Anyone familiar with “sour” crude knows that hydrogen sulfide, or H2S, is the culprit. High concentrations of this highly toxic gas can occur naturally in many petroleum reservoirs. Other fields seem to turn sour when water is injected to enhance the recovery of oil or natural gas. Hydrogen sulfide not only diminishes the value of crude, but if not handled properly, it also presents a serious danger to workers exposed to it. Even minimal exposure to H2S can cause nausea, fatigue, headaches, burning eyes, coughing, and shortness of breath, while extended exposure can lead to asphyxiation and respiratory failure. Heavier than air, hydrogen sulfide can accumulate in low lying unventilated areas, and while the noxious gas can sometimes be recognized by a smell similar to rotten eggs, often even lethal concentrations of H2S can be difficult to detect until it is too late. Beyond the serious health risks, H2S is also corrosive to storage tanks, pipelines and rail cars, and the toxic vapors it creates when stored can also be highly flammable. Therefore, stabilizing, or sweetening, sour crude becomes a critical function for drilling operators, midstream companies, and refineries operating in areas where sour crude is prevalent. Sweetening sour crude typically involves a chemical treatment process that strips H2S from the crude to a concentration level that can be safely stored and transported. The industry standard is considered to be 10 ppmw (Parts Per Million by Weight) limit, but some industry players will turn away any crude oil that has H2S levels higher than 5 ppmw. Most conventional H2S mitigation methods are less than ideal. Removal agents, or scavengers, are typically chemical solutions that essentially consume hydrogen sulfide molecules. These scavengers, though, often leave additives that contaminate the crude. Other methods can cause a loss in crude oil volumes. Despite their shortcomings, however, until now these treatment methods have been the norm. Jason Groves, CEO with newcomer RevEnergy, believes the company’s proprietary RevH2S system can help revolutionize H2S remediation. Designed in collaboration with leading engineering firm AECOM, the RevH2S is a patented, closed-loop module that can safely reduce hydrogen sulfide in sour crude to less than 4 ppmw (and even to 0 pppw in some cases) – that’s far lower than the industry standard of 10 ppmw. And unlike conventional H2S mitigation methods, RevH2S causes no volume loss and leaves no chemical additives in the treated crude. “The result is a simply sweeter crude that is safer to transport and store,” says Groves. Groves explains that a skid-based RevH2S unit, which is roughly the size of a cargo container (about 40 x 8 feet), is designed to be transportable and provide for quicker installation and construction period when compared to a stick built system, reducing construction costs and setup time. RevH2S uses an inert gas to safely strip H2S from sour crude without causing a chemical reaction or changing the properties of the crude. And because the gasses are completely contained and continuously recycled and reused within the unit, no residual gasses are ever emitted into the atmosphere. The RevH2S unique and simple design can treat a broad range of sour feed gas flow rates and H2S concentrations. A single RevH2S unit can treat 3,000 to 9,000 bpd of sour crude with hydrogen sulfide concentration levels up to 300 ppmw. Crude oil with higher H2S concentrations can be repeatedly cycled through the RevH2S unit, so there is no limit to the H2S levels the RevH2S can treat and even the sourest crude can achieve nearly undetectable H2S concentrations. Crude oil capacities of more than 9,000 bpd can be treated using multiple RevH2S units, making it scalable for various production volumes so higher treatment capacities can be easily achieved. “Sweeter crude is not only safer, but it’s also more commercially viable, so it makes sense that industry players invest in technology that treats this sour gas in crude oil,” says Groves. “RevEnergy’s RevH2S is an advanced solution that we believe surpasses other commercial treatment methods because it strips H2S to a concentration level that is far lower than the industry standard with no volume loss.” Despite its advanced features, Grove promises that the cost of the RevH2S is comparable to other commercial H2S treatment methods. The RevH2S also has the advantage of a closed-loop system – because there are no emissions to endanger the environment, no Title V permit is required, which can also save users significant time and money. “For RevEnergy, it’s not about where H2S remediation is today, it’s about where it should be – and we’re ready to take it there,” says Groves.
RevEnergy has designed an innovative method for safely reducing hydrogen sulphide (H2S) content in sour crude. A highly toxic gas, H2S reduces the value of crude and threatens the health of anyone exposed to it, making stabilising or sweetening sour crude essential for companies and refineries. RevEnergy’s RevH2S is a patented, closed-loop module that can reduce H2S in crude to between 0 pppw and 4 ppmw, significantly lower than the 10 ppmw industry standard. The method also improves on traditional techniques as it causes no loss of volume and doesn't leave any chemical additives.