Petroleum University of Technology Iranian Journal of Oil and Gas Science and Technology 2345-2412 11 2 2022 04 01 The Effect of Using Conocarpus Extract as a Green Inhibitor on Steel Corrosion in Hydrochloric Acid Environment in Oil Well Acidizing 28 45 149126 10.22050/ijogst.2022.326955.1622 EN Gholamreza Rashed Associate Professor, Department of Mechanical Engineering, Petroleum University of Technology, Abadan, Iran Maryam Salehi MS Student, Department of Technical Inspection Engineering, Petroleum University of Technology, Abadan, Iran Mohammadreza Shishesaz Associate Professor, Department of Inspection Engineering, Petroleum University of Technology, Abadan, Iran Iman Danaee Associate Professor, Abadan Faculty of Petroleum Engineering, petroleum university of Technology, Abadan, Iran Journal Article 2022 01 29 The effect of using Conocarpus extract as a green inhibitor on the corrosion behavior of mild steel in a 1 M HCL environment is investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The impedance tests show that the polarization resistance increases from 29 for the blank solution to 299 for the solution containing 2500 ppm of Conocarpus extract. The polarization test results show that at room temperature, the corrosion current density for the blank solution decreases from 3.5 × 10^–4 to 2.6× 10^–5 for the solution containing 2500 ppm of Conocarpus extract, and the potential is shifted to negative values. The polarization test is performed at three temperatures of 25, 55, and 85 °C. The results show that the efficiency of 1925 ppm decreases from 93% at room temperature to 86% at 85 °C. The high-temperature efficiency does not decline significantly, indicating the effectiveness of Conocarpus extract at high temperatures. The FTIR tests also prove that the corrosion inhibitory effect of Conocarpus extract is due to the presence of heteroatoms such as N, S, and O. The adsorption isotherm results show that the adsorption of the extract as a single layer on the surface is consistent with the Langmuir isotherm. https://ijogst.put.ac.ir/article_149126_1f1a4bd215978344f39b1a1275f769a6.pdf