—This study presents a comprehensive analysis of the Balkassar oilfield in the Potwar Basin, Pakistan. It integrates seismic reflection data, a 3D subsurface horizon model, and geochemical and petrophysical data. Evaluating the Lockhart Formation’s geochemical properties using well cuttings reveals consistent patterns of relatively low to fair total organic carbon (TOC). S2 values suggest a fair generation potential with a mixed Type II–III kerogen composition. Seismic facies analysis identifies five distinct categories with parallel attributes. Horizons from lower Permian to Eocene show varying amplitudes and prevalent parallel to wavy internal configurations. Geometries, mainly sheet-to-wedge, enhance stratigraphic understanding. The 3D seismic interpretation reveals the Lockhart Formation’s structural traits, with pronounced northwest dip and gentler southeast inclination. Faults flanking the formation truncate its limbs. A significant contour closure in the northwest, confined by fault boundaries, signifies attractive hydrocarbon potential. Petrophysical analysis indicates an average 9.17% porosity. Dominated by limestone, the formation shows average water saturation of around 25.29% and hydrocarbon saturation of roughly 74.71%, indicating favorable reservoir properties. The Lockhart Formation holds promise as a reservoir rock within the Potwar Basin, though its source rock suitability is limited. This study enhances understanding of Balkassar’s geological complexities and contributes to knowledge of hydrocarbon exploration in the Potwar Basin.
{"title":"Seismic Facies Analysis, 3D Horizon Mapping, Source and Reservoir Rock Characteristics of the Paleocene Sequence in Potwar Basin, Pakistan: with Emphasis on Petroleum Potential Prospect","authors":"Syed Bilawal Ali Shah","doi":"10.2113/rgg20234590","DOIUrl":"https://doi.org/10.2113/rgg20234590","url":null,"abstract":"—This study presents a comprehensive analysis of the Balkassar oilfield in the Potwar Basin, Pakistan. It integrates seismic reflection data, a 3D subsurface horizon model, and geochemical and petrophysical data. Evaluating the Lockhart Formation’s geochemical properties using well cuttings reveals consistent patterns of relatively low to fair total organic carbon (TOC). S2 values suggest a fair generation potential with a mixed Type II–III kerogen composition. Seismic facies analysis identifies five distinct categories with parallel attributes. Horizons from lower Permian to Eocene show varying amplitudes and prevalent parallel to wavy internal configurations. Geometries, mainly sheet-to-wedge, enhance stratigraphic understanding. The 3D seismic interpretation reveals the Lockhart Formation’s structural traits, with pronounced northwest dip and gentler southeast inclination. Faults flanking the formation truncate its limbs. A significant contour closure in the northwest, confined by fault boundaries, signifies attractive hydrocarbon potential. Petrophysical analysis indicates an average 9.17% porosity. Dominated by limestone, the formation shows average water saturation of around 25.29% and hydrocarbon saturation of roughly 74.71%, indicating favorable reservoir properties. The Lockhart Formation holds promise as a reservoir rock within the Potwar Basin, though its source rock suitability is limited. This study enhances understanding of Balkassar’s geological complexities and contributes to knowledge of hydrocarbon exploration in the Potwar Basin.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139273090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Agasheva, A. Gudimova, V.S. Chervyakovskii, A. M. Agashev
––The paper presents data on the contents of major and trace elements in garnet xenocrysts from kimberlites of the highly diamondiferous V. Grib pipe (1100 grains) and weakly diamondiferous TsNIGRI-Arkhangelskaya pipe (446 grains). We have established that the high diamond potential of the V. Grib kimberlite pipe is due to several factors related to the composition and structure of the lithospheric mantle represented by kimberlite: (1) a “cold” regime, with a heat flow of 36–38 mW/m2; (2) a thick “diamond window” (70–102 km), with the depth level of the lower boundary of the lithospheric mantle estimated at >200 km; (3) the high degree of preservation of diamondbearing peridotites under the P–T conditions of diamond stability despite the high degree of impregnation of the lithospheric-mantle rocks by high-temperature silicate melts. The low diamond content of the TsNIGRI-Arkhangelskaya kimberlite pipe as compared with the V. Grib pipe is due to the following factors: (1) a more intense heat flow in the lithospheric mantle, 38–42 mW/m2; (2) a thinner “diamond window”, 10–60 km, with the depth level of the lower boundary of the lithospheric mantle estimated at <200 km; (3) weak impregnation of the rocks of the middle and lower lithospheric mantle by CHO fluid/melt, which might have induced diamond formation; (4) minimum preservation of diamond-bearing peridotites in the lower lithospheric mantle, partly because of the possible impregnation of this zone by high-temperature silicate melts.
{"title":"Contrasting Diamond Potentials of Kimberlites of the V. Grib and TsNIGRI-Arkhangelskaya Pipes (Arkhangelsk Diamondiferous Province) as a Result of the Different Compositions and Evolution of the Lithospheric Mantle: Data on the Contents of Major and Trace Elements in Garnet Xenocrysts","authors":"E. Agasheva, A. Gudimova, V.S. Chervyakovskii, A. M. Agashev","doi":"10.2113/rgg20234569","DOIUrl":"https://doi.org/10.2113/rgg20234569","url":null,"abstract":"––The paper presents data on the contents of major and trace elements in garnet xenocrysts from kimberlites of the highly diamondiferous V. Grib pipe (1100 grains) and weakly diamondiferous TsNIGRI-Arkhangelskaya pipe (446 grains). We have established that the high diamond potential of the V. Grib kimberlite pipe is due to several factors related to the composition and structure of the lithospheric mantle represented by kimberlite: (1) a “cold” regime, with a heat flow of 36–38 mW/m2; (2) a thick “diamond window” (70–102 km), with the depth level of the lower boundary of the lithospheric mantle estimated at >200 km; (3) the high degree of preservation of diamondbearing peridotites under the P–T conditions of diamond stability despite the high degree of impregnation of the lithospheric-mantle rocks by high-temperature silicate melts. The low diamond content of the TsNIGRI-Arkhangelskaya kimberlite pipe as compared with the V. Grib pipe is due to the following factors: (1) a more intense heat flow in the lithospheric mantle, 38–42 mW/m2; (2) a thinner “diamond window”, 10–60 km, with the depth level of the lower boundary of the lithospheric mantle estimated at <200 km; (3) weak impregnation of the rocks of the middle and lower lithospheric mantle by CHO fluid/melt, which might have induced diamond formation; (4) minimum preservation of diamond-bearing peridotites in the lower lithospheric mantle, partly because of the possible impregnation of this zone by high-temperature silicate melts.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"54 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139273742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
––Investigating Early Eocene and Paleocene deposits within the Punjab Platform, Pakistan, involved comprehensive analysis using advanced geochemical and petrophysical techniques. This study evaluates the source potential of three formations: Nammal and Sakesar of Early Eocene age and Dungan and Ranikot of Palaeocene age. The Sakesar Formation, a reservoir rock, was evaluated through interpretation of wireline logs to estimate key petrophysical properties—porosity, water saturation, and hydrocarbon saturation. Geochemical investigations focused on total organic carbon content and Rock-Eval pyrolysis of twenty-one cutting samples from a well. These samples displayed TOC values ranging from 0.21 to 2.04 wt.% and S2 values ranging from 0.09 to 2.14 mg HC/g rock. Analysis positioned all samples within the immature window zone with Type II/III and Type III kerogen, suggesting limited generative potential. Findings suggest limited hydrocarbon generation from these formations. Petrophysical analysis indicated average porosity of 11.2%, water saturation of 32.58%, and hydrocarbon saturation of 67.42% for the Sakesar Formation, categorizing it as average to good reservoir potential. This study highlights complex geochemical and petrophysical characteristics of these formations. While Sakesar shows promising reservoir qualities, significant hydrocarbon generation potential from Nammal, Dungan, and Ranikot formations is constrained. Informed decision-making is crucial when considering these formations as hydrocarbon sources.
{"title":"Investigation of Source and Reservoir Rock Petroleum Generative Potential of Early Eocene and Paleocene Sequences of the Punjab Platform Basin, Pakistan: A Geochemical and Petrophysical Approach","authors":"Syed Bilawal Ali Shah","doi":"10.2113/rgg20234591","DOIUrl":"https://doi.org/10.2113/rgg20234591","url":null,"abstract":"––Investigating Early Eocene and Paleocene deposits within the Punjab Platform, Pakistan, involved comprehensive analysis using advanced geochemical and petrophysical techniques. This study evaluates the source potential of three formations: Nammal and Sakesar of Early Eocene age and Dungan and Ranikot of Palaeocene age. The Sakesar Formation, a reservoir rock, was evaluated through interpretation of wireline logs to estimate key petrophysical properties—porosity, water saturation, and hydrocarbon saturation. Geochemical investigations focused on total organic carbon content and Rock-Eval pyrolysis of twenty-one cutting samples from a well. These samples displayed TOC values ranging from 0.21 to 2.04 wt.% and S2 values ranging from 0.09 to 2.14 mg HC/g rock. Analysis positioned all samples within the immature window zone with Type II/III and Type III kerogen, suggesting limited generative potential. Findings suggest limited hydrocarbon generation from these formations. Petrophysical analysis indicated average porosity of 11.2%, water saturation of 32.58%, and hydrocarbon saturation of 67.42% for the Sakesar Formation, categorizing it as average to good reservoir potential. This study highlights complex geochemical and petrophysical characteristics of these formations. While Sakesar shows promising reservoir qualities, significant hydrocarbon generation potential from Nammal, Dungan, and Ranikot formations is constrained. Informed decision-making is crucial when considering these formations as hydrocarbon sources.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"67 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139272705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
—In bottom sediments of the New Siberian sedimentary basin and adjacent geostructures of the East Siberian Sea, we identified СН4, as well as its limit and unsaturated homologues (up to and including C5H12), CO2, CO, H2, He, H2S, O2, N2, and Ar. Isotope-gas-geochemical parameters δ13С СО2, СН4 and С2Н6, of the molecular mass of hydrocarbon fraction and genetic coefficients indicate the presence of both syngenetic and epigenetic gases of various gas sources in sediments, including recent sediments, peatlands, coal-bearing and gas-bearing formations, solid bitumen, igneous formations, accumulations of gas hydrates and prognostic condensate-gas, condensate, oil-and-gas and gas-and-oil reservoirs. Concentrations of CO2 and CO reach 29.25 and 0.06 cm3/kg, CH4 and the sum of its homologues – 5.93 and 0.031, Н2 and He – 0.78 and 0.318, H2S – 0.092 cm3/kg; this indicates that gas-geochemical anomalies, exceeding the anomaly criteria by 6–124 times, form in bottom sediments. The formation and distribution of abnormal concentrations of natural gases depend on the complex influence of gas-controlling factors – geological structure, fold and fault tectonics, magmatism, coal-oil-gas content, bituminous content, organic saturation, lithological composition, water-physical and reservoir properties of sediments, hydrogeological, geocryological and other conditions for accumulation of natural gases or their degassing.
{"title":"Geological Aspects of the Formation and Distribution of Gas Anomalies in Bottom Sediments of the New Siberian Sedimentary Basin and Adjacent Geostructures of the East Siberian Sea","authors":"A. Gresov, A. Yatsuk","doi":"10.2113/rgg20234594","DOIUrl":"https://doi.org/10.2113/rgg20234594","url":null,"abstract":"—In bottom sediments of the New Siberian sedimentary basin and adjacent geostructures of the East Siberian Sea, we identified СН4, as well as its limit and unsaturated homologues (up to and including C5H12), CO2, CO, H2, He, H2S, O2, N2, and Ar. Isotope-gas-geochemical parameters δ13С СО2, СН4 and С2Н6, of the molecular mass of hydrocarbon fraction and genetic coefficients indicate the presence of both syngenetic and epigenetic gases of various gas sources in sediments, including recent sediments, peatlands, coal-bearing and gas-bearing formations, solid bitumen, igneous formations, accumulations of gas hydrates and prognostic condensate-gas, condensate, oil-and-gas and gas-and-oil reservoirs. Concentrations of CO2 and CO reach 29.25 and 0.06 cm3/kg, CH4 and the sum of its homologues – 5.93 and 0.031, Н2 and He – 0.78 and 0.318, H2S – 0.092 cm3/kg; this indicates that gas-geochemical anomalies, exceeding the anomaly criteria by 6–124 times, form in bottom sediments. The formation and distribution of abnormal concentrations of natural gases depend on the complex influence of gas-controlling factors – geological structure, fold and fault tectonics, magmatism, coal-oil-gas content, bituminous content, organic saturation, lithological composition, water-physical and reservoir properties of sediments, hydrogeological, geocryological and other conditions for accumulation of natural gases or their degassing.","PeriodicalId":506591,"journal":{"name":"Russian Geology and Geophysics","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139271186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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