Cementing Tool and Method for Using Same

Abstract

A cementing tool is provided for use in cementing in casing or pipe in a well bore. The tool has an outer sleeve and an inner sleeve slidably disposed therein. The outer and inner sleeves can comprise aligned openings that allow cement to pass through once an opening seat disposed inside the inner sleeve slides down to expose the openings to the interior of the tool. The inner sleeve has convex protrusions extending outwardly from the inner sleeve and configured as circumferential seals to contact the inner wall of the outer sleeve in an interference fit. When the inner sleeve is moved downward to close off the openings in the outer sleeve, the interference seals prevent pressurized fracking fluid from exiting the tool through the outer sleeve openings.

What is claimed is: 
     
         1 . A cementing tool for cementing in a casing in a well bore, the cementing tool comprising:
 a) a tubular outer sleeve defining a passageway therethrough, the outer sleeve comprising a first upper end configured to couple to a first pipe disposed thereabove, the outer sleeve further comprising at least one first opening disposed through a first sidewall of the outer sleeve;   b) a tubular bottom subassembly operatively coupled to a first lower end disposed on the outer sleeve, the bottom subassembly configured to couple to a second pipe disposed therebelow;   c) a tubular inner opening sleeve slidably disposed in the outer sleeve above the bottom subassembly;   d) a tubular inner sleeve disposed in the outer sleeve above the inner opening sleeve, the inner sleeve further comprising at least one second opening disposed through a second sidewall of the inner sleeve, the inner sleeve comprising a first seal circumferentially disposed about the second sidewall above the at least one second opening, the inner sleeve comprising a second seal circumferentially disposed about the second sidewall above the first seal, the inner sleeve configured to move from a first upper position, wherein the at least one second opening is substantially aligned with the at one least first opening to provide communication between the at least one first opening and the passageway, to a first lower position wherein the first seal is disposed below the at one least first opening and the second seal is disposed above the at least one first opening to prevent communication between the at least one first opening and the passageway; and   e) a tubular opening seat slidably disposed between the inner sleeve and the inner opening sleeve, the tubular opening seat configured to move from a second upper position, wherein the opening seat prevents communication between the at least one first opening and the passageway, to a second lower position wherein the at least one first opening is in communication with the passageway.   
     
     
         2 . The cementing tool as set forth in  claim 1 , wherein one or both of the first and second seals are integral to the inner sleeve. 
     
     
         3 . The cementing tool as set forth in  claim 1 , wherein one or both of the first and second seals further comprises an interference fit between the inner sleeve and the outer sleeve. 
     
     
         4 . The cementing tool as set forth in  claim 3 , wherein one or both of the first and second seals comprises a convex profile. 
     
     
         5 . The cementing tool as set forth in  claim 4 , wherein an outer diameter of one or both of the first and second seals is greater than an inner diameter of the outer sleeve. 
     
     
         6 . The cementing tool as set forth in  claim 5 , wherein the outer diameter is greater than the inner diameter by a range of 0.007 inches to 0.012 inches. 
     
     
         7 . The cementing tool as set forth in  claim 4 , wherein the convex profile comprises a radius in the range of 0.4 inches to 0.6 inches. 
     
     
         8 . The cementing tool as set forth in  claim 4 , wherein the convex profile comprises a width in the range of 0.3 inches to 0.4 inches. 
     
     
         9 . A method for cementing in a casing in a well bore, the method comprising the steps of:
 a) providing a cementing tool configured for cementing in the casing in the well bore, the cementing tool comprising:
 i) a tubular outer sleeve defining a passageway therethrough, the outer sleeve comprising a first upper end configured to couple to a first pipe disposed thereabove, the outer sleeve further comprising at least one first opening disposed through a first sidewall of the outer sleeve, 
 ii) a tubular bottom subassembly operatively coupled to a first lower end disposed on the outer sleeve, the bottom subassembly configured to couple to a second pipe disposed therebelow, 
 iii) a tubular inner opening sleeve slidably disposed in the outer sleeve above the bottom subassembly, 
 iv) a tubular inner sleeve disposed in the outer sleeve above the inner opening sleeve, the inner sleeve further comprising at least one second opening disposed through a second sidewall of the inner sleeve, the inner sleeve comprising a first seal circumferentially disposed about the second sidewall above the at least one second opening, the inner sleeve comprising a second seal circumferentially disposed about the second sidewall above the first seal, the inner sleeve configured to move from a first upper position, wherein the at least one second opening is substantially aligned with the at least one first opening to provide communication between the at least one first opening and the passageway, to a first lower position wherein the first seal is disposed below the at least one first opening and the second seal is disposed above the at least one first opening to prevent communication between the at least one first opening and the passageway, and 
 v) a tubular opening seat slidably disposed between the inner sleeve and the inner opening sleeve, the tubular opening seat configured to move from a second upper position, wherein the tubular opening seat prevents communication between the at least one first opening and the passageway, to a second lower position wherein the at least one first opening is in communication with the passageway; 
   b) placing the cementing tool in a string of casing pipe and inserting the string into the well bore;   c) shutting off the string below the cementing tool;   d) moving the tubular opening seat from the second upper position to the second lower position; and   e) injecting cementing into the string wherein cement flows from the passageway through the at least one first and second openings into an annular space surrounding the casing.   
     
     
         10 . The method as set forth in  claim 9 , when a sufficient amount of cement has been placed in the annular space, moving the inner sleeve from the first upper position to the first lower position. 
     
     
         11 . The method as set forth in  claim 9 , wherein one or both of the first and second seals are integral to the inner sleeve. 
     
     
         12 . The method as set forth in  claim 9 , wherein one or both of the first and second seals further comprises an interference fit between the inner sleeve and the outer sleeve. 
     
     
         13 . The method as set forth in  claim 12 , wherein one or both of the first and second seals comprises a convex profile. 
     
     
         14 . The method as set forth in  claim 13 , wherein an outer diameter of one or both of the first and second seals is greater than an inner diameter of the outer sleeve. 
     
     
         15 . The method as set forth in  claim 14 , wherein the outer diameter is greater than the inner diameter by a range of 0.007 inches to 0.012 inches. 
     
     
         16 . The method as set forth in  claim 13 , wherein the convex profile comprises a radius in the range of 0.4 inches to 0.6 inches. 
     
     
         17 . The method as set forth in  claim 13 , wherein the convex profile comprises a width in the range of 0.3 inches to 0.4 inches.