Browse

You are looking at 141 - 150 of 152 items for :

  • Earth and Environmental Sciences x
  • Refine by Access: Content accessible to me x
Clear All
Central European Geology
Authors:
Péter Bajcsi
,
Tamás Bozsó
,
Róbert Bozsó
,
Gábor Molnár
,
Viktor Tábor
,
Imre Czinkota
,
Tivadar M. Tóth
,
Balázs Kovács
,
Félix Schubert
,
Gábor Bozsó
, and
János Szanyi

Our research team has developed a new well completion and rework technology involving lasers. The system is made up of a high-power laser generator and a custom-designed directional laser drilling head. The laser head is attached to a coiled tubing unit to maximize production and to carry out special downhole tasks. In this phase of the development effort, laser technology is particularly well suited to cost-efficiently drill short laterals from existing wells in a single work phase, drilling through the casing and cement as well as the formation. The technology, which is an extended perforation solution, enables a more intensive interaction with the downhole environment and supports cutting edge subsurface engineering scenarios such as barite removal. Laser-induced heat treatment appears to be a suitable alternative to effectively remove the almost immovable deposits and scales from thermal water-well pipes.

Open access

Budapest is famous for its thermal springs and spas and outstanding thermal water resources. In the 21st century renewable energy utilization — including the use of geothermal energy — became the focus of interest. Improving the use of the different forms of geothermal energy requires the assessment of their possibilities. The potential for deep geothermal doublet systems for direct heating in Budapest was evaluated based on the temperature conditions, the depth and reconnaissance of the carbonate reservoir. NW Buda is not appropriate for thermal water exploration. SW and SE Budapest have better temperature conditions but the lithology of the reservoir is uncertain. Beneath Pest the thermal water is well exploitable. It is obvious from the map of the region that the area is promising; however, due to the hydraulic continuity of the system, reinjection is desirable. Considering the reliability of the employed data the geothermal potential map is suitable only for general orientation and guidance.

The geothermal potential map for Groundwater-sourced Heat Pump Systems (GHPS; scale = 1:40,000) was assembled by evaluating the thickness and appearance of the gravel strata and water table, complemented by the sulfate content as an aggressive component of groundwater. The original geothermal potential map series can be used for the evaluation of potential sites in Budapest. It can be concluded that the Buda side of the Danube River is almost entirely unsuitable for shallow groundwater-based heat pump installations. The only areas under consideration are Óbuda and the riverbanks. On the Pest side, there is no gravel in the central part; the largest areas close to the river and in the immediate surroundings are uncertain, with patches of suitable and possible categories. The southern and eastern area of Pest is the most prospective for GHPS installation. The potential maps only consider natural parameters; however, installation may be strongly influenced by the urbanization and the city environment.

Open access
Central European Geology
Authors:
Tamás Madarász
,
Péter Szűcs
,
Balázs Kovács
,
László Lénárt
,
Zoltán Fejes
,
Andrea Kolencsik-Tóth
,
István Székely
,
László Kompár
, and
Imre Gombkötő

The Institute of Environmental Management at the University of Miskolc, as a major Hungarian research entity in groundwater management, is dedicated to finding solutions to regional issues of global sustainable water resource management challenges, thus further developing its scope of groundwater management competence. WELLaHEAD is an EU-funded fundamental research program coordinated by the faculty members of the institute, covering a broad spectrum of relevant groundwater related research topics based on Northern Hungarian test sites. The research concept is described in the detailed Research Plan of the project, and after 14 project months some of intermediate results can be presented from three research modules.

Open access

The Triassic karstic aquifer is the system with the greatest potential for the utilization of thermal waters in Serbia. As an integral part of the Dinaric tectonic unit, the Triassic aquifer extends widely over the western part of the Serbian territory and is characterized by cold waters. In contrast, the same but confined type of aquifer overlain by thick Tertiary sediments in the Pannonian Basin has significant geothermal potential. The major potential for tapping geothermal flow is in the southern and southwestern parts of the Pannonian Basin (Srem) and in the adjacent areas of Mačva and Semberija in the Sava tectonic graben. In these areas the Triassic karstic aquifer has been tapped by several boreholes with depths ranging from 400 m to 2400 m. The temperature of the hottest water exceeds 75 °C, while maximal discharge is 40 l/s.

Although the prospect of wider utilization of geothermal energy undoubtedly exists, some Serbian national plans count on a limited contribution of geothermal energy in renewable energy sources of only 4%. This is probably due to the low level of current utilization, and the inefficient use of even some highly productive wells with a high water temperature, such as those drilled in the most prosperous Mačva region.

Open access