scholarly journals Reservoir Quality of Upper Jurassic Corallian Sandstones, Weald Basin, UK

Geosciences ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 446
Author(s):  
Dinfa Vincent Barshep ◽  
Richard Henry Worden
Keyword(s):  
Carbon Capture ◽  
Carbon Capture And Storage ◽  
Upper Jurassic ◽  
Reservoir Quality ◽  
Main Process ◽  
Shallow Marine ◽  
Porosity And Permeability ◽  
Calcite Cement ◽  
Diagenetic Evolution

The Upper Jurassic, shallow marine Corallian sandstones of the Weald Basin, UK, are significant onshore reservoirs due to their future potential for carbon capture and storage (CCS) and hydrogen storage. These reservoir rocks, buried to no deeper than 1700 m before uplift to 850 to 900 m at the present time, also provide an opportunity to study the pivotal role of shallow marine sandstone eodiagenesis. With little evidence of compaction, these rocks show low to moderate porosity for their relatively shallow burial depths. Their porosity ranges from 0.8 to 30% with an average of 12.6% and permeability range from 0.01 to 887 mD with an average of 31 mD. The Corallian sandstones of the Weald Basin are relatively poorly studied; consequently, there is a paucity of data on their reservoir quality which limits any ability to predict porosity and permeability away from wells. This study presents a potential first in the examination of diagenetic controls of reservoir quality of the Corallian sandstones, of the Weald Basin’s Palmers Wood and Bletchingley oil fields, using a combination of core analysis, sedimentary core logs, petrography, wireline analysis, SEM-EDS analysis and geochemical analysis to understand the extent of diagenetic evolution of the sandstones and its effects on reservoir quality. The analyses show a dominant quartz arenite lithology with minor feldspars, bioclasts, Fe-ooids and extra-basinal lithic grains. We conclude that little compactional porosity-loss occurred with cementation being the main process that caused porosity-loss. Early calcite cement, from neomorphism of contemporaneously deposited bioclasts, represents the majority of the early cement, which subsequently prevented mechanical compaction. Calcite cement is also interpreted to have formed during burial from decarboxylation-derived CO2 during source rock maturation. Other cements include the Fe-clay berthierine, apatite, pyrite, dolomite, siderite, quartz, illite and kaolinite. Reservoir quality in the Corallian sandstones show no significant depositional textural controls; it was reduced by dominant calcite cementation, locally preserved by berthierine grain coats that inhibited quartz cement and enhanced by detrital grain dissolution as well as cement dissolution. Reservoir quality in the Corallian sandstones can therefore be predicted by considering abundance of calcite cement from bioclasts, organically derived CO2 and Fe-clay coats.

scholarly journals EXAMINING THE PROCESS OF DECOMPOSITION AND CARBON CYCLING IN 'FADAMA' COASTAL WETLANDS: A CASE STUDY OF HEAPING WETLANDS ECOSYSTEM

2020 ◽  
Vol 4 (3) ◽  
pp. 10-16
Author(s):  
George Dasat Shwamyil ◽  
G. Danjuma ◽  
E. S. Chundusu
Keyword(s):  
Organic Matter ◽  
Ecosystem Services ◽  
Carbon Cycling ◽  
Carbon Capture ◽  
Carbon Capture And Storage ◽  
Wetland Soil ◽  
Low Oxygen ◽  
Decomposition Of Organic Matter ◽  
Plateau State

Wetlands provide several ecosystem services including carbon capture and storage, water filtration, nutrient cycling, and support agriculture among others. The biogeochemical process and decomposition parameters in ‘Fadama' wetland soils comprising of Gada biyu, Pwomol and Kpang referred to as sites A, B, and C respectively all of Heipang District in Barkin Ladi, Plateau State was investigated using standard operating procedures (SOP). Results of investigations revealed that soils from Kpang had slightly higher water content (34.52%) than those from Pwomol (33.48%) and Gada biyu (32.03%). While soils from Gada biyu had the highest solid organic matter (SOM) (10.79%) followed by Pwomol (8.15%) as Kpang had the least (7.85%). Gada biyu soils had the lowest Phenol oxidases activity (1536.56 nmol dicq g-1 h-1) while those from Pwomol (5340.44 nmol dicq g-1 h-1) was highest. All sites had similar concentrations of soil phenolics (76.58 µg g-1, 79.98µg g-1, and 83.25µg g-1). The activity of hydrolyses (β-glucosidase) in Gada biyu soil (2.93 nmol g-1 min-1) was lower than those from Pwomol (6.13 nmol g-1 min-1). These parameters indicate the level of biogeochemical processes in the soil at each site. Gada biyu had the highest rate of CH4 (0.84 ug g-1h-1) flux. Decomposition of organic matter, carbon cycling and greenhouse gas storage in wetland soil, is due to the anoxic condition comprising of low oxygen availability, cool temperatures, anaerobic conditions, reduced microbial activity, and the quality of organic matter substrates in such soils.  Anthropogenic disturbances affecting wetlands must be discouraged to promote vital ecosystem services.

PROSPECTIVITY AND EXPLORATION HISTORY OF THE BARROW SUB-BASIN, WESTERN AUSTRALIA

1997 ◽  
Vol 37 (1) ◽  
pp. 117 ◽  
Author(s):  
P.W. Baillie ◽  
E.P. Jacobson
Keyword(s):  
Lower Cretaceous ◽  
Source Rocks ◽  
Reservoir Quality ◽  
Liquid Hydrocarbons ◽  
Reservoir Rocks ◽  
Long Period ◽  
Porosity And Permeability ◽  
History Of ◽  
Hydrocarbon Reserves

The Carnarvon Basin is Australia's leading producer of both liquid hydrocarbons and gas. Most oil production to date has come from the Barrow Sub-basin. The success of the Sub-basin is due to a fortuitous combination of good Mesozoic source rocks which have been generating over a long period of time, Lower Cretaceous reservoir rocks with excellent porosity and permeability, and a thick and effective regional seal.A feature of Barrow Sub-basin fields is that they generally produce far more petroleum than is initially estimated and booked, a result of the excellent reservoir quality of the principal producing reservoirs.Structural traps immediately below the regional seal (the 'top Barrow play') have been the most successful play to date. Analysis of 'new' and 'old' play concepts show that the Sub-basin has potential for significant additional hydrocarbon reserves.

The anatomy of a fractured reef from Cyprus: a possible analogue for the Eastern Mediterranean carbonate reservoirs

2021 ◽  
Author(s):  
Stefano Patruno ◽  
Ian Abdallah ◽  
Vittorio Scisciani ◽  
Ernestos Sarris ◽  
Fabio Colantonio
Keyword(s):  
Shallow Water ◽  
Carbon Capture ◽  
Eastern Mediterranean ◽  
Dominant Role ◽  
Carbon Capture And Storage ◽  
Fracture Aperture ◽  
North East ◽  
Porosity And Permeability ◽  
The Impact ◽  
Carbonate Buildup

<p>The core of the island of Cyprus hosts the inverted Troodos ophiolitic zone, whose flanks are overlain by autochthonous sedimentary rocks, mostly comprising Cenozoic-age carbonate shelf units. Some of these units are likely analogous to the Miocene part of the Levantine Basin “Zohr-like” carbonate buildup reservoirs, which are playing a dominant role in the present-day gas prospectivity and long-term potential for CO<sub>2</sub> carbon capture and storage in the Eastern Mediterranean.</p><p>The study location hosts a steep sided carbonate hill (c. 90 m elevation and about 0.35 km<sup>2</sup> total area. This hill corresponds to a lower Miocene shallow-water Terra Member carbonate buildup (Pakhna Formation), inclusive of a well-developed reefal biohermal fossil community at the summit. The buildup can be subdivided into four main depositional sub-units (informally called ‘beds’). Each of these approximately horizonal “beds” is about 5-20 m thick and hosts a number of near-vertical open fracture and minor fault sets, further enlarged by meteoric diagenesis. The lack of vegetation makes this a world-class example of shallow-water buildup available for geological analyses.</p><p>In this work, we have focused on the reservoir-scale physical properties and stratigraphic architecture of the reef outcrop, and in particular on the impact that the fracture and karst networks can be expected to play on the porosity and permeability properties of these rocks. We have utilized 133 drone photographs, subsequently “patched” together in a 3D Digital Terrain Model (DTM) using CMD-MVS; this software takes a series of pictures and creates a 3D point cloud from them thereby solving the problem of structure from motion (SFM). Several photographs have been additionally georeferenced and the visible fracture networks mapped in GIS. Furthermore, fieldwork analyses have been carried out and the following fracture properties measured at several representative locations utilizing linear scanline sampling and circular scanline methods: fracture orientation, aperture, spacing, length, intensity. Finally, representative samples have been collected from the field in order to measure their porosity and permeability properties.</p><p>Our analysis suggests the presence of a dominant fracture and fault set, striking approximately NE-SW to ESE-WNW. Additional relatively randomly-oriented, minor fracture sets are also present. Fracture intensity from the linear scanline method varies from 3 fractures per meter to the north-east to 6 fractures per meter to the south-west. The fracture aperture ranges from 0.01 to 1 meter. The studied shallow-water carbonate is characterized by high permeability and moderate porosity, with likely anisotropic flow properties along the main fracture sets. The presence of fractures enlarged by subaerial dissolutions is likely the key property controlling the reservoir parameters of these rocks, although further analyses are needed to find out whether such dissolution is associated with the present-day outcrop exposure to meteoric leaching, or was developed earlier on and can be reasonably expected in the subsurface.</p>

Mapping porosity anomalies in deep Jurassic sandstones – an example from the Svane-1A area, Danish Central Graben

1969 ◽  
Vol 23 ◽  
pp. 13-16 ◽  
Author(s):  
Tanni Abramovitz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Upper Jurassic ◽  
Reservoir Quality ◽  
Oil Accumulation ◽  
The North ◽  
The North Sea ◽  
Sandstone Reservoirs ◽  
High Temperature High Pressure

Hydrocarbon-bearing Upper Jurassic sandstone reservoirs at depths of more than 5000 m may form a future exploration target in the Danish Central Graben (Fig. 1). The Upper Jurassic sandstone play in the Danish sector has historically been less successful than in the neighbouring Norwegian and British sectors of the North Sea. This is mainly due to poor reservoir quality of the sandstones. However, the discovery in 2001 of an oil accumulation at a depth of more than 5000 m in the Svane-1 well has triggered renewed interest in the Upper Jurassic High Temperature – High Pressure (HTHP) sandstone play in Danish waters. The Jurassic plays comprise sandstone reservoirs deposited in a variety of environments, ranging from fluvial to deep marine.

Reservoir quality and its relationship to facies and provenance in Middle to Upper Jurassic sequences, northeastern North Sea

Clay Minerals ◽  
2000 ◽  
Vol 35 (1) ◽  
pp. 77-94 ◽  
Author(s):  
M. Ramm
Keyword(s):  
Grain Size ◽  
North Sea ◽  
Close Relationships ◽  
Upper Jurassic ◽  
Reservoir Quality ◽  
Burial History ◽  
Deep Burial ◽  
Porosity And Permeability ◽  
Reservoir Sandstones ◽  
Initial Texture

AbstractClose relationships are demonstrated between reservoir quality, lithofacies, provenance and burial history in the Jurassic Brent and Viking Groups in the Norwegian North Sea. Porosity and permeability are strongly and systematically related to the initial texture and composition of the sandstones. Porosity variations are related to the amount of compaction, which is more severe in matrix-rich than in clean facies, and quartz cementation, which is most important in clean facies. Permeability variations are related to porosity and facies-controlled variations in grain size, and abundance and texture of intergranular fines. Illitization of early diagenetic kaolins require K, which is derived mainly from dissolution of K-feldspar. Sediments were sourced from K-feldspar- poor provenances during the maximum progradation of the Brent Group, and sandstones deposited at this time are less exposed to illitization and have better permeability at deep burial than reservoir sandstones that initially contained more K-feldspar.

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