Faculty of Mining, Geology and Petroleum Engineering Repository
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Geothermal potential of gas fields in Međimurje County : master's thesis
No full textKontinuirani pad proizvodnje nafte i plina u Republici Hrvatskoj povećava potrebu za pronalaženjem alternativnih izvora energije. U ovom slučaju to je geotermalna energija. Geotermalni potencijal na području Panonske nizine jedan je od najvećih na području EU. Ta se prednost može iskoristi na području Murske, Savske, Dravske i Slavonsko – srijemske depresije. Na području Murske depresije i Međimurske županije trenutno se nalaze istražna područja Međimurje – 5 i Merhatovec za geotermalne vode koje je raspisala Agencija za ugljikovodike u 2022. godini. U blizini istražnih područja nalaze se tri plinska polja: Vukanovec, Zebanec i Vučkovec. Navedena plinska polja nalaze se već u kasnoj fazi eksploatacije ugljikovodika te je ovim radom ispitana mogućnost prenamjene plinskih bušotina u geotermalne bušotine. Prikazani su svi podaci o plinskom poljima i bušotinama (položaj eksploatacijskog polja, geološka osnova, litostratigrafskih podaci, položaj bušotine, konstrukcija i Drill Stem testovi). Na izdvojenim bušotinama Vukanovec – 1, Zebanec – 1 Jug, Međimurje – 1 i Vučkovec – 1 provedena je analiza osjetljivosti u programu WellPerform te je na taj način ispitan geotermalni potencijal Međimurske županije.The continuous decline in oil and gas production in the Republic of Croatia increases the need to find alternative sources of energy. In this case it is geothermal energy. Geothermal potential in the area of the Pannonian Basin is one of the largest in the EU. This advantage can be used in the Murska, Sava, Drava and Slavonsko-Srijem depressions. In the area of the Muar Depression and Međimurje County, there are currently Međimurje - 5 and Merhatovec exploration areas for geothermal waters, which were announced by the Hydrocarbons Agency in 2022. There are three gas fields near the research areas: Vukanovec, Zebanec and Vučkovec. The aforementioned gas fields are already in the late phase of hydrocarbon exploitation, and this work examined the possibility of converting gas wells into geothermal wells. All data on the gas field and wells are presented (position of the exploitation field, geological basis, lithostratigraphic data, position of the well, construction and Drill Stem tests). A sensitivity analysis was carried out in the WellPerform program on the selected wells Vukanovec – 1, Zebanec – 1 Jug, Međimurje – 1 and Vučkovec – 1, and thus the geothermal potential of Međimurje County was examined
Uloga država članica BRICS-a na svjetskom tržištu plina : završni rad
No full textU završnom radu je pojedinačno analiziran položaj trenutnih devet država članica BRICS-a. Uz osnovnu analizu proizvodnje, izvoza, uvoza te rezervi svake države, analizirani su i geopolitički odnosi država unutar grupacije BRICS te odnosi država članica sa susjednim državama po pitanju trgovine prirodnim plinom
Petrografska analiza migmatitnih gnajseva, kimberlita i litijskih pegmatita iz Finske : završni rad
No full textMigmatitni gnajsevi, kimberliti i litijski pegmatiti s različitih lokaliteta na području Finske, analizirani su na makroskopskoj i mikroskopskoj razini. Uzorci su podijeljeni u tri skupine prema svojem mineralnom sastavu, genezi i načinu postanka. Mineralni sastav migmatitnih gnajseva je u svim uzorcima sličan. Glavni su granat, kvarc, ortoklas, mikroklin, plagioklas, biotit, muskovit i flogopit. Sekundarni, alteracijski minerali, su sericit i minerali glina. Krupnozrnate su teksture, a struktura im je heterogena. Kimberlit ima porfirnu teksturu, s istaknutim krupnozrnatim mineralima unutar hijalinskog matriksa. Struktura uzorka je vulkanoklastična odnosno kristaloklastična. Najveći udio istraživanog uzorka kimberlita čine alteracije. Glavni minerali litijskih pegmatita su spodumen, petalit, lepidolit, kvarc, ortoklas, mikroklin, plagioklas i klinopiroksen. Akcesorni minerali su kasiterit, turmalin, rutil i zoisit, a sekundarni minerali su minerali glina i sericit. U uzorcima su primijećene post-kristalizacijske modifikacije koje su uvjetovane promjenom P-T uvjeta. Nakon kristalizacije svi uzorci bili su izloženi hidrotermalnim alteracijama, poput kloritizacije, sericitizacije, serpentinizacije i prehnitizacije te supergenim alteracijama limonitizacije i kristalizaciji minerala glina
Analysis of the current locations of municipal waste disposal sites and proposal of criteria for future landfill site selection : master's thesis
No full textUvjeti koji su propisani u Republici Hrvatskoj i uvjeti iz dodatne literature u ovom diplomskom radu objedinjeni su te predloženi kao novi uvjeti koje lokacija odlagališta komunalnog otpada treba zadovoljiti. Korištenjem programa QGIS, uvjeti su prikazani s ciljem predstavljanja provedbe dijela postupka odabira lokacije odlagališta za pet najvećih gradova u Republici Hrvatskoj. Također korištenjem programa QGIS, prikazane su i analizirane postojeće lokacije za gradove Zagreb, Split, Rijeku, Osijek i Zadar na temelju predloženih uvjeta.The criteria that are legally prescribed in the Republic of Croatia as well as the criteria from the additional literature, in this master's theisis have been integrated and proposed as new criteria that have to be pleased during landfill site selection. Using QGIS program, the criteria are shown with the aim of presenting the implementation of part of the procedure for landfill selection for the five largest cities in the Republic of Croatia. Also using QGIS program, locations of existing landfills are shown and analysed based on the proposed criteria for the cities od Zagreb, Split, Rijeka, Osijek and Zadar
Revitalization of oil wells for the use of geothermal water with the possibility of seasonal thermal energy storage in water-saturated layers : master's thesis
No full textZadatak diplomskog rada bio je analizirati petrofizikalne karakteristike ležišta pomoću bušotinskih podataka naftnog polja Dugo Selo te promotriti analize rezultata testiranja ležišta. Na temelju toga, procijenjena je mogućnost revitalizacije bušotina za korištenje geotermalne vode uz sezonsko skladištenje toplinske energije u zavodnjenim slojevima. Na odabranoj mikrolokaciji izvedeni su proračuni dinamičkog tlaka korištenjem programskog paketa WellPerform, koji je dizajniran za analizu gradijenata tlaka u bušotinama u odnosu na protok, vrstu fluida, udio otopljenog plina, karakteristike ležišta i tehničkih parametara bušotina. Svrha korištenja softvera bila je da se dobiju IPR krivulje koje omogućavaju proračun dinamičkih tlakova pri određenim protocima kod dugoročne proizvodnje i sukladno tome odredi položaj električne potopne pumpe. Koristeći se podatcima potrošnje električne pumpe i visine dizanja napravljen je proračun potrošnje električne energije sukladno dubini smještaja. Gringartenovim obrascem i Ramey-Nabor metodom procijenjeno je trajanje izotermne proizvodnje za proizvodno-utisni scenarij.The task of the master's thesis was to analyze the petrophysical characteristics of the reservoir using well data from the Dugo Selo oil field and to review the analysis of reservoir test results. Based on this, the possibility of revitalizing the wells for the use of geothermal water with the potential for seasonal thermal energy storage in water-saturated layers was assessed. At the selected microlocation, dynamic pressure calculations were performed using the WellPerform software package, which is designed to analyze pressure gradients in wells in relation to flow, fluid type, dissolved gas content, reservoir characteristics, and technical well parameters. The purpose of using the software was to obtain IPR curves that allow the calculation of dynamic pressures at specific flow rates for long-term production, and based on these, determine the position of the electric submersible pump. Utilizing the electric pump consumption data and the lifting height, an electric energy consumption calculation was made according to the installation depth. Gringarten's model and the Ramey-Nabor method were used to estimate the duration of isothermal production for the production-injection scenario
Tehnologije napuštanja eksploatacijskih bušotina : završni rad
No full textPostupak napuštanja bušotina predstavlja završni dio radnog vijeka svake bušotine, koji u posljednjem desetljeću doživljava snažan rast popraćen značajnim udjelom troškova u životnom vijeku bušotine. Suvremeni međunarodni standardi te regulative propisane na razini države obvezuju operatora polja na dovođenje bušotinskog prostora u prvobitno stanje, prilikom čega se uspješnost napuštanja bušotine očituje u sprječavanju migracije nafte, plina ili ostalih štetnih tvari u vodonosnike. Prilikom projektiranja operacije napuštanja bušotine potrebno je razmotriti konstrukcijske elemente kanala bušotine, kao i ostale aspekte tog procesa kao što su: mjesto postavljanja čepa, kontrola slojnog tlaka, stanje bušotine, postavljanje i stvrdnjavanje cementnog čepa, uspostavljanje statičkih uvjeta u bušotini, raspoloživost opreme te svakako troškove. Problemi koji karakteriziraju ovakav proces su tehničke, tehnološke i financijske prirode. Drugim riječima, potrebno je pronaći moguća rješenja prilikom odabira materijala i metoda čepljenja bušotine te izabrati najpovoljnije koje će biti dovoljno sigurno za radnike, rudarski objekt i okoliš. U konačnici, nakon što se aktivnosti u bušotini ili proizvodnja fluida prekinu, status bušotine treba razjasniti. Općenito, mogu se definirati tri različita statusa: obustava rada bušotine, privremeno napuštena ili trajno napuštena bušotina
The impact of centroid-based landslide inventory and statistical methods on landslide susceptibility assessment (Gornja Dubrava, City of Zagreb) : master's thesis
No full textU okviru istraživanja prikazan je utjecaj vrste ulaznog inventara klizišta (poligonski i točkasti) i statističke metode na rezultate procjene podložnosti na klizanje. Za procjenu podložnosti na klizanje korištena je kvantitativna bivarijantna statistička metoda Weight of evidence, te metode strojnog učenja Slučajna šuma i Logistička regresija. Postupak analize podložnosti na klizanje uključuje prikupljanje i obradu ulaznih podataka, izradu geomorfoloških, geoloških, hidroloških i antropogenih karata faktora klizanja, izradu modela i karata podložnosti na klizanje, verifikaciju modela metodom ROC krivulje te klasifikaciju konačnih karata u tri klase podložnosti na klizanje. Usporedba dobivenih rezultata analize podložnosti na klizanje pokazuje da su metode Weight of evidence i Logistička regresija stabilne bez obzira na oblik ulaznog inventara klizišta, dok je metoda Slučajne šume osjetljiva na promjenu geometrijskog oblika inventara, što ju čini manje pogodnom za lokalna mjerila s točkastim inventarom. Iz navedenog proizlazi da odabir metode i oblika ulaznog inventara klizišta treba prilagoditi ciljevima istraživanja i zahtjevima analize, pri čemu točkasti inventar klizišta, koji ne odražava detaljne inženjerskogeološke uvjete na terenu, nije preporučljiv za analize u krupnom mjerilu.The research presented examines the impact of landslide inventory type (polygonal and centorid) and statistical method on the results of landslide susceptibility analysis. The assessment was conducted using the quantitative bivariate statistical method "Weight of Evidence," as well as machine learning methods, specifically Random Forest and Logistic Regression. The process of landslide susceptibility analysis includes collecting and processing input data, creating landslide factor maps (geomorphological, geological, hydrological, and anthropogenic), developing models and susceptibility maps, verifying the models using the ROC curve method, and classifying the final maps into three susceptibility classes. The comparison of the landslide susceptibility analysis results indicates that the Weight of Evidence and Logistic Regression methods are stable regardless of the landslide inventory type, while the Random Forest method is sensitive to changes in inventory type, making it less suitable for local analyses with centroid-based inventories. These results suggests that the choice of method and landslide inventory type should be adapted to specific research goals and analytical requirements and that centroid-based inventories, which do not reflect the 'real' conditions in the field, are not recommended for local-scale analyses
Reservoir quality evaluation: unveiling diagenetic transformations through mineralogical and petrophysical analyses of the Upper Miocene lacustrine sandstones in the Pannonian Basin System, Croatia
No full textThe Upper Miocene lacustrine sandstones of the North Croatian Basin, located in the southwestern Pannonian Basin System, represent significant reservoirs for hydrocarbon exploration, yet their diagenetic evolution remains poorly understood. This study offers a comprehensive investigation into the diagenesis of these sandstones, analyzing samples from 14 exploration wells in the Sava and Drava depressions. Using petrographic analyses, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), and petrophysical measurements, we aimed to explain the diagenetic processes affecting reservoir quality and hydrocarbon productivity. Our results reveal a consistent grain size distribution, modal composition, and diagenetic alterations across both depressions. Compaction, evidenced by evolving grain contacts and pressure dissolution, leads to a depth-dependent reduction in porosity. Carbonate cements, notably calcite and Fe-dolomite/ankerite, are primary contributors to reduction of primary intergranular porosity, alongside clay minerals, quartz, feldspar, etc. Secondary porosity resulting from dissolution and redistribution processes also significantly influences overall porosity evolution. Clay minerals, detrital and authigenic, exhibit a complex interplay with other diagenetic processes, further reducing porosity and permeability. Authigenic clay minerals, including illite, chlorite, and kaolinite, act as pore-filling cement or coatings, hindering fluid flow. Paragenetic processes delineate the intricate relationship between mineralogical transformations and petrophysical properties, defining reservoir quality. Understanding diagenetic dynamics is essential for predicting reservoir quality, fluid migration pathways, and hydrocarbon productivity. This study fills a crucial knowledge gap regarding the diagenesis of the Upper Miocene lacustrine sandstones in the southwestern part of the Pannonian Basin System, providing insights vital for the energy sector and supporting sustainable resource development in the region
Geochemical factors as a tool for distinguishing geogenic from anthropogenic sources of potentially toxic elements in the soil
No full textPotentially toxic element (PTE) contamination of soils and their sources remains one of key global environmental concerns. Agricultural soil in Kalinovac, Podravina region, Croatia is the subject of this study. The main aims include determining the concentration and distribution of PTEs in the soil, differentiation between possible geogenic and anthropogenic sources, and determining the correlation between the analysed PTEs and soil parameters. To achieve these objectives, geochemical analyses of the soil in the study area were carried out. Spatial distribution of the individual PTE contents, enrichment factors (EF), contamination factors (CF), and geoaccumulation index (Igeo) were created using GIS tools. In addition, statistical data processing was carried out, including the calculation of the correlation matrix, hierarchical cluster analysis (HCA), and factor analysis. The obtained results show that certain elements such as lead, chromium, copper, and cadmium were predominantly of anthropogenic origin in the study area, while others tended to have more geogenic origin. By applying different methods used in this study, it is possible to distinguish between geogenic and anthropogenic sources of PTEs in soils of this type