Delay coating for wellbore isolation device
AssigneesHalliburton Energy Services, Inc., Board of Regents, The University of Texas System
InventorsMichael Linley Fripp, Xiaoguang Allan Zhong, Kejia Yang, Walter Voit, Nelson Yan Loo Lee, Yong Dai Tan, Bing Hong Chee, Ee Wen Wong
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Abstract
A wellbore isolation device includes a mandrel, a sealing element disposed around at least a portion of the mandrel, and a delay coating disposed on at least a portion of an outer surface of the sealing element. The sealing element includes a swellable material and the delay coating covers a cross-linked polymer. The delay coating is configured to swell or degrade in a wellbore fluid.
Claims20
A wellbore isolation device comprising:
- a mandrel;
- a sealing element disposed around at least a portion of the mandrel, wherein the sealing element comprises a swellable material;
- and
- a delay coating disposed on at least a portion of an outer surface of the sealing element, wherein the delay coating comprises a cross-linked polymer, and the delay coating is configured to swell or degrade in a wellbore fluid;
- wherein the delay coating comprises a thiol polymer comprising a swellable functional group selected from a polyethylene glycol-based hydrogel, an aerogel, poly(lactic acid), poly(glycolic acid), poly(vinyl alcohol), and/or poly(N-isopropylacrylamide).
A method of isolating a portion of a wellbore comprising:
- disposing a tubular string comprising a wellbore isolation device incorporated therein within a wellbore in a subterranean formation, wherein the wellbore isolation device comprises:
- a cylindrical sealing element with an internal bore, wherein the sealing element comprises a swellable material that is configured to swell in a first wellbore fluid;
- and
- a delay coating disposed on at least a portion of an outer surface of the sealing element, wherein the delay coating comprises a cross-linked polymer and is configured to swell or degrade in a second wellbore fluid,
- introducing the second wellbore fluid within the wellbore to cause the delay coating to swell or degrade;
- and
- introducing the first wellbore fluid within the wellbore to cause the sealing element to swell such that the sealing element exhibits a radial expansion,
- wherein the second wellbore fluid may be the same or different from the first wellbore fluid;
- and
- wherein the delay coating comprises a thiol polymer comprising a swellable functional group selected from a polyethylene glycol-based hydrogel, an aerogel, poly(lactic acid), poly(glycolic acid), poly(vinyl alcohol), and/or poly(N-isopropylacrylamide).
A method of manufacturing a wellbore isolation device comprising:
- disposing a sealing element around at least a portion of a cylindrical mandrel, wherein the sealing element comprises a swellable material;
- and
- disposing a delay coating on at least a portion of an outer surface of the sealing element, wherein the delay coating comprises a cross-linked polymer and is configured to swell or degrade in a wellbore fluid,
- wherein disposing the delay coating comprises spraying a first liquid onto the outer surface of the sealing element, wherein the first liquid comprises a cross-linkable polymer, and then spraying a second liquid onto the first liquid to cure the first liquid,
- wherein the delay coating comprises a thiol polymer comprising a swellable functional group selected from a polyethylene glycol-based hydrogel, an aerogel, poly(lactic acid), poly(glycolic acid), poly(vinyl alcohol), and/or poly(N-isopropylacrylamide).
Dependencies are inferred from the claim text.