The Perspectives And Roles of Renewable Energy Sources in the Economic Development of Peripheral Areas of Hungary
Abstract The everyday use of renewable energy sources is necessary and indispensable in today’s modern world, partly because of the difficult handling of environmental problems caused by the increasing use of fossil energy sources, and partly because of the still increasing energy demand. Concerning alternative energy sources, Hungary has great potential in geothermal energy, which can mean a breakout especially for the peripheral, disadvantaged micro-regions while developing their future strategies. This was the motivation of our research. In our study, we intended to highlight the economic development perspectives of the Hungarian micro-regions lagging behind regarding the renewable energy potential.
HIGH PRESSURE AND TEMPERATURE ( GEOPRESSURED) GEOTHERMAL RESERVOIRS IN HUNGARY
Hungary is in a favorable geothermal position because of its geological conditions. The reason for this is the doming of the crust and the lithosphere, i. e. the tectosphere, located under the Pannonian basin. As a result, the heat flow density and geothermal gradient are higher than the world average. The Basin areas of the country are filled with Neogene sediments with low thermal conductivity. They insulate relatively well the base of the basin, which consists of higher thermal conductivity Precambrian-Paleozoic-Mesozoic rocks underlying them at depths, in some places, of 7000 m. At the boundary of the two formations the temperature increases sharply. The temperature is not the same in the same depth. The temperature and the geothermal gradient depend mainly on the depth of the tectosphere, the local heat flows, and the thermal conductivity of the rocks. It is a characteristic of the thermal conditions of the base of basin that the geothermal gradient is higher in the more outlying areas than under the deep basin. Where the rocks of the base of basin have appropriate productivity and permeability, it is possible to achieve wet steam production even from a relatively shallow depth. In such reservoirs the formation pressure can be more than twice the hydrostatic pressure. Such reservoirs were mainly formed in karstified carbonate rocks or brittle rocks by tectonic and hydraulic breccia formation. The breccia reservoirs are connected to the main tectonic feeder with wrench faults of the Pannonian Basin in the direction of the NE-SW strike or local reverse fault zones. Three such reservoirs have been identified by deep drilling but, on the basis of theoretical considerations, there can be several others. The deep wells which discovered these reservoirs are described below. On the basis of magnetotelluric and SiO2 temperature measurements, it appears that the high temperature fluids flow into the reservoirs from deeper formations than those explored by the boreholes.
Migration and Accumulation of Oil and Natural Gas Generated from Neogene Source Rocks in the Hungarian Part of the Pannonian Basin
The secondary migration pathways of Neogene-sourced hydrocarbons have been determined by analyzing the Neogene stratigraphy, the source horizons and their maturation levels, the seals and carrier beds and the oil and gas geochemistry of the discovered traps containing accumulations. Most of the Neogene-sourced hydrocarbons have been generated from deep basin shales and trapped in basement highs and adjacent Neogene reservoirs, in Neogene stratigraphic traps on the flanks of the basement highs and in delta plain reservoirs. The main pathways for secondary migration of deep basin-sourced hydrocarbons are the basal zone, the prodelta turbidites, and the delta slope and delta plain deposits. This study suggests models by which knowledge of migration can be applied to exploration problems.