What Is Sour Gas? Key Insights for Aspiring Energy Professionals

The term “sour gas” refers to natural gas resources that have a higher concentration of acidic gases, namely hydrogen sulfide (H₂S) and carbon dioxide (CO₂), than sweet natural gas.

“Acid gas” is often used to refer to H₂S because of its corrosive properties to pipelines, as well as its noxious effects on human health. It has a distinct odour of rotten eggs. However, at higher concentrations, it becomes difficult to detect.

How Sour Gas Is Treated and Processed

Unlike sweet gas, which requires minimal processing at the extraction site, the natural gas stream from sour fields requires the conversion of sulfur compounds into elemental sulfur before transport, a step termed “sweetening.” This is achieved through:

• Claus Process: Invented in the late 19th century by a German engineer called Carl Friedrich Claus, the Claus process isolates hydrogen sulfide using amine solutions to produce elemental sulfur that is then used in multiple industries. This is the most prevalent and important sweetening process.
• Stretford Process: A liquid reduction-oxidation (redox) reaction developed in the 1940s to isolate hydrogen sulfide.
• SulFerox Process: A Shell proprietary process
  that uses ferric ions (Fe3+) in solution to oxidise hydrogen sulfide into elemental sulfur and ferrous ions (Fe2+).
• Thiopaq O&G Process: A process that uses a bacterium called Thiobacillus to oxidise hydrogen sulfide. It is used in cases where the Claus process might be too costly to run because the production volume is too small
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The Role of Sour Gas in Malaysia’s Energy Sector

As a leading exporter of liquefied natural gas (LNG), Malaysia has been expanding operations in recent years, becoming the 5th largest LNG exporter in 2022, according to the International Gas Union report of the year

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With legacy sweet gas fields maturing and their yield steadily declining, it’s up to other gas reserves to ensure Malaysia not only maintains leadership as a LNG exporter, but also to secure its energy needs for the future.

At Shell, we understand this unique situation, so the company has invested in projects where the untapped potential of sour gas can be better explored.

In September of 2022, we announced the development of the Rosemari-Marjoram onshore plant as the largest Sarawak Shell Berhad (SSB) onshore project since the 1970s.

Rosemari and Marjoram are both sour gas deepwater fields, expected to yield

800 million m³/year when production starts in 2026.

Why Start a Job in the Sour Gas Industry?

It’s estimated that over 40% of the world’s natural gas

reserves are located in sour fields. This figure means that opportunities to tap into these resources are still widely available.

Although, historically, it was considered difficult and uneconomic to pursue developmental projects for sour gas, the current technological landscape makes these projects within reach.

Approaching your future as an energy professional with an open mind and determination is bound to be more rewarding in the long term. Gaining the required knowledge and skills to hone your experience within the sour gas industry should prove invaluable for your future career.

Essential Skills and Job Opportunities in Sour Gas

Shell Malaysia harbours an environment where you can learn and grow as an energy professional. Your contributions to sustainability and energy transition should also be a driving force to push you forward in your sour gas career.

If you are intrigued by the potential for growth within the field of sour gas, you should also be aware that this line of work presents some challenges unique to it. That said, you will also get the chance to use your specialised skills to solve the complex problems that come with the territory.

Key Skills for Working with Sour Gas

Here are the most important skills needed to work with sour gas safely and efficiently:

Safety Management

It’s not a secret that handling sour gas comes with safety risks, especially since hydrogen sulfide is a known irritant and is considered poisonous even at relatively low concentrations.

Completing your safety training and abiding by industry protocols for handling the acid gas stream is crucial for preventing personal injury and workplace incidents. 

Technical Expertise

Whether you work in drilling, reservoir, production, mechanical, electrical, or process engineering, your technical skills are needed to make sure the extraction and refinement equipment and procedures are up to industry standards and working as expected.

Analytical and Problem-Solving Skills

Since hydrogen sulfide is highly corrosive and toxic, it’s critical to have developed problem-solving skills for situations when equipment issues arise. Knowing how to handle these situations should prevent production delays and bodily injury.

Why Choose Shell

With an 80% share in the Rosemari-Marjoram project, Shell is a crucial stakeholder in Malaysia’s energy production future while maintaining an international outlook of sustainable business practices.

Becoming part of this vibrant, multicultural work environment, where you can learn and grow as an energy professional, is a sure boost to your career in the sour gas industry.

Start Your Professional Journey in Sour Gas with Shell Malaysia

Sour gas might have been historically one of the least lucrative fossil fuels. However, with the current advancements in extraction, sweetening, and refinement, it’s proving to be a huge part of Malaysia’s energy future, as evidenced by the Rosemari-Marjoram project.

Ready to take the next step in your energy journey? Explore exciting opportunities in sour gas operations and beyond at Shell Malaysia. Start your journey today by visiting our Careers Page.