Coupling agent to enhanced coupling of optical fibers deployed in subsurface wells
A coupling agent for deployment around an optical fiber in a subsurface wellbore, the coupling agent including a curable or non-curable compound that can form into a reversible polymerized gel state located around at least a portion of the optical fiber and there is a gel-optical fiber interface strain gradient that is greater than a wellbore fluid-optical fiber strain gradient. A method of deploying an optical fiber in a fluid path of a subsurface wellbore and introducing a coupling agent in the fluid path.
1. A coupling agent for deployment around an optical fiber in a subsurface wellbore, the coupling agent comprising:
a curable or non-curable compound that can form into a reversible polymerized gel state located around at least a portion of the optical fiber and there is a gel-optical fiber interface strain gradient that is greater than a wellbore fluid-optical fiber strain gradient.
2. The coupling agent of claim 1 , wherein the gel-optical fiber interface strain gradient is at least 166 percent greater than the wellbore fluid-optical fiber strain gradient.
3. The coupling agent of claim 1 , wherein the non-curable compound includes a polyacrylate.
4. The coupling agent of claim 1 , wherein the non-curable compound includes a polyamide.
5. The coupling agent of claim 4 , wherein the curable compound further includes a curable polymetric resin.
6. The coupling agent of claim 5 , wherein the curable polymeric resins include an epoxy resin.
7. The coupling agent of claim 5 , wherein the curable compound further includes one or more of a solvent, a hardening agent, a coupling agent, or a wetting agent.
8. The coupling agent of claim 1 , wherein the non-curable compound includes a polymerizable organic monomer.
9. The coupling agent of claim 8 , wherein the non-curable compound further includes a delinking agent.
10. The coupling agent of claim 1 , wherein the non-curable compound includes a gelling agent that includes hydratable polymers.
11. The coupling agent of claim 1 , wherein the non-curable compound includes a fluid loss control agent.
12. The coupling agent of claim 1 , wherein the non-curable compound includes a foamable compounds.
13. The coupling agent of claim 1 , wherein the coupling agent is part of a formation testing apparatus.
14. The coupling agent of claim 13 , wherein the formation testing apparatus includes the optical fiber and a fiber conveyor.
15. The coupling agent of claim 14 , wherein the optical fiber and the fiber conveyor are disposable.
16. The coupling agent of claim 13 , wherein the formation testing apparatus includes one or more of a fluid displacement device, a reservoir that includes the coupling agent or a waveguide-based distributed sensing module.
17. A method, comprising:
deploying an optical fiber in a fluid path of a subsurface wellbore; and
introducing a coupling agent in the fluid path, wherein the coupling agent includes a curable or non-curable compound that can form into a reversible polymerized gel state, the curable or non-curable compound is located around at least a portion of the optical fiber and there is a gel-optical fiber interface strain gradient that is greater than a wellbore fluid-optical fiber strain gradient.
18. The method of claim 17 , wherein the coupling agent is introduced during or after the deploying of the optical fiber.
19. The method of claim 17 , including pumping a pig through the fluid path during or after the introducing of the coupling agent.
20. The method of claim 17 , further including conducting a formation-sensing operation through the optical fiber when the coupling agent is in the polymerized gel state.