Authors

Abstract

Steel corrosion and erosion-corrosion have an important role in oil fields
utilizing steel pipelines. Therefore; in the present work corrosion, erosion and
erosion-corrosion tests are studied individually to investigate the interaction
between corrosion and erosion processes and to quantify the synergy (that caused
by erosion) in realistic flow environments.
The experimental work tests were done using special device which was
designed and manufactured according to (G 73) ASTM with certain modifications.
The experimental work tests were achieved using traditional weight loss
technique to measure weight loss rates in (gmd) unit. Also the microstructure
observations of the test specimens are studied.
It was observed that whole tests were conducted on oil pipe (X 60) made of
low carbon steel in plate form, tests were made on corrosion using 3.5 wt %
sodium chloride. (NaCl) solution as sea water purged with CO2 gas as the corrosive
medium in crude oil, erosion using 1 wt % silica sand as the erodent in distilled
water purged with N2 gas as anti corrosive medium to get erosion just during
erosion and erosion-corrosion using the same mentioned medium in the corrosion
but in erosion-corrosion 1 wt % silica sand was added as slurry to that medium, all
tests above were done under pumped media except in case of corrosion and
pumped media had constant pressure of 1 bar, flow rate Q = 36 L/min, temperature
≈ 25 ºC and pH = 4.4 for corrosive and erosive-corrosive media but pH = 7.4 for
erosive medium.
After traditional weight loss technique was achieved, it was found that
corrosion rate C.R (0.18144 gmd) was the smallest, erosion rate E.R (0.80214gmd)
was greater than corrosion rate (C.R), but erosion-corrosion rate EC.R
(3.99161gmd) was the biggest ie. (EC.R was greatest), in addition synergy
(0.0315g) was calculated by using special equation related to weight loss which
was measured in (g) unit.