Effect of various compositions on corrosion rate of steel in formation water and freezing temperature of high-paraffin model oil

Abstract

The effects of Gossypol resin and NDP-6 reagents and Z-1 composition (the mixture of NDP-6+Gossypol resin at the ratio of 9:1) on the corrosion rate of steel in the formation water and the freezing temperature of high-paraffin model oil were investigated for the first time under laboratory conditions. In the experiments, a model oil sample prepared in a ratio of 2:1 of commercial oils from Narimanov and Absheron fields of SOCAR was used as a research object, and a formation water sample taken from well No. 1082 of “Bibiheybatneft” OGPI, SOCAR was used as an electrochemical corrosion medium. It was determined that the new composition had a more effective impact on the corrosion rate in H2S-containing formation water and the freezing temperature of high-paraffin oil sample than individual reagents. Thus, the highest efficiency for gossypol resin was observed at a concentration of 110 mg/l, when the corrosion rate was 0.09 g/m2h (corrosion protection efficiency of 98%). The most effective indicator for NDP-6 depressant additive was 1000 g/t, and the freezing temperature of high-paraffin model oil was stated to decrease from +160С to –20С. However, the strongest effect has been observed for the Z-1 composition. Thus, the composition with a concentration of 700 g/t reduces the corrosion rate in the formation water from 4.30 g/m2h to 0.04 g/m2h (corrosion protection efficiency of 99%) and the freezing temperature of model oil from +160С to –90C.