Editorial Type:
Article Category: Research Article
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Online Publication Date: 01 Jul 2017

CO2 SOLUBILITY AND DIFFUSIVITY AND RAPID GAS DECOMPRESSION RESISTANCE OF ELASTOMERS CONTAINING CNT

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Page Range: 562 – 574
DOI: 10.5254/rct.17.83726
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ABSTRACT

Understanding the structure–property relationship of elastomers is of critical importance in developing next-generation elastomers for high-pressure, high-temperature (HPHT) applications and in extending the application temperature and pressure range of existing oilfield products. Gas dissolution and diffusion in elastomers are essential to understanding the relationship among elastomer structures, rapid gas decompression (RGD) resistance, and sealing performance. Solubility and diffusivity (or diffusion efficiency) of carbon dioxide (CO2) in hydrogenated nitrile butadiene rubber (HNBR) and fluoroelastomers (FKM) comprising carbon nanotubes (CNT) were measured using a gravimetric method. The Rubotherm method was also used to estimate the solubility and swelling of HNBR in both subcritical liquid and supercritical CO2. It was demonstrated that CNT had a direct impact on CO2 solubility, diffusion, and mechanical properties of elastomers, hence improving the RGD resistance of the elastomers.

Copyright: 2017
<sc>Fig</sc> . 1.
Fig . 1.

Test system for gravimetric method measurement.

<sc>Fig</sc> . 2.
Fig . 2.

Desorption of CO2 from HNBR control elastomer sample and fitting with Eq. 1.

<sc>Fig</sc> . 3.
Fig . 3.

Desorption of CO2 from HNBR control elastomer sample and fitting with Eq. 2.

<sc>Fig</sc> . 4.
Fig . 4.

Magnetic suspension balance, Rubotherm measurement system.

<sc>Fig</sc> . 5.
Fig . 5.

Effect of relative surface area of carbon black on CO2 diffusivity (samples from CB

study).

<sc>Fig</sc> . 6.
Fig . 6.

Effect of relative surface area of carbon black on CO2 solubility (samples from CB study).

<sc>Fig</sc> . 7.
Fig . 7.

Comparison of the CNT and carbon black on CO2 diffusivity.

<sc>Fig</sc> . 8.
Fig . 8.

Surface chemistry of carbon black and functionalized CNT.

<sc>Fig</sc> . 9.
Fig . 9.

Comparison of the CNT and carbon black on CO2 solubility.

<sc>Fig</sc> . 10.
Fig . 10.

CO2 solubility at different pressures from the Rubotherm method (22 °C).

<sc>Fig</sc> . 11.
Fig . 11.

Pressure dependence of elastomer swelling at different temperatures.

<sc>Fig</sc> . 12.
Fig . 12.

Time dependence of CO2 content in FKM samples after removal from the high-pressure chamber.

<sc>Fig</sc> . 13.
Fig . 13.

O-ring cross section after RGD test based on NORSOK M-710.

Contributor Notes

*Corresponding author. Email: xchen51@cameron.slb.com
Received: 01 Sept 2016
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