Liner seal and method of use

A downhole tool for use in a tool string, said downhole tool comprising:

• a liner screen for location at a predetermined position in a well bore;
• a liner seal attached to an upper end of said liner screen and defining a set position sealingly engaged with said well bore for sealing an upper portion of an annular volume between said liner screen and said well bore;
• said liner seal comprising:
• an inner sleeve having a lower end connected to said liner screen, an upper end, and an inside surface defining an annular collet receiving groove therein;
• an outer sleeve slidingly disposed around said inner sleeve upper end, said outer sleeve having an upper and a lower end;
• and
• an annular sealing member having an upper end attached to said outer sleeve lower end and a lower end attached to said inner sleeve at an intermediate position thereon, said sealing member being radially outwardly deflected into sealing engagement with said well bore when said outer sleeve is moved from an original position to a relatively converged position with respect to said inner sleeve, said converged position corresponding to said liner seal set position, such that said upper and lower ends of said annular sealing member are moved toward one another;
• and
• a releasing mechanism for attaching said liner seal to said tool string and non-rotationally releasing said liner seal from said tool string such that said tool string may be removed from said well bore with said liner seal and said liner screen remaining positioned in said well bore, said releasing mechanism comprising:
• a body portion attached to said tool string and having a plurality of collet fingers extending downwardly therefrom, each collet finger defining a collet portion, said collet portions being adjacent said groove when in an original position;
• and
• a releasing mandrel slidably positioned in said body portion and having a collet displacing portion at a lower end thereof for outwardly displacing said collet portions into engagement with said groove when in an engaging position;
• whereby, as said releasing mandrel is moved from said engaging position to a releasing position, said collet displacing portion is moved away from said collet portions such that said collet portions are disengaged from said groove and thereby release said liner seal from said tool string.

A method of positioning and packing a liner screen in a well bore, said method comprising the steps of:

• releasably connecting a liner seal to a lower end of a tool string;
• engaging said liner screen with a lower end of said liner seal;
• lowering said tool string into said well bore and locating said screen at a predetermined position in said well bore;
• packing gravel below said liner seal in an annular volume between said screen and said well bore;
• releasing said liner seal from said tool string by applying pressure to a pressure actuated release mechanism interconnecting said liner seal with a lower end of said tool string, thereby displacing a plurality of collets from a first position engaging said liner seal to a second position releasing said liner seal;
• setting said liner seal for sealing engagement with said well bore and thereby sealingly enclosing an upper portion of said annular volume;
• and
• preventing disengagement of said liner seal from said well bore.