Hulladéklerakók és környezetük állapotfelmérése geofizikai módszereinek fejlesztése = State qualification of waste sites and their surroundings and geophysical methods development for this purpose

Kutatásokat végeztünk a függvényinverziós módszerek fejlesztésére. Ennek egyik része az 1D előremodellezésen alapuló ún. 1.5D geoelektromos függvényinverziós vizsgálatok geológiai struktúrák esetére Módszert dolgoztunk ki az inverzióban a sorfejtési együtthatók számának meghatározására. Megállapítottuk, hogy a 1.5D inverzió változékony(tipikusan 2D) szerkezetek kimutatásánál nagy hibákat okozhat, ezért erre a közelítést alkalmazó módszerre annak folytatásaként ráépítettük az un. kombinált 2D (2.5D) inverziós módszert. Ezzel a módszerrel 2D/3D-véges differencia előremodellezést alkalmazva bonyolult szerkezetek is megfelelő pontossággal kimutathatók. Függvényinverziós módszert fejlesztettünk ki a szeizmikus refrakciós adatok és a geoelektromos adatok együttes kiértékelésére. Új felszíni geoelektromos módszert fejlesztettünk ki a hulladéklerakók természetes és mesterséges aljzatszigetelésének vizsgálatára. 3D véges differencia programmal végeztünk olyan számítógépes modellvizsgálatokat, amely alapján az új módszer mérési rendszere kialakítható és a mérési adatok kiértékelhetők a szigetelési sérülések kimutatására. A mérési módszer lényege, hogy az egyik áramelektródát a hulladéklerakó felszínére kell elhelyezni (szóba jöhet ennek speciális területi vagy vonalszerű kialakítása), a mérőelektródát/elektródákat a felszínen elhelyezve az elektromos potenciál vagy potenciálkülönbség eloszlásából lehet a sérülés helyére következtetni. | Our function inversion method developments concentrate on the evaluation of resistivity data . The 1.5D geoelectric function inversion - which based on 1D forward modeling - is suitable for examing the geological structures. We developed method to determined the optimum number of coefficients in the inversion. We established that the 1.5D inversion can cause significant errors in case of changeable structures that's why we added the combined 2D (2.5) inversion method for the 1.5D one. With this procedure if we use finite difference method for forward modeling we can determine the geoelectric parameters of the complicated structures with adequate accuracy. We developed function inversion method to evaluate the refraction and resistivity data together. After the development of the algorithm and the program we test them on synthetic and field data. We developed a new surface geoelectric method to study the natural and artificial impermeable layers of waste sites. We made studies with 3D finite difference program. By the results of the study the new measurement system can be developed and the faults of the impermeable layers can be detected. The essence of the method is that the current electrodes are placed on the surface (along the line, or regional configuration) of the waste deposit and using surface measuring electrodes and we are able to infer the place of faults from the electric potential or potential difference distribution

Integrated Sustainability Assessment: Exergy, Emergy, Life Cycle Assessment

Methodological tools such as Life Cycle Assessment (LCA), Exergy Analysis (ExA), and Emergy Analysis (EmA) that account for sustainability indicators in environmental, economic, and/or social dimensions, cannot provide an assessment under these three dimensions in a robust way by themselves. This research is proposing a sustainability assessment framework to obtain a unified performance metric (Integrated Sustainability Index, ISI) to assess the Triple Bottom Line – TBL. LCA, ExA, and EmA indicators are implemented in a complementary but not interchangeable manner, providing additional information for sustainability decision-making. The systematic approach is on a conceptual definition and calculation of sustainable environmental, social, and economic disaggregated indicators. These are then systematically combined into an Integrated Sustainability Index (ISI). EmA evaluates sustainability from a “donor-side” perspective, by assigning values to the environmental efforts and investment of nature to make and support flows, materials, and services; the system boundary is the geosphere. ExA evaluates sustainability through exergy efficiency under a “user-side” evaluation process (system boundary is the technosphere). LCA evaluates it based on the quantification of environmental impact by water, soil, and air emissions, caused by the use and processing of resources to provide products or services as a “user-side” method. The proposed sustainability index presents a comprehensible hierarchic structure supported by LCA, ExA, and EmA methodologies. The integration of social, environmental, and economic components into an index that also allows for the adjustment of externalities reducing the risk of subjectivity is a new approach to assessing sustainability

A new method of pressure drop modelling in sandstone rocks

Production capacity of any hydrocarbon reservoir is the most important question that needs to be answered. This depends on both the obtainable drawdown between the well and reservoir and the petrophysical properties (pore size distribution, wettability properties, saturations etc.) of the porous rock material. Permeability, introduced by Darcy is the parameter describing restrictions present during fluid flow in porous media. Although this method is the one currently accepted and implemented in the industry it has a major flaw because it considers flow in the geometric (total) rather than the effective volume, where it truly develops. During this study a new approach of flow restriction modelling was found, where flow restrictions, measured from sandstone plug samples were compared with the theoretic flow volumes which are equal to the total pore volumes, constructed of steel capillaries of equal diameter. Results show that flow restrictions of incompressible fluids in sandstone can be demonstrated by the new model

Performance comparison of U-tube and coaxial borehole heat exchangers with numerical simulations

It is well known that geothermal heat is a virtually unlimited energy source beneath the ground, which is formed by the radioactive decay of naturally unstable elements. However geothermal energy has been utilized since the ancient ages, it is still a mission for humanity – even in the times of energy crisis with high prices – to find sustainable solutions for high-efficiency heat energy production. Apart from the conventional hydrothermal wells and production/injection systems, an increasing attention is drawn into deep coaxial heat exchangers and heat pumps, utilized in a single wellbore. Optimization of these systems need to be done with an increased care, however it is possible with results obtained from a set of numerical simulations. The present paper investigates hypothetical, single deep “U”, “double-U” and coaxial arrangements under different flow rates, where the main target was to analyze efficiency of each model, with short time thermal response simulations

Numerical Demonstration of an Unconventional EGS Arrangement

A new EGS arrangement, Robust EGS (REGS), is studied for its potential benefits for wide-spread applications for clean, carbon-free, electrical energy generation. Numerical simulations are carried out to prove the key benefit of REGS in a simple, but effective, geologic heat exchanger arrangement with large, stabilized fracture aperture and controlled flow zones. The numerical model results show the estimated potential energy capacity and the converted value to electrical energy generation over a 30-year operation time period for two simple REGS arrangements. The results may assist EGS investors and drilling companies in deciding whether the investment and operation can be made profitable for the wide-scale application of REGS for green energy generation

Metainformation System of the Hungarian Central Statistical Office

The article gives detailed information on the metainformation system of the HCSO. It presents the history from the beginning up to the latest improvements. A separate chapter of the paper provides an international overview

Fracture system characterization by Pressure Probe

Pressure Probe (PreP) is in effect a simplified penetrometer: it measures the mechanical resistivity of the soil at shallow depths dropping the probe always from the same height. The resolution of this technique is very good. It is able to detect e.g., fractures due to their decreased mechanical resistance if they are covered, but in a shallow depth with a reasonable sampling distance. An example will be demonstrated where fracture system of a slowly-moving landslide was characterized enabling also its delineation. In spite of that its maximal penetration is only about 0.5 m it may also give information from remarkable depths in case if fractures reach close to the surface indicating the borders of geological structures in larger depth. An example from India will be shown to present such results. All results have been verified by geoelectric measurements. PreP may also indicate any kind of hidden holes indirectly

A hazai fosszilisszénhidrogén-vagyonban rejlő lehetőségek

Hazánk szénhidrogén-kutatás és -termelés szempontjából érett területnek számít. A jelentős méretű előfordulások felfedezése és termelésbe állítása már megtörtént. A közelmúlt felfedezései azonban azt bizonyítják, hogy további felfedezések tehetők az országban. A 3D szeizmikus mérések, a számítástechnikai eszközök és a mérőműszerek fejlődése lehetővé tette, hogy új, kisebb telepeket fedezzünk fel. A pettendi felfedezés 30 kútja akár napi 14,2 ezer hordó olajat is termelhet, amely jelentősen növeli a magyarországi olajtermelést. A Vecsés-2-es kút napi 600 hordó olajat termel. A két Komádiban és egy Álmosdon lefúrt sekély kút naponta 750 hordó egyenérték szénhidrogén-termelést produkál. A Nyékpusztai tömött homokkőből (nem hagyományos tároló) évente 45 millió köbméter gázt és 45 ezer köbméter kondenzátumot terveznek a felszínre hozni. Az új találatok bizonyítják azt, hogy van lehetőség az energiahordozó kutatásában, a felfedezett mennyiségek azonban csak a termelés csökkenését tudják ellensúlyozni. Fontos lenne, hogy más energiaforrásokkal, például a geotermikus energia fokozásával pótoljuk a hiányzó energiamennyiséget

Archeogeophysical application of non-traditional geoelectric arrays : a case study in a north-east Hungary site

With the continuous development of multielectrode geoelectrical tomography (ERT) as a geophysical technique, we became able to detect small size targets. In this paper, we present ERT interpretation results obtained at an archaeological site in Szendrő village in northeastern Hungary, where a 17th century fortress once stood. Several historical notes and a collapsed entrance recall the existence of tunnels under the fortress and a water well of uncertain depth. To detect these structures, geoelectrical multielectrode measurements were carried out using conventional and quasi-null arrays. The quasi-null array applies the arrangement of the current (A and B) and potential electrodes (M and N) in a special way, i.e., the electrodes A, M, B, N follow each other in line in special distances from each other. The horizontal sensitivity of the resistivity profiling method using these types of arrays has been proven to be better than that of the Wenner or other conventional arrays. The comparative study aims not just to investigate the archeological features, but to test the sensitivity of the non-traditional quasi-null arrays to these two-dimensional inhomogeneities. As a result, the optimal array can be chosen, and the identification and delineation of shallow structures can be made more reliably. In this paper, we present the very first archeogeophysical field measurements carried out by the gamma quasi null array (γqnull)

On the application of combined geoelectric weighted inversion in environmental exploration

Geophysical surveying methods are of great importance in environmental exploration. Inversion-based data processing methods are applied for the determination of geometrical and physical parameters of the target model. The use of this geoelectric inversion method is advantageous in environmental research where highly reliable information with large spatial resolution is required. The 2D combined geoelectric inversion (CGI) method performs more accurate parameter estimation than conventional 1D single inversion methods by efficiently decreasing the number of unknowns of the inverse problem (single means that data sets of individual vertical electric sounding stations are inverted separately). The quality improvement in parameter space is demonstrated by comparing the traditional 1D inversion procedure with a 2D series expansionbased inversion technique. The CGI method was further developed by weighting individual direct current geoelectric data sets automatically in order to improve inversion results. The new algorithm was named combined geoelectric weighted inversion, which extracts the solution by a special weighted least squares technique. It is shown that the new inversion methodology is applicable to resolve near-surface structures such as rapidly varying layer boundaries, laterally inhomogeneous formations and pinch-outs