Four massive white cylindrical storage tanks stand out prominently at the chemical industrial park in Xiaoliugou Village, Qinghuabian Town, Baota District, Yan'an City, Shaanxi Province. Beside the tanks, a network of interwoven pipelines connects natural gas processing units, with liquefaction cold boxes, compressors, and regasification equipment arranged in orderly fashion. In the central control room not far away, workers keep a close watch on computer screens, monitoring real-time operational data such as temperature, pressure, and flow rates of the production facilities. This was the scene witnessed by a reporting team during a recent visit to the Qinghuabian Natural Gas Liquefaction Station of Shaanxi Yanchang Petroleum Natural Gas Co., Ltd.
These enormous white storage tanks serve as critical infrastructure for ensuring winter natural gas supply in the region. The Qinghuabian station was formerly known as the Yan'an Natural Gas Storage, Peak-Shaving and Supporting LNG Project. As a comprehensive natural gas utilization project integrating storage, liquefaction processing, and helium extraction, it carries a total investment of approximately 2.65 billion yuan, covers about 487 mu of land, and includes four LNG storage tanks each with a capacity of 50,000 cubic meters, designed to produce 400,000 tons of LNG annually and extract 160,000 cubic meters of helium per year.
In late August of this year, after more than two years of construction and commissioning, the project successfully produced qualified LNG products and achieved its first batch of external sales the following day. It has now entered the trial production phase. In recent years, as the "coal-to-gas" transition continues to advance, demand for natural gas from residential use, urban heating, and industrial production has been steadily increasing, particularly during the winter heating season when consumption typically rises significantly. How to store natural gas during low-demand periods and supplement supply promptly during peak-demand periods has become a practical challenge that regional energy security efforts must address.
As a large provincial-level state-owned enterprise in Shaanxi Province, Yanchang Petroleum bears the important responsibility of ensuring stable regional energy supply while advancing the development and utilization of natural gas resources. The construction of the Yan'an Natural Gas Storage, Peak-Shaving and Supporting LNG Project represents a concrete measure by which Yanchang Petroleum has proactively improved its natural gas reserve and regulation capacity based on the actual regional energy supply and demand situation. According to the plan, the Qinghuabian station can add approximately 120 million cubic meters of natural gas storage and peak-shaving capacity, enhancing the comprehensive utilization efficiency of natural gas resources while providing support for the stable winter natural gas supply in Yan'an and surrounding areas.
Building a "Super Reservoir" for Natural Gas
"The primary function of our project is not just producing LNG — more importantly, it is tasked with natural gas storage and peak-shaving," Bai Xinhong, station manager of the Qinghuabian station, told reporters. In the past, natural gas produced in Yan'an and surrounding areas was partly delivered directly to downstream users through pipeline networks and partly transported to other regions by tanker trucks after liquefaction processing. With increasing winter natural gas demand, how to store natural gas during low-demand periods has become an important issue for ensuring residential gas supply.
Natural gas supply has fairly obvious seasonal characteristics. Particularly in northern regions, the concentrated gas demand brought by winter heating places significant peak-shaving pressure on natural gas supply. Without adequate storage facilities, once prolonged low-temperature weather occurs or gas demand grows rapidly within a short period, the supply pressure on natural gas pipeline networks could increase accordingly. For state-owned enterprises responsible for ensuring energy supply, building storage and peak-shaving facilities is not only a necessity for improving the natural gas industry chain and enhancing resource utilization efficiency, but also an important means of strengthening regional energy supply security.
"When the weather is warm, gas consumption is relatively low, so we can store natural gas. When the winter heating peak arrives, we regasify the stored natural gas and feed it into the pipeline network, playing a role in shaving peaks and filling valleys," Bai Xinhong explained. Reporters learned that the feedstock gas for the Qinghuabian station comes from Yanchang Petroleum's upstream natural gas pipeline network. After purification treatment, the natural gas enters the liquefaction cold box, where the temperature is gradually reduced to approximately minus 162 degrees Celsius, transforming from gaseous to liquid state with a significant reduction in volume. According to commonly used engineering conversion formulas, approximately 625 cubic meters of natural gas can be reduced to about 1 cubic meter after liquefaction, making it easier to store and transport.
At the Qinghuabian station, the liquefied natural gas is then transported to the four large LNG storage tanks within the plant area. According to Bai Xinhong, these four tanks have a total storage capacity of 200,000 cubic meters, designed to hold approximately 88,000 tons of LNG, corresponding to a natural gas storage and peak-shaving capacity of about 120 million cubic meters. The LNG in the tanks has two main destinations. One is to be loaded into LNG transport tanker trucks and sold to different regions via road transportation; the other is to be reconverted into gaseous natural gas through regasification equipment when winter natural gas demand increases, and fed back into the natural gas pipeline network.
"What is stored is liquid natural gas. When needed, it is heated and regasified, then transported through pipelines so that residents can use it directly at home," Bai Xinhong said. The project includes a regasification unit with a capacity of 40,000 cubic meters per hour. According to the project plan, the Qinghuabian station can provide approximately 50 days of peak-shaving gas source support for Yan'an and surrounding areas. The formation of this storage and peak-shaving capacity means that the region will have more ample gas source adjustment space when responding to concentrated winter natural gas demand. Especially under extreme low-temperature weather or tight natural gas supply conditions, reserve gas sources can play an emergency supplementary role to a certain extent, improving the stability of regional natural gas supply.
From this perspective, the construction of the Qinghuabian station is not simply adding a natural gas processing facility, but a concrete practice by which Yanchang Petroleum combines enterprise production and operations with regional energy security. By improving natural gas storage, peak-shaving, and emergency guarantee capabilities, Yanchang Petroleum has further strengthened its sense of responsibility in ensuring residential gas supply while expanding its natural gas industry chain.
Extracting "Golden Gas" from Natural Gas
For the Qinghuabian station, natural gas can not only be liquefied and stored, but another product with relatively high added value — helium — can also be further extracted from BOG (boil-off gas). "Our project mainly produces two products — one is LNG, and the other is helium. Helium is a rare gas and also an important strategic resource," Bai Xinhong told reporters. Unlike LNG, which is mainly used for residential living, industrial fuel, and vehicle fuel, helium is widely used in aerospace, semiconductor manufacturing, nuclear magnetic resonance, superconducting technology, and special metal smelting, among other fields, and is therefore called "golden gas."
However, helium extraction is not easy. Bai Xinhong explained that the main component of natural gas is methane, which may contain small amounts of helium. Some gas sources even have helium concentrations of less than 100 ppm, so whether helium can be separated economically and effectively places high demands on process technology. Reporters learned that the Qinghuabian station mainly recovers helium from the boil-off gas (BOG) generated by LNG storage tanks, and then returns the remaining natural gas to the fuel gas system to improve comprehensive resource utilization efficiency. The project is designed with an annual helium extraction capacity of 160,000 cubic meters. While undertaking the task of natural gas storage and peak-shaving, the recovery and utilization of high-value-added helium resources also gives this project more diversified industrial value. By combining natural gas liquefaction processing with rare gas extraction, Yanchang Petroleum has further expanded the space for comprehensive utilization of natural gas resources while improving its natural gas industry layout.
The Qinghuabian station is not Yanchang Petroleum's first helium extraction project. According to Bai Xinhong, Yanchang Petroleum Natural Gas Company currently has 6 natural gas liquefaction stations and 1 branch company, located in Yan'an and Yulin, with total LNG production capacity reaching 1.9 million tons per year and designed helium production capacity reaching 760,200 cubic meters per year. Among the company's 7 production units, 5 have been equipped with helium extraction facilities. In addition to helium extraction, a high degree of intelligence and automation is also a major feature of the Qinghuabian station. Reporters observed in the project's central control room that workers use computer screens to conduct centralized monitoring of various production processes including natural gas purification, liquefaction, and storage.
"During normal production, not many people are needed on-site for operations — adjustments are mainly made through the central control room," Bai Xinhong said. Compared with some natural gas liquefaction stations built by Yanchang Petroleum in earlier periods, the new facilities use automated control and interlock protection systems that can automatically adjust some operating parameters and reduce manual intervention. At the same time, reporters observed on-site that the plant area is also equipped with two intelligent inspection robots that can check equipment and pipeline parameters such as temperature, pressure, and flow rates as well as leakage conditions along preset routes. However, because natural gas is flammable and explosive, on-site personnel are still needed for regular inspections to promptly identify equipment faults and abnormal conditions.
It is worth noting that the Qinghuabian station has achieved full domestication of equipment. According to Bai Xinhong, compared with some imported equipment used in earlier periods, domestic equipment has more advantages in procurement costs, later maintenance, and spare parts supply, helping to reduce production and operation costs. In terms of actual production results, domestic equipment is already fully comparable to imported equipment. For natural gas storage and peak-shaving projects, the stability of equipment operation is not only related to the enterprise's production efficiency, but also to whether the storage and peak-shaving function can be effectively deployed at critical moments. From automated control of production facilities to the application of intelligent inspection equipment, and further to the domestication of key equipment, the Qinghuabian station is providing guarantees for the safe and stable operation of natural gas processing and storage peak-shaving facilities through technological upgrading.
More than 90 years ago, the Central Red Army overcame numerous hardships and dangers and victoriously arrived at Wuqi Town in northern Shaanxi in October 1935. Today, on this yellow earth that carries red memories, from large storage tanks enabling seasonal natural gas reserves to the extraction of high-value-added helium, Yanchang Petroleum Natural Gas Company is exploring new paths for the comprehensive utilization of natural gas resources. Behind industrial development, ensuring stable regional energy supply is equally an important responsibility of this large provincial-level state-owned enterprise in Shaanxi Province. As the storage and peak-shaving capacity of the Qinghuabian station is gradually released, this natural gas storage and peak-shaving project built on the Loess Plateau will not only add another layer of security for winter energy supply in Yan'an and surrounding areas, but also serve as a concrete example of Yanchang Petroleum proactively fulfilling its social responsibility as a state-owned enterprise and serving local economic and social development.
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