Synthesis Of Cottonseed-oil Derivatives Corrosion Inhibitors And Study On Inhibition Properties

The process of oil well acidizing is a technology which has been widely used in most oil fields of domestic and overseas. Hydrochloric acid, hydrofluoric acid or other acids (such as fluoboric acid) is injected into the stratum. Through the acid-fracturing process, dissolve the blockage in the flow, expand permeability channel of rock in reservoir and format artificial cracks. So the output of oil and gas increase obviously as oil and gas channels become unobstructed.In recent years, as deeper and hotter wells were drilled, stimulation acid was exposed to hotter conditions, intensifiers and high-temperature acidizing corrosion inhibitors are badly demanded. Meanwhile, environmental pollution and ecological damage caused by corrosion inhibitor has been realized by scholars, so the orientation of research work in the future is"green corrosion inhibitor"."Green corrosion inhibitor"is to investigate pollution prevention of oil-field at the molecular level and to design chemical structure by chemistry method, In this method, to reduce or eliminate the generation of manufacture hazardous materials and application of chemicals. The purpose for the application of"green corrosion inhibitor"is to develop novel, environmentally and friendly corrosion inhibitor.As is known that cotton is the specialty of Xinjiang province, the area of cotton plant in Xinjiang is 20.65 percents of the whole country. How to make full use of the valuable resource is a significant work.In this paper, four cottonseed oil corrosion inhibitors were synthesized. The corrosion inhibitor performance for N80 steel in 15% HCl solution was studied by grav1metric measurements, potentiodynamic polarization curves, electrochemical limpedance and Scanning electron microscopy (SEM), In additional, the inhibition properties were investigated by the addition with other additives (surfactants, anion active substances and propargyl alcohol), the results indicate that the additives improve the corrosion inhibitor performance. The relationship between compound corrosion inhibitor system and corrosion hours, corrosion temperature was discussed as well.In chapter 2, cottonseed oil imidazoline quaternary salt inhibitors were synthesized by cottonseed-oil and triethylenetetramine. In order to discuss the synthetical conditions, three factors were chosen, which were reactant ratio, reaction time and catalyst amount. The orthogonal experiment analysis indicates that the best values of three factors are as follows: the ratio of cottonseed oil to triethylenetetramine is 1.8:1, reaction time is 8 hours, the amount of catalyst (boric-acid) is 0.2% respectively. The structures were characterized by IR spectrum, the results show that 1608cm-1 was the characteristic absorption peak of imidazole ring.In chapter 3, the inhibition properties of synthesized cottonseed oil imidazoline corrosion inhibitor for 15% HCl solution were evaluated by grav1metric measurements, potentiodynamic polarization curves, electrochemical limpedance and scanning electron microscopy (SEM). The results indicate that three corrosion inhibitors have good performances. With the increasing concentration of corrosion inhibitors, inhibition efficiency also increases. When the amount increases to certain concentration, the inhibition efficiency would be slightly decreased. Moreover, the cottonseed oil imidazoline corrosion inhibitor mixed with other additives (OP-10, KI and propargyl alcohol) enhances inhibition efficiency obviously. Finally, the relationship between compound corrosion inhibitor performance and corrosion hours/corrosion temperature was investigated, the results show that compound inhibitors have good performance at different to the corrosion temperature and corrosion hours.In chapter 4, cottonseed amide corrosion inhibitor was synthesized, and the inhibition properties for 1:6 DTS-HC solution were evaluated by grav1metric measurements.The result indicates that the corrosion inhibitors have good performance. Furthermore, the relationship between compound corrosion inhibitor performance and corrosion hour was studied.