4 results on '"Twaróg, Anna"'
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2. DISTRIBUTION OF LIGHT HYDROCARBONS IN THE SELECTED AREA OF THE CARPATHIAN FOREDEEP – CASE STUDY FROM SE POLAND.
- Author
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Góra, Adrianna, Sechman, Henryk, Guzy, Piotr, and Twaróg, Anna
- Subjects
SOIL air ,SURFACE of the earth ,HYDROCARBONS ,GEOCHEMICAL surveys ,GAS condensate reservoirs ,SOIL sampling - Abstract
Light hydrocarbons migrate from the petroleum accumulations to the Earth’s surface through faults and fractures. The occurrence of these hydrocarbons in the near-surface zone forms the basis for the surface geochemical methods. The purpose of these methods is to record and analyze the distributions of micro-concentration of gaseous hydrocarbons. The paper presents the results of surface geochemical survey carried out in the “Kosina” hydrocarbon concession block in SE part of the Carpathian Foredeep. The surveys were conducted along 6 measurements profiles. A total of 270 soil gas samples were collected and analyzed for methane and higher gaseous hydrocarbons. The maximum concentrations of CH
4 , total alkanes C2 -C5 , total alkenes C2 -C4 reached: 2.6 vol.%, 0.532 ppm and 8.25 ppm, respectively. These analytical results enabled us to calculate the geochemical indicators CH4 /∑C2 -C5 and C2 H6 /C3 H8 which allowed to evaluate the character of deep hydrocarbon accumulations. The first indicator suggest that observed surface geochemical signature represents the hydrocarbon migration mostly from deep-seated petroleum accumulations. The values of CH4 /∑C2 -C5 varied from 6.02 – 141318.7 ppm with mean value – 845.7 ppm. Additionally, the statistical parameters and histogram distributions of C2 H6 /C3 H8 indicator values suggest the dominance of condensate and condensate-gas accumulations at depths. Furthermore, normalized and filtered values of methane, total alkanes C2 -C5 and total alkenes C2 -C4 were placed on the structural map of the base of the Miocene strata. Small zones of anomalous concentrations of total alkanes C2 -C5 are concentrated in the northern part of the area and occur above elevation of Miocene base as well as in the adjacent subsided zone. Measured concentrations and their normalized values plotted and then integrated with the seismic image. The results of study show the possibility of occurrence of relatively small accumulation of conventional gas trapped in Miocene compact structure, formed above the elevation of the Miocene strata. The condensate gas mostly migrated from deep-seated parts of the Miocene horizons. [ABSTRACT FROM AUTHOR]- Published
- 2019
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3. DISTRIBUTIONS OF LIGHT HYDROCARBONS IN THE NEAR SURFACE ZONE OF THE MARGINAL PART OF THE CARPATHIAN FOREDEEP AND OUTER CARPATHIANS - CASE STUDY FROM SE POLAND.
- Author
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Góra, Adrianna, Guzy, Piotr, Twaróg, Anna, Górska-Mruk, Ewelina, and Sechman, Henryk
- Subjects
GEOCHEMISTRY ,HYDROCARBONS ,SOIL air ,GEOCHEMICAL surveys ,FOSSIL fuels - Abstract
The paper presents the results of surface geochemical surveys carried out using "free gas method" in "Brzesko-Wojnicz" area in the SE part of the Poland. The surveys were conducted along 2 measurement profiles. A total of 341 soil gas samples were collected from 1.2 m depth below the surface. Maximum concentrations of CH4, total alkanes C
2 - C5 , total alkenes C2 -C4 reached: 27,1 vol.%., 45,3 ppm and 0,174 ppm, respectively. In total, in the analyzed area there are anomalous concentration of total C2 -C5 alkanes (over 3σ above calculated background mean) in 121 measurement points, comprising 9 zones ranging from 200 m to a 2 kilometres. Calculated hydrocarbon ratios CH4 /ΣC2 -C5 (C1 /ΣC2 -C5 ) and C2 H6 /C3 H8 (C2 /C3 ) allow to define the presence of compositionally diversified, deep hydrocarbon accumulations. The statistical parameters and histogram distributions of the above-mentioned ratios show dominance of condensate-oil character of deep-seated sources with the presence, in some samples, of the effects of current biochemical processes. The highest number of anomalies of total alkanes C2 -C5 was determined over the Wojnicz thrust slice, particularly in the area of significant increase in thickness of autochthonous miocene sediments. The Wojnicz thrust slice is bordered to the south by the Dębno thrust slice, over where a decay of anomalous indications of total alkanes C2 -C5 was observed. Besides, the thrust fault zone of this thrust slice collectively with the marginal part of the Outer Carpathian may create barriers to the potential migration and microseepage of hydrocarbons from deeper miocene horizons and from flysch sediments. The conducted analysis indicates that the number and distribution of surface geochemical anomalies point to the possibility of the occurrence of deep-seated accumulations, but the penetration of gas ingredients to the surface is determined predominantly by the tectonics of the area. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
4. Integrated surface geochemical and seismic surveys for hydrocarbon exploration - A case study from southern Poland.
- Author
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Maślanka, Adrianna, Sechman, Henryk, Twaróg, Anna, Cichostępski, Kamil, Wojas, Anna, and Durlej, Michał
- Subjects
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GEOCHEMICAL surveys , *SEISMIC surveys , *MAGNETIC anomalies , *MAGNETIC susceptibility , *SOIL air - Abstract
Surface geochemical surveys were carried out in the Pawłosiów area in the eastern part of the Carpathian Foredeep. The research included an analysis of the molecular composition of soil gas samples as well as measurements of the calcite content, magnetic susceptibility and pH of soil samples. The results obtained were integrated with a geological-seismic model. Changes in the concentrations of total alkanes C 2 –C 5 in relation to changes in indirect geochemical indicators showed "compensatory" character. This means that in places where alkane concentrations were increasing, negative anomalies of magnetic susceptibility and a decrease in pH values were observed. It may be related to the intensity of the oxidation processes or reduction of the magnetic minerals in, as well as the reduced permeability of, the Miocene layers in the zones analysed. Moreover, the complex geochemical-geophysical interpretation showed a zone of anomalous values of the total C 2 –C 5 alkanes in the Pawłosiów area, which is suitable for prospecting. The research performed proved that a thorough analysis of the seismic record allowing subtle DHI anomalies appearing within the Miocene formations to be located, combined with the use of direct and indirect geochemical indicators, can help in identifying an area in terms of hydrocarbon potential. This applies in particular to this type of foreland basin, within which geological formations lie flat, and positive structures (anticlines) are hardly visible in seismic sections. In this type of structure, hydrocarbons can be accumulated in traps of a hybrid character (conventional and unconventional). The extensive zone of geochemical and geophysical anomalies found in the area of Pawłosiów may indicate the presence of this type of hydrocarbon accumulation. Comprehensive research, including direct and indirect geochemical methods in combination with a seismic survey, allows for a better assessment of the hydrocarbon potential of the studied area. • Direct and indirect surface geochemical indicators help interpret DHI seismic anomalies. • Alkane anomalies are associated with a decrease in magnetic susceptibility. • CH 4 and C 2 H 6 mainly migrate to the surface from shallow Miocene horizons, while C 3 H 8 and C 4 H 10 from deeper Miocene layers. • Integrated analysis of geochemical and geophysical indicators can help in the search for hybrid natural gas accumulations. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
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