Uni-directional unitary anchor slip

Claim 2

A unitary well tool anchor slip for ahchoring a well tool or well packer in the casing of an oil well, said slip comprising: a generally cylindrical tubular member having a dual axis bore passage therethrough; a plurality of gripping teeth having a curved boundary profile, said teeth being located on one side of said member near one end; a second plurality of gripping teeth having a curved boundary profile, said second plurality of teeth located on the opposite side of said member near the opposite end; an abutment shoulder located at one edge of one end of said member, said member end having a canted surface leading away from said abutment shoulder; and, a compound abutment surface on the member end opposite said abutment shoulder, said compound surface having a flat surface extending from the central cylindrical axis to the edge of said member containing said gripping teeth and a radially curved surface extending from said central axis to the opposite edge of said member end.

Claim 3

The anchor slip of claim 1 wherein said dual axis bore passage is arranged to contain a plurality of tubular mandrels therein and is further adapted to pivot about said mandrels on dual axes, with the first of said dual axes substantially coinciding with the central, longitudinal cylindrical axis of said anchor slip, and said second axis beng canted from said first axis at an angle of from 5 to 45*, with a preferable angle of about 18*.

Claim 4

The anchor slip of claim 2 wherein said member has a pivoting center of rotation along the central, longitudinal cylindrical axis of said member and located at a distance of one-half of the cylindrical length of said member from said flat surface, and the radius of curvature of said radially curved surface is equivalent to one-half the cylindrical length of said member, with said curved surface being tangent to said flat surface at said central cylindrical axis.

Claim 5

The anchor slip of claim 3 wherein said member further comprises a longitudinal slot passing through one side of said member from the inner bore to the outer surface thereof and extending only partially along said one side of said member; said slot arranged adjacent to a cylindrical spring slot formed into the remaining portion of said member wall and aligned substantially parallel with the central cylindrical axis of said member.

Claim 6

A uni-directional gripping member for use on one or more conduit strings in a wellbore, said gripping member adapted for gripping the wellbore in one direction of longitudinal movement of said member and further adapted to allow non-gripping movement of the member in either longitudinal direction in the wellbore comprising: a generally cylindrical tubular member having a first bore passage passing longitudinally there-through generally parallel to the longitudinal central axis thereof and adapted to receive said one or more conduit strings in slidable relationship; a second bore passage passing through said member and intersecting said first bore passage at an angle thereto, whereby said member can be pivoted on said conduits from a well-bore non-engaging position to a wellbore contact position whereby diametrically opposite edges of said member contact the wellbore simultaneously; gripping teeth on said member along said diametrically opposite edges of said member, said teeth arranged to contact and grip the wellbore upon pivoting of said member on said conduit string; a canted face on one end of said member, said face having an abutment surface thereon along the outer edge of said member arranged to abut a flat surface on said conduit string and introduce rotational moments in said member; and, a dual surface end on said member opposite said canted face end, said dual surface end having a flat surface normal to the central cylindrical axis of said member and a curved surface tangent to said flat surface at said central axis said curved surface being on the same side of said member as said abutment surface but longitudinally spaced therefrom, and said curved surface having a radius of curvature equal to the distance from the point of said tangency to the pivot center of said member.

Claim 7

A uni-directional gripping member for use on one or more conduit strings in a wellbore, said gripping member adapted for gripping the wellbore in one direction of longitudinal movement of said member and further adapted to allow non-gripping movement of the member in either longitudinal direction in the wellbore comprising: a generally cylindrical tubular member having a first bore passage passing longitudinally there-through generally parallel to the longitudinal central axis thereof and adapted to receive said one or more conduit strings in slidable relationship; a second bore passage passing through said member and intersecting said first bore passage at an angle thereto, whereby said member can be pivoted on said conduits from a well-bore non-engaging position to a wellbore contact position whereby diametrically opposite edges of said member contact the wellbore simultaneously; gripping teeth on said member along said diametrically opposite edges of said member, said teeth arranged to contact and grip the wellbore upon pivoting of said member on said conduit string; a canted face on one end of said member, said face having an abutment surface thereon along the outer edge of said member arranged to abut a flat surface on said conduit string and introduce rotational moments in said member; and, a dual surface end on said member opposite said canted face end, said dual surface end having a flat surface normal to the central cylindrical axis of said member and a curved surface tangent to said flat surface at said central axis said curved surface being on the same side of said member as said abutment surface but longitudinally spaced therefrom, and said curved surface having a radius of curvature equal to the distance from the point of said tangency to the pivot center of said member.

Claim 8

The gripping member of claim 5 wherein said member has a cylindrical length which is substantially greater than the diameter of the wellbore and a cylindrical diameter smaller than the diameter of the wellbore, with said curved surface having a center of curvature coinciding with the pivot center of said member, said pivot center lying on the central, cylindrical longitudinal axis of said member and being a distance of one-half the cylindrical length of said member from said point of tangency.

Claim 9

The gripping member of claim 6 wherein said first and second bore passages are each adapted to receive two parallel, spaced apart, conduit strings and said second bore passage intersects said first bore passage at an angle of from 5 to 45*, with a preferable angle of from 16 to 20*.