Defined as a piggyback basin, the Plio-Pleistocene Sant'Arcangelo basin is one of the more re... more Defined as a piggyback basin, the Plio-Pleistocene Sant'Arcangelo basin is one of the more recent onshore sedimentary basin of the Southern Apennines. Extensive field studies allow to reinterpret the whole stratigraphy of the basin in a more simple and significant way. Five unconformity-bounded units ("groups") have been recognised : The (1) Catarozzo Group (late Pliocene) unconformably overlies pre-Miocene units, and it is composed of a flood-dominated fan-delta marine (C1) and restricted-marine (C2) systems bounded by a sharp contact with a total thickness up to 650 meters. The (2) Aliano Group (late Pliocene - early Pleistocene) includes an up to 1,400 meters thick succession of flood-dominated fan-delta systems, with facies ranging from poorly organised alluvial conglomerates in the west to massive marine mudstones in the east. Two sub-units have been recognised, bounded by a regional unconformity, which shows an abrupt passage from marine (A1) to restricted-marine...
The sedimentary characteristics and petrophysical properties of the reservoir of the second/lower... more The sedimentary characteristics and petrophysical properties of the reservoir of the second/lower member of the Lower Permian Shanxi Formation (P1s2) in Sulige Gas Field, Central China are studied by means of thin section petrography and scanning electron microscopy. This article highlights the relationship between reservoir quality and sedimentary environments, explains the differences in reservoir petrophysical properties in different sedimentary environments, discusses the influence of clastic components and authigenic minerals on the reservoir, and finally, provides the basis for the prediction of relatively high‐quality reservoir in P1s2 of the study area. The results show that the sandstones formed as a meandering river deposit in the south of the study area are fine‐grained, mainly composed of lithic fragments of quartz sandstone, metamorphic, and volcanic rock lithic fragment, with high content of matrix and poor sorting, average porosity of 5.09%, and average permeability of 0.20 × 10−3 μm2. The braided river sedimentary deposits in the north are coarse‐grained, mainly composed of quartz sandstone sedimentary rock lithic fragment, with low content of matrix, good sorting, and more developed dissolution pores. The average porosity is 6.16%, and the average permeability is 0.53 × 10−3 μm2. Among the authigenic minerals, siderite, calcite, and illite block, the pores between the grains reduce the porosity. Siliceous cement often indicates better reservoir petrophysical properties. The siliceous cement is more common in braided river deposits in the north area, in which the channel bar detailed facies are conducive to retain more primary pores or form secondary pores, thus forming better reservoirs.
Bioturbated heterolithic clastic reservoirs are often characterized by clean sandstones forming t... more Bioturbated heterolithic clastic reservoirs are often characterized by clean sandstones forming thin levels, small patches, and burrow infills. This scenario makes precise estimation of percentage of sandstone (net-to-gross) a very difficult task. At present, there are no tools available that allows a straightforward quantification of the sand content using core pictures. In this work, a novel technique that uses core photographs is presented. Using computer vision processing software it is possible to determine the composition of the analyzed cores. The method is based on an automatic segmentation of contrasted core photographs and the subsequent analysis through image processing. This methodology allows precise estimation of the sandstone percentage (ISA, image sandstone analysis) at a variable and fully customized sample rate. The results are continuous logs that can be fully integrated with other conventional core and well logs. A similar procedure was applied to the analysis an...
An outgrowth of the 2008 AAPG Hedberg Conference on Sediment Transfer from Shelf to Deep Water, S... more An outgrowth of the 2008 AAPG Hedberg Conference on Sediment Transfer from Shelf to Deep Water, Studies in Geology 61 was designed specifically to explore the growing interest in hyperpycnal and associated flows and hyperpycnites as significant contributors to the deep-water sedimentary record. The topic of hyperpycnal flows and their deposits, hyperpycnites, has recently emerged as the latest in a long list of hotly debated topics on deep-water sedimentary processes, environments, and deposits. This collection of chapters offers important new insights into the sediment delivery system to deep-marine waters.
New micropaleontological and stratigraphical data of the Lotena Formation at Barda Norte locality... more New micropaleontological and stratigraphical data of the Lotena Formation at Barda Norte locality suggest that the Picún Leufú sub-basin was connected to open marine conditions at least until latest Oxfordian- early Kimmeridgian. These data reinforce the hypothesis of a temporary physical disconnection between the Picún Leufú sub-basin and the Neuquén Basin. The transitional characteristics of the palynological assemblages containing taxa recognized in Argentina since the Late Jurassic and the presence of sporomorphs belonging to the Stereisporites pandoi Zone (late Oxfordian) suggest a latest Oxfordian - early Kimmeridgian age for the analyzed deposits. According to the micropaleontological and stratigraphical analysis, the age of the Lotena Formation in the Picún Leufú sub-basin could span from the middle Callovian to the late Oxfordian-early Kimmeridgian. The microfossils (palynomorphs and foraminifers) suggest a moderate energy marginal- marine environment, located close to the ...
espanolEl analisis palinofacial de muestras de afloramiento del Grupo Cuyo (Jurasico Medio) fue l... more espanolEl analisis palinofacial de muestras de afloramiento del Grupo Cuyo (Jurasico Medio) fue llevado a cabo en estratos de la Sierra de Chacaico, suroeste de la Cuenca Neuquina. Nuestros resultados son la base para interpretar los cambios paleoambientales y paleoclimaticos en el area, y para evaluar el potencial oleogenetico de estas rocas. El analisis de las biofacies muestra que determinados grupos de plantas dominaron el escenario terrestre, particularmente las cheirolepidiaceas y, en menor proporcion, por las araucariaceas, caytoniales, cicadaceas, podocarpaceas y helechos. Se infiere, para el Grupo Cuyo, ambientes marinos marginales para las formaciones Los Molles y Lajas, hasta continentales para la Formacion Challaco. Para la Formacion Los Molles se infieren condiciones calidas y semiaridas, en tanto que para la Formacion Lajas, condiciones climaticas calidas y aridas para la base y, hacia el techo, relativamente humedas. La evaluacion cuali/cuantitativa de la materia orga...
Defined as a piggyback basin, the Plio-Pleistocene Sant'Arcangelo basin is one of the more re... more Defined as a piggyback basin, the Plio-Pleistocene Sant'Arcangelo basin is one of the more recent onshore sedimentary basin of the Southern Apennines. Extensive field studies allow to reinterpret the whole stratigraphy of the basin in a more simple and significant way. Five unconformity-bounded units ("groups") have been recognised : The (1) Catarozzo Group (late Pliocene) unconformably overlies pre-Miocene units, and it is composed of a flood-dominated fan-delta marine (C1) and restricted-marine (C2) systems bounded by a sharp contact with a total thickness up to 650 meters. The (2) Aliano Group (late Pliocene - early Pleistocene) includes an up to 1,400 meters thick succession of flood-dominated fan-delta systems, with facies ranging from poorly organised alluvial conglomerates in the west to massive marine mudstones in the east. Two sub-units have been recognised, bounded by a regional unconformity, which shows an abrupt passage from marine (A1) to restricted-marine...
The sedimentary characteristics and petrophysical properties of the reservoir of the second/lower... more The sedimentary characteristics and petrophysical properties of the reservoir of the second/lower member of the Lower Permian Shanxi Formation (P1s2) in Sulige Gas Field, Central China are studied by means of thin section petrography and scanning electron microscopy. This article highlights the relationship between reservoir quality and sedimentary environments, explains the differences in reservoir petrophysical properties in different sedimentary environments, discusses the influence of clastic components and authigenic minerals on the reservoir, and finally, provides the basis for the prediction of relatively high‐quality reservoir in P1s2 of the study area. The results show that the sandstones formed as a meandering river deposit in the south of the study area are fine‐grained, mainly composed of lithic fragments of quartz sandstone, metamorphic, and volcanic rock lithic fragment, with high content of matrix and poor sorting, average porosity of 5.09%, and average permeability of 0.20 × 10−3 μm2. The braided river sedimentary deposits in the north are coarse‐grained, mainly composed of quartz sandstone sedimentary rock lithic fragment, with low content of matrix, good sorting, and more developed dissolution pores. The average porosity is 6.16%, and the average permeability is 0.53 × 10−3 μm2. Among the authigenic minerals, siderite, calcite, and illite block, the pores between the grains reduce the porosity. Siliceous cement often indicates better reservoir petrophysical properties. The siliceous cement is more common in braided river deposits in the north area, in which the channel bar detailed facies are conducive to retain more primary pores or form secondary pores, thus forming better reservoirs.
Bioturbated heterolithic clastic reservoirs are often characterized by clean sandstones forming t... more Bioturbated heterolithic clastic reservoirs are often characterized by clean sandstones forming thin levels, small patches, and burrow infills. This scenario makes precise estimation of percentage of sandstone (net-to-gross) a very difficult task. At present, there are no tools available that allows a straightforward quantification of the sand content using core pictures. In this work, a novel technique that uses core photographs is presented. Using computer vision processing software it is possible to determine the composition of the analyzed cores. The method is based on an automatic segmentation of contrasted core photographs and the subsequent analysis through image processing. This methodology allows precise estimation of the sandstone percentage (ISA, image sandstone analysis) at a variable and fully customized sample rate. The results are continuous logs that can be fully integrated with other conventional core and well logs. A similar procedure was applied to the analysis an...
An outgrowth of the 2008 AAPG Hedberg Conference on Sediment Transfer from Shelf to Deep Water, S... more An outgrowth of the 2008 AAPG Hedberg Conference on Sediment Transfer from Shelf to Deep Water, Studies in Geology 61 was designed specifically to explore the growing interest in hyperpycnal and associated flows and hyperpycnites as significant contributors to the deep-water sedimentary record. The topic of hyperpycnal flows and their deposits, hyperpycnites, has recently emerged as the latest in a long list of hotly debated topics on deep-water sedimentary processes, environments, and deposits. This collection of chapters offers important new insights into the sediment delivery system to deep-marine waters.
New micropaleontological and stratigraphical data of the Lotena Formation at Barda Norte locality... more New micropaleontological and stratigraphical data of the Lotena Formation at Barda Norte locality suggest that the Picún Leufú sub-basin was connected to open marine conditions at least until latest Oxfordian- early Kimmeridgian. These data reinforce the hypothesis of a temporary physical disconnection between the Picún Leufú sub-basin and the Neuquén Basin. The transitional characteristics of the palynological assemblages containing taxa recognized in Argentina since the Late Jurassic and the presence of sporomorphs belonging to the Stereisporites pandoi Zone (late Oxfordian) suggest a latest Oxfordian - early Kimmeridgian age for the analyzed deposits. According to the micropaleontological and stratigraphical analysis, the age of the Lotena Formation in the Picún Leufú sub-basin could span from the middle Callovian to the late Oxfordian-early Kimmeridgian. The microfossils (palynomorphs and foraminifers) suggest a moderate energy marginal- marine environment, located close to the ...
espanolEl analisis palinofacial de muestras de afloramiento del Grupo Cuyo (Jurasico Medio) fue l... more espanolEl analisis palinofacial de muestras de afloramiento del Grupo Cuyo (Jurasico Medio) fue llevado a cabo en estratos de la Sierra de Chacaico, suroeste de la Cuenca Neuquina. Nuestros resultados son la base para interpretar los cambios paleoambientales y paleoclimaticos en el area, y para evaluar el potencial oleogenetico de estas rocas. El analisis de las biofacies muestra que determinados grupos de plantas dominaron el escenario terrestre, particularmente las cheirolepidiaceas y, en menor proporcion, por las araucariaceas, caytoniales, cicadaceas, podocarpaceas y helechos. Se infiere, para el Grupo Cuyo, ambientes marinos marginales para las formaciones Los Molles y Lajas, hasta continentales para la Formacion Challaco. Para la Formacion Los Molles se infieren condiciones calidas y semiaridas, en tanto que para la Formacion Lajas, condiciones climaticas calidas y aridas para la base y, hacia el techo, relativamente humedas. La evaluacion cuali/cuantitativa de la materia orga...
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