In the deep-well oil exploration field and in other extreme applications, high pressures and temperatures act together to stress components, and those effects are aggravated over time. Withstanding high pressure alone is a challenge — one that becomes more complex when elevated temperatures are added to the mix. Increased exposure time to these hostile environments adds yet a further complication.
Kryoflex Hermetic Connectors
Using the patented Kryoflex® polycrystalline ceramic, PacAero can manufacture reliable high-pressure/high-temperature hermetic connectors and feedthrus that meet these environmental challenges. The controlled CTE and chemical bonding properties of Kryoflex allows rugged hermetic seals with excellent electrical characteristics, even in extreme high-pressure/high-temperature environments.
Kryoflex XTS - 300oC/30,000 PSI Applications
This specific formulation of Kryoflex is enhanced for maximum connector reliability in very high-temperature, high-pressure environments,
Hermetic electrical feedthru connectors used in downhole LWD (Logging While Drilling) and MWD (Measure While Drilling) applications face unique reliability challenges due to highly elevated temperatures and pressures, as well as corrosive water and moisture. These conditions may deteriorate electrical insulation and lead to catastrophic electrical failures.
To help our customers better solve those challenges, PacAero developed a high-strength Kryoflex XTS sealing material. This diamond-like polycrystalline ceramic that provides a highly reliable hermetic seal for feedthru connectors that operate in high-temperature and high-pressure water/fluid based downhole harsh environments.
Kryoflex XTS sealing material can be used to seal conductive pins (X750, Alloy52, BeCu, Ti-alloy, Pt/Ir etc.) into a range of metal shell materials (Inconel alloys, Ti-alloy, Kovar, and stainless steels).
The sealed electrical feedthrus manufactured with this material have been evaluated under 300oC/30,000 PSI in a water-fluid environment designed to replicate down-hole drilling conditions. Figure 1 below shows the duration of the HP/HT electrical feedthru package test under 200oC/30,000 PSI simulated downhole water-fluid conditions. The connector remained hermetic to 1.0 x 10-9 cc He/sec at 1 ATM.
Under those conditions, Kryoflex XTS sealed electrical feed-thru connectors also exhibit high levels of insulation resistance. The Figure 2 shows that an electrical feedthru sealed with Kryoflex XTS sealing material could have ~10,000 megaohms electrical insulation resistances even at 300oC, 2X the industrial accepted 5,000 megaohms standard requirement.
Electrical feedthrus sealed with Kryoflex XTS ceramic sealing material also exhibit exceptional material bonding strength when exposed to the high-levels of shock and vibrations that these components are exposed to while under temperature and pressure. Figure 3 below shows the results of a 0-30,000 PSI pressure shock-cycle test at ambient and 200oC. Again, the feedthru passed hermetic testing to 1.0 x 10-9 cc He/sec at 1 ATM.
The Kryoflex XTS sealing material has not only high mechanical strength but also has high voltage application that could be up to 45KV while keeping 5,000 megaohm insulation resistance. Furthermore, Qnnect provides finite-element-analysis (FEA)-based HPHT electrical feedthru and connector designs that ensure sufficient reliability and performance under -100C to 300C and 0 to 30,000 PSI harsh conditions. Figure 4 below shows a typical FEA-based design on a HPHT bulkhead feedthru design with Inconel 718 as metal header, 0.064” diameter Inconel X750 as pin material, for 5KV/2.5A downhole logging tool application. The performance of such a bulkhead feedthru at zero pressure condition has a safety factor of better than 2 at temperature of <25oC and has a safety factor of better than 3 at temperatures of 150-200oC. Since Kryoflex XTS material has about 103KPSI compressive strength, it enables such a HPHT feedthru to have 35KSI compression capacity with safety factor of 3. Thus, all designed electrical feedthru assembly will be of safety factor of 3, operable under 30 KSI pressure and 300oC temperature downhole or subsea environment. In addition, the hydrophobic properties of the Kryoflex XTS sealing material allow HSG electrical feedthrus and connectors applicable in both water-based and oil-based mud/fluid wellbores.
Kryoflex XTS represents a significant advancement in hermetic sealing technology for high-pressure, high-pressure applications. To learn more about this material, please download our whitepaper.