Downhole Tool System and Method

Abstract

The present invention comprises a novel thread form and slip alignment device and method for anchoring drillable downhole tools, such as fracturing plugs, bridge plugs, or cement retainers within a wellbore. The slips are oriented circumferentially about upper and lower cones between upper and lower slips and upper and lower load members whereby the downhole tool is capable of withstanding piston forces resulting from differential pressure from above and below the set position through the utilization of a sealing element to maintain differential pressure from above and/or below the tool. Upon wellbore pressure application above and/or below the plug, relative axial movement between the mandrel and the slips, tool, and cones occurs until halted by an upper and lower stop disposed on the mandrel at each distal and proximate end. Further, components used in the slip alignment feature may be manufactured from weak materials or anisotropic material properties for milling.

What is claimed is: 
     
         1 . 
     
     
         2 . A high shear strength accepting thread form comprising:
 a mandrel having a radial circumference, a first end and a second end;   said mandrel exhibiting a hollow or solid inner diameter and an angler thread disposed about said radial circumference, exteriorly, composed of two opposing flank faces;   said flank faces composed of a major diameter, a minor diameter, a flank angle and a flank pitch;   a flank intersection forming a flank tooth angle at the connection of two flank faces exteriorly where joining flank faces create an obtuse profile angle;   a sleeve composed of accepting interior angular thread for receipt of inserted mandrel;   said sleeve exhibiting said accepting interior angular thread exhibiting a reciprocal angle in relation to said angular thread disposed about said radial circumference, exteriorly, composed of two opposing flank faces.   
     
     
         3 . The high shear strength accepting thread form of  claim 2 , wherein the wedging action between said accepting interior angular thread, exhibiting a reciprocal angle in relation to said exterior angular thread disposed about said radial circumference of said outer thread of the mandrel which creates a supportive communication between each opposing flank face creating radial component forces to increase the collapse load into the mandrel, decreases the burst load into the sleeve and reduce the axial shear force component action on the shear diameter. 
     
     
         4 . The high shear strength accepting thread form of  claim 2 , wherein the thread form may be oriented in a right-handed or left-handed direction of twist. 
     
     
         5 . The high shear strength accepting tread form of  claim 2 , wherein the applied force realized by the thread form lessens compression or tension forces on assembled components, dissipates the result of applied pressure over a piston area, and reduces torque applied to the threaded connection. 
     
     
         6 . The high shear strength accepting tread form of  claim 2 , wherein the mandrel and sleeve configuration may be solid tubulars, single or double ended collets with a plurality of fingers, subassemblies with expandable or collapsible keyed members containing matching thread profiles, body lock ring split rings, barrel springs, or helical sleeve springs with matching thread profiles that can ratchet in one or both axial directions through applied axial load or torque and are prevented from moving in one or more directions. 
     
     
         7 . The high shear strength accepting tread form of  claim 2 , wherein the connection between said mandrel and said sleeve may be further connected through pins, rods, screws, keys, epoxy, thread locker, or any other aligning, diverting, or securing feature installed or applied to the thread or surrounding connection. 
     
     
         8 . The high shear strength accepting tread form of  claim 2 , wherein the connection between said mandrel and said sleeve may be tapered for high shear strength and thread sealing applications utilizing lower shear strength materials, such as composites. 
     
     
         9 . The high shear strength accepting tread form of  claim 2 , wherein said thread form is constructed of structural fiber layer orientation for each component where layered manufacturing methods include filament winding, convolute winding, sheet wrapping, sheet laminate, or any other additive form of manufacturing including molded component manufacturing which may be circumferentially oriented about the axis of each component, conically oriented about the axis of each component at constant or varying angle patterns or where each component shares the same orientation angle or dissimilar orientation angles. 
     
     
         10 . The high shear strength accepting tread form of  claim 2 , wherein said thread form is constructed of structural fiber layer orientation that is perpendicularly oriented about the axis of each component. 
     
     
         11 . The high shear strength accepting tread form of  claim 2 , wherein said thread form is perpendicularly oriented about the axis of each component that may be of molded plastics, additive manufactured materials, and/or may be combined in any combination with components made from isotropic material properties, uniformly distributed crystalline structures, and/or disintegrating electrolytic material. 
     
     
         12 . A downhole apparatus for borehole use, comprising:
 a mandrel having a first and a second end;   a tubular member comprising at least one external surface formed therein;   a sealing element disposed on said mandrel between the first and second ends and compressible to engage a borehole;   at least one slip disposed about first and/or second end of sealing element and disposed on said mandrel;   said slip having a first end evidencing a tapered internal surface and a second end having one or more aligning features;   a member disposed adjacent to the second end of one or more slips having at least one aligning feature such that said slip is aligned by said member aligning feature with or without the addition of further aligning components between the slip and member interface;   
     
     
         13 . The downhole apparatus of  claim 12 , wherein the components of said apparatus may be made of readily milled material, such as composite, ceramic, molded phenolic, low density metal, and/or similar material. 
     
     
         14 . The downhole apparatus of  claim 12 , wherein the mandrel may encompass a passage way that can harbor a ball landed on a seat with a valve or installed pub. 
     
     
         15 . The downhole apparatus of  claim 12 , wherein the mandrel has a plurality of spot faces for installation of shear screws. 
     
     
         16 . A method of slip alignment for the placement and securing of a downhole apparatus disposing said apparatus between a cone and guide member comprising the following steps:
 conforming said cone and said slip adjacent along tapered faces and the slip and load member shoulder adjacently against either a tapered or perpendicular face;   assuring the interface between the slip and guide member shoulder is shared by a plurality of aligning features extending radially outward to control orientation of the slip relative to the load member throughout all functions of the downhole apparatus thus controlling orientation of the slip relative to the cone throughout the same functions of the downhole apparatus;   confirming that the orientation of the slip and guide member is such that, when the slips ride up the cone and anchor against the wellbore wall, the resulting uniform placement of split petals impart a circumferentially symmetric load distribution into the supporting cone;   confirming an alignment feature disposed between the slip and guide member interface may be features of each constituent component in the form of grooved and or guiding geometry, may be added components used to follow guide geometry, and/or a combination thereof   
     
     
         17 . The method of  claim 16 , wherein said downhole apparatus is a hydraulic fracturing plugs, bridge plugs, or cement retainers, consist of a mandrel with or without a through inner diameter bore, where outer components disposed concentrically about the mandrel and outer components may contain any number of load rings, slips, cones, packing elements, end stops, pins, and shearing devices. 
     
     
         18 . The method of  claim 16 , wherein a setting tool adapter kit is utilized to fasten a downhole apparatus to a setting tool and hold said downhole apparatus axially and concentrically in place 
     
     
         19 . The method of  claim 16 , wherein one or more of the components used in the slip alignment feature are manufactured to be easily milled and from materials with weak material or anisotropic material properties, such as, but not limited to composite, ceramic, molded phenolic, magnesium alloys, low density metals and molded plastics, such as for use in fracturing plugs, bridge plugs, and/or cement retainers.