Diagenetic destruction of reservoir potential in shallow marine sandstones of the Broadford Beds (Lower Jurassic), north-west Scotland: depositional versus burial and thermal history controls on porosity destruction

Searl, Alison

doi:10.1016/0264-8172(94)90090-6

Cited by 12 publications

(9 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Lower Jurassic Pabba Shale Formation and Broadford Beds Formation (which transitions into the Blue Lias Formation within the southern Hebrides), are predominantly argillaceous but contain localised deposits of sandstones, mainly in the east of the SOHB (Fig. 17) (Searl 1994;Cox & Sumbler 2002). The sandstones' distribution was determined by the paleotopography and sediment entry points into the basin (Searl 1994;Cox & Sumbler 2002).…”

Section: Lower Jurassic Reservoirsmentioning

confidence: 99%

“…17) (Searl 1994;Cox & Sumbler 2002). The sandstones' distribution was determined by the paleotopography and sediment entry points into the basin (Searl 1994;Cox & Sumbler 2002). An example of the localised sandstones deposition is provided by the Hallaig Sandstone Member, a member of the Pabba Shale Formation, which is represented on Skye and Raasay as a sandstone dominated unit with microfaunas, suggesting deposition within a paralic environment (Fig.…”

Section: Lower Jurassic Reservoirsmentioning

confidence: 99%

“…In the MB there is a less pronounced divide between the proximal and distal facies, with thin sandstones encountered by the Minch 1 well, located in the centre of the basin (BP 1990). The reservoir potential of Lower Jurassic sandstones is considered to be poor due to their low initial depositional porosities and permeabilities, resulting from the sandstones high carbonate and clay rich detrital compositions, compounded by high levels of cementation (Searl 1992;Searl 1994). The sandstones beds are also observed to be predominantly localised, causing difficulty with correlation of individual beds (Searl 1994).…”

Section: Jurassicmentioning

confidence: 99%

See 2 more Smart Citations

Geology and petroleum prospectivity of the Sea of Hebrides Basin and Minch Basin, offshore NW Scotland

Fyfe

Schofield

Holford

et al. 2021

View full text Add to dashboard Cite

The Sea of Hebrides Basin and Minch Basin are late Palaeozoic-Mesozoic rift basins located to the northwest of the Scottish mainland. The basins were the target of small-scale petroleum exploration from the late 1960s to the early 1990s, with a total of three wells drilled within the two basins between 1989 and 1991. Although no commercially viable petroleum discoveries were made, numerous petroleum shows were identified within both basins, including a gas show within the Upper Glen 1 well in Lower Jurassic limestones. Organic rich shales have been identified throughout the Jurassic succession within the Sea of Hebrides Basin, with one Middle Jurassic (Bajocian-Bathonian) shale exhibiting a Total Organic Carbon content of up to 15 wt%. The focus of this study is to review the historic petroleum exploration within these basins, and to evaluate whether the conclusions drawn in the early 1990s of a lack of prospectivity remains the case. This was undertaken by analysis of seismic reflection data, gravity and aeromagnetic data and sedimentological data, from both onshore and offshore wells, boreholes and previously published studies. The key findings from our study suggest that there is a low probability of commercially sized petroleum accumulations within either the Sea of Hebrides Basin or the Minch Basin. Ineffective source rocks, likely due to low maturities (due to lack of burial) and the fact that the encountered Jurassic and Permian-Triassic reservoirs are of poor quality (low porosity and permeability) has led to our interpretation of future exploration being high risk, with any potential accumulations being small in size. While petroleum accumulations are unlikely within the basin, applying the knowledge obtained from the study could provide additional datasets and insight into petroleum exploration on other northeast Atlantic margin basins, such as the Rockall Trough and the Faroe-Shetland Basin.

show abstract

Section: Lower Jurassic Reservoirsmentioning

confidence: 99%

Section: Lower Jurassic Reservoirsmentioning

confidence: 99%

Section: Jurassicmentioning

confidence: 99%

See 1 more Smart Citation

Geology and petroleum prospectivity of the Sea of Hebrides Basin and Minch Basin, offshore NW Scotland

Fyfe

Schofield

Holford

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In fact, the advective, focused circulation of hydrothermal fluids related to rifting and/or magmatism has been observed in several present and ancient geothermal systems (e.g. McDowell & Paces, 1985;Schiffman et al, 1985;Searl, 1994;Pitman et al, 1998 and references therein). Sandstones in basins developed on extensively thinned and fractured crust are commonly affected by episodic flow of thermal fluids through faults, mostly during active tectonism, described as 'seismic pumping ', or 'seismic valving' (e.g.…”

Section: Implications For Basin Evolutionmentioning

confidence: 99%

Dickite in shallow oil reservoirs from Recôncavo Basin, Brazil: diagenetic implications for basin evolution

Bóna

Dani²,

Ketzer³

et al. 2008

Clay miner.

View full text Add to dashboard Cite

Fluvial and aeolian sandstones of the Sergi Formation are the most important reservoirs of the Recôncavo Basin, Brazil. Optical and scanning electron microscopy, X-ray diffraction and infrared spectroscopy revealed the occurrence of dickite, a clay mineral indicative of deep burial conditions (T >100ºC), in the shallow Buracica (630–870 m) and Água Grande (1300–1530 m) oilfields. Vermicular dickite replaces K-feldspar and plagioclase grains, and fills intra- and inter-granular pores. Its vermicular habit is a product of pseudomorphic kaolinite transformation during burial. The presence of dickite is in accordance with the intensity of compaction, post-compactional quartz cementation and δ18O values of calcite cements (T up to 109ºC). These petrological features of deep burial, as well as apatite fission-track analyses, indicate that uplift and erosion of at least 1 km, and probably >1500 m, affected the central part of the Recôncavo Basin and possibly the entire region. This uplift has not been detected previously by conventional structural and stratigraphic models.

show abstract

“…The contact is obscured by approximately 10 m of dead ground at Neist Point, but the first exposed eruptive deposits comprise subaerial sheet lavas. The sedimentary rocks below the subaerial lavas are dominated by Middle Jurassic shallow marine siliciclastic sediments (Searl, 1994;Morton, 1999;Hesselbo and Coe, 2000) and estuarine strata with many coarse-grained facies, crossbedding sedimentary structures, and nonmarine shales (Morton, 1983;Harris, 1989). The subbasalt sediments have locally been extensively intruded by dolerite sheet intrusions.…”

Section: Onshore: Isle Of Skye Scotlandmentioning

confidence: 99%

Mafic intrusions, hydrothermal venting, and the basalt-sediment transition: Linking onshore and offshore examples from the North Atlantic igneous province

et al. 2017

View full text Add to dashboard Cite

The emplacement of large intrusive complexes into sedimentary basins can have profound effects on host sedimentary rocks including deformation, thermal aureole metamorphic reactions, alteration of fluid-flow pathways, and the formation of associated hydrothermal vent complexes (HVCs). These processes can in turn have major implications for petroleum systems on the local and regional scale, and can contribute to global climate change due to the production and outgassing of greenhouse gases, such as CH 4 and CO 2 . Imaging these features and assessing their implications from seismic data beneath extrusive volcanic cover is challenging due to heterogeneities in the volcanic pile and at the basalt-sediment transition. We have evaluated combined field and laboratory petrophysical data from the Isle of Skye, Scotland, where we identify a seismic-scale example of extensive intrusions interacting with the base-basalt transition. We have also evaluated a unique onshore example of a linked sill and associated HVC cutting up through the lava sequence. We compare these field results with HVCs from reflection seismic data across the Vøring Marginal High, offshore Norway, where subbasalt saucer-shaped intrusions are also seen associated with HVCs cutting the lava sequence. Seismic imaging problems associated with the velocity heterogeneity of volcanic sequences, along with a historical lack of highquality 3D data in volcanic regions worldwide, is suggested as having largely precluded the identification of these features in the past. The under-representation of these hydrothermal vents in the literature has key implications for the future appraisal of intrusion-related outgassing effects on the global climate such as those related to the Palaeocene Eocene Thermal Maximum, along with subbasalt petroleum prospectivity where they may alter maturation and migration pathways.

show abstract

Diagenetic destruction of reservoir potential in shallow marine sandstones of the Broadford Beds (Lower Jurassic), north-west Scotland: depositional versus burial and thermal history controls on porosity destruction

Cited by 12 publications

References 29 publications

Geology and petroleum prospectivity of the Sea of Hebrides Basin and Minch Basin, offshore NW Scotland

Geology and petroleum prospectivity of the Sea of Hebrides Basin and Minch Basin, offshore NW Scotland

Dickite in shallow oil reservoirs from Recôncavo Basin, Brazil: diagenetic implications for basin evolution

Mafic intrusions, hydrothermal venting, and the basalt-sediment transition: Linking onshore and offshore examples from the North Atlantic igneous province

Contact Info

Product

Resources

About