DETERMINING RESERVOIR CONTINUITY IN THE LAMINARIA FORMATION BY INTEGRATED GEOLOGICAL STUDY

2001 ◽  
Vol 41 (1) ◽  
pp. 415 ◽  
Author(s):  
D.C. Barr ◽  
A.F. Kennaird ◽  
J. Fowles ◽  
N.G. Marshall ◽  
V.L. Cutten
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Sea Level ◽  
Clay Content ◽  
Coarse Grained ◽  
Log Data ◽  
Reservoir Performance ◽  
Subaqueous Dunes ◽  
Reservoir Sandstones ◽  
Reservoir Potential

A recent geological study, integrating sedimentological core-derived descriptions with ichnofacies, high resolution biostratigraphy and wireline log data, establishes the lateral continuity of reservoir sandstones in the Laminaria Formation. By defining a hierarchy of bedding surfaces and correlating this hierarchy with major correlation surfaces, and lateral and vertical facies patterns, it was possible to identify genetically related sediment packages between 12 wells in the study area.The Laminaria Formation is interpreted to have been deposited on a tide and storm-influenced marine shelf, and was strongly influenced by fluctuations in sea level. The formation consists of a series of progradational parasequences, each dominated by good quality, fine- to medium-grained sandstone. These sandstones are believed to have formed as subaqueous dunes or sand banks, exhibiting blanket-like geometry over much of the area. Several sandstones are capped by thin, intraclast-rich layers that mark transgressive surfaces of erosion. These surfaces can be traced across the study area and, therefore, act as important correlative markers.Evidence of gradual transgression, which ultimately led to the drowning of the system, is seen near the top of the formation. Clay content increases upward, while grain size and bedding thickness generally decrease. However, several thin, laterally extensive, medium- to coarse-grained sandstones exist, improving reservoir potential in this part of the formation.The results of this study are being used to estimate reserves and assess reservoir performance, and will serve as a basis for future geological and petrophysical modelling work.

USE OF THE LIQUID LIMIT IN CHARACTERIZING CLAY SOILS

1972 ◽  
Vol 52 (3) ◽  
pp. 457-464 ◽  
Author(s):  
B. P. WARKENTIN
Keyword(s):  
Grain Size ◽  
Surface Area ◽  
Clay Minerals ◽  
Amorphous Material ◽  
Clay Content ◽  
Liquid Limit ◽  
Coarse Grained ◽  
Clay Soils

An index property for clay soils is sought to give the information that grain size gives about coarse-grained soils. The liquid limit is suggested as such an index property. The liquid limit is closely related to surface area for clay soils containing tabular clay minerals. This relation exists also for soils containing allophane or amorphous material. In addition to estimating surface area, liquid limit also gives information about the nature of the surface. In this respect it is a more useful measurement than clay content.

Controls on the reservoir quality of Late Cretaceous Springar Formation deep-water fan systems in the Vøring Basin

2017 ◽  
Vol 8 (1) ◽  
pp. 247-257 ◽  
Author(s):  
Alana Finlayson ◽  
Angela Melvin ◽  
Alex Guise ◽  
James Churchill
Keyword(s):  
Grain Size ◽  
Late Cretaceous ◽  
Clay Content ◽  
Coarse Grained ◽  
Reservoir Quality ◽  
Low Permeability ◽  
Quality Model ◽  
Depositional Facies ◽  
Porosity And Permeability ◽  
Vøring Basin

AbstractA new reservoir quality model is proposed for the Late Cretaceous Springar Formation sandstones of the Vøring Basin. Instead of a depth-related compactional control on reservoir quality, distinct high- and low-permeability trends are observed. Fan sequences which sit on the high-permeability trend are characterized by coarse-grained facies with a low matrix clay content. These facies represent the highest energy sandy turbidite facies within the depositional system, and were deposited in channelized or proximal lobe settings. Fan sequences on the low-permeability trend are characterized by their finer grain size and the presence of detrital clay, which has been diagenetically altered to a highly microporous, illitic, pore-filling clay. These fan sequences are interpreted to have been deposited in proximal–distal lobe environments. Original depositional facies determines the sorting, grain size and detrital clay content, and is the fundamental control on reservoir quality, as the illitization of detrital clay is the main mechanism for reductions in permeability. Core-scale depositional facies were linked to seismic-scale fan elements in order to better predict porosity and permeability within each fan system, allowing calibrated risking and ranking of prospects within the Springar Formation play.

High-resolution records of grain-size and depositional environment correlated to the Homo erectus Nariokotome Boy site, West Turkana, Kenya

2021 ◽  
Author(s):  
Conner O'Reilly ◽  
Catherine C. Beck ◽  
Jeroen H. van der Lubbe ◽  
Craig S. Feibel ◽  
Bruce Wegter ◽  
...  
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Homo Erectus ◽  
Eastern Africa ◽  
Coarse Grained ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Sedimentary Sequences ◽  
Grain Size Distributions ◽  
Material Grain Size

<p>The Turkana Basin in northern Kenya contains a robust record of hominin fossils, including Nariokotome Boy (discovered from the NK3 site), the most complete H. erectus specimen found to date. Understanding the paleoenvironmental context in which hominins such as H. erectus evolved has been an objective of decades of research in eastern Africa. Here, we present a study using grain size analyses to infer the paleoenvironmental conditions responsible for the deposition of the sedimentary sequences directly associated with NK3. We resampled a ~14 m interval at from the West Turkana Kaitio (WTK13) core, collected as part of the Hominin Sites and Paleolakes Drilling Project. This interval ties directly to the outcrop where Nariokotome Boy was recovered. By sampling continuously at 0.5 cm intervals (~7 yrs/sample), we document the paleoenvironment in ultra high-resolution (i.e. a scale relevant to a hominin life) that directly correlates to the NK3 site. Over 350 sediment samples were pre-treated to remove carbonate, biogenic silica, and other organic material from detrital material. Grain size distributions were measured on a Malvern Mastersizer 3000 using wet suspension. Based on these analyses, the interval was dominated by silt, which was further investigated using end-member modeling. A four end-member solution explained on average 99% of the population variability. The bottom of the interval was more coarse-grained, with an abrupt fining transition at 38.83 meter below surface (mbsf), which corresponds with the transition out of a tuffaceous interval (Natoo tuff) and into a pedogenically modified interval. This correlation is significant as the top of this tuff is the surface upon which Nariokotome Boy was recovered. Previous facies and grain size analyses revealed and quantified Turkana’s dynamic lake level history. However, our grain size analysis provides unprecedented resolution for the paleoenvironment during which Nariokotome Boy lived. Our 0.5 cm sampling resolution enables us to quantify depositional changes on a scale comparable with previous descriptive facies analyses and to refine transitions between paleosols, fluvial deposits, and lacustrine deposition at the interface of these three paleoenvironments enabling us to reconstruct a dynamic lakeshore environment during the lifetime of the Nariokotome Boy.</p>

Determining the post-glacial evolution of a northeast Pacific coastal fjord using a multiproxy geochemical approachThis article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.

2008 ◽  
Vol 45 (11) ◽  
pp. 1331-1344 ◽  
Author(s):  
Tara S. Ivanochko ◽  
Stephen E. Calvert ◽  
John R. Southon ◽  
Randolph J. Enkin ◽  
Judith Baker ◽  
...  
Keyword(s):  
High Resolution ◽  
Sea Level Rise ◽  
Sea Level ◽  
Ocean Circulation ◽  
Ice Core ◽  
Coarse Grained ◽  
Last Deglaciation ◽  
Northeast Pacific ◽  
Ice Core Record ◽  
Effingham Inlet

A 40.32 m piston core recovered from Effingham Inlet, on the west coast of Vancouver Island, provides the basis for a high-resolution geochemical study of the last deglaciation and the Holocene. Glacial retreat, basin isolation, sea-level rise, and productivity variations are determined using proxies for sediment composition (K/Al, Fe/Al, Mg/Al), grain size (Ti/Al, Zr/Al), sedimentary redox conditions (Mo/Al, U/Al), and productivity (wt.% organic carbon, wt.% opal). As local ice retreated and marine waters inundated the basin, coarse-grained glacimarine sediments were replaced by finer grained, laminated, opal-rich sediments. During meltwater pulse-1a, the dominance of local crustal rise over eustatic sea-level rise resulted in the progressive restriction of ocean circulation in Effingham Inlet and the formation of a temporary freshwater lake. The transition into stable Holocene conditions was initiated at ∼12 700 BP, which corresponds to the onset of the Younger Dryas, as identified by the Greenland Ice core Project (GRIP) ice core δ18O record and was completed by 10 700 BP, ∼800 years after the GRIP ice core record stabilized. Holocene Mo/Al and U/Al ratios range between 12–35 (×104) and 1–3.4 (×104), respectively, indicating that although large-amplitude, high-frequency fluctuations occur, the sediments of Effingham Inlet inner basin have remained organic rich and oxygen depleted for the entire Holocene period. The combination of anoxic bottom waters and a Holocene sedimentation rate of 217 cm/ka have preserved a high-resolution record of environmental change in the northeast Pacific over the last 11 000 years.

The pelagic archive of short-term sea-level change in the Cretaceous: a review of proxies linked to orbital forcing

2019 ◽  
Vol 498 (1) ◽  
pp. 39-56 ◽  
Author(s):  
Michael Wagreich ◽  
Veronika Koukal
Keyword(s):  
Grain Size ◽  
Sea Level ◽  
Gamma Ray ◽  
Clay Content ◽  
Sea Level Change ◽  
Point Of View ◽  
Heavy Minerals ◽  
Deep Time ◽  
Level Change ◽  
Sea Level Oscillations

AbstractDeep-time sea-level oscillations in the Milankovitch-band of orbital cyclicities govern deposition in the pelagic realm mainly by varying siliciclastic input. Pelagic sediments from the Cretaceous greenhouse climate phase provide a valuable archive for sea-level change. Although sea-level variations are of negligible amplitude compared with depositional water-depths, direct physical proxy data are based on higher and coarser siliciclastic input during sea-level lowstand and regressions, and include coarser grain size and grain-size parameters as well as the heavy mineral and clay content. Chemical proxies that relate to siliciclastics are manganese, titanium and zirconium, often normalized v. aluminium. Further proxies provide the ratios of strontium v. calcium, controlled by shelf carbonate erosion, and partly redox-sensitive elements like uranium and thorium. From a mineralogical point of view, the total amount of siliciclastics and their diversity relating to heavy minerals provides sea-level information in hemipelagites, as well as the phyllosilicate content v. biogenic pelagic background deposition of carbonate and siliceous microfossils in pelagites. In addition, measurements of gamma ray emission, linked to U, Th, K content and magnetic susceptibility may relate to sea-level cycles and various other more climate-dependent proxies like oxygen isotopes of fossil calcite and compositional maturity of hemipelagic sediments.

Using high-resolution portable OSL (POSL) profiling to characterize Holocene beach ridges at Lake Schweriner See, NE-Germany

2020 ◽  
Author(s):  
Marie-Luise Adolph ◽  
Reinhard Lampe ◽  
Sebatian Lorenz ◽  
Torsten Haberzettl
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Lake Level ◽  
Osl Dating ◽  
Coarse Grained ◽  
Beach Ridge ◽  
Beach Ridges ◽  
The Past ◽  
Depositional Processes ◽  
Ne Germany

<p>Beach ridges are a promising geoarchive to study lake-level variations as they indicate former lake-level maxima. Detecting paleo-shorelines and knowing their elevation, inner structure and age. This helps to quantify lake-level highstands, the duration of elevated lake levels as well as to reconstruct sedimentation processes as important indicators of either external forcing (e.g., higher precipitation/lower evaporation) or anthropogenic impacts (e.g., mill stowage) in the past. In this study, a quantitative paleohydrological reconstruction of lake Schweriner See, NE-Germany, should be achieved by a combination high-resolution multi-proxy analysis on sediment cores from both distal and littoral but also from onshore parts. This poster focuses on the onshore part of the eastern shoreline where a succession of beach ridges is located within a distance of up to 600 m away from the recent shoreline and up to 1.5 m above today’s lake level. This indicates both a greater extension and a higher water level in the past. Here we examine these beach ridges using high-resolution luminescence profiling (POSL, 5-15 cm intervals) with a SUERC portable OSL unit combined with full OSL dating (coarse grain quartz SAR protocol) and independent radiocarbon dating to obtain ages of lake-level maxima as well as a (relative) age distribution within and between individual beach ridges. We measured the water content, loss-on-ignition and grain size variation to characterize the beach ridges and their depositional processes but also to estimate the influences of these parameters on the luminescence signal.</p><p>The sandy beach ridges are deposited on peat, which overlays mainly lacustrine silty and calcareous sediment. The upper 20-40 cm are enriched in humus. This stratigraphy demonstrates a silting-up sequence and development of a wetland, which was affected by a dynamic lake-level development.The dominating grain size within the ridges is coarse grained sand with small gravel and occasionally thin organic layers in between. The initial results of full OSL dating gives a hint that all beach ridges were deposited during the Holocene. The luminescence profiles typically show an increase in photon counts with depth in the upper part, which was influenced by humus enrichment. The luminescence in the otherwise mainly organic and lime free sands below behave differently with depth in each beach ridge. The total photon count either 1) decreases perhaps influenced by a higher groundwater table in the past or reworking of older nearby beach ridges, 2) increases, offering the possibility to extract relative sedimentation rates, but sometimes has leaps to smaller values or 3) fluctuates around a mean value indicating a potential rapid sediment accumulation. Fluctuating values might also occur due to bioturbation.</p><p>In this study, high resolution POSL profiling in combination with grain-size analysis proved to be a promising tool to investigate lacustrine beach ridges and their depositional processes. The method turned out to be valuable to not only select the right sample for OSL dating but also to get a better understanding of beach ridge deposition at Schweriner See.</p>

THE INFLUENCE OF GRAIN SIZE ON FLUVIO-DELTAIC RESPONSE TO SEA-LEVEL SIGNALS

2019 ◽  
Author(s):  
Rebecca L. Caldwell ◽  
◽  
Tao Sun ◽  
Sarah Baumgardner ◽  
Ashley D. Harris
Keyword(s):  
Grain Size ◽  
Sea Level

FORAMINIFERAL TRANSFER FUNCTION FOR HIGH-RESOLUTION SEA-LEVEL RECONSTRUCTION DURING HOLOCENE IN SUNDA SHELF, OFF MALAYSIA WATERS

2020 ◽  
Author(s):  
Fatin Izzati Minhat ◽  
◽  
Nazihah Azmi ◽  
Nazihah Azmi ◽  
Nur Hidayah Roseli ◽  
...  
Keyword(s):  
High Resolution ◽  
Transfer Function ◽  
Sea Level ◽  
Sunda Shelf

scholarly journals Wave Propagation Characteristics in Gas Hydrate-Bearing Sediments and Estimation of Hydrate Saturation

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 804
Author(s):  
Lin Liu ◽  
Xiumei Zhang ◽  
Xiuming Wang
Keyword(s):  
Gas Hydrate ◽  
Clay Content ◽  
Clean Energy ◽  
Compressional Wave ◽  
Physical Parameters ◽  
Well Log ◽  
Log Data ◽  
Phase Velocities ◽  
Hydrate Saturation ◽  
Hydrate Bearing Sediments

Natural gas hydrate is a new clean energy source in the 21st century, which has become a research point of the exploration and development technology. Acoustic well logs are one of the most important assets in gas hydrate studies. In this paper, an improved Carcione–Leclaire model is proposed by introducing the expressions of frame bulk modulus, shear modulus and friction coefficient between solid phases. On this basis, the sensitivities of the velocities and attenuations of the first kind of compressional (P1) and shear (S1) waves to relevant physical parameters are explored. In particular, we perform numerical modeling to investigate the effects of frequency, gas hydrate saturation and clay on the phase velocities and attenuations of the above five waves. The analyses demonstrate that, the velocities and attenuations of P1 and S1 are more sensitive to gas hydrate saturation than other parameters. The larger the gas hydrate saturation, the more reliable P1 velocity. Besides, the attenuations of P1 and S1 are more sensitive than velocity to gas hydrate saturation. Further, P1 and S1 are almost nondispersive while their phase velocities increase with the increase of gas hydrate saturation. The second compressional (P2) and shear (S2) waves and the third kind of compressional wave (P3) are dispersive in the seismic band, and the attenuations of them are significant. Moreover, in the case of clay in the solid grain frame, gas hydrate-bearing sediments exhibit lower P1 and S1 velocities. Clay decreases the attenuation of P1, and the attenuations of S1, P2, S2 and P3 exhibit little effect on clay content. We compared the velocity of P1 predicted by the model with the well log data from the Ocean Drilling Program (ODP) Leg 164 Site 995B to verify the applicability of the model. The results of the model agree well with the well log data. Finally, we estimate the hydrate layer at ODP Leg 204 Site 1247B is about 100–130 m below the seafloor, the saturation is between 0–27%, and the average saturation is 7.2%.

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