5 results on '"Twaróg, Anna"'
Search Results
2. RESULTS OF SURFACE GEOCHEMICHAL SURVEY IN THE AREA OF MOŁODYCZ GAS DEPOSIT IN THE CARPATHIAN FOREDEEP (SE POLAND).
- Author
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Góra, Adrianna, Sechman, Henryk, Twaróg, Anna, Guzy, Piotr, and Michna, Michał
- Subjects
PETROLEUM prospecting ,SOILS ,MIOCENE Epoch ,PROSPECTING ,REGOLITH - Abstract
Surface geochemical method is an important technique in petroleum exploration. The purpose of this method is to record and analyze the distribution of micro-concentration of gaseous hydrocarbons, which migrate from subsurface accumulations to the nearsurface zone. The paper presents the results of surface geochemical survey carried out in the area of the Mołodycz gas deposit of the Carpathian Foredeep. A soil-gas geochemical survey was carried out along the six sampling lines corresponding to the seismic section. A total of 192 soil gas samples were collected from 1.2 m depth below the surface and then analyzed chromatographically. The maximum concentration of CH
4 , total alkanes C2 -C4 , total alkenes C2 -C4 reached: 369.1 ppm, 3.5 ppm and 4.6 ppm, respectively. Based on the concentrations measured in the soil gas the C2 H6/C3 H8 (C2 /C3 ) ratio was calculated, which allowed to evaluate the character of deep hydrocarbon accumulations. The statistical parameters, histogram distribution and scatter-plots of ethane versus propane concentrations shown dominance signals characteristic for gas-condensate accumulations. Moreover, normalized and filtered values of the total alkanes C2 -C4 concentrations were drawn against structural map of the gas horizon of the Miocene strata. Anomalous concentrations of total alkanes C2 -C5 were found in 11 zones. These zones were the effect of the migration from sources located at various depths. Such a comparison demonstrated also that hydrocarbon accumulations can be expected outside the known contours of the gas deposit. Results of surface geochemical survey combined with the geological studies and geophysical surveys provide a valuable source of comprehensive information about the explored area and can be a new perspective for exploration in a hydrocarbon provinces. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
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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 analysis of geoelectric and surface geochemical data for exploration of subsurface hydrocarbon accumulations (Carpathian Foredeep, SE Poland).
- Author
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Twaróg, Anna, Stefaniuk, Michał, Sechman, Henryk, and Guzy, Piotr
- Subjects
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HYDROCARBONS , *METHANE , *MINERALIZATION , *MAGNETOTELLURIC prospecting , *ELECTROMAGNETIC prospecting - Abstract
The search for hydrocarbon deposits in the Carpathian Foredeep is dominate by seismic methods. However, chances for additional discoveries of oil and gas will be increased by the integration of geochemical methods with non-seismic methods. The authors document mutual relationships between data obtained from surface geochemical survey and surface geoelectric survey. The geoelectric and geochemical surveys were run along 8 linear profiles positioned over the Rudka gas deposit discovered in Miocene sediments. This deposit is located over the margin of the Ryszkowa Wola Horst (Carpathian Foredeep). The Rudka deposit accumulates microbial gas generated under strictly defined conditions (microbial reduction of carbon dioxide). Soil gas samples were collected from a depth of 1.2 m at 177 sites and analyzed for methane, alkanes, alkenes, and non-hydrocarbon components. Maximum concentrations of CH 4 , total alkanes C 2 -C 5 and total alkenes C 2 -C 4 are 1200.0 ppm, 16.49 ppm and 0.289 ppm, respectively. The high concentrations of methane correlated with high values of C 1 /∑(C 2 -C 4 ) ratio indicate the presence of recent (microbial) methane whereas higher alkanes detected in soil gases originated from deep hydrocarbon accumulations. Two methodological variants of magnetotelluric survey were applied: natural field magnetotelluric soundings and controlled-source audiomagnetotelluric profiling. The interpreted resistivity values of Miocene sediments change from 0.6 to 20 Ωm but higher resistivities, locally exceeding 100 Ωm also occur in the near-surface zone. The lateral decreases of resistivity observed in the cross-sections may be linked to tectonic discontinuities. Changes of resistivity values identified in the magnetotelluric profiles and interpreted as the signs of “gas chimneys” correlate well with anomalous concentrations of total alkanes C 2 -C 5 . The multistage analysis of the results of surface geochemical and geoelectric surveys demonstrated that gas-saturated zones may extend beyond the known contour of the Rudka gas deposit. These results demonstrate that geoelectric and geochemical data collected in the near-surface zone are valuable complements of conventional hydrocarbon exploration methods. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
5. 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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