Rotating Control Devices (RCDs) experience shorter life in higher temperature wells because the existing RCD rotary seals are being pushed beyond their limit. For several years we have been evaluating different seal liner materials for the KLS high-pressure rotary lip seal that can successfully operate at these higher temperatures. We recently completed the most successful high temperature RCD rotary test of a KLS seal.
A KLS seal using our -38 liner material was run on our RCD rotary seal test fixture. The operating conditions were 500 psi differential pressure, 190 RPM on a 10.50” mandrel, and with the surrounding fluid between 221°F (105°C) and 250°F (121°C). Note that the standard liner material for the KLS rotary seal, designated as -34, is challenged when the surrounding fluid temperature is above 205°F (96°C).
As seen in Figure 1, the KLS seal with the -38 liner material was in very good condition after testing and could have continued running. Also shown in Figure 1 is the post-test condition of KLS seals using our -33 and our -35 liner materials. While all three KLS seals met the 100-hour minimum operating duration, established by industry standard API 16RCD, the KLS seal with the -38 liner material ran significantly longer at the test conditions (214 hours) and at the highest average temperature. Additionally, the KLS seal with the -33 material liner (144 hours) and the KLS with the -35 material liner (147 hours) suffered a sealing breach before reaching our internal test target of 200 hours.
We are planning more tests of KLS seals with the -38 KEI liner material to better understand the material limits at RCD rotary seal conditions.
To discuss implementing KLS Seals with the -38 liner material in your RCD, contact us at 281-240-6500, or e-mail our team. See our rotary shaft seal catalog for available off-the-shelf sizes.
Test setup
The RCD rotary seal test is configured to simulate the differential pressure that the inboard pressure retaining KLS seal of an RCD is exposed to when with the lubricant pressure between a pair of lip seals is balanced to the wellbore pressure and the pressure of the fluid above the inboard seal is at low pressure. This RCD rotary sealing arrangement is described in Chapter E6 of the Kalsi Seals Handbook.
The low-pressure and high-pressure fluid used in the test setup is Mobil SHC 632 (ISO 320 viscosity grade). Low pressure coolant is circulated through the mandrel to remove some of the seal-generated heat. The temperature of the oil just above and just below the test seal is recorded. The locations where the temperature is recorded are indicated by the thermocouple locations in Figure 2.
