Henrik Friis - Academia.edu (original) (raw)

Papers by Henrik Friis

Geological Survey of Denmark and Greenland Bulletin, 2019

High porosity is a key factor for good reservoir sandstones for both hydrocarbon and geothermal e... more High porosity is a key factor for good reservoir sandstones for both hydrocarbon and geothermal energy exploitation. The porosity of sandstones generally decreases with increased burial depth due to compaction and cementation. However, some sandstones in the North Sea show higher porosity than expected for their burial depth, due to the presence of microquartz coatings (e.g. Aase et al. 1996; Hendry & Trewin 1995; Jahren & Ramm 2000; Maast et al. 2011). Siliceous sponge spicules have been documented to be an internal source of silica that promotes microquartz coatings (e.g. Hendry & Trewin 1995; Aase et al. 1996). Siliceous sponge spicules, the solid ‘skeleton’ of sponges, consist of opal-A and will dissolve when exposed to higher temperatures, thereby causing supersaturation of the formation water with respect to opal-CT and quartz, resulting in nucleation of numerous small (1–5 µm) quartz crystals (Williams et al. 1985; Hendry & Trewin 1995). To predict reservoir quality it is im...

Bulletin of the Geological Society of Denmark, 2020

Pristinely preserved mineral pseudomorphs called glendonites, up to 1.6 m long, from the Palaeoge... more Pristinely preserved mineral pseudomorphs called glendonites, up to 1.6 m long, from the Palaeogene strata of Denmark allow detailed crystallographic characterisation and add to the understanding of the transformation of the precursor mineral, ikaite (CaCO3·6H2O), to calcite, which constitutes the glendonite. We describe Danish pseudomorphs after ikaite from two localities and formations: the Early Eocene Fur Formation and the Late Oligocene Brejning Formation. This detailed study highlights that key aspects such as morphology and mode of occurrence of these ancient glendonites are identical to those of their parent mineral ikaite, when it grows in marine sediments. Systematic distortion of the angles in glendonite and marine sedimentary ikaite relative to the ideal ikaite symmetry may arise due to the incorporation of organic matter into the crystal structure, and we demonstrate the similarity between modern and ancient ikaite formation zones in the marine sedimentary realm with re...

Rendiconti online della Società Geologica Italiana, 2014

ABSTRACT A recently exposed section on the Fur island in Denmark spans the base of the Paleocene-... more ABSTRACT A recently exposed section on the Fur island in Denmark spans the base of the Paleocene-Eocene Thermal Maximum (PETM). The section represents an offshore facies of the North Sea Basin. The base of the CIE of the PETM is established in the section by carbon isotope analysis of TOC and of a specific biomarker for marine Thaumarchaeota (Schoon et al., 2013). Several lithologic features in this section indicate major environmental change coinciding with the beginning of the PETM. The most important of these features are two quadruple volcanic ash layers occurring immediately below a thin density flow deposit (see below). The lowest sample showing the δ 13 C excursion is taken just above this density flow deposit. The total thickness of these pre-PETM ash layers is ca.10 cm and the ash layers must therefore represent an important episode of NE Atlantic Paleogene volcanism. They are followed by two thin ash layers occurring a few centimeters above the base of the CIE. The pre-PETM ash layers are older than the previously known, and well studied, ash layers of the NE Atlantic volcanism, the so-called positive and negative numbered ash series of Bøggild (1918). The main part of the Bøggild ash series occurs in post-PETM sediments (Pedersen et al., 2011). No other ash layers are known from the underlying Upper Paleocene sediments (Østerrende Clay and Holmehus Formation) in this or other previously studied Danish sections. The occurrence of ash layers prior to the onset of the CIE lends support to previous suggestions that NE Atlantic volcanism was a trigger of the global warming of the PETM (e.g. Svensen et al., 2004). In the Fur section, sea-floor conditions changed from oxic (indicated by bioturbation and absence of lamination) to anoxic (indicated by a fine lamination) immediately above the upper quadruple ash layer, i.e., within sample resolution simultaneous with the start of the CIE. Previous observations suggest a similar shift to anoxic bottom waters in the offshore settings of the entire North Sea Basin at the beginning of the PETM (Refe). Organic geochemistry of the Fur section indicates that the euxinia at this site reached the photic zone during the entire PETM (Schoon et al., in review). The lowermost 5 cm of the PETM section is a small density flow deposit witnessing transient sea-floor instability right at the onset of the PETM. The density flow may have been triggered by an increased sediment load, as there is evidence for an increased sedimentation rate during the PETM in the Danish Subbasin (CH-C unpublished data). This is the only observation of a density flow in Danish onshore sections of the entire Upper Paleocene and Lower Eocene. It is noteworthy that sea-floor instability has previously been shown to coincide with the beginning of the PETM in the western North Atlantic (Katz et al., 1999). The local nature of the density flow in the Fur section may be due to a local sloping of the seafloor caused by movement in one of the nearby salt structures. The dinoflagellate genus Apectodinium was probably favoured by warmth and high nutrient levels, and showed a global abundance peak in neritic environments during the PETM (Crouch et al., 2001). Apectodinium increases in the Fur section from less than 2% below, to ca. 50% within the density flow and in the overlying anoxic clay of the CIE (Stolleklint Clay of the Ølst Formation). In summary, the new Fur section shows ash layers of a significant volcanic episode immediately below sediments from the PETM, supporting NE Atlantic volcanism as a trigger of the PETM. The base of the PETM is a local density flow deposit, which was probably caused by an increased sedimentation rate during the PETM. The bottom waters became anoxic and in the surface waters a bloom of Apectodinium began at the start of the PETM.

Terra Nova, 2013

ABSTRACT The possible influence on diagenesis of oil migration into reservoir sandstones is impor... more ABSTRACT The possible influence on diagenesis of oil migration into reservoir sandstones is important for understanding their development. Although many studies have addressed the question of continued growth of diagenetic minerals after oil emplacement, there is little clear evidence of the timing of mineral growth relative to oil emplacement, nor of the possible mechanisms of continued mineral growth. This study presents an example of continued cementation by pore‐lining chlorite during and after the migration of oil into a Palaeocene turbidite sandstone reservoir near the Faroe Islands. Chlorite developed in two different textures. One texture occurs on framework grain surfaces adjacent to open pore space in contact with oil. The other texture occurs close to framework grain contacts where contact with oil appears to have been prevented by residual pore‐water menisci. The meniscus crystals are larger than those from open pore, implying that diagenetic clay mineral growth has continued after oil emplacement.

74th EAGE Conference and Exhibition - Workshops, 2012

ty-depth and permeability-depth trends, established for all cored intervals of the Gassum Formati... more ty-depth and permeability-depth trends, established for all cored intervals of the Gassum Formation. The porosity-depth and permeability-depth trends represent sandstones alteration during burial due to mechanical compaction and diagenesis. The focus of this study is on the Gassum Formation, which has the largest potential and is the main target for planned geothermal wells in Denmark, as it is widely distributed and generally occurs within the depth interval of 800-3000 m, thereby reaching sufficient high temperatures and still assumed to maintain the required porosity and permeability. The Gassum Formation occurs with thicknesses of 50–150 m in central and distal areas of the Danish part of the Norwegian−Danish Basin, thickening locally in association with salt structures and major faults (up to 300 m in the Sorgenfrei−Tornquist Zone) and thinning or being absent on the structural highs, such as the Skagerrak−Kattegat Platform and the Ringkobing−Fyn High (Fig. 1). The Gassum Formation consists of shoreface, fluvial, estuarine, lacustrine, lagoonal and marine facies (Nielsen 2003).

Bulletin of the Geological Society of Denmark

New data from the Proterozoic basement and scattered Palaeozoic sediments in the Ringkøbing–Fyn H... more New data from the Proterozoic basement and scattered Palaeozoic sediments in the Ringkøbing–Fyn High including zircon U–Pb geochronometry, heavy mineral compositions and whole rock geochemistry is presented here to provide a frame of reference for detrital provenance studies. The Ringkøbing–Fyn High is a WNW–ESE trending structural high including subcropping basement rocks, and the results indicate that it is a southerly extension of the Fennoscandian Shield. The zircon data show matching age distribution patterns in crystalline basement rocks obtained from two drill sites, the Glamsbjerg-1 and Grindsted-1 wells. They both record a characteristic Telemarkian accretionary event at 1.51 and 1.48 Ga and a Sveconorwegian metamorphic overprinting at 1.08 Ga. Furthermore, the dominant age intervals in the Glamsbjerg High (1.55–1.48 Ga) and the Grindsted High (1.51–1.44 Ga) suggest that rocks of the Gothian orogeny (that ended at 1.52 Ga) are only present in the eastern part of the Ringkøb...

Marine and Petroleum Geology

Sandstones of the Middle Cambrian Deimena Group are commercially important as they make up the la... more Sandstones of the Middle Cambrian Deimena Group are commercially important as they make up the largest part of the hydrocarbon-bearing reservoir in 15 oil fields discovered in West Lithuania. However, the sandstones are characterised by a very complicated spatial distribution of reservoir quality. In order to better understand the distribution of reservoir properties and their controlling parameters, eighty-two sandstone samples from twenty-one boreholes were studied by means of thin section description, scanning electron microscopy, using backscattered and cathodoluminescence modes and clay fraction analyses. Generally, the sandstones are strongly cemented by quartz, resulting in almost total destruction of porosity but porous domains with preserved early stage quartz cement occur in a complex pattern. The close location of the early and late stage overgrowth types indicates that some sandstone parts were preserved from intense authigenic quartz precipitation. We believe that early carbonate cement was such an inhibitor. Detrital quartz grains in carbonate cemented domains are mostly free of authigenic quartz and as a rule show weakly compacted fabric as compared to the quartz cemented parts. Moreover, large secondary pores are located close to the carbonate cemented domains and indicate that some carbonate cement eventually dissolved. Apparently, the best reservoir properties within the generally strongly quartz cemented Deimena Group sandstones are found in domains where dissolution of the early carbonate cement took place.

A section of uppermost Tertiary fluvial deposits in which a less resistant heavy-mineral associat... more A section of uppermost Tertiary fluvial deposits in which a less resistant heavy-mineral association overlies a more resistant one is presented. The character of the succession is discussed in relation to weathering processes and it is concluded that weathering of the uppermost Tertiary fluvial deposits took place shortly after deposition.

Marine and Petroleum Geology, Apr 1, 2007

Elemental geochemistry of 1131 sandstone samples has been used to characterise five Palaeogene sa... more Elemental geochemistry of 1131 sandstone samples has been used to characterise five Palaeogene sandstone members in a system of density flow deposits within an incised submarine canyon, Danish North Sea. Diagenetic overprinting has complicated the use of most main and trace elements, but a group of ''heavy mineral bound'' elements with low mobility (Ti, Y, Zr, Nb and Th) has proved highly potential for correlation. The individual sandstone members exhibit very consistent relations between the ''heavy mineral elements'' along the canyon and, based on Zr/Ti plots, two families of sandstone members can be distinguished. The families are recognised on variations in inclination and intersection of linear regression lines which are related to subtle variations in provenance/source area. The inclination is believed to be controlled by the detrital heavy mineral (HM) suite and composition, whereas the intersections are controlled by the background contribution, such as HM inclusions in detrital rock forming minerals, e.g. quartz and/or feldspar, as well as substituted and/or adhered elements in glauconite. The correlation pattern has been used to suggest a re-interpretation of the stratigraphic relation of some of the sands.

Marine and Petroleum Geology, 2009

The Hermod sand of the Stine Segments, Siri Field, Danish North Sea, displays large permeability ... more The Hermod sand of the Stine Segments, Siri Field, Danish North Sea, displays large permeability variations (1-600 mD). These permeability variations represent horizontal layering in the reservoir, largely formed by diagenetic processes. They have a significant impact on reservoir performance, because horizontal producers in fairly thin reservoirs ($30 m) are protected against bottom-water influx and can produce water-free for long periods of time. This paper presents the results of a detailed multidisciplinary study where the observed variation in permeability can be explained by two main diagenetic phases: silica, as opal cement and microquartz, and berthierine, a serpentine mineral that is closely related to chlorite. Opal/microquartz and berthierine cements dominate in separate parts of the reservoir bodies. Opal/ microquartz cemented sands have high permeability (typically 500-600 mD). Berthierine cement has a different growth pattern in the oil and water zones, resulting in intermediate permeability in the oil zone (typically 50-100 mD) and very low permeability in the water zone (typically 1-10 mD).

Et stort geokemiprojekt omhandlende Siri Fairway kernerne, blev startet i 2003. Projektet var et ... more Et stort geokemiprojekt omhandlende Siri Fairway kernerne, blev startet i 2003. Projektet var et samarbejde mellem partnerne i Siri Fairway licenserne, DONG Energy, Altinex OIL (nu Noreco Oil), RWE Dea og Paladin (nu Talisman) og Geologisk Institut, Aarhus Universitet. Projektet havde ingen specifikke modeller og teser der skulle afprøves, men skulle bredt undersøge om geokemiske tilgangsvinkler kunne hjaelpe med olie efterforskning og-produktion i Siri Fairwayen. Mere end 20 efterforsknings-og vurderingsbrønde blev undersøgt, repraesenterende omkring 1200 kernemeter sediment.

The paper deals with heavy-mineral analyses of white sand deposits from the southern Fyn and surr... more The paper deals with heavy-mineral analyses of white sand deposits from the southern Fyn and surrounding islands. The heavy-mineral association is dominated by the unstable minerals garnet, epidote and hornblende; furthermore pyroxene is present. The mineral-grains are mainly well-rounded. On pyroxenes the well-rounded surfaces are modified by later corrosion. Thus the sediments are physically mature and chemically immature. This is supposed to be the result of longlasting transportation under chemically inggressive conditions in a cold climate. The deposition probably took place at the transition between Eemian and Weichselian.

To foredrag om nogle foreløbige resultater af et større forskningsprojekt vedrørende de jyske ung... more To foredrag om nogle foreløbige resultater af et større forskningsprojekt vedrørende de jyske ung-Tertiaere sedimenter, forelagt ved Dansk Geologisk Forenings forårsmøde i Aarhus 13. maj 1972, refereres af foredragsholderne.

The cementation pattern of some of the blocks from the basal conglomerate of the Amager Grønsand ... more The cementation pattern of some of the blocks from the basal conglomerate of the Amager Grønsand is described. There are four distinct phases of mineral growth in these sandstone blocks 1) drusy apatite, 2) drusy and blocky quartz in remnant pore (occurs as patches only); 3) poikilotopic calcite in remnant pores (occurs as patches only) and 4) cryptocrystalline apatite in a narrow zone at the margin of the sandstone block. Where the drusy apatite has been removed by later fracturing, quartz has formed overgrowths rather than drusy and blocky cement.

Quartz is an important cementing material in siliciclastic sandstones that can reduce porosity an... more Quartz is an important cementing material in siliciclastic sandstones that can reduce porosity and permeability severely. For efficiently predicting and extrapolating petrophysical properties such as porosity and permeability, the controls on the occurrence and the degree of quartz cementation need to be better understood. Because it is generally difficult to identify specific sources for quartz cement, many models attempting to explain quartz cementation conclude that external sources of silica are needed to explain the observed quantity of quartz cement, such as the mass transfer between sandstone and shale. Cambrian sandstones in Lithuania have abundant quartz cement which has significant effect on reservoir properties. The detrital quartz grains have been dissolved extensively along the shale-quartz contacts zones, making it a natural laboratory to study the influence of mass transfer between sandstone and shale to quartz cementation on petrophysical properties and reservoir qua...

Basin Research, 2015

ABSTRACT Zircon U–Pb geochronometry, heavy mineral analyses and conventional seismic reflection d... more ABSTRACT Zircon U–Pb geochronometry, heavy mineral analyses and conventional seismic reflection data were used to interpret the provenance of the Lower Triassic Bunter Sandstone Formation. The succession was sampled in five Danish wells in the northern part of the North German Basin. The zircon ages found in the Bunter Sandstone show that sediment supply was mainly derived from the Ringkøbing-Fyn High and the Variscan belt and not from the Fennoscandian Shield as previously believed. Seismic reflection data document that the Ringkøbing-Fyn High was a local barrier for sediment transport. Provenance analysis is an invaluable tool of correlation and subdivision of the Bunter Sandstone in this marginal basin setting. This is because the succession includes many hiatuses so the cyclo-, magneto-, and bio-stratigraphic frameworks established elsewhere in the basin cannot readily be applied here.Zircon ages in the Volpriehausen Member (lower Bunter Sandstone) indicate derivation from source areas located to the south of the North German Basin that are of late Neoproterozoic to Carboniferous age. The dominant age population with a peak age of 337 Ma corresponds to the culmination of Variscan high-grade metamorphism, whereas a secondary age population with a peak at 300 Ma matches the timing of volcanism and magmatism at the Carboniferous/Permian boundary in the northern Variscan belt. The Ringkøbing-Fyn High also supplied some sediment to the Volpriehausen Member. The zircon ages obtained from the Solling Member (upper Bunter Sandstone) match basement ages from the Ringkøbing-Fyn High and show that sediment contributions came mainly from the north. The age distributions are dominated by Mesoproterozoic zircon grains with a Sveconorwegian metamorphic overprint. The heavy mineral assemblage of the Solling Member is uniform and has a high garnet content compared to the contemporaneous sediments in the southern part of the North German Basin. This finding confirms that a local source supplied most of the sediment in the northern part of the basin. The most promising reservoir in the basin area is the aeolian Volpriehausen Member since the sandstone constitutes a lateral continuous unit. This is because sediment from the Variscan belt was transported by wind activity across the North German Basin when it was dried out. The alluvial to ephemeral fluvial Solling Member may be a good reservoir in the platform areas and marginal basin areas, but the variable sand content makes it difficult to predict the reservoir quality.This article is protected by copyright. All rights reserved.

Journal of Asian Earth Sciences, 2015

ABSTRACT The Daheishan giant porphyry Mo deposit is located at the eastern segment of the CAOB, N... more ABSTRACT The Daheishan giant porphyry Mo deposit is located at the eastern segment of the CAOB, NE China. The ore-bearing intrusion of Daheishan deposit is a Jurassic granitic complex that includes Changgangling biotite granodiorite, Qiancuoluo sedate granodiorite, and Qiancuoluo granodioritic porphyry. Mineralization consists of disseminated, breccia and veined types. The hydrothermal fluids show significant magmatic signatures, as evidenced by the hydrogen and oxygen isotopic compositions of quartz and sulfur isotopic characteristics of ores. Consistence of lead isotopic compositions of the sulfides and the Daheishan intrusive complex further indicate a close relationship between the mineralization and magma. The fluid inclusions in quartz comprise of predominant aqueous two-phase as well as gas-rich fluid inclusions and a small number of daughter mineral-bearing inclusions. The gas species in the fluid inclusions are H2O, CO2, N-2, CH4, C2H6, Ar* and minor H2S; the liquid compositions are SO42-, Cl-, Na+, K+, Ca2+ and Mg2+. Raman spectroscopy on individual fluid inclusions reveals a main gaseous composition of H2O, minor H2S and CO2. The fluid system in Daheishan Mo deposit can be described as NaCl-KCl-H2O type. Fluid inclusion microthermometry reveals subsolidus homogenization temperatures for fluid inclusions in the magmatic quartz phenocrysts (T-h = 400-450 degrees C, salinities = similar to 21 eq. wt.%), suggesting an obliteration of higher temperature history of the porphyry system by the superimposed processes. Most of the mineralization occurred at temperature range of 220-360 degrees C, or higher. The temperature and salinity decreased to 100-170 degrees C and 0-15 eq. wt.%, respectively, when the hydrothermal fluid activities were gradually ending. No distinct evolution pattern based on the homogenization temperature or stable isotopic analyses is observed among the different mineralization stages. Mineralization was supposed to be related to the multi-phased boiling of fluids, instead of the gradual cooling of fluids. Pressure may be more critical than temperature in controlling the precipitation of molybdenite.