Controlled Swell-Rate Swellable Packer and Method

Abstract

A controlled swell-rate swellable packer comprises a mandrel, a sealing element, and a jacket. The sealing element is disposed about at least a portion of the mandrel, and the jacket covers at least a portion of an outer surface of the sealing element. The jacket comprises a substantially impermeable material with respect to a swelling agent that is configured to cause the sealing element to swell.

What is claimed is: 
     
         1 . A controlled swell-rate swellable packer comprising:
 a mandrel;   a sealing element, wherein the sealing element is disposed about at least a portion of the mandrel; and   a jacket, wherein the jacket covers at least a portion of an outer surface of the sealing element, and wherein the jacket comprises a substantially impermeable material with respect to a swelling agent that is configured to cause the sealing element to swell.   
     
     
         2 . The controlled swell-rate swellable packer of  claim 1 , wherein the mandrel comprises a tubular body generally defining a continuous axial flowbore. 
     
     
         3 . The controlled swell-rate swellable packer of  claim 1 , wherein the sealing element comprises a swellable material. 
     
     
         4 . The controlled swell-rate swellable packer of  claim 3 , wherein the swellable material comprises a water-swellable material, an oil-swellable material, or any combination thereof 
     
     
         5 . The controlled swell-rate swellable packer of  claim 3 , wherein the swellable material comprises a compound selected from the group consisting of: a natural rubber, an acrylate butadiene rubber, a polyacrylate rubber, an isoprene rubber, a choloroprene rubber, a butyl rubber (IIR), a brominated butyl rubber (BIIR), a chlorinated butyl rubber (CIIR), a chlorinated polyethylene (CM/CPE), a neoprene rubber (CR), a styrene butadiene copolymer rubber (SBR), a sulphonated polyethylene (CSM), ethylene acrylate rubber (EAM/AEM), an epichlorohydrin ethylene oxide copolymer (CO, ECO), an ethylene-propylene rubber (EPM and EDPM), an ethylene-propylene-diene terpolymer rubber (EPT), an ethylene vinyl acetate copolymer, a fluorosilicone rubber (FVMQ), a silicone rubber (VMQ), poly 2,2,1-bicyclo heptene (polynorborneane), an alkylstyrene, a crosslinked substituted vinyl acrylate copolymer, and any combination thereof. 
     
     
         6 . The controlled swell-rate swellable packer of  claim 3 , wherein the swellable material comprises a water-swellable material, and wherein the swellable material comprises a compound selected from the group consisting of: a nitrile rubber (NBR), a hydrogenated nitrile rubber (HNBR, HNS), a fluoro rubber (FKM), a perfluoro rubber (FFKM), tetrafluorethylene/propylene (TFE/P), a starch-polyacrylate acid graft copolymer, a polyvinyl alcoholcyclic acid anhydride graft copolymer, isobutylene maleic anhydride, an acrylic acid type polymer, a vinylacetate-acrylate copolymer, a polyethylene oxide polymer, a carboxymethyl cellulose type polymer, a starch-polyacrylonitrile graft copolymer, polymethacrylate, polyacrylamide, a non-soluble acrylic polymer, sodium bentonite, and any combination thereof. 
     
     
         7 . The controlled swell-rate swellable packer of  claim 3 , wherein the swellable material is characterized by a particle size of from about 0.1 microns to about 2000 microns. 
     
     
         8 . The controlled swell-rate swellable packer of  claim 1 , wherein the jacket covers at least about 75% of the outer surface of the sealing element. 
     
     
         9 . The controlled swell-rate swellable packer of  claim 1 , wherein the jacket comprises a fluoro-elastomer, a plastic, polyethylene, polypropylene, or combinations thereof. 
     
     
         10 . A method of making a controlled swell-rate swellable packer, comprising:
 providing a mandrel having at least one sealing element disposed about at least a portion thereof;   masking at least a portion of any exposed portions of the sealing element with a mask;   applying a jacket to the sealing element;   removing the mask; and   providing a controlled swell-rate swellable packer.   
     
     
         11 . The method of  claim 10 , wherein the mask is configured to cover a portion of the sealing element. 
     
     
         12 . The method of  claim 10 , wherein the mask comprises at least one of a grid-like pattern, a diamond pattern, or a random pattern. 
     
     
         13 . The method of  claim 10 , wherein the mask is formed from at least one of paper, plastic, wires, metals, a fibrous material, or any combination thereof. 
     
     
         14 . The method of  claim 10 , wherein applying the jacket to the sealing element comprises at least one of spraying a liquideous or substantially liquideous material onto the sealing element, painting a liquideous or substantially liquideous material onto the sealing element, or dipping the sealing element into a liquideous or substantially liquideous material. 
     
     
         15 . The method of  claim 10 , further comprising drying the jacket before removing the mask. 
     
     
         16 . A method of utilizing a controlled swell-rate swellable packer, comprising:
 providing a controlled swell-rate swellable packer, wherein the controlled swell-rate swellable packer comprises a sealing element and a jacket, wherein the jacket is disposed on a first portion of an outer surface of the sealing element, and wherein a second portion of the outer surface of the sealing element is uncovered;   disposing a tubular string having the controlled swell-rate swellable packer incorporated therein within a wellbore; and   activating the controlled swell-rate swellable packer.   
     
     
         17 . The method of  claim 16 , wherein the controlled swell-rate swellable packer further comprises a mandrel, wherein the sealing element is disposed circumferentially about at least a portion of the mandrel. 
     
     
         18 . The method of  claim 16 , wherein the sealing element comprises a swellable material. 
     
     
         19 . The method of  claim 16 , wherein activating the controlled-rate swellable packer comprises contacting at least a portion of the controlled swell-rate packer with a swelling agent. 
     
     
         20 . The method of  claim 19 , wherein the swelling agent comprises a water-based fluid, an oil-based fluid, or any combination thereof. 
     
     
         21 . The method of  claim 19 , wherein contacting at least the portion of the controlled swell-rate packer with the swelling agent comprises contacting the second portion of the outer surface of the sealing element with the swelling agent. 
     
     
         22 . The method of  claim 19 , wherein contacting at least the portion of the controlled swell-rate packer with the swelling agent comprises contacting the second portion of the outer surface of the sealing element with the swelling agent for at least 2 days.