Vibrational tool with rotating engagement surfaces and method

A method to provide a vibration tool for use with a tubular string in a well bore through which drilling fluid is pumped, comprising:

• providing a housing attachable to said tubular string;
• mounting a reciprocating member within said housing for reciprocating movement with respect to said housing;
• rotatably mounting a symmetrical mass within said housing for relative rotation with respect to said housing;
• mounting a spring to urge said reciprocating member into engagement with said mass so that said mass is positioned for spring-loaded engagement with said reciprocating member;
• providing a first pair of variable shaped engagement surfaces wherein a first variable shaped engagement surface is mounted to said spring loaded member and a second variable shaped engagement surface is mounted to said mass that is urged into engagement said first variable shaped engagement surface by said spring, whereby said relative rotation of said mass with respect to said spring loaded member results in reciprocal motion of said reciprocating member as said first variable shaped engagement surface and said second variable shaped engagement surface rotate with respect to each other;
• and
• utilizing fluid flow through said housing to rotate said mass.

A vibration tool for use with a tubular string in a well bore through which drilling fluid is pumped, comprising:

• a housing attachable to said tubular string;
• a reciprocating member within said housing for reciprocating movement with respect to said housing;
• a rotatable mass within said housing mounted for rotation in response to flow of said drilling fluid;
• a spring mounted to urge reciprocating member into engagement with said rotatable mass;
• a pair of engagement surfaces comprising a first engagement surface mounted on said reciprocating member and a second engagement surface mounted on said rotatable mass, said pair of engagement surfaces being urged into engagement with said spring, said pair of engagement surfaces comprising a plurality of varying surfaces, whereby when said rotatable mass rotates then said reciprocating member reciprocates in response to interaction between said pair of engagement surfaces.