Study on the properties and mechanism of triazine sulfur removal agents for oil-based drilling fluid

At present, the use of oil-based drilling fluids is an effective means of achieving efficient drilling. Because of the complex geological conditions, the sulfur content of oil-based drilling fluids increases with increasing drilling time, which has become a difficult problem restricting the exploitation of oil and gas resources. The oil-soluble triazine sulfur remover XN was synthesized from octylamine and formaldehyde, and its structure was characterized by infrared spectroscopy (FTIR) and nuclear magnetic hydrogen spectroscopy (1HNMR). The synthesis conditions of the sulfur removal agent XN were further studied. Simultaneously, the sulfur removal, corrosion, and compatibility of the sulfur removal agent XN in oil-based drilling fluid were studied. The results show that under the conditions of 1% desulfurizer dosage system, 70 °C desulfurization temperature, 30 min desulfurization time, and 100r/min stirring intensity, the optimal desulfurization efficiency of the desulfurizer is 93.09%, and it has good compatibility with oil-based drilling fluid and certain corrosion inhibition performance. When the amount of desulfurizer is 0.2%, the optimal desulfurization efficiency is 93.09%. The maximum corrosion rate is only 0.09 mm·a−1. The desulfurization mechanism of XN was studied using infrared and hydrogen nuclear magnetic resonance spectroscopies. Because XN exhibits good sulfur removal performance in oil-based systems, it is expected to be used as a sulfur removal agent in oil-based drilling fluids with high sulfur content in oil and gas fields.