Production chemical regulations in the North Sea oil and gas sector restrict the use of environmentally harmful substances and require chemical providers to replace such products with environmentally acceptable alternatives. Environmentally acceptable corrosion inhibitors that are used in oil and gas production are non-toxic, biodegradable, and have a low impact on the marine environment. Such inhibitors are designed to protect mild steel from the effects of corrosion in systems containing acid gas, organic acids, and the influence of temperature. In this work, two oilfields in the North Sea required the development of environmentally acceptable corrosion inhibitors, to replace environmentally harmful products. The new products were required to offer similar or improved efficacy to the incumbent inhibitors in a sour environment and to be cost-effective. Laboratory tests were performed to represent field conditions and ranged in temperature, H2S, and CO2 concentration as well as water cut and shear stress. Products were found to be effective to the corrosion rate limit of <4 mpy and with no pitting.
The decomposition process of ancient marine species in the seabed for millions of years coupled with the presence of specific geological conditions such as high pressures and temperatures led to the formation of what is known today as fossil fuels. For this reason, they can be found either on the earth's surface where ancient seas were located or beneath the seabed. Considering that the ocean covers three-quarters of the Earth's surface the offshore oil and natural gas exploration entail an enormous economic and strategic benefit.1
Since the first offshore well produced oil in shallow waters near Summerland, California in 1897 2 drilling activity has moved to deeper areas driven by a remarkable improvement in technology. Nowadays the offshore production is high with the North Sea, the Gulf of Mexico, the Atlantic Ocean off Brazil and West Africa, the Arabian Gulf, and the seas off of South East Asia being the most productive areas. In the United States alone, the offshore federal production in 2020 reached approximately 641 million barrels of oil and 882 billion cubic feet of gas, almost all of which was produced in the Gulf of Mexico. In addition, the Bureau of Ocean Energy Management (BOEM) attached to the U.S. Department of Interior estimated the untapped fossil fuel reserves in the outer continental shelf at 68.79 billion barrels of oil and 229.03 trillion cubic feet of gas.3
