ISSN 0354-8724 (hard copy) | ISSN 1820-7138 (online) Implementation Opportunities of Geothermal Energy Systems in the Peripheries along the Border of Hungary and Romania Balázs KulcsárA Received: March 13, 2015 | Revised: August 12, 2015 | Accepted: September 1, 2015 Abstract With the utilization of the available potentials and technologies, geothermal energy may contribute to the reduction of the quantities of the emitted contaminants and greenhouse gases, as well as the de- velopment of peripheral regions. Towards this end, such governmental measures are needed that set up a favourable regulatory environment, and put the financial funds for the support of implementation in place so that geothermal energy resources could complement the currently used, conventional ener- gy carriers, and more efficient settlement development could be achieved. In this context, the Univer- sity of Debrecen and the University of Oradea have conducted joint studies with the purpose of making a realistic assessment of geothermal energy resources in the region of Săcueni–Létavértes and examin- ing the options of long-term utilization. The research has been multidisciplinary, and thus embraced the field of geography, geodetics, well drilling, automation, mechanical engineering and tourism. The prin- cipal goal has been the utilization of geothermal energy with the largest possible efficiency in the area of Săcueni and Létavértes. Key words: geothermal energy, settlement management, settlement development, regional develop- ment, Létavértes, Săcueni Introduction thermal water could be transported, and what types From the broad-scaling studies, this article intends of users could be served with thermal water. The anal- to highlight the importance of geothermal energy in ysis has relied on the empirical data of the system op- settlement development in view of the region of Lé- erated by Aquaplus Kft. in Kistelek as concerning tavértes and Săcueni, on the basis of the available ge- transportability, as well as the Lindal diagram, which othermal potentials. Beyond the general description designates the areas of use for thermal waters of var- of the geologic, hydrogeologic properties, the geother- ied temperatures. In the analysis, I have further ex- mal endowments of the microregion of Létavértes– amined the distances of the surrounding settlements Săcueni are also specified alongside the parameters of from Săcueni and Létavértes, and assumed that the the thermal wells that have already been established, center of the potential geothermal systems can be the current situation of thermal water utilization. these two settlements. In the light of the distance val- This analysis has examined who those potential ues, the empirical data of the transportability of the consumers in the two settlements could be, whose de- thermal water and the values of the Lindal diagram, mands for heat and water could be efficiently satisfied such an area can be designated where thermal waters by a geothermal system operated in the two settle- of varied temperatures can be utilized. ments. In theory, with an appropriate volume of ther- Below it will be explained and confirmed that ther- mal water in place, what a local district or range Lé- mal water in the region could be optimally used for tavértes and Săcueni could supply, to what a distance sanitary hot water, district heating, swimming pool A University of Debrecen Faculty of Engineering, H-4028 Debrecen, Ótemető u. 2-4; [email protected] 88 Geographica Pannonica • Volume 19, Issue 3, 88-100 (September 2015) Balázs Kulcsár and bathing services, i.e. the purposes of communal MPa overpressure can be found at a depth of 1200 me- heat supply and tourism. In any multiphase utiliza- ters, and then from 2200 meters the extent of the over- tion, it is agriculture that can be the final user. For this pressure exceeds 10 MPa. It is quite likely that the lay- reason, I have considered it to be necessary to exam- ers under the examined area feature similarly high ine the positive aspects of the utilization of thermal hydrostatic pressure as the Biharkeresztes region. The water in the field of the maintenance of public institu- overpressure reservoirs are closed, and therefore their tions, economic development and tourism. exploitation potentials depend on the regional storage factors. As a consequence the reservoir cannot be uti- lized without reinjection at all (Tóth, 2006). In view Geothermal endowments of the establishment of artificial geothermal systems (EGS), there are several promising sites in the Panno- Geological bases of the region nian Basin. The best parameters can be found in the The examined settlements are situated on the eastern southern and southeastern part of the Great Plain, in edge of the Great Plain, in an area called Érmellék be- particular on the edges of the deep basins and the el- tween the regions of Nyírség and Szilágyság. The re- evated base mountainous areas in between the basins, gion encompassing Létavértes and Săcueni located 17 including the region of Derecske lying in the vicinity km from each other lies over a deep subgrade depres- of the studied area (Dövényi, et al., 2005). sion (Gribovszki, Szeidovitz, 2002). This area wedged between the Flysch belt and the Békési Depression has Geothermal endowments of Săcueni been well explored for geothermal findings in the past The data that is available in connection with the ther- decades, its thermal water production has been made mal wells having been established since the 1980s in known by the hydrocarbon exploratory drillings car- Săcueni are encouraging in view of the more effec- ried out in the surroundings, as well as the regional tive exploitation of the potentials. In these wells, the geophysical research results, and thus the area seems temperature of thermal water is in the range of 50– to be promising in view of geothermal energy produc- 80°C, comes to the surface at a pressure of 0.5–0.8 tion. MPa, while its chemical composition – HCO3, Cl, Na, A consequence of the structural development of the I, Br – makes it suitable for therapeutic purposes and area is that the subgrade of the Pannonian Basin is use in bathing facilities in addition to geothermal en- only 20–25 km thick, i.e. it is quite thin in comparison ergy utilization. Its phenol content varies between 1.8 to the average. Such thinning of the crust was created and 2.55 mg, which should be handled as a source of by deep circulations within the mantle (Molnár, 1984). environmental risk in case it is discharged into sur- In this region, the geothermal gradient is 4.5°C/100 m, face recipients (Erdei, et al., 2010). The thermal wa- which brings about 35–40°C temperature at a depth of ter springing up on the surface suggests a closed, fos- 500 meters, 55–60°C at 1000 meters, and up to 100– sil reservoir, which would call for reinjection (Bálint, 130°C at 2000 meters (Mádlné Szőnyi, 2008). From the Szongoth, 2010). decomposed and sedimentary rocks making up even In the course of the exploratory drilling works thousands of meters of thickness under the surface commenced in 1968, the crude oil probes no. 4058, – comprising sand, sandstone, siltstone, clay in the 4055, 4056 and 4031 revealed gasoline in two collect- Great Plain –, thermal water featuring temperatures ing layers at a depth of 1700–1800 meters in the Low- over 30°C can be explored in most of the basin (Liebe, er Pannonian layers. The petroleum fraction sourc- 2001). Some of the water bodies found there are fossil es soon became depleted, and the subsequent drilling waters, as well as reservoirs supplied from the border- operations created only wells of weak pressure, and ing mountains. The highest temperature that can po- therefore the exploitation was discontinued in 1995. tentially be exploited from the Upper Pannonian sed- Since 1980, it has been drilling no. 4058 that has iment does not reach 100°C anywhere, meaning that found thermal water at a depth of 1226–1456 meters, this area belongs to low-enthalpy systems. The water in the Upper Pannonian layers, with 11.5 l/sec yield, at permeability of the Upper Pannonian sand and sand- a temperature of 84°C. At the same depth, probe no. stone (Great Plain Aquifer) is 10ˉ5 m/s, and therefore 4055 also brought up 81°C water at a 28 l/sec rate. In up to 10–100 cc m/h water yield can be produced from addition to the foregoing, 10 more drilling sites have the wells. The sediment under the Great Plain Aquifer produced thermal water with drilling no. 4057, 4076 is made up of water-trapping siltstone and clay. In and and 1704 serving water of 86–92°C. These well capac- under the water traps, overpressure prevails every- ities have never been fully employed. Nowadays, the where at varied locations throughout the area. In the water is used for the heating and sanitary hot water regions lying closer to the examination areas, such as supply of the Thermal Baths, Kinder Factory, Mayor’s in the surroundings of Biharkeresztes, however, 2–6 Office, Petőfi Sándor Lyceum of Theoretical Studies, Geographica Pannonica • Volume 19, Issue 3, 88-100 (September 2015) 89 Implementation Opportunities of Geothermal Energy Systems in the Peripheries along the Border of Hungary and Romania Table 1. Figures of thermal wells in Săcueni region (Ciucanu, 2010). Registration Number Temperature (°C) Base Depth (m) Discharge (l/s) Status 752 76 1456 3.0 Standby 4055 81 1800 28 4057 92 4058 84 1456 11.5 Standby 4076 85 1691 11.5 Standby 4691 81 1447 7.5 In use 4692 60 1364 10.0 Preservation 4694 1436 Preservation 4696 1560 Preservation 4697 1596 Preservation 1704 83 1680 13.0 In use 4696 84 25 Standby 4497 84 17 Standby LEGEND CH-drilling from CH-drilling developed thermal well from water-drilling developed thermal well Figure 1.