Downhole Apparatus

Abstract

A downhole cementing apparatus ( 10 ) comprises a body ( 18 ) and a sealing arrangement ( 20 ) mounted on the body. The cementing apparatus ( 10 ) is deployable through a downhole tool ( 12 ) with a volume of cement ( 14 ). The sealing arrangement ( 20 ) is configured to define a varying point of sealing contact axially along the sealing arrangement with an inner surface of a downhole tool ( 12 ) as the cementing apparatus ( 10 ) is deployed through said tool.

1 . A downhole cementing apparatus deployable through a downhole tool with a volume of cement, comprising:
 a body; and   a sealing arrangement mounted on the body and configured to define a varying point of sealing contact axially along the sealing arrangement with an inner surface of a downhole tool as the cementing apparatus is deployed through said tool.   
     
     
         2 . The apparatus of  claim 1 , wherein providing a varying point of sealing contact permits a seal to be provided at all times during passage of the apparatus through the downhole tool. 
     
     
         3 . The apparatus of  claim 1 , wherein the sealing arrangement comprises at least one seal member for sealingly engaging the inner surface of the downhole tool. 
     
     
         4 . The apparatus of  claim 3 , wherein at least one seal member is operable to swab or wipe the inside of the downhole tool during deployment through said tool. 
     
     
         5 . The apparatus of  claim 1 , wherein the sealing arrangement comprises a plurality of seal members arranged along the body. 
     
     
         6 . The apparatus of  claim 4 , comprising at least one spacer to provide an axial spacing between at least two seal members. 
     
     
         7 . The apparatus of  claim 5 , wherein the seal members are spaced so that at least one seal member provides sealing contact with the inner surface of the downhole tool during deployment through said tool. 
     
     
         8 . The apparatus of  claim 5 , wherein the radial extent of the seal members is configured such that at a first axial location in the downhole tool a first seal member cooperates with the downhole tool to provide a sealing contact, and at a second axial location within the downhole tool the first seal member does not provide sealing contact and a second seal member cooperates with the downhole tool to provide a sealing contact. 
     
     
         9 . The apparatus of  claim 3 , wherein at least one seal member defines a cup shape. 
     
     
         10 . The apparatus of  claim 3 , wherein at least one seal member defines a disc shape. 
     
     
         11 . The apparatus of  claim 3 , wherein at least one seal member is disposed on a mandrel. 
     
     
         12 . The apparatus of  claim 11 , wherein the mandrel comprises at least one module. 
     
     
         13 . The apparatus of  claim 11 , wherein the mandrel comprises a plurality of modules. 
     
     
         14 . The apparatus of  claim 11 , wherein at least one module supports at least one seal member. 
     
     
         15 . The apparatus of  claim 11 , wherein an identifier is provided to facilitate identification of at least one module or seal member. 
     
     
         16 . The apparatus of  claim 11 , wherein the mandrel comprises at least one spacer module for providing an axial spacing between at least two seal members. 
     
     
         17 . The apparatus of  claim 12 , wherein a connection arrangement is provided for coupling at least two modules of the mandrel together. 
     
     
         18 . The apparatus of  claim 1 , wherein the downhole tool comprises a tool for use in treating a subterranean formation. 
     
     
         19 . The apparatus of  claim 1 , wherein the downhole tool comprises a tool for use in fracturing a subterranean formation. 
     
     
         20 . The apparatus of  claim 1 , wherein the apparatus is deployable through an axial flow passage or throughbore of the downhole tool. 
     
     
         21 . A downhole method comprising:
 deploying an apparatus through a downhole tool, wherein the apparatus comprises a sealing arrangement;   establishing a point of sealing contact between the sealing arrangement and an inner surface of the downhole tool; and   varying the point of sealing contact axially along the sealing arrangement during deployment through the downhole tool.   
     
     
         22 . The method of  claim 21 , comprising providing the varying point of sealing contact between a plurality of axially spaced seal members within the sealing arrangement. 
     
     
         23 . The method of  claim 22 , wherein at a first axial location within the downhole tool, a first seal member cooperates with the downhole tool to provide a first point of sealing contact. 
     
     
         24 . The method of  claim 23 , wherein at a second axial location within the downhole tool the first point of sealing contact is removed, and a second seal member cooperates with the downhole tool to provide a second point of sealing contact. 
     
     
         25 . The method of  claim 21 , comprising pumping the apparatus through the downhole tool. 
     
     
         26 . The method of  claim 21 , comprising passing a volume of cement through the downhole tool on one axial side of the apparatus. 
     
     
         27 . The method of  claim 21 , comprising:
 deploying first and second apparatuses through the downhole tool, wherein each apparatus includes a respective sealing arrangement;   deploying a volume of cement intermediate the first and second apparatuses;   establishing a point of sealing contact between the respective sealing arrangements and an inner surface of the downhole tool; and   varying the respective points of sealing contact axially along the respective sealing arrangements during deployment through the downhole tool.   
     
     
         28 . The method of  claim 21 , comprising or forming part of a downhole cementing operation. 
     
     
         29 . The method of  claim 21 , comprising treating a subterranean formation via the downhole tool. 
     
     
         30 . The method of  claim 21 , wherein the downhole tool comprises a tool for use in fracturing a subterranean formation. 
     
     
         31 . A downhole system, comprising:
 a downhole tool; and   an apparatus for deployment through the downhole tool, wherein the apparatus comprises a sealing arrangement configured to define a varying point of sealing contact axially along the sealing arrangement with an inner surface of the downhole tool during deployment through said tool.   
     
     
         32 . The downhole system of  claim 31 , wherein the apparatus comprising a plurality of axially spaced seal members, wherein the axial spacing of the seal members is configured such that at a first axial location in the downhole tool one of the seal members cooperates with the downhole tool to provide a sealing contact and at a second axial location within the downhole tool said seal member permits passage of fluid and at least one other of the seal members cooperates with the downhole tool to provide a sealing contact. 
     
     
         33 . The downhole system of  claim 31 , wherein the downhole tool comprises a tool for use in treating a subterranean formation. 
     
     
         34 . The downhole system of  claim 31 , wherein the downhole tool comprises a tool for use in hydraulic fracturing. 
     
     
         35 . The downhole system of  claim 31 , wherein the downhole tool comprises a tool housing defining a central bore and including a fluid port. 
     
     
         36 . The downhole system of  claim 31 , wherein the downhole tool comprises a valve sleeve. 
     
     
         37 . The downhole system of  claim 31 , wherein the downhole tool comprises a catching apparatus. 
     
     
         38 . The downhole system of  claim 31 , wherein the downhole tool comprises an indexing mechanism. 
     
     
         39 . A method for inhibiting adherence of cement to a downhole tool of a string, comprising coating a surface of the tool with sugar grease. 
     
     
         40 . The method of  claim 39 , comprising directing a volume of sugar grease through the string. 
     
     
         41 . The method of  claim 39 , wherein the downhole tool comprises a tool for use in treating a subterranean formation. 
     
     
         42 . The method of  claim 39 , wherein the downhole tool comprises a tool for use in hydraulic fracturing. 
     
     
         43 . The method of  claim 39 , wherein the downhole tool comprises a tool housing defining a central bore and including a fluid port. 
     
     
         44 . The method of  claim 39 , wherein the downhole tool comprises a valve sleeve. 
     
     
         45 . The method of  claim 39 , wherein the downhole tool comprises a catching apparatus. 
     
     
         46 . The method of  claim 39 , wherein the downhole tool comprises an indexing mechanism. 
     
     
         47 . The method of  claim 39 , comprising directing a volume of cement through the downhole tool. 
     
     
         48 . The method of  claim 39 , comprising using a downhole apparatus comprising a body and a sealing arrangement mounted on the body to direct sugar grease through the downhole tool. 
     
     
         49 . A downhole cementing method, comprising:
 directing a volume of cement through a string comprising a fracturing tool; and   directing the cement into an annulus surrounding at least a portion of the string.   
     
     
         50 . The method of  claim 49 , comprising performing a fracturing operation after the cement has been directed into the annulus. 
     
     
         51 . The method of  claim 49 , comprising deploying an apparatus through the string with the volume of cement, wherein the apparatus comprises:
 a body; and   a sealing arrangement mounted on the body and configured to define a varying point of sealing contact axially along the sealing arrangement with an inner surface of a downhole tool as the cementing apparatus is deployed through said tool.   
     
     
         52 . The method of  claim 49 , comprising disposing a first apparatus on a downhole side of the volume of cement. 
     
     
         53 . The method of  claim 52 , comprising disposing a second apparatus on an uphole side of the cement. 
     
     
         54 . The method of  claim 49 , comprising coating surfaces of the fracturing tool with an inhibitor configured to inhibit adherence of cement to the surface.