Why Singapore Built A 150m-Deep Oil Cave | Singapore Hour

Key Concepts

• Underground oil storage
• Land reclamation
• Rock mechanics
• Water seepage control
• Hydrocarbon storage
• Safety management
• Real-time monitoring
• Underground infrastructure

Jurong Rock Caverns (JRC): Southeast Asia's First Underground Oil Storage Facility

• Location and Purpose: The Jurong Rock Caverns (JRC) is located 150 meters below ground, carved out of solid granite beneath the seabed off the coast of Jurong Island, Singapore. It serves as Southeast Asia’s first underground oil storage facility, designed to support Singapore’s energy and chemical industries.
• Jurong Island's Development: Jurong Island was created in the 1990s through land reclamation, becoming a leading energy and chemical hub with over a hundred global companies operating there.
• Strategic Decision: Singapore made a strategic decision to build the JRC to optimize land use due to its limited surface area (716 square kilometers). Storing oil underground frees up surface land that would otherwise be occupied by large above-ground tanks.

Construction and Engineering Challenges

• Scale and Depth: The JRC is Singapore's deepest underground infrastructure project, equivalent to a 54-story building or the height of the Pyramid of Giza.
• Storage Capacity: The facility has four large caverns and one smaller cavern, providing a total storage capacity of 1.47 million cubic meters of liquid hydrocarbons, equivalent to 600 Olympic-sized swimming pools.
• Blasting and Rock Stability: The construction involved blasting through solid granite. Professor Wu, a rock science expert, was brought in to ensure the caverns could be dug safely. Rock samples were collected and tested to ensure they remained stable after blasting. Tests confirmed that the surrounding rock provided sufficient support.
  • "We collect the rock samples from the cavern level and we take them to the lab for testing. And during the test, we crush the rock to check if it is still strong enough after blasting. We found that even after the damage, the rock is still stable enough, because the rock was supported by the surroundings."
• Water Seepage Control: A major challenge was preventing seawater from seeping into the caverns through fractures in the rock. Engineers mapped the water paths and sealed the fractures with cement paste.
• Controlled Water Saturation: The goal was not to eliminate water seepage entirely but to control it. Some water flow was desired to ensure the rock was fully saturated, which helps confine the oil inside the cavern without leakage. However, excessive water flow needed to be prevented to maximize oil storage space.

Operational Aspects and Safety Measures

• Jetty Operations: Oil is transferred from ships at the jetty through pipelines and pumped underground into the caverns via a valve manifold area.
• Operations Tunnel: The only access to the sealed caverns is through the operations tunnel, which serves as a main artery for equipment installation, maintenance, and inspections.
• Maintenance and Inspection: Regular checks are conducted on pumps and pipelines to ensure the oil flows smoothly. Corrosion is marked for maintenance.
• Safety Protocols: Safety is paramount due to the risk of hydrocarbon vapor leaks. Maintenance teams regularly scan for gas leaks to ensure the air is safe and the risk of fire is minimized.
• Control Center: A 24/7 control center monitors the entire system in real-time, tracking every valve and pipeline. Flow rates and pressure are monitored to ensure operations stay within safe parameters.
  • "At the moment, we are facilitating a discharge operation request from a vessel at the jetty. And it's being discharged into the caverns. So we are monitoring the flow rate and the pressure, just to make sure all these conditions are operating within the operating range and it's safe."

Significance and Future Implications

• Knowledge and Capabilities: The JRC project has provided Singapore with valuable engineering knowledge, safety management expertise, and operation and maintenance capabilities.
• Blueprint for Future Projects: The JRC serves as a blueprint for future underground infrastructure solutions.
  • "Jurong Rock Caverns has helped us to gain intensive engineering knowledge, safety management and operation and maintenance capabilities. So JRC is not just a storage cavern, it is a blueprint for us to plan the next underground infrastructure solutions."
• Optimizing Land Use: The JRC demonstrates the potential of underground spaces for optimizing land use in a space-constrained environment.
• Turning Constraints into Possibilities: The project showcases how innovative engineering can transform challenges into opportunities, turning solid granite into storage and constraints into possibilities.

Conclusion

The Jurong Rock Caverns represent a significant achievement in underground engineering and infrastructure development. It not only provides a crucial oil storage facility for Singapore but also serves as a model for future underground projects, demonstrating how innovative solutions can address land constraints and create new possibilities for urban development.