Podziemne magazynowanie węglowodorów w kawernach solnych w Polsce — wymiar strategiczny i możliwości poprawy stanu środowiska naturalnego

Abstract

Storage of hydrocarbons in salt caverns — strategic significance and the use of salt brine as a medium for improvement of environment.A b s t r a c t . Storage of strategic hydrocarbon resources (petroleum, fuel and natural gas resources) in subsurface repositories (geologic structures) is a strategic necessity in countries largely dependent on oil and gas supply from abroad. Benefits of creating strategic petroleum reserves (SPRs) and natural gas storage facilities for these countries are obvious: SPRs are a first line of defense against interruption in critical oil and natural gas supplies, and they provide economic security and increase regional stability. Easily accessible sites located near the nodes of existing pipelines, main industrial centers and NATO bases should be targeted for safe storage of liquid fuels, crude oil or gas. With little national storage capacity, Poland has been near extremis a few times due to interruptions in the flow of crude oil and natural gas. It is in the Polish national interest for the country to establish a Strategic Petroleum Reserve for liquid fuels and natural gas reserves, which would provide a cushion against the negative impacts of a hydrocarbon shortage on its economy and national security. The same problem concerns most of the new NATO member countries in Central and Eastern Europe (Estonia, Latvia, Lithuania, Slovakia, Czech Republic, and Hungary). These countries are potential beneficiaries of this project. Among them, only Poland is blessed with abundant geologic salt structures, i.e. thick bedded salts and salt domes. Therefore, Poland can provide storage capacity also for the NATO allies (and other EU members). The Department’s agent in this effort is the Polish Geological Institute (PGI), performing duties of the Polish Geological Survey. PGI established cooperation with the Idaho National Laboratory (INL) in the United States and the Turkish Petroleum Corporation (TPAO). The project was accepted and implemented as a short-term project in April 2005 (NATO-CCMS project EAP.CMS PS 982185). The purpose of this project was to evaluate the feasibility of using subsurface salt deposit repositories for strategic oil, liquid fuel and gas storage, and for using generated brines to improve the ecological and environmental conditions of the Baltic Sea. The last expansion of NATO involves the necessity of developing new military bases, including the need for safe storage of logistic fuels. Occurrence of salt domes nearby most of the planned bases in Poland provides an excellent place for safe (both from the military and environmental point of view) storage of fuels. Only dry salt caverns (without use of salt brine, operated by pressurized nitrogen) will be applied for logistic fuel storage. Previous experimental studies had shown that some logistic fuels (including jet fuels) stored in salt caverns for five years did not change significantly as far as concerns their chemical and physical properties and they were still fully usable after five years of such storage. Construction of fuel repositories for NATO bases in salt domes also provides an environmental advantage. The traditional approach (adopted for example in the existing NATO “Minimum Military Requirement” and Capability Package — CP 22) uses steel tanks. However, surface steel tanks are exposed to natural weather hazards and potential terrorist attack — not mentioning their vulnerability to warfare attacks. Steel tanks hidden at a shallow depth (up to some 20 m) in the ground are much more expensive, although somewhat safer—the threats mentioned above are reduced. However, underground storage of fuel poses another threat — leakage of toxic fuel might be hazardous to groundwater supplies. Construction inexpensive repositories at a depth of several hundred meters, in naturally isolated rock salt, make them safe concerning any contamination of the environment and other threats. Above all, such repositories meet strategic requirements — they are practically immune to any warfare attack. Five salt domes in central Poland were indicated as the most suitable sites for logistic fuel repositories and preliminary geological assessment was prepared. In the future this project should gain more interest because of security issues and may warrant further investigation for Poland as well as other NATO countries. Construction of repositories in salt provides a substantial cost advantage (underground salt repositories are about 85% - 800 % less costly than traditional surface steel tanks). Moreover, storage of hydrocarbons in geologic structures is much safer from a strategic and ecological point of view. Most of the salt deposits considered for an SPR in Poland were formed in the Late Permian epoch. The proposed full scale project also addresses potential ecological problems connected with the by-product from leaching large salt caverns. Construction of large strategic petroleum repositories can produce tens of million of tons of salt brine. As the big petroleum repositories will likely be built at the Baltic Sea coast, this project involves a new paradigm concerning treatment and disposal of the excess salt brine. The salt brine can be used as an agent for re cultivation of the Baltic sea-bottom where anoxic conditions prevail. Due to the influx of anthropogenic contaminants (industrial discharges, phosphate and nitrogen communal and agricultural pollutants, etc.), the periodic, natural influx of heavier and well-oxygenated waters from the North Sea can no longer cope with the negative effects of resulting eutrophication. This is by far the most severe ecological problem in the entire Baltic Sea region. It is proposed that diluted and oxygenated, but somewhat heavier than sea water salt brine be pumped through a pipeline directly to the deeper parts of the Baltic Sea. The enhanced (oxygenated) salt brine could serve to re-establish the life and improve the ecological environment in the Baltic Sea bottom, a positive environmental impact. This project may contribute to fulfillment of at least four of the general objectives of NATO-SPS projects—it reduces to a minimum the negative environmental impact of both civil and military repositories, it conducts regional studies including cross-border activities (particularly in the field of Baltic Sea protection), by building new repositories it can serve to prevent possible crises related to scarcity of energy resources from interruption of oil or gas supplies, and it addresses emerging risks to the environment by using salt brine as an agent contributing to biological recovery of the Baltic Sea.