Study of the effect of the composition of high-paraffin oil on their freezing temperature and on the corrosion aggressivity of formation water

The effects of gossypol resin and NDP-6 reagents, as well as the Z-1 composition prepared in the ratio of NDP-6 + gossypol resin = 9:1 on the corrosion aggressiveness of formation water and freezing temperature of high-paraffin model oil were investigated for the first time in laboratory conditions. During the experiments, a model oil sample prepared in a 2:1 ratio of commercial oil from Narimanov and Absheron fields of SOCAR was used as a research object. The electrochemical corrosion medium was a formation water sample taken from well No. 1082 of “Bibiheybatneft” OGPI, SOCAR. It was determined that compared to individual reagents, the new composition has a more effective impact on the corrosion rate in H2S formation water and the freezing temperature of high-paraffin oil sample. As a result of the conducted research, it was found out that as the concentration of reagents increases, the efficiency of the effect also increases. Thus, the highest protection efficiency for gossypol resin was observed at a concentration of 110 mg/l, resulting in the corrosion rate of 0.09 g/m2 · h (98% corrosion protection efficiency). The most effective indicator for NDP-6 depressant additive was at 1000 g/t, reducing the freezing temperature of high-paraffin model oil from +16°С to –2°С. However, the strongest effect was observed in Z-1 composition. At a concentration of 700 g/t, it reduced the corrosion rate in the formation water from 4.30 g/m2 · h to 0.04 g/m2 · h (99% corrosion protection efficiency) and the freezing temperature of model oil from +16°С to –9°C, respectively (163% of the effect on freezing temperature). Thus, based on the results obtained from the experiments, the efficiency of individual reagents and the composition based on both reagents was calculated. The highest efficiency was observed at a concentration of 700 g/t for the composition “NDP-6 + gossypol resin = 9:1” (conditional name – Z-1).