped portion of the body about the throat of the ball passage. 
     
     
         29 . The decelerator device of  claim 25 , wherein the body further comprises a ball seat engagement portion configured for fixation to a ball seat anchored in a tool of a pipe string of a subterranean well. 
     
     
         30 . The decelerator device of  claim 21 , wherein the ball decelerating body has a height that is configured to reduce impact forces imparted on the ball. 
     
     
         31 . The decelerator device of  claim 30 , wherein the height is less than a predetermined height and the ball decelerating body reduces the shock on the ball. 
     
     
         32 . The decelerator device of  claim 30 , wherein the height is greater than a predetermined height and the ball decelerating body decelerates the ball prior to contacting the ball seat. 
     
     
         33 . The decelerator device of claim  1 , wherein the deformable, solid-state yielding material is elastically deformable under subterranean well conditions. 
     
     
         34 . The decelerator device of  claim 33 , wherein the body is annulus shaped about the throat of the ball passage. 
     
     
         35 . The decelerator device of  claim 34 , wherein the deformable, solid-state yielding material continuously extends across the annulus shaped portion of the body about the throat of the ball passage. 
     
     
         36 . The decelerator device of  claim 34 , wherein the deformable, solid-state yielding material contains voids therein, in the annulus shaped portion of the body about the throat of the ball passage. 
     
     
         37 . The decelerator device of  claim 33 , wherein the body further comprises a ball seat engagement portion configured for fixation to a ball seat anchored in a tool of a pipe string of a subterranean well. 
     
     
         38 . A ball-actuated downhole tool configured to interconnect into a pipe string of a subterranean well, the ball-actuated downhole tool comprising:
 a tool housing within which a ball seat is located, the ball seat having a ball engaging, sealing surface forming an entrance to a fluid flow channel through the ball seat;   the fluid flow channel through the ball seat being cylindrical shaped and having a flow channel diameter;   a decelerator device located adjacent the ball seat for slowing the speed of a moving sealing ball approaching the ball seat, the decelerator device comprising:
 a ball decelerating body having a ball passage therethrough; 
   the ball passage comprising a ball entrance port located at a top end of the body that directs the moving ball from an open mouth of the entrance port into a drag-inducing throat of the ball passage, the throat being cylindrical shaped and having a diameter substantially equal to the diameter of the cylindrical flow channel through the ball seat; and
 at least a portion of the body forming an annulus about the throat of the ball passage and comprising a deformable, solid-state yielding material that displaces away from a centerline of the ball passage as a sealing ball having a greater diameter than the throat of the ball passage passes through the annulus. 
   
     
     
         39 . The ball-actuated downhole tool of  claim 38 , wherein the ball entrance port is frustoconical shaped. 
     
     
         40 . The ball-actuated downhole tool of  claim 38 , wherein the ball passage is funnel shaped.