Liner top test packer

Abstract

A liner hanger test packer assembly includes an axially translated liner top dressing mill having a calibrated shear mechanism for securing the mill at a first, top dressing position. Tool string load on the mill bearing upon the liner top in excess of the calibrated shear mechanism allows the mill to shift to a second axial position where abutment edges around the Mill base engage a tripping mechanism to drive slips against the casing wall above the liner hanger. The tripping mechanism also expands the packer seal against the casing I.D. above the liner hanger. No additional load may be imposed on the liner hanger after the anchor slips have engaged.

1 . A well workstring assembly comprising: 
 (a) an expandable sealing element for sealing an annulus between a workstring tube and a wellbore wall having a well bore liner hanger secured thereto;    (b) an expandable anchoring element for securing said workstring tube to said well bore wall; and,    (c) a liner hanger engagement tool having a rotational drive assembly with said workstring tube, said drive assembly having a calibrated failure mechanism for securing said hanger engagement tool at a position of disengagement from said anchoring and sealing elements.    
     
     
         2 . A well workstring assembly as described by  claim 1  wherein the anchoring and sealing element disengagement position of said hanger engagement tool that is secured by said failure mechanism is at a first axial position along said workstring tube.  
     
     
         3 . A well workstring assembly as described by  claim 2  wherein operation of said calibrated failure mechanism allows an axial translation of said hanger engagement tool to a second position for operative expansion of said anchoring and sealing elements.  
     
     
         4 . A well workstring assembly as described by  claim 3  wherein said hanger engagement tool is a cutting mill.  
     
     
         5 . A wellbore workstring having a packer assembled therewith, said packer comprising: 
 (a) an expandable bore sealing element;    (b) an expandable bore anchoring element;    (c) a liner hanger engaging element; and,    (d) a tripping mechanism linking said liner hanger engaging element with said bore sealing element and said bore anchoring element to expand said sealing element and anchoring element upon exceeding a predetermined workstring load on said hanger engaging element.    
     
     
         6 . A wellbore workstring as described by  claim 5  wherein said liner hanger engaging element is a liner top dressing mill  
     
     
         7 . A wellbore workstring as described by  claim 5  wherein said tripping mechanism comprises a calibrated shear device whereby a predetermined workstring load on said dressing mill causes the failure of said shear device and the expansion of said sealing element and said anchoring element.  
     
     
         8 . A liner top test packer having an expandable sealing element, an expandable casing anchor element, and a liner top milling tool, said milling tool connected to a tripping mechanism having a calibrated shear device whereby structural failure of said shear device expands said anchor element.  
     
     
         9 . A liner top test packer as described by  claim 8  wherein structural failure of said shear mechanism also expands said sealing element.  
     
     
         10 . A method of testing the hydrodynamic seal of a wellbore liner ger set within a supporting casing bore, the method comprising the steps of: 
 (a) assembling a wellbore workstring having a liner hanger engaging element, anchor slips and a packer element;    (b) running said workstring into a wellbore casing having a liner hanger;    (c) engaging said hanger engaging element against said liner hanger to set said anchor slips and packer element against said casing above said liner hanger; and,    (d) imposing a pressure differential across said liner hanger.    
     
     
         11 . A method as described by  claim 10  wherein said hanger engaging element is rotatively driven by said workstring.  
     
     
         12 . A method as described by  claim 11  wherein said hanger engagement element is axially translated form a first position to a second position to set said anchor slips and packer element.  
     
     
         13 . A method as described by  claim 11  wherein a rotative drive coupling of said hanger engaging element to said workstring is calibrated to restrict a transfer of engagement force to said anchor slips.  
     
     
         14 . A method as described by  claim 12  wherein said anchor slips and packer elements are engaged by exceeding a force capacity on a calibrated failure element between said workstring and said hanger engaging element.  
     
     
         15 . A method as described by  claim 13  wherein failure of said calibrated failure element allows said hanger engaging element to translate axially against said anchor slips.  
     
     
         16 . A method as described by  claim 14  wherein said hanger engaging element is a cutting mill.