Gas Storage Capacity and System Reform

"Addressing the supply gap at its root and successfully achieving the natural gas supply targets as planned still requires accelerating the reform of the oil and gas sector, and improving the market mechanism design for gas storage and other stages," an industry expert frankly stated.

In August, the National Energy Administration's Oil and Gas Department, among other departments, released the "China Natural Gas Development Report 2017," stating that compared to developed countries in Europe and the United States, China's natural gas pipeline and underground gas storage facilities still lag significantly. As of the end of last year, China's pipeline mileage per 10,000 square kilometers of land area was approximately 70 kilometers, only 12% of the United States'. The underground gas storage facilities had a working gas volume of 6.4 billion cubic meters, accounting for just 3.1% of consumption, far below the global average of 10%. Han Xiaoping, the Chief Information Officer of China Energy Network, further explained that in Europe, the storage level now accounts for 15% of consumption levels. In the United States and Russia, the two major natural gas producers, the storage volumes have reached 120 billion and over 70 billion cubic meters respectively, accounting for 15.4% and 18.8% of consumption. The National Development and Reform Commission had also publicly stated that China's gas storage facilities are facing slow construction speeds and insufficient peak-shaving capabilities, urgently requiring incentives for investment in gas storage facility construction to enhance the guarantee of natural gas supply.

Han Xiaoping stated that the production cost of natural gas is higher than that of coal, and the level of pipeline construction for natural gas transportation needs improvement, with a higher waste rate along the route compared to coal transportation. The profitability of natural gas companies is not ideal, and whether to continue subsidizing natural gas companies, and how to balance the benefits of natural gas companies with subsidies, are among the reform challenges faced by various regions.

1.2.3 LNG Storage Tank Gas Supply Process:

All valves on the tanks to be pressurized, except for the root valve and the emergency cutoff valve, are in the closed position.

2. Open the lower liquid inlet valve of the low-temperature storage tank and the valves for boosting liquid and vapor phases, check that both valves before and after the boosting vaporizer are in the open position.

3. Open the low-temperature cutoff valve before the gasifier, the ambient temperature flanged ball valve after the gasifier, and all valves required to be opened in the pressure regulation system.

4.A. When the gas supply is less than 1000-2000 Nm3/h, one storage tank is sufficient for the gas supply requirements.

5. Output Liquids

5.1 When the tank pressure exceeds the outlet pressure by more than 0.15 MPa, slowly open the liquid outlet valve to initiate the gas supply operation.

5.2 Record the liquid storage tank number and the start of gas supply.

5.3 Pay close attention to the liquid level, pressure changes, and flow and pressure variations at the outlet of the storage tank during gas supply.

1.2.4 LNG Tank Self-Pressurization Operation Procedure

1. During manual operation, open the valves: the boost liquid phase valve, the boost gas phase bypass valve, and the vaporizer inlet valve, allowing LNG to flow directly into the self-boosting vaporizer. After vaporization, it enters the LNG storage tank. At this point, closely monitor the pressure; close the boost liquid phase valve when the pressure in the LNG storage tank reaches the desired level.

2. Cautionary Notes:

(1) During operation, the LNG low-temperature storage tank must ensure that the upper liquid level is ≤90% and the lower liquid level is ≥15%.

(2) When manually operating the self-pressurizing system, it is strictly prohibited to leave the scene unattended.

(3) When the self-pressurizing system is in operation, the depressurizing system should be turned off.

3. Important Notes:

(1) During operation, the LNG tank must maintain a liquid level of ≥15%.

(2) When operating manually, the site must be strictly supervised at all times.

1.2.5 Risk Analysis and Countermeasures

When loading and unloading LNG tankers, operators should wear masks, static-dissipative work clothes, and antifreeze gloves, etc.

2) When unloading LNG tankers, it is strictly prohibited to move the vehicles to avoid breaking the loading and unloading hoses, which could lead to a large-scale LNG leak.

3) When LNG is present in the pipeline, both ends' valves cannot be closed simultaneously.

4) Absolutely no touching or stepping on low-temperature pipelines and equipment.

6) Under no circumstances should moisture, oil, or mechanical impurities enter the pipeline to prevent blockages.

7) Absolutely no敲打, fire drying, or water spraying on the frozen areas.

8) To ensure the safety of the working environment, operators must wear protective gear. Static electricity from the human body must be neutralized before entering the station. Open flames are strictly prohibited within the site's operational area, and the use of non-explosion-proof tools and electronic devices is forbidden.

9) Strictly follow the operation ticket system, execute according to the steps outlined on the ticket. There must be at least two on-site operators, one to perform and one to supervise, to ensure safety in operations.

10) Conduct safety education before operation, implement on-site safety precautions effectively. In case of danger, know how to evacuate and control the situation.