Gas Storage, Reliable Support for Energy Security
The storage industry is more than century-old. Some countries like the US have over 400 natural gas underground storage facilities. Iran is the world's second largest gas reserves, and has one of the most expanded gas transmission networks. However, it is at the beginning of road with regard to underground natural gas storage. Iran has about 1% of world gas storage capacity. This strategic industry would be profitable and serve as are liable support in energy supply and exports.
Mahmoud Nemati, director of gas storage projects, speaks about achievements in this sector in an interview with" Iran Petroleum".
Where does gas storage stand in the world today?
The United Nations Economic Committee releases an annual report about storage across the globe. Some data is surprising. There are more than 400 storage sites in the US and even its tropical areas. The first gas storage site was built in Canada more than a century ago. The issue of gas storage takes up added significance for European countries which mainly import natural gas. Some nations like Russia rely on their numerous storage sites to supply domestic needs, while gaining revenue from exports.
When was the issue of storage taken into consideration in Iran?
Up to 2007 the issue of storage was discussed sporadically. But after a cold spell struck in that year, causing accidents in the north, decision-makers realized that sitting atop huge gas reserves could not on its own guarantee national energy security. Since then, the issue of storage with the objective of energy security stability and avoiding possible problems became serious.
What complications are storage projects faced with in terms of extent and technology?
Generally speaking, storage is an underground operation which is carried out on a large scale. In fact, we store gas in huge quantities in underground facilities, which are totally different from surface facilities. Currently, we are enjoying technological capacities for wells and storage in hydrocarbon reservoirs. But we would need to acquire knowhow and technology with regard to equipment and storage in aquifers and salt domes. To that effect, we have obligated contractors to hire foreign technologically-capable partners.
Underground gas storage to ensure energy supply during consumption peak is a major advantage of the storage industry. Could you elaborate on that?
In the winter when household consumption is multiplied, we would need resources in addition to what we have at our disposal in order to meet the consumers’ needs during consumption peak. Furthermore, in order to produce oil from the reservoirs with pressure fall-off, we would have to inject gas. Should injection come to a halt in the winter due to the priority of domestic needs, oil recovery will decline. Therefore, storage facilities would be a blessing under such circumstances.
How can storage support exports?
We have currently gas export deals with neighboring countries. Such agreements take up added significance in the winter. Should we fail to use our stored gas in the winter in response to growing domestic consumption, we will have to cut gas exports, in which case we will be imposed heavy fines. Such losses will even surpass gas export revenue achieved in several years.
What are the strategic advantages of storage?
As you know, some areas like northeastern Iran are located far from production spots. In case Khangiran reservoir, which covers the main needs of consumers in that area, faces any fall-off in the long-term, gas supply to Khorasan and the mega city of Mashhad will be faced with problems. In order to prevent any problem with gas supply, we will have two options: First, we need to build a new pipeline, which would impose exorbitant costs upon us. Second, we can develop storage sites around the cities, in which case we can recover gas in the winter which is stored in the summer. It is noteworthy that sometimes pipes may be damaged due to acts of God and natural disasters like floods or earthquake. Under such conditions we can sit idly and cut gas supply to cities until the problem is resolved. The gas storage sites built around mega cities are of great help during times of crisis. By dipping into these reservoirs we can supply gas to cities for a short period of time as long as damage is repaired.
In addition to the depleted hydrocarbon reservoirs, what other options are there for underground gas storage?
Our top priority in storage is depleted oil and gas fields. If in some areas, hydrocarbon reserves are not available we will go towards aquifers, i.e. reservoirs which have the properties of reservoirs but they contain water instead of hydrocarbon. In such cases, we deplete the water and store gas instead. The third priority for storage is using underground salt domes. These structures are in fact thick salt layers with big volume. We wash and solve the salt layers and use the created space for storage. In Iran, we are using the three types of hydrocarbon storage tanks, aquifers and salt domes.
Given the significance of energy supply security for northern and northeastern areas, which areas are envisaged for that purpose?
The Shourijeh gas storage project is over now and the second phase of development of this field will start soon. In that area, there is also the Qezel Tappeh gas field which we have under study. As far as the significance of development of storage fields is concerned, it would be sufficient to say that implementation of these projects would make NIGC independent of new pipes, and would put an end to dependence on gas imports from Turkmenistan.
Could you update us on gas storage in central Iran?
In fact, except Sarajeh, there is no other field available for this purpose in central Iran. Our studies bear proof to such conclusion. Sarajeh was the first field that came on-stream in Iran. The second phase of this field is under way. Due to the lack of any other hydrocarbon storage facility but Sarajeh, the Kashan salt dome is being developed for storage. The gas storage project in Kashan’s Nasrabad (a salt dome) is now in the phase of development with drilling operation under way. The Yurthsha aquifer is also located in central Iran and we have to make decision about it.
Talking about northwest, could you tell us about fields envisaged for storage in that area?
Primary studies have been conducted on the Bankul and Baba Qir fields, and we are currently in the process of planning for drilling in those fields. Currently, the bulk of feedstock for the Ilam refinery is supplied from Tang-e Bijar, and due to the necessity of gradual fall-off from this field, it is necessary that the Bankul and Baba Qir fields become operational in the shortest possible time to enable us to supply feedstock for the refinery. In the Yasuj area, we have the Mokhtar field under study. It is now in the phase of pre-feasibility study.
Anything else you would like to add?
Gas storage would create a strategic advantage for the country due to its economic advantages, safety and accessibility. Achieving this important objective would be a must for our country due to the necessity of supplying this clean energy at home. Compared with gas transmission through pipeline, gas storage projects are more cost-effective and they would guarantee the security of energy supply to people and industries. It is noteworthy that the authority for all those fields has been delegated from NIOC to NIGC, and it means that our organization is now stepping into the upstream sector. Some fields are depleted, but some others are still able to produce. They would be used as storage sites after depletion. The 6th Five-Year Economic Development Plan requires us to supply 13% of gas needs from storage sites and we are determined to develop underground facilities all across the country, particularly in cold areas in order to use them when gas flow is cut.