János Szanyi

New geothermal well-completion and rework technology by laser

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.

Sustainable Geothermal Reservoir Management Using Geophysical and Hydraulic Investigations

Dept. of Mineralogy Geochemistry and Petrology, University of Szeged, Egyetem u. 2-6. Szeged, H6722, Hungary, szanyi@iif.u-szeged.hu, koborb@yahoo.com, tmedgyes@yahoo.com, barcza.marton@freemail.hu, balint.andras87@gmail.com, kiss.sandor@geo.u-szeged.hu Dept. of Hydrogeology & Engineering Geology, University of Miskolc, Miskolc-Egyetemvaros, H-3515, Hungary, kovacs.balazs@gama-geo.hu Dept. of Soil Sciences and Agrochemistry, Szent Istvan University, Pater Karoly u. 1., Godollő H-2100, Hungary, imre@czinkota.hu

District Heating System with Geothermal Energy Use in Szeged, Southern Great Plain Region, Hungary

Geothermal energy is widely known for its reliable, weather-independent and renewable energy. Hungary is one of the best places for geothermal energy in Europe, since the earths crust is significantly thinner beneath Hungary than elsewhere. Geothermal energy is used mostly for heating and supplying baths with thermal water. Our study gives a comprehensive view of geothermal energy utilization for stakeholders and all those interested in the geothermal potential of Hungary and Central-Eastern Europe.

Evaluation and optimization of multi-lateral wells using MODFLOW unstructured grids

Abstract Multi-lateral wells have been increasingly used in recent years by different industries including oil- and gas industry along with coal bed methane- and water production. The common purpose of these wells is to achieve a higher production rate per well. More and more sophisticated well patterns and geometries can be implemented in practice which calls for improved modelling techniques. Complicated well geometries and small lateral diameters require high resolution models in the vicinity of the wells. With structured finite difference grids this can only be achieved by unnecessary refinements even far away from the wellbores. However the model may still suffer from orientation problems if laterals do not coincide with the rows or columns of the rectangular mesh. In the present work, we applied unstructured grids to model multi-lateral wells and compared the results to structured models. We used the MODFLOW-USG code, which simulates groundwater flow using a generalized control volume finite-difference approach, allowing grids other than orthogonal structured grids to be applied. This offers a solution for orientation and resolution problems. The second part of the paper aims to optimize multi-lateral well geometry by evaluating the effect of length, angle and number of laterals.

The effect of thermal water aeration and water—rock interaction

This paper aims at determining the behavior of thermal water brought to surface and how this might impact reinjection wells and the rock during reinjection. The biggest problem is that reinjection wells are predisposed to choking. We searched for a method to examine this process, including a model for physico-chemical changes in the water—rock interaction. Two different samples of powdered rock (designated α and β) were analyzed using thermal water samples from production and reinjection wells. The pH shows significant differences between the samples from wells where free water treatment was carried out, and those from the aerated thermal waters, as well as for the rock sample. Basically, a decrease in sediment volume can be obtained by increasing the pH. The salt effect was more coherent. Its result was an interesting case of W-shaped graphs from the producing well. On the other hand there is virtually no difference between the samples with acid titration.

A half century of reservoir property changes in the Szentes geothermal field, Hungary

The general characterization of the Hungarian Szentes geothermal field is presented based on the review of previous research and is supplemented with the analysis of well hydraulic tests. Forty thermal wells were included in the study area, producing mainly from Upper Pannonian sandstone reservoirs. The intensive and long-term production of thermal water reservoirs without reinjection resulted in significant reservoir pressure decrease from natural conditions. By means of deep-well pressure build-up curves, deep-well capacity curves and surface pressure curves the reservoir condition changes were described in the last half century.