Assessment of Internal Tubular Coating Using Flow Loop

Assessment of coating performance under flowing condition by using a proprietary flow loop system has been established. The 2 3/8" flow loop was designed to maintain a flow rate of 0.03-0.04 m3/sec, pressure of 3300kPa and temperature of 150°C to simulate actual field condition. Test section consisting of two 35" straight tubes with 45° elbow was internally coated and connected to the flow loop which was run continuously for 14 days with deionized water under the specified test condition. Upon completion, visual inspection, EIS and linear abrasion test were done on the test section to evaluate the coating integrity post exposure. Small blisters were noted at the elbow section potentially due to the improper surface preparation and/or higher fluid velocity at the bend section. Impedance value of 107 Ω/cm2 is a magnitude higher than the acceptance limit of 106 Ω/cm2 while abrasion resistance was found less than the set limit of <100mg/1000 cycles. The flow loop test has been shown to be a reliable tool to evaluate the effect of wall shear stress and fluid erosion on internal tubular coating.