Panonian Basin Research Articles

A NEW MODEL FOR PRODUCED WATER TREATMENT IN ELEMIR OIL FIELD

<p>The oil reservoirs of the southeastern part of the Panonian basin are characterized by considerable presence of water,i.e.waterdrive. The hydrocarbon reservoirs are mostly in the middle and final production stages. The water production is especially significant in wells producing with an installed Electrical Submersible Pump (ESP). As production continues, it is a realistic expectation that the water cut increases as well.The rapid production of water has affected fluid production in a significant way.Produced water in the Elemir oilfield is gathered, treated and then injected into the porous layers through several wells.The current system for the preparation and treatment of produced water in the Elemir oilfield has functioned with evident technical issues.The main problems are increased volumes of produced fluids and the deposition of solids (scales) in water treatment system. In thisarticle, a new model for produced water treatment is presented, including technical, economic and environmental aspects. A new model fulfils volumetric requirements, improves oil/water separation and suspended solids removal which lead to better injection performance.</p>

Double-difference relocation of the 29 January 2011 ML 4.5 Oroszlány earthquake and its aftershocks and its relevance to the rheology of the lithosphere and geothermal prospectivity

In the central part of Hungary, an earthquake with the local magnitude of 4.5 occurred near the town of Oroszlany, on 29 January 2011. The main shock and its more than 200 aftershocks were recorded by a significant number of three-component seismic stations, which enabled us to perform multiple event location on the event cluster. We applied the double difference, HypoDD method to relocate the aftershock sequence in order to identify the pattern of active faulting. We used the extended International Seismological Centre location algorithm, iLoc to determine the initial single event locations for the aftershock sequence and applied multiple event location algorithm on the new hypocenters. To improve both location precision and accuracy, we added differential times from waveform cross correlation to the double-difference multiple event location process to increase the accuracy of arrival time readings. We show that both HypoDD collapses the initial, rather diffuse locations into a smaller cluster and the vertical cross-sections show sharp images of seismicity. Some of the relocated events in the cluster are ground truth quality with a location accuracy of 5 km or better. Having achieved accurate locations, we further examined the extent of the seismogenic zone. We investigated the relationship between geothermics and seismicity through strength profiles constructed for the study area. The aftershocks of the Oroszlany earthquake are dominantly in the range of 5–10 km, fitting well to the extent of the thin brittle part of the crust. It shows that the events are well in accordance with a thermally attenuated lithosphere and elevated geothermal gradient in the upper crust and basin sediments. These findings underline the geothermal prospectivity of the Panonian Basin. © 2017, Akademiai Kiado.

A NEW FREEWARE PROGRAM FOR THE PROBABILITY OF SUCCESS CALCULATION OF NEW GAS DISCOVERIES WITHIN THE CROATIAN PART OF THE PO DEPRESSION

The aim of this paper is to introduce an application in the form of a transparent freeware program which can be used for the assessment of the Probability of Success (abbr. POS, also POS and geological probability are synonyms) in finding new gas discoveries within the Croatian part of the Po depression. A deterministic approach is applied and includes five geological categories (traps, reservoirs, source rocks, migration and hydrocarbon preservation) with certain geological events that depend on the geological settings of the Northern Adriatic subsurface. The chosen probability classes include five, three or two numerical and textual values as follows: 1.00 for certain, 0.75 for very probable, 0.66 and 0.50 for reliable / probable, 0.33 and 0.25 for unreliable / low probable and 0.05 for not proven / improbable events. The program is made as an improvement in the sense of faster calculation according to a previous assessment that was based on a previously published Croatian model of the POS using Microsoft Excel and GeoProbe Modeling 1.1 program as an example, which is used to calculate the geological probability of hydrocarbon discoveries for the Croatian part of the Panonian Basin System. The program is in English and it is done in the C# programming language.

Collision-related Early Paleozoic evolution of a crustal fragment from the northern Gondwana margin (Slavonian Mountains, Tisia Mega-Unit, Croatia): Reconstruction of the P–T path, timing and paleotectonic implications

An orthogneiss from the oldest metamorphic complex at Mt. Papuk (Tisia Mega-Unit, Croatia) enables the quantification of the P–T evolution of Early Paleozoic rocks of the Panonian Basin basement in contrast to neighboring peri-Gondwanan terrains which are significantly overprinted by pre-Variscan, Variscan, and Alpine events. Two different groups of Ce-rich monazite within oval-shaped corona microstructures have been observed. Age dating of the corona cores yielded two populations with average ages of 528±7 (2σ) Ma and 465±7Ma, respectively. Furthermore, an Y-rich group, found inside garnet cores, was dated at 616±23Ma. Th-rich monazite included in garnet rims yielded an age of 491±6Ma. The youngest monazite group at 417±20Ma is located inside mica. The orthogneiss precursor was a calc-alkaline to high-K calc-alkaline igneous peraluminous crustal rock (diorite) from an active continental marginal setting. The calculated P–T pseudosection in the MnNCKFMASHTO system in combination with assemblage characteristics and mineral chemistry data provides good constraints on the P–T evolution: for stage I peak P–T conditions of 13kbar and 670°C were derived followed by stage II, which was characterized by moderate cooling accompanied by uplift to mid-crustal levels (5.2kbar and 610°C). Subsequently, the system cooled to 480°C at ~4.4kbar (stage III). Formation of titanite rims on ilmenite suggests further cooling to 4kbar and 400°C (stage IV). The clockwise P–T path implies exhumation from a tectonically thickened crustal setting (ca. 45km depth at a geothermal gradient of ~15°C/km) to mid-crustal levels (ca. 18km) followed by cooling at depths <14km. Crustal thickening was due to the collision of a continental plate (Gondwana) with a smaller plate, which was underthrust.

Water balance of Slovenia 1971 – 2000

The water is becoming more and more valuable natural resource. The increasing water demand and climate changes are making water a precious and not always available valuable. The water balance is the most appropriate way to make a full overview of water cycle in Slovenia, to find general information about hydrological characteristics of drainage basins, precipitation, evaporation and runoff. The article presents the methodology and the results of the Water balance project of Slovenia. Slovenia has the geographical position at the juncture of 4 main European georegions: The Alps, the Panonian Basin, the Mediterranean and the Dinaric Mountains. This makes the territory very diverse also from a hydrological point of view. Our major watershed divides the precipitation runoff into two watershed areas – the Adriatic Sea and the Black Sea. Due to this watershed almost all the Slovenia's rivers have headwaters in our territory. Water balance is calculation of water inputs and outputs over the defined area. The basic elements of the water balance include all the inflows and outflows for a given basin and serve for the computation of the water regime of a catchment area. It is defined by the parameters precipitation (P), evaporation (E), discharge (Q) and the change of the water reserves (dS). Main results of the water balance elements for the 1971 – 2000 period for Slovenia are: Average annual precipitation in Slovenia is 1579 mm, average annual evapotranspiration is 717 mm and calculated runoff is 862 mm. Compared to water amounts in the World, where the average precipitation is 750 mm, evapotranspiration is 480 mm and runoff is 270 mm, Slovenia shows an abundance of water quantities. Also the runoff coefficient with 55 % is much higher as 36 % of the world. The major questions remain if we are capable to live with this water amounts within the limits of sustainable development and what will be the effects of climate change to water balance.

Hail characteristics of different regions in continental part of Croatia based on influence of orography

Settled in the mid latitudes of the Northern Hemisphere, Croatia is exposed to the frequent occurrence of severe thunderstorms and hail, especially in the continental part between Sava, Drava and Mura rivers (Panonian basin). On the basis of hail data collected in continental part of Croatia (26,800 km 2) in period 1981–2006, it is found that in this area of Croatia which is protected from hail, two different areas can be identified: western (hilly) part with the greatest number of days with hail, and eastern (generally flat) part which has mostly minimum days with hail. Through spatial distribution of hailfall duration, it is shown that majority of quadrants with longer average duration of hailfall is in front of the mountain, and concerning the analysis of Cb-cells movement, it is also found that the areas with greater diameter of hail can be found in front of the mountain.

Crustal-scale extension in the central Pannonian basin

Within the Hungarian segment of the Panonian basin, a 100-km-long seismic reflection profile images the sedimentary fill of two major depressions and their associated crustal signatures. These deep (∼7000 m) subbasins are asymmetric half grabens, bounded along their western margins by low-angle crust-penetrating subparallel listric faults. The hanging walls are intensely fractured and comprise pre-Tertiary basement and upper-crustal rocks. The footwalls are formed by uplifted and ductilely deformed middle to lower crust. The crust is relatively thin (25–27 km) and decoupled by well-defined detachment faults. The Moho has a gentle northeasterly dip and a spatially variable seismic signature. The seismic images imply that the present crustal setting of the area was developed contemporaneously through the northeastward extension of the Pannonian basin.