| Abstract |
The objective of this program is to determine the best elastoers for use in medium temperature geothermal wells, with emphasis on binary plants in which isobutane is the working fluid. Fifteen companies submitted thirty four high temperature elastomer compounds for test. Tensile specimens were immersed in 375 F brine, isobutane and four types of oil for 120 hours. Eight compounds were selected based upon the least change in weight, volume, ultimate tensile, hardness and elasticity. These eight were tested as static O-ring seals in brine, isobutane and ASTM #1 oil. Test temperatures were 375F, 450F and 510F. The tests lasted 46 hours with a 3000 psi pressure differential across the seal. The major conclusion was that the EPDM O-rings are superior to the others tested in each of the three fluids. The EPDM compounds surprisingly withstood ASTM #1 oil- a conclusion that would not be reached using immersion test results. |