Hard formation insert and process for making the same

Abstract

A drilling insert includes a cylindrical body and a top portion of the drilling insert. The top portion is on top of the cylindrical body providing a contact area, wherein the contact area provides a flat area for distributing contact stress when the drilling insert impacts the formation.

1 . A drilling insert comprising:
 a cylindrical body; and   a top portion of the drilling insert on top of the cylindrical body providing a contact area, wherein the contact area provides a flat area for distributing contact stress when the drilling insert impacts the formation.   
     
     
         2 . The drilling insert of  claim 1 , wherein the top portion is a dome shaped member with a truncated tip, and the flat area provided by the truncated tip is pre-formed. 
     
     
         3 . The drilling insert of  claim 2 , wherein the truncated tip is created by electro discharge machining (EDM). 
     
     
         4 . The drilling insert of  claim 2 , wherein the truncated tip is created by pre-shaping the drilling insert before performing a high pressure high temperature manufacturing process. 
     
     
         5 . The drilling insert of  claim 1 , wherein a width of the flat area is a function of a penetration depth of the drilling insert. 
     
     
         6 . The drilling insert of  claim 1 , wherein a width of the flat area is two times a penetration depth of the drilling insert. 
     
     
         7 . The drilling insert of  claim 1 , wherein the drilling insert is utilized in a percussive drill bit. 
     
     
         8 . The drilling insert of  claim 1 , wherein the top portion includes a surface layer, and the surface layer is modified to form the flat area during use of the drilling insert. 
     
     
         9 . The drilling insert of  claim 8 , wherein the surface layer comprises a material that deform to form the flat area under contact stresses during drilling. 
     
     
         10 . The drilling insert of  claim 8 , wherein the surface layer comprises a material that wears away to form the flat area during drilling. 
     
     
         11 . A drilling insert comprising:
 a cylindrical body; and   a top portion of the drilling insert on the cylindrical body providing a contact area for impacting a formation, wherein the top portion is dome shaped with a truncated tip.   
     
     
         12 . The drilling insert of  claim 11 , wherein the truncated tip provides a flat area of contact for distributing contact stress, and the flat area is preformed. 
     
     
         13 . The drilling insert of  claim 12 , wherein a width of the flat area of contact is two times a penetration depth of the drilling insert. 
     
     
         14 . The drilling insert of  claim 12 , wherein a width of the flat area of contact is a function of a penetration depth of the drilling insert. 
     
     
         15 . The drilling insert of  claim 11 , wherein the truncated tip is created by electro discharge machining (EDM). 
     
     
         16 . The drilling insert of  claim 13 , wherein the truncated tip is created by pre-shaping the drilling insert before performing a high pressure high temperature manufacturing process. 
     
     
         17 . The drilling insert of  claim 11 , wherein the drilling insert is utilized in a percussive drill bit. 
     
     
         18 . The drilling insert of  claim 11 , wherein the top portion includes a surface layer, and the surface layer is modified to form the flat area during use of the drilling insert. 
     
     
         19 . The drilling insert of  claim 8 , wherein the surface layer comprises a material that deform to form the flat area under contact stresses during drilling. 
     
     
         20 . The drilling insert of  claim 8 , wherein the surface layer comprises a material that wears away to form the flat area during drilling.