Organic Metamorphism and Geothermal History: Microscopic Study of Organic Matter and Thermal Evolution of Sedimentary Basins

ISBN-13: 9789027725011 / Angielski / Miękka / 1987 / 312 str.

Paul Robert

Opis

The optical studies of fossil organic matter in reflected light have made great progress in recent decades with the development of coal petrology, completed around the end of the 1970s by fluorescence examination. As they are complementary to the studies in transmitted light (palynology) and organic geochemistry developed for petroleum exploration purposes, they have become a much used tool in the recognition of sedimentary thermal transformations. For more than fifteen years within the Elf-Aquitaine Group, these studies have been applied in their various aspects to furnish a better geological understanding of basins during exploration. They have enabled us to define liquid and gas hydrocarbon domains which they differentiate and have also enabled a better characterization of sedimentary environments. Perhaps the most unexpected result of these studies has been to reconstruct the thermal history of the basins. Unforeseen but promising, when deduced from the thermicity of the sedimentary cover, the crust thermicity forms a determining link-element between the deep tectonics and the basin formation. Over the last ten years, the significance of this theme of research has been reinforced thanks to the impressive development of geodynamic studies following the general change in ideas brought about by plate tectonics. The present-day geothermal studies, conducted simultaneously in the oceanic and continental domains, have provided it with an argumentation and richer references.

Recenzje

` .. the book will be of particular value as a reference source. '
Journal of Petroleum Geology, vol.12, No.1, Jan. 1989

Spis treści

One The Thermal Diagenesis of Organic Matter and the Methods of Paleogeothermal Analysis.- 1. The Thermal Diagenesis of Organic Matter.- 1.1. Historical developments.- 1.2. General concepts: writings on organic metamorphism; the key-role of burial.- 1.2.1.Bostick’s work.- 1.2.1.1. Thermal simulations.- 1.2.1.2.Burial metamorphism.- 1.2.2. Case studies of Canadian basins by Hacquebard..- 1.2.3.Examples taken from French works.- 1.2.3.1. Case studies of Saharan oil and gas deposits.- 1.2.3.2. Case of gas deposits in South Aquitaine (France).- 1.3. General concepts: the appearance of the geothermy-burial duality.- 1.3.1. The thermal effects of eruptive events and volcanism.- 1.3.1.1. The metamorphic belt encircling the Pier granite of the Narragansett basin (Rhode Island, U.S.A.).- 1.3.1.2. Formation of natural cokes in the contact-zone of a basaltic dyke in the Ruhr Carboniferous.- 1.3.1.3. The identification of deep magmas along the edge of the Variscan range: case study of the Erkelenz basic massif.- 1.3.2. Published evidence of paleogeothermal variations occurring during geological history.- 1.3.2.1. American basins.- 1.3.2.1.1. Damberger’s research, 1974.- 1.3.2.1.2. Pusey’s work (1973), North Texas.- 1.3.2.2. Studies of European basins.- 1.3.2.3. The Australian Cooper basin.- 1.4. General concepts: progress towards a geothermal history influenced by time and space, and related to the geological history of basins. Search for a link with tectonics.- 1.4.1. German works.- 1.4.1.1. The aulacogen.- 1.4.1.2. The orogenic foreland basin.- 1.4.1.3. The subduction-collision area.- 1.4.2. Other German studies: the Rhenish Schistose Massif.- 1.4.3. Study of Saharan basins.- 1.4.4. Australian basins: the general relationship between thermal events and the creation of the Australian continent.- 2. Methods and Means of Paleothermal Analysis.- 2.1. Theoretical basis of chemical kinetics applied to thermal evolution of organic matter.- 2.1.1. Principles behind the mathematical simulation of thermal alteration of organic matter.- 2.1.1.1. First order reaction.- 2.1.1.2. The role of temperature: the Arrhenius relationship.- 2.1.2. Applications.- 2.1.2.1. Karweil’s graph (1956, 1975).- 2.1.2.2. Diagram of Hood et al. (1975).- 2.1.2.3. The Lopatin method (1971).- 2.1.2.4. Simulations by Tissot (1969) and Tissot & Espitalié (1975).- 2.1.2.5. The Diagen program.- 2.1.2.6. Conclusion.- 2.2. Elements of geothermy.- 2.2.1. General data.- 2.2.1.1. Some useful definitions units.- 2.2.1.2. Heat transfer by conduction.- 2.2.1.3. The concept of thermal potential.- 2.2.1.4. Applications.- 2.2.2. The geothermy of oceans and continents.- 2.2.3. The geothermal maps of some basins.- 2.2.3.1. Classification of geothermal maps and profiles.- 2.2.3.1.1. Comments.- 2.2.3.1.2. The North Sea.- 2.2.3.2. Conclusion: factors responsible for variations in the deep flows.- 2.3. Methods for reconstructing the thermal history of geological series.- 2.3.1. VRo vertical curves for wells.- 2.3.1.1. Recording the VRo curves.- 2.3.1.2. Interpretation of the VRo curves.- 2.3.1.2.1. Classification of the VRo curves.- 2.3.2. The statistical study of vertical VRo increase.- 2.3.2.1. Statistical analysis.- 2.3.2.2. Consequences.- 2.3.3. The reflectance of bitumens.- 2.3.4. Plotting rank curves on horizontal or vertical planes.- 2.3.4.1. Principles used for interpretation.- 2.3.4.2. Examples.- 2.3.4.2.1. Vertical patterns.- 2.3.4.2.2. Horizontal patterns.- 2.3.5. Information obtained from the maturation/migration of hydrocarbons and natural coking.- 2.3.6. The Tgrad/Tiso method of Kantsler et al. (1978a, b).- 3. The Shallow Transmission of Deep Thermal Flows Examples of very conductive or non-conductive series.- 3.1. Series with high heat conducting lithologies.- 3.1.1. The effect of high heat conducting series on geothermy.- 3.1.2. Case study of the Congo: a non- or slightly migrated salt layer.- 3.1.2.1. Wells O, Y and N.- 3.1.2.2. The three remaining wells: V, U and R.- 3.1.3. Gabon: diapiric columns of Aptian salt.- 3.1.3.1. The effect of diapirs on present geothermy, factors to consider.- 3.1.3.2. The effect on the thermal evolution of OM, the various factors involved.- 3.1.4. Case study of the salt bearing basin of North West Germany.- 3.1.5. Case study of carbonate series: the Middle East.- 3.2. An example of a lithology with poor heat conductivity: the overpressured Akata formation in the Niger delta.- 3.2.1. Geological framework.- 3.2.1.1. The deltaic series.- 3.2.2. The general characteristics of OM dispersed in the series.- 3.2.3. The thermal evolution of OM.- 3.2.4. Present geothermy: its relation with the Akata.- 3.2.5. Interpretation: the role of the Akata formation in thermal conduction.- 3.2.6. Conclusions on the thermal barrier effect of undercompacted formations.- Two The Study of Organic Matter in Reflected Light and Fluorescence.- 4. The Optical Analysis of Sedimentary Organic Matter in Reflected Light and Fluorescence.- 4.1. Methods and means.- 4.2. Microscopical examination in reflected light.- 4.2.1. The measurement of reflectance.- 4.2.1.1. Plotting on diagrams.- 4.2.1.2. Statistical calculation.- 4.2.1.3. The case of anisotropic coals.- 4.2.2. Microhardness.- 4.2.3. Etching.- 4.3. Microscopical examination in the fluorescence mode.- 4.3.1. Principle.- 4.3.2. Equipment.- 4.3.3. The fading effect.- 4.3.4. Photometric measurements.- 4.3.4.1. Spectral fluorescence.- 4.3.4.2. Quantitative fluorescence.- 4.3.5. The ‘global’index of fluorescence.- 5. Attempts at Classification of Organic Matter.- 5.1. The notion of ‘rank’.- 5.2. The maceral concept.- 5.3. The maceral classification: the three groups of macerals.- 5.4. Other classifications.- 5.4.1. Soviet classifications.- 5.4.2. French classifications.- 6. The Main Groups of Organic Matter.- 6.1. The coaly primary macerals.- 6.1.1. The inertinite group.- 6.1.1.1. Fusinite.- 6.1.1.2. Semifusinite.- 6.1.1.3. Macrinite.- 6.1.1.4. Inertodetrinite.- 6.1.1.5. Sclerotinite.- 6.1.2. The vitrinite group.- 6.1.2.1. The properties of vitrinite.- 6.1.2.2. Classification of vitrinites.- 6.1.2.2.1. The huminite varieties.- 6.1.2.2.2. Vitrinite (s.s.) varieties.- 6.1.2.3. Vitrinite as a rank indicator.- 6.1.2.4. The fluorescent vitrinites.- 6.1.3. The exinite group.- 6.1.3.1. The‘leaf’secretions.- 6.1.3.1.1. Cutinite.- 6.1.3.1.2. Fluorinite.- 6.1.3.1.3. Terpenite.- 6.1.3.2. Resinite.- 6.1.3.3. Suberinite.- 6.1.3.4. Sporinites.- 6.1.3.5. Algae and alginate.- 6.1.3.5.1. The unicellular algae.- 6.1.3.5.1.1. Tasmanaceae.- 6.1.3.5.1.2. Leiosphaerideae.- 6.1.3.5.1.3. Microfilamentous and/or Schizophyceae algae.- 6.1.3.5.2. The colonial algae.- 6.1.3.5.2.1. A special genus: the ‘colonial algae’ of the Niger delta.- 6.2. The structureless primary matters.- 6.2.1. The fluorescent groundmasses or organomineral associations.- 6.2.1.1. The sapropelic groundmasses.- 6.2.1.1.1. The lacustrine sapropelic groundmasses.- 6.2.1.1.1.1. Microscopical characteristics.- 6.2.1.1.1.2. Known examples.- 6.2.1.1.1.3. Geochemical and sedimentological characteristics.- 6.2.1.1.2. The marine sapropelic groundmasses.- 6.2.1.1.2.1. Microscopical criteria.- 6.2.1.1.2.2. General distribution.- 6.2.1.1.2.3. Geochemical and sedimentological criteria.- 6.2.1.2. The humic groundmasses.- 6.2.1.2.1. Microscopical characteristics.- 6.2.1.2.2. Deposits.- 6.2.1.2.3. Origin and geochemical properties.- 6.2.2. Bituminite.- 6.2.3. The diffuse OM in rocks: formation, conservation.- 6.3. The secondary macerals and the liquid or solid products of coalification.- 6.3.1. Oil and hydrocarbons.- 6.3.2. Exsudatinite.- 6.3.3. Micrinite.- 6.3.4. Bitumens.- 6.3.4.1. Criteria for distinguishing bitumens under the microscope.- 6.3.4.2. The microhardness of bitumens.- 6.3.4.3. Bitumen fluorescence.- 6.3.4.4. Bitumen reflectance.- 6.3.4.5. Distribution of bitumens.- 7. The Rank Evaluation of Dispersed Organic Matter.- 7.1. Optical methods.- 7.1.1. The vitrinite Ro in dispersed OM: difficulties and limitations.- 7.1.1.1. Scarcity of coaly fragments.- 7.1.1.2. True diagnosis of vitrinite.- 7.1.1.3. Causes of error.- 7.1.1.3.1. Cavings in drill cuttings.- 7.1.1.3.2. Alteration due to oxidation.- 7.1.1.3.3. Reworking of coals from older series.- 7.1.2. Bitumen Ro, a useful complement.- 7.1.3. Spectral fluorescence.- 7.1.3.1. Sporinites.- 7.1.3.2. Algae.- 7.1.3.3. Other fluorescent subjects.- 7.1.4. TAI: index of thermal alteration in TL.- 7.1.4.1. Historical.- 7.1.4.2. Development of the current method.- 7.2. Rank measurements by spectroscopical methods.- 7.2.1. ESR (Electron Spin Resonance).- 7.2.1.1. Principle.- 7.2.1.2. Technology and application.- 7.2.2. The spectroscopy of infrared absorption.- 7.2.2.1. Principle and technology.- 7.2.2.2. Application to diagenesis.- 8. The Alterations of Coal.- 8.1. The initial stages of coalification: humification and gelification.- 8.1.1. The principal precursor substances.- 8.1.2. Humification.- 8.1.2.1. The progress of humification with rank.- 8.1.3. Gelification.- 8.2. Coalification jumps.- 8.3. Coking.- 8.3.1. The coking process.- 8.3.2. The factors behind coking.- 8.3.2.1. Coal rank.- 8.3.2.2. Maceral composition.- 8.3.2.3. The rate of temperature rise.- 8.3.3. The petrology of cokes.- 8.3.4. Natural cokes, coal pyrolysis and coalification.- 8.3.5. Coking and graphitation.- 8.3.6. Natural regional phenomena.- 8.4. The oxidation of coals.- 8.4.1. The first studies.- 8.4.2. Alpern and Maume studies.- 8.4.3. The author’s attempts.- 9. Organic Matter Transformation: Hydrocarbon Generation.- 9.1. Historical development.- 9.2. Control by geochemical and optical analyses.- 9.3. Hydrocarbon precursors.- 9.4. Modes of hydrocarbon expulsion.- 9.5. Generation of gas.- 9.5.1. The catagenetic gas.- 9.5.2. The biogenic, early gas.- Summary.- Three A Paleogeothermal Survey of a Sequence of Sedimentary Basins Through the Study of Organic Metamorphism in Boreholes.- 10. The Rhine Valley, Continental Tertiary Trough.- 10.1. General location.- 10.2. Geological context.- 10.2.1. The stratigraphic series.- 10.2.2. The development of the Tertiary layers and the tectonic evolution of the trough.- 10.2.3. The organic fades.- 10.3. The thermal evolution of the series.- 10.3.1. Alsace: organic diagenesis.- 10.3.2. The north, German area: organic diagenesis.- 10.3.3. Present-day geothermy.- 10.3.4. A comparison of geothermy and paleogeothermy.- 10.3.5. Reconstruction of the thermal history of the basin.- 11. The Congo Basin, Lower Cretaceous Trough, Forerunner of The South Atlantic Oceanic Opening.- 11.1. Originality and interest of the basin.- 11.2. Geological framework.- 11.2.1. The lithostratigraphic succession.- 11.2.1.1. The prerift series.- 11.2.1.2. The oceanic series.- 11.3. Development of the main sedimentary formations.- 11.3.1. The presalt series.- 11.3.2. The marine (oceanic) series.- 11.3.3. The organic fades.- 11.3.3.1. Presalt series.- 11.3.3.2. Postsalt series.- 11.4. Thermal evolution of the basin.- 11.4.1. Rank evaluation of OM.- 11.4.2. The diagenetic variations of the series.- 11.4.3. Present-day geothermy.- 11.4.4. Interpretation of the diagenetic variations: an attempt to reconstruct the thermal history of the basin.- 12. The Red Sea, Active Oceanic Rift.- 12.1. Geological framework.- 12.2. Present-day geothermy.- 12.3. Thermal evolution of the sedimentary series.- 12.3.1. A deep well A.- 12.3.2. Three wells B1, B2 and C.- 12.3.3. The Gulf of Suez.- 12.4. Conclusion.- 13. The Japanese Archipelago, Island Arc or Oceanic Convergent Zone.- 13.1. Introduction.- 13.2. Geological framework.- 13.3. Coal evolution and present geothermy.- 13.4. General survey of the metamorphism of island arcs and convergent Systems.- 13.4.1. Japan.- 13.4.2. General case: other old metamorphic belts.- 13.4.3. Case of the Mariana arc.- 13.5. Attempt at a historical reconstruction.- 14 Upper Bavaria, Foreland of the Alpine Collision.- 14.1. Geotectonic framework.- 14.2. Organic diagenesis and geothermy.- 14.2.1. The autochthonous molassic basin in the foreland and below the nappe.- 14.2.2. Nappe of subalpine molasse.- 14.2.3. The flysch and Helvetics nappe.- 14.3. Conclusion.- 15. The Rhenish Paleozoic Massifs, The Ardenne and the Rhenish Schistose Massif: Complex Orogens.- 15.1. The caledonian cycle.- 15.1.1. Geological history.- 15.1.2. Organic diagenesis.- 15.2. The variscan cycle.- 15.2.1. The successive steps of the Breton phase in the Devonian of the Rhenish Schistose Massif.- 15.2.2. Variscan orogenesis: its three successive phases.- 15.2.2.1. The German region.- 15.2.2.2. Relationships with the neighbouring zones.- 15.2.3. Coalification.- 15.2.4. Neighbouring regions: general review.- 15.2.4.1. The North-Pas de Calais basin, in France.- 15.2.4.2. In Belgium, the Campine and southern basins.- 16. The Mesozoic Aulacogen or Bramsche Massif.- 16.1. Geological framework of north-west germany.- 16.1.1. The Harz.- 16.1.2. The Bramsche Massif.- 16.2. Coalification in the bramsche massif.- 16.2.1. Historical.- 16.2.2. Data and comments.- 16.3. Conclusion.- 17. The Lacq Region, Thermal Cretaceous Dome in Front of the Pyrenean Range.- 17.1. General features.- 17.2. Geological framework.- 17.2.1. The stratigraphic series.- 17.2.1.1. The Triassic.- 17.2.1.2. The Jurassic.- 17.2.1.3. The Cretaceous.- 17.2.1.4. The Lower Tertiary.- 17.2.2. Tectonic outlines of the Lacq region.- 17.2.3. General characteristics of the OM in the sedimentary series.- 17.2.3.1. Jurassic.- 17.2.3.2. Cretaceous.- 17.3. Thermal evolution.- 17.3.1. Present-day geothermy of the basin.- 17.3.2. Organic diagenesis of the series, Methodology.- 17.3.3. Organic diagenesis. Description of well sections.- 17.3.3.1. Wells located on the productive structures.- 17.3.3.1.1. The Lacq structure.- 17.3.3.1.2. The Meillon-St Faust structure.- 17.3.3.2. Wells located on the edges and in the Arzacq syncline.- 17.3.4. Interpretation of the diagenesis curves. Attempt at reconstructing the thermal history.- 17.3.4.1. Peculiarities of the Ro curves.- 17.3.4.2. Vertical location of the ‘diagenetic front’.- 17.3.4.3. The thermal significance of this diagenetic front.- 17.3.4.4. Attempt at a reconstruction of the regional geothermal history.- 17.4. Evolution eastwards and below the pyrenean front: lannemezan wells.- 17.5. Conclusion.- Four Mineral Diagenesis: Comparison with Organic Diagenesis.- 18. Rock Metamorphism: The Role of Temperature and the ‘Basement Effect’ Concept.- 18.1. Review of elementary notions on rock metamorphism.- 18.2. The basement effect.- 19. Mineral Diagenesis or ‘Premetamorphism’. Evolution of Clay Minerals.- 19.1. Clay and allied minerals.- 19.1.1. Brief description of clay and allied minerals.- 19.1.2. Genetic conditions and environment.- 19.1.3. Specificity of methods used to analyse clay minerals.- 19.2. Diagenetic transformations of phyllosilicates.- 19.2.1. Smectite disappearance.- 19.2.2. Kaolinite disappearance.- 19.2.3. The (irregular) mixed layers.- 19.2.4. Illite crystallinity.- 19.2.5. The Logic of clay Mineral Transformations.- 19.2.6. Characteristic minerals of the anchizone.- 20. Case Histories of Basin Diagenetic Surveys Using Clay Minerals In Comparison With Organic Evolution.- 20.1. The smectite tertiary series.- 20.1.1. The Gulf of Mexico.- 20.1.2. The Niger delta.- 20.1.3. The Upper Rhine Valley.- 20.2. The paleozoic sahara basins.- 20.2.1. The lllizi basin.- 20.2.2. The Ahnet-Mouydir basin.- 20.3. ‘Black Earths’ region of south-eastern France.- 20.3.1. Kaolinite distribution.- 20.3.2. Illite crystallinity.- 20.4. The Douala basin (Cameroons) and the Logbaba wells.- 20.4.1. Clay mineral survey.- 20.4.2. Organic diagenesis.- 20.5. Attempt at a synthesis: interpretation.- 20.5.1. Application to the Nagele 1 well.- 20.5.2. Second application: the Lacq region.- 20.5.3. Attempt at a graphic (and geodynamic) classification of these facts.- 20.6. Additional explanations.- 20.6.1. VRo equivalence to the smectite base.- 20.6.2. The thermal history of the Black Earths basin.- 20.7. Summary.- General Outlines.- 21. Main Results.- 21.1. The presence of paleogeothermal phases.- 21.2. Relationship between deep flows and the tectonic history.- 21.3. Tectonic-thermal classification of basins.- 21.3.1. Basins with a ‘normal’ or near normal geothermy.- 21.3.2. Hypothermal basins.- 21.3.3. Hyperthermal basins.- 21.3.3.1. The arc/back-arc areas, or internal zones of convergent systems.- 21.3.3.2. Divergent zones of the crust.- 21.4. Relationship between the tectonic activity and geothermy of the basins.- Conclusion.- References.- Abstracts.- General Index.- Geographical Index.- Index of Authors.- Glossary of Specialized Terms.