Vietnam Industrial Parks InfoGate ! Industrial Zones ! Export Processing Zones ! Down to the largest underground warehouse in Southeast Asia under construction in Vietnam, 200m deep above sea level

These days, the underground LPG storage project of Hyosung Vina Chemical Co., Ltd. in Phu My town, Ba Ria - Vung Tau province is rushing construction to keep up with the schedule. This is an important item of the polypropylene factory project invested by Hyosung Vina, with a total investment of 1.35 billion USD.

When we reached the mouth of the construction well, two ladders, each with a load of 50 tons, were going up and down continuously. The ladder is big, carrying heavy but running smoothly. People on the luck ladder feel like they don’t know they are moving. On the crates of dump trucks from the ground "crawling" up are blocks of rock taken up at a depth of nearly 200m.

Talking to us, the investor said that up to now, the underground LPG storage is about to be completed with 95% of the work done. It is expected that in June 2021, the underground LPG storage will be isolated. The export - import of LPG will be done by dozens of special pipes and pumps. At that time, the tunnels were all sealed, "sealed" with four concrete "buttons" 5m thick. And all activities related to underground storage are monitored by pressure and seismic sensors.

Previously, the land area of more than 60 hectares of the project was just a marshy area. But by the end of April 2021, factories, gas tanks, and massive gas separation towers have sprung up. In particular, deep below that cluster of factories are the two largest underground gas storage in Southeast Asia.

Why is it important to design underground LPG storage in swampy and mangrove areas? According to the explanation of experts who are constructing underground warehouses, the geological survey shows that about 60m from the ground to a depth of mud and soft soil. But from 60m deep down next is solid granite. Mr. Wie Chol Ryang - managing director of the underground warehouse - affirmed that this underground warehouse has almost absolute safety, even in earthquakes, tsunamis or volcanoes. That is a prerequisite for Hyosung to deploy underground storage.

Young female engineer Pham Thi Hong - operator of the underground warehouse - told us more that besides being located at a depth of more than 110m to nearly 200m above sea level, surrounded by hard rock, the underground storage is still intact. designed, constructed in the shape of an egg so that the pressure is not concentrated in one point but evenly distributed. Plus other technical safety factors so that LPG stored in underground storage does not leak out.

In particular, this area is close to a deep-water river to be a port. Mr. Wie Chol Ryang added that this underground warehouse has a lifespan of 50 years and after 50 years, if replacing the pipeline system and ancillary parts, it can be extended. And especially, Mr. Kim Young Ki - deputy general director of Hyosung Vina - said the cost to build underground warehouses is more economical than building floating warehouses, while the land use efficiency is high.

Engineer Pham Thi Hong introduces the scale and operating principle of LPG underground storage - Photo: DONG HA

We went to the LPG underground storage project with the enthusiastic help of young Vietnamese engineers. They introduced the underground warehouse, the project’s production and business activities from importing to the port, putting it into underground storage and then mixing and exporting factories.

Engineer Pham Thi Hong just graduated from Hanoi University of Science and Technology, has worked for Hyosung Vina for more than a year. She said she was very happy to pass the investor’s auditions to take on the role of underground warehouse operator. Although the warehouse has not been operated yet, she has thoroughly grasped the principles and operating principles, especially the safety conditions.

This female engineer said that looking at her colleagues who are operating polypropylene factory 1 from February 2020, she found that young Vietnamese engineers worked very well, meeting the strict requirements of the owner. fourth. And civil engineer Hoang Trung (36 years old), who oversees the underground warehouse project for Hyosung Vina, said he was very happy to work at a tunnel project deep underground.

Visitors to the underground warehouse, Mr. Trung became a guide. "Few people have the honor of being trusted by foreign investors to supervise the construction of such a large underground warehouse. So I am very happy and proud to work at a unique project in Vietnam" - technical Master of the Center.

Talking about Vietnamese engineers and workers, Mr. Wie Chol Ryang - who has experience in construction of two underground gas storage tanks in Korea since decades ago - said that Vietnamese personnel are hard-working, friendly and skilled. good technique, especially high quality welding technique. He also likes Vietnamese people because they are sociable and have similar thinking and personality to Koreans.

The building has the most

Stone truck under the underground warehouse - Photo: DONG HA

LPG underground storage consists of two gas tunnels, both with dome and egg shape. In which, the deepest point of the propnane underground storage is located at a depth of -150m to -172m, the deepest bottom of the warehouse is -192m above sea level. This warehouse has a capacity of 170,000 tons with 4 storage compartments, each compartment is 17m wide and 22m high.

Butane gas storage is located at depths from -110m to -132m, with the deepest point being -152m above sea level. This warehouse has a capacity of 70,000 tons with 2 compartments. The total length of the storage tunnel is nearly 4.8km.

Representative of Hyosung Vina confirmed that with this size and capacity, the LPG underground warehouse in Ba Ria - Vung Tau is considered the largest in Southeast Asia.

In addition, on the ground Hyosung also built 10 gas tanks, each with a capacity of 4,000 tons. This is also the largest gas tank in the world because so far the tanks of the same type can only hold about 1,000-2,000 tons.

To create products from gas, the investor imported to Vietnam and installed at the factory a gas separation tower nearly 120m high and 10m in diameter. It is also the tallest and largest air separation tower in the world.

How to dig underground storage

In order to dig underground gas storage underground, a tunnel used for construction must first be dug. This tunnel is nearly 100m deep and has a diameter of 21m. From this construction tunnel, dig further two ways and deep down to create two storage tunnels as mentioned above.

To prevent and seal between the construction tunnel and the gas tunnel, concrete layers 5m thick are poured. Then the construction tunnel will be pumped with water. Along with that, two tunnels to thread the pump pipes to the warehouse are also filled with water. This is to make the gas cellar surrounded by water.

In addition, people also drill and create "water curtains" around the tunnel. "It is so that the hydrostatic pressure of the water around the tunnel is greater than the pressure of the gas. Thanks to that, the gas does not leak out," explained engineer Hong.