Downhole Mixing Of Encapsulated Plug Components For Primary Cementing A Well

Abstract

A two part encapsulated cementing system is mixed downhole in a method of primary cementing a well. Using this two part system, one of the components is first placed in the annulus of the well. Next, the other component is placed in the annulus above the first placed component. Densities of the components have been selected such that the density of the second placed component is sufficiently higher then the density of the first placed component to facilitate gravity mixing of the two components as the second placed component moves through the first placed component and in the process activation occurs.

1 . A method of primary cementing a well comprising a well bore and a pipe residing in the well bore forming an annulus between the pipe and well bore, the method comprising:
 (A) providing an encapsulated component A and an encapsulated component B, wherein component A and component B will upon contact form into a hard impermeable mass, and each having a density greater than the density of the well fluid;   (B) selecting a first component and a second component from the group consisting of encapsulated component A and an encapsulated component B, wherein the first component and the second component are different, and the density of the second component is higher than the density of the first component;   (C) placing the first component in the annulus;   (D) placing the second component in the annulus at a point above the first component that will allow for gravity flow of the second component down into contact with the first component.   
   
   
       2 . The method of  claim 1 , wherein steps (C) and (D) are carried out utilizing one or more of a dump bailer; pumping through tubing, drillpipe, work strings or tubulars; gravity flow; and bull heading. 
   
   
       3 . The method of  claim 1 , wherein the first component is the encapsulated component A, and the second component is the encapsulated component B. 
   
   
       4 . The method of  claim 1 , wherein the first component is the encapsulated component B, and the second component is the encapsulated component A. 
   
   
       5 . The method of  claim 1 , wherein the well fluid density is in the range of about 8.33 ppg up to about 20.0 ppg, the encapsulated component A density is in the range of about 8.33 ppg up to about 22.0 ppg, and the encapsulated component B density is in the range of about 8.33 up to about 22.0 ppg. 
   
   
       6 . The method of  claim 1 , wherein component A is selected from the group consisting of Na 2 SiO 3 , NaPO 3 ,CaHPO 4 , Silica, Al 2 (HPO 4 ) 3 ,and, MgO, and wherein component B is selected from the group consisting of Ca(OH) 2 , AlOOH, Ca(OH) 2 +base, silica+acid, Alumina+base, NaAlO 2 , MgCl 2 . 
   
   
       7 . A method of primary cementing a well comprising a well bore and a pipe residing in the well bore forming an annulus between the pipe and well bore, the method comprising:
 (A) providing an encapsulated component A and an encapsulated component B, wherein component A and component B will upon contact form into a hard impermeable mass, and each having a density greater than the density of the well fluid;   (B) selecting a first component and a second component from the group consisting of encapsulated component A and an encapsulated component B, wherein the first component and the second component are different, and the density of the second component is higher than the density of the first component;   (C) placing the first component in the annulus;   (D) placing the second component in the annulus at a point above the first component that will allow for gravity flow of the second component down into contact with the first component; and   (E) allowing the first and second components to gravity contact and form a hard impermeable mass.   
   
   
       8 . The method of  claim 7 , wherein steps (C) and (D) are carried out utilizing one or more of a dump bailer; pumping through tubing, drillpipe, work strings or tubulars; gravity flow; and bull heading. 
   
   
       9 . The method of  claim 7 , wherein the first component is the encapsulated component A, and the second component is the encapsulated component B. 
   
   
       10 . The method of  claim 7 , wherein the first component is the encapsulated component B, and the second component is the encapsulated component A. 
   
   
       11 . The method of  claim 7 , wherein the well fluid density is in the range of about 8.33 ppg up to about 20.0 ppg, the encapsulated component A density is in the range of about 8.33 ppg up to about 22.0 ppg, and the encapsulated component B density is in the range of about 8.33 up to about 22.0 ppg. 
   
   
       12 . The method of  claim 7 , wherein component A is selected from the group consisting of Na 2 SiO 3 , NaPO 3 , CaHPO 4 , Silica, Al 2 (HPO 4 ) 3 , and, MgO, and wherein component B is selected from the group consisting of Ca(OH) 2 , AlOOH, Ca(OH) 2 +base, silica+acid, Alumina+base, NaAlO 2 , MgCl 2 . 
   
   
       13 . A cemented well comprising:
 a well bore;   a pipe residing in said well bore forming an annulus between said pipe and well bore;   a first component residing in the annulus; and,   a second component having a density greater than the density of the first component, and residing in the annulus at a point above the first component that will allow for gravity flow of the second component down into the first component, wherein the first component and a second component are selected from the group consisting of encapsulated component A and an encapsulated component B, wherein the first component and the second component are different, and the density of the second component is higher than the density of the first component.   
   
   
       14 . A cemented well comprising:
 a well bore;   a pipe residing in said well bore forming an annulus between said pipe and well bore;   a first component residing in the annulus; and,   a second component having a density greater than the density of the first component, and in the state of gravity flowing thru the first component, wherein the first component and a second component are selected from the group consisting of encapsulated component A and an encapsulated component B, wherein the first component and the second component are different, and the density of the second component is higher than the density of the first component.