Assessment of an unusual European Shale Gas play: the Cambro-Ordovician Alum Shale, southern Sweden

2012 ◽  
Author(s):  
Wilfred Pool ◽  
Mark Geluk ◽  
Janneke Abels ◽  
Graham John Tiley ◽  
Erdem Idiz ◽  
...  
Keyword(s):  
Shale Gas ◽  
Southern Sweden ◽  
Alum Shale

From shale oil to biogenic shale gas: retracing organic-inorganic interactions in the Alum Shale (Furongian-Lower Ordovician) in southern Sweden

AAPG Bulletin ◽  
2015 ◽  
Vol 99 (05) ◽  
pp. 927-956 ◽  
Author(s):  
Hans-Martin Schulz ◽  
Steffen Biermann ◽  
Wolfgang van Berk ◽  
Martin Krüger ◽  
Nontje Straaten ◽  
...  
Keyword(s):  
Shale Gas ◽  
Shale Oil ◽  
Southern Sweden ◽  
Alum Shale ◽  
Lower Ordovician

Generation and origin of natural gas in Lower Palaeozoic shales from southern Sweden

1969 ◽  
pp. 37-40
Author(s):  
Niels Hemmingsen Schovsbo ◽  
Arne Thorshøj Nielsen
Keyword(s):  
Source Rocks ◽  
Southern Sweden ◽  
Hydrocarbon Gases ◽  
Biogenic Gas ◽  
South Central ◽  
Alum Shale ◽  
Marine Source ◽  
Lower Palaeozoic ◽  
Background Gas ◽  
Origin Of Natural Gas

The Lower Palaeozoic succession in Scandinavia includes several excellent marine source rocks notably the Alum Shale, the Dicellograptus shale and the Rastrites Shale that have been targets for shale gas exploration since 2008. We here report on samples of these source rocks from cored shallow scientific wells in southern Sweden. The samples contain both free and sorbed hydrocarbon gases with concentrations significantly above the background gas level. The gases consist of a mixture of thermogenic and bacterially derived gas. The latter likely derives from both carbonate reduction and methyl fermentation processes. The presence of both thermogenic and biogenic gas in the Lower Palaeozoic shales is in agreement with results from past and present exploration activities; thermogenic gas is a target in deeply buried, gas-mature shales in southernmost Sweden, Denmark and northern Poland, whereas biogenic gas is a target in shallow, immature-marginally mature shales in south central Sweden. We here document that biogenic gas signatures are present also in gas-mature shallow buried shales in Skåne in southernmost Sweden.

Skeletal carbonate productivity and phosphogenesis at the lower–middle Cambrian transition of Scania, southern Sweden

2009 ◽  
Vol 147 (1) ◽  
pp. 59-76 ◽  
Author(s):  
J. JAVIER ÁLVARO ◽  
PER AHLBERG ◽  
NIKLAS AXHEIMER
Keyword(s):  
Primary Productivity ◽  
Microbial Mats ◽  
High Energy ◽  
Nutrient Supply ◽  
Energy Conditions ◽  
Southern Sweden ◽  
Middle Cambrian ◽  
Alum Shale ◽  
Shale Formation ◽  
Reducing Environment

AbstractThe lower–middle Cambrian transitional interval of Scania is largely represented by condensed limestone beds, lithostratigraphically grouped in the Gislöv Formation (1–5.7 m thick), and the Forsemölla and Exsulans Limestone beds (lower part of the Alum Shale Formation, up to 4 m thick). The strata display a combination of skeletal carbonate productivity, episodic nucleation of phosphate hardground nodules, and polyphase reworking recorded on a platform bordering the NW corner of Baltica. The shell accumulations can be subdivided into three deepening-upward parasequences, separated by distinct erosive unconformities. The parasequences correspond biostratigraphically to the Holmia kjerulfi, Ornamentaspis? linnarssoni and Ptychagnostus gibbus zones, the latter two generally being separated by a stratigraphic gap that includes the middle Cambrian Acadoparadoxides oelandicus Superzone. Except for the Exsulans Limestone, the carbonates reflect development of a prolific epibenthic biota, dominated by filter-feeding nonreefal chancelloriid–echinoderm–sponge meadows, rich in trilobites and brachiopods, and which were subjected to high-energy conditions. The absence of microbial mats or veneers encrusting the erosive surfaces of these event-concentration low-relief shoal complexes may be related to long hiatal episodes resulting in microboring proliferation. High levels of nutrient supply resulted in high primary productivity, eutrophic conditions, glauconite precipitation, phosphogenesis (in some case microbially mediated) and microendolithic infestation. An early-diagenetic mildly reducing environment is suggested by the presence of authigenic (subsequently reworked) pyrite, which contrasts with the syndepositional normal oxygenated conditions reflected by macroburrowing and the abundance of benthic fossils.

scholarly journals Shale gas investigations in Denmark: Lower Palaeozoic shales on Bornholm

1969 ◽  
Vol 23 ◽  
pp. 9-12 ◽  
Author(s):  
Niels Hemmingsen Schovsbo ◽  
Arne Thorshøj Nielsen ◽  
Kurt Klitten ◽  
Anders Mathiesen ◽  
Per Rasmussen
Keyword(s):  
Shale Gas ◽  
Black Shales ◽  
Rock Properties ◽  
Groundwater Exploitation ◽  
Lower Silurian ◽  
Gas Source ◽  
Alum Shale ◽  
Lower Palaeozoic ◽  
Global Sea Level ◽  
Deep Exploration

The Cambrian to Lower Silurian succession in Denmark is mostly composed of organic-rich black shales that were deposited in an epicontinental sea during a period of high global sea level (Haq & Schutter 2008). The mid-Cambrian to early Ordovician Alum Shale was intensively studied in the 1980s for its source-rock properties (e.g. Buchardt et al. 1986). Recent attention has focused on its potential as an unconventional shale gas source (Energistyrelsen 2010). On southern Bornholm, many wells have been drilled through the Lower Palaeozoic succession because of its importance for groundwater exploitation. In western Denmark, only the deep exploration wells Slagelse-1 and Terne-1 have penetrated the Alum Shale, and knowledge of the unit west of Bornholm is thus very limited (Fig. 1).

HERE’S THE ‘BEEF’—TIMING OF OVERPRESSURING IN THE CAMBRIAN ALUM SHALE, SOUTHERN SWEDEN

2017 ◽  
Author(s):  
Neil S. Fishman ◽  
◽  
Sven O. Egenhoff ◽  
Heather Lowers ◽  
Steven Schlaegle
Keyword(s):  
Southern Sweden ◽  
Alum Shale

Integrated Cambrian biostratigraphy and carbon isotope chemostratigraphy of the Grönhögen-2015 drill core, Öland, Sweden

2018 ◽  
Vol 156 (06) ◽  
pp. 935-949 ◽  
Author(s):  
PER AHLBERG ◽  
FRANS LUNDBERG ◽  
MIKAEL ERLSTRÖM ◽  
MIKAEL CALNER ◽  
ANDERS LINDSKOG ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Global Scale ◽  
Carbonate Facies ◽  
Southern Sweden ◽  
Middle Ordovician ◽  
Alum Shale ◽  
Carbon Isotope Excursion ◽  
Upper Stage ◽  
Shale Formation ◽  
Isotope Analyses

AbstractThe Grönhögen-2015 core drilling on southern Öland, Sweden, penetrated 50.15 m of Cambrian Series 3, Furongian and Lower–Middle Ordovician strata. The Cambrian succession includes the Äleklinta Member (upper Stage 5) of the Borgholm Formation and the Alum Shale Formation (Guzhangian–Tremadocian). Agnostoids and trilobites allowed subdivision of the succession into eight biozones, in ascending order: the uppermost Cambrian Series 3 (Guzhangian) Agnostus pisiformis Zone and the Furongian Olenus gibbosus, O. truncatus, Parabolina spinulosa, Sphaerophthalmus? flagellifer, Ctenopyge tumida, C. linnarssoni and Parabolina lobata zones. Conspicuous lithologic unconformities and the biostratigraphy show that the succession is incomplete and that there are several substantial gaps of variable magnitudes. Carbon isotope analyses (δ13Corg) through the Alum Shale Formation revealed two globally significant excursions: the Steptoean Positive Carbon Isotope Excursion (SPICE) in the lower–middle Paibian Stage, and the negative Top of Cambrian Excursion (TOCE), previously referred to as the HERB Event, in Stage 10. The δ13Corg chemostratigraphy is tied directly to the biostratigraphy and used for an improved integration of these excursions with the standard agnostoid and trilobite zonation of Scandinavia. Their relations to that of coeval successions in Baltoscandia and elsewhere are discussed. The maximum amplitudes of the SPICE and TOCE in the Grönhögen succession are comparable to those recorded in drill cores retrieved from Scania, southern Sweden. The results of this study will be useful for assessing biostratigraphic relations between shale successions and carbonate facies on a global scale.

Sign in / Sign up

Export Citation Format

Share Document