Paleofluidum fejlődés tér-és időbeli sajátosságai a Szeghalom-Dóm és a környező metamorf hátak példáján = Temporal and spatial comparison of the paleofluid evolution in the Szeghalom dome and in the neighbrouring metamorphic highs

Konfokális lézer szkenning mikroszkóp (CLSM) alkalmazásával a szénhidrogén zárványok folyadék-gáz arányának meghatározása mellett - a fluoreszcens szín és homogenizációs hőmérséklet értékek ismeretében -, jellemezhetővé váltak a homogén bezáródású olajzárvány együttesek. A szénhidrogén zárványok CLSM képalkotás révén történő térfogatarány-meghatározásának pontosítása érdekében két lépcsős, standardizálási folyamatot végeztünk. Ehhez kvarcban, magas nyomású vizes-, ill. KH2PO4-ben, fluoreszcein-tartalmú szintetikus zárványokat hoztunk létre. Szénhidrogén-zárványok Raman mikrospektroszkópiás felvételeinek új megközelítésben történő értelmezésével jellemeztem a Szeghalom- (SzD) és Furta-dómok kvarc anyagú repedéskitöltéseiben megjelenő, kondenzátum típusú fluidumok bezáródási körülményeit, és elkülönítettem egymástól a heterogén fluidum állapot ill. az utólagos rekrisztallizáció létrehozta azonos szöveti bélyegeket. Kémiai- és biológiai marker vizsgálatok alkalmazásával bizonyítottuk, hogy a SzD-on jelenleg termelt kőolaj megegyezik a repedésekben kivált kvarc kristályokban csapdázódott szénhidrogénnel; anyakőzetük közös, krétánál fiatalabb korú. A repedéskitöltések komplex vizsgálata kimutatta, hogy a furtai terület repedésrendszerének cementációja a szeghalmi területen kivált, késői kvarc fázisra jellemző fluidumok jelenlétében játszódott le. Később a Furta-dóm repedésrendszere - helyenként napjainkig - egy szén-dioxid domináns fluidum hatása alá került. | The petroleum inclusions assemblages were unambiguously characterized using confocal laser scanning microscopy (CLSM), in view of fluorescence colour and temperature of homogenization To improve the accuracy of volume fraction estimation using CLSM imaging on hydrocarbon inclusions, standardization process was done in two main steps. Two-phase, aqueous inclusions in quartz at high confining pressure as well as fluorescein-bearing aqueous inclusion in KH2PO4 crystals at room conditions were synthesized. Applying a new approach during the interpretation of Raman spectra obtained on petroleum inclusions of the Szeghalom (SzD) and Furta domes, it is possible to determine the physical conditions of trapping. I was able to divide whether the similar textural features were produced by heterogeneous trapping or post-entrapment modification (e.g. necking down). By chemical and biological marker analysis, I proved that the live oil and the inclusion oil of the SzD have a common, post-Cretaceous source rock. The sequence of the fracture cement phases of the Szeghalom and Furta domes are similar. However, the parent fluid of the quartz cement in the Furta dome shows similarities in chemical and physical properties at the time of trapping only to the late stage fluid of the SzD. After termination of the fracture cementation and a new brittle event, a unique carbon dioxide-bearing fluid migrated in the fracture network of the Furta dome

Preliminary fluid inclusion microthermometry results from secondary inclusion planes crosscutting a metamorphic quartz lens from the Mecsekalja Zone metamorphic complex

In this study, new microthermometric data of fluid inclusions distributed along planar assemblages crosscutting a metamorphic quartz lens from the Mecsekalja Zone metamorphic complex are presented. Three fluid generations are defined, none of which have previously been identified by earlier paleofluid evaluations of the study area. Petrographic description of the host quartz is provided to identify textures related to crystalloplastic deformation resulting from ductile deformation. The textural relationship of the studied assemblages to the dynamic recrystallization features is discussed. The possible affinities of the fluids introduced in this study to those identified in the region by previous authors are discussed. The affinities and timing of the fluid flow events are discussed based on the physicochemical properties of the fluids. One local carbonic (high XCO2) fluid is recognized. A high- and a moderate-salinity fluid generation are also revealed. The relationship of these fluid generations to those defined in earlier studies from the Mórágy Granite and the Baksa metamorphic complex contributes new knowledge to the recognition of the regional paleofluid evolution

Paleofluid evolution of the fractured basalt hydrocarbon reservoir in the Üllés-Ruzsa-Bordány area, SE Hungary

Abstract Volcanic successions of the Kecel Basalt Formation (KBF) occur in the southern part of the Pannonian Basin. As a result of periodic submarine eruptions, the basaltic and pyroclastic rock horizons were intercalated with layers of the Late Miocene Endrod Marl Formation, which is regarded as one of the most important hydrocarbon source rocks in the area. The KBF was discovered through almost 30 wells between 2,200 and 2,900 meters of depth. Due to the high fracture porosity, some parts of the formation show good reservoir characteristics and act as important migration pathways of hydrocarbon-bearing fluids. Since the reservoir is presumably fracture-controlled, this study concentrates on the evolution of fractures crosscutting the rock body. Based on textural and mineralogical features, four distinct vein types can be distinguished, of which the first three types are discussed in this paper. Beside calcite, quartz, feldspar, and chlorite, the veins are cemented by various zeolite minerals. The vertical dimension of the dominant zeolite zone indicates the burial-diagenetic type of zeolite zonation and suggests subsidence of the subaqueous basalt after formation

Near vein metasomatism along propylitic veins in the Baksa Gneiss Complex, Pannonian Basin, Hungary

In many parts of the metapelitic (gneiss, mica schist) rock section of the Baksa Complex, significant wall-rock alteration is observable along the Ca-Al silicate veins, which show a di → ep ± czo →sp → ab ± kfs → chl → adu → prh → py → cal mineral sequence (FINTOR et al., 2009). These alterations appear as narrow (few cm thick) bleached margins beside thin veins, and broad alteration bands along thick veins where detailed epidotization and chloritization of the adjacent rock are recognizable. Based on petrographic and mineralogical examination of the altered wallrocks, metasomatic zones with characteristic mineral paragenesis can be distinguished: Zone 1 (ab + ttn ± ep), Zone 2 (ep + chl+ ttn + ab ± ser), Zone 3 (chl + ep + ser + rt ± ttn), Zone 4 (ser ± chl). Bulk rock chemical analyses were made from the different metasomatic zones. The results show that fluid circulated in the propylitic veins caused metasomatic alteration of the wall-rock, with transport of considerable amount of Ca2+ toward the adjacent rocks. The hydrothermal leaching almost totally removed the K, Fe, Mg, and Mn ions from the wall rock. The main alteration processes are the epidotization and chloritization of biotite, and albitization of micas (muscovite + biotite) content of metapelites. Based on mobilization of different cations alteration was due to? to a near neutral fl uid (~pH 5–7). The pervasive hydrothermal leaching caused significant secondary porosity (cavities) in the altered domains, which were partially filled by epidote. Fluid inclusions of cavity filling epidote indicate a similar character (Th: 180–360 °C; Salinity: 0.2–1.6 mass% eq. NaCl) to that can be found in Ca-Al silicate veins. The alteration most probably occurred in the 360–480 °C temperature range as products of \u27near vein metasomatism\u27 and the altered rock can be related to the propylite metasomatic family

Near vein metasomatism along propylitic veins in the Baksa Gneiss Complex, Pannonian Basin, Hungary

In many parts of the metapelitic (gneiss, mica schist) rock section of the Baksa Complex, significant wall-rock alteration is observable along the Ca-Al silicate veins, which show a di → ep ± czo →sp → ab ± kfs → chl → adu → prh → py → cal mineral sequence (FINTOR et al., 2009). These alterations appear as narrow (few cm thick) bleached margins beside thin veins, and broad alteration bands along thick veins where detailed epidotization and chloritization of the adjacent rock are recognizable. Based on petrographic and mineralogical examination of the altered wallrocks, metasomatic zones with characteristic mineral paragenesis can be distinguished: Zone 1 (ab + ttn ± ep), Zone 2 (ep + chl+ ttn + ab ± ser), Zone 3 (chl + ep + ser + rt ± ttn), Zone 4 (ser ± chl). Bulk rock chemical analyses were made from the different metasomatic zones. The results show that fluid circulated in the propylitic veins caused metasomatic alteration of the wall-rock, with transport of considerable amount of Ca2+ toward the adjacent rocks. The hydrothermal leaching almost totally removed the K, Fe, Mg, and Mn ions from the wall rock. The main alteration processes are the epidotization and chloritization of biotite, and albitization of micas (muscovite + biotite) content of metapelites. Based on mobilization of different cations alteration was due to? to a near neutral fl uid (~pH 5–7). The pervasive hydrothermal leaching caused significant secondary porosity (cavities) in the altered domains, which were partially filled by epidote. Fluid inclusions of cavity filling epidote indicate a similar character (Th: 180–360 °C; Salinity: 0.2–1.6 mass% eq. NaCl) to that can be found in Ca-Al silicate veins. The alteration most probably occurred in the 360–480 °C temperature range as products of \u27near vein metasomatism\u27 and the altered rock can be related to the propylite metasomatic family

Palaeofluid evolution in a fractured basalt hosted reservoir in the Üllés-Ruzsa-Bordány area, southern sector of the Pannonian Basin

Extensive Miocene volcanic activity produced basaltic and pyroclastic successions, which were penetrated by many wells in the area of Üllés-Ruzsa-Bordány, in the western and central part of the Great Hungarian Plain. The Kecel Basalt comprises primary porosity from a high proportion of vesicles and significant secondary fracture porosity, as well. Due to the significant fracture porosity, some depth intervals show good reservoir characteristics, although the fractures crosscutting the rock body are partly or entirely cemented by various minerals. Based on the textural and mineralogical features, four distinct vein types can be distinguished, named after their volumetrically most abundant cement phases, i.e. potassium-feldspar (Kfp-), calcite (Cal-), laumontite (Lmt-) and analcime (Anl-) types. This study focuses on probably the youngest of these vein types, the Anl-type. Based on the study of veins and mineral sequences, the direction of temperature changes cannot be given unequivocally for every stage of cementation, but crystallization of the Anl-type veins might have occurred at lower temperatures than the formation of the Lmt-type veins. Fluid inclusion studies suggest that hydrocarbon migration and accumulation took place after cementation of the first three vein types (Kfp-, Cal- and Lmt-types). In the newly opened fracture system, two types of hydrocarbon (HC1 and HC2)-bearing fluid inclusion assemblages were captured during precipitation of analcime and later zeolites. This refers to two stages of hydrocarbon migration in the fracture system. Observations of the fluorescence colours and low temperature behaviours of the hydrocarbon-bearing inclusions, the earlier HC1 petroleum-inclusions captured heavier (presumably less mature oils), while the later ones (HC2) lighter (presumably more mature) oils. The HC2 petroleum seems to be very similar to the crude oil sampled in a well in the area based on their fluorescence parameters.</p