The UAE holds huge potential in the sour gas sector – the world’s seventh largest gas reserves, according to some estimates, amounting to approximately 212tn cubic feet – of which a large proportion is sour. As a result, several technically challenging projects to exploit this potential are under development in the country.
Krishnaswamy Iyer, director – UAE, Egypt, Iraq and Qatar, WorleyParsons, said: “The UAE is becoming the centre of gas conditioning, evidenced by [projects such as] the Al Hosn Gas project, the upcoming Shuwaihat gas field development, and the Hail field and Bab gas field, which will be pivotal in coming years.”
Taking the lead in developing gas fields with very high hydrogen sulphide (H2S) concentrations, the Abu Dhabi National Oil Company (ADNOC) has collaborated with leading IOCs to develop Shah and Bab – two of the biggest sour gas fields in the world. However, although most of the gas fields in the Middle East are sour, some operators in the region are reluctant to consider such processing schemes due to health, safety and environment (HSE) concerns and the perceived risks of operating complications and corresponding production losses.
Many of the non-associated sour gas fields in the Middle East have acid gas (H2S + CO2) concentrations in the range of 50% or more. Gas production from such fields involves increased capital and operating costs associated with the removal of these impurities. Emphasising the importance of developing non-associated gas fields, however, Angie Slavens, managing director, UniverSUL Consulting, said: “Associated gas from oilfields may be somewhat lower in H2S content, but because it is a by-product of oil production, the rate at which associated gas can be produced is completely dependent on the oil production rate. To meet the region’s energy needs, independent from oil export demand, non-associated gas fields must be developed.”
A milestone project
Al Hosn Gas operates the most advanced sour gas project in the UAE, the Shah gas field, located south-west of Abu Dhabi. The field was was initially considered unsafe for extraction since the reserve has very high levels of H2S and CO2. The development of more robust equipment has now made it possible to extract the gas in a cost-efficient, environmentally friendly fashion, however.
In 2011, ADNOC and Occidental Petroleum signed an agreement to develop this field in a project that will contribute significantly to the energy needs of the UAE over the next 30 years by providing clean-burning fossil fuel to consumers. The project, which produced its first gas in 2015, represents a $10bn investment.
The largest ultra-sour gas development project in the world, the project processes around 1bn cubic feet per day (bcf/d) of sour gas into 0.5 bcf/d of usable gas. The methods used by Al Hosn Gas project to address technological and economic challenges – including the recovery of sulphur on an unprecedented level – are being closely watched by the industry worldwide.
Lucrative demand for sulphur
A sulphur granulation facility is a key facet of Al Hosn Gas project and is expected to produce 3.4mn tonnes of sulphur per year – equivalent to 5% of the world’s supply. The project is expected to ship up to 7mn tonnes of granulated sulphur per year via the Etihad Railway to the Ruwais refinery in Abu Dhabi.
“The Middle East benefits from a fairly close proximity to many of the world’s largest sulphur consumers – China, Morocco, and India – reducing transportation costs, and making sulphur production a more lucrative venture here than in many other parts of the world,” said Slavens.
“Current sulphur production rate in the UAE is approximately 16,500 MTPD (six MMTPA), making it the world’s largest sulphur-producing nation.”
The UAE is likely to be the world’s largest sulphur producer for the foreseeable future, and many international sour gas and sulphur experts will focus on the region, supporting its growth.
