Diagenesis of Hunton Group Carbonates (Silurian) West Carney Field, Logan and Lincoln Counties, Oklahoma, U.S.A.

2020 ◽  
Vol 1 ◽  
pp. 30-51
Author(s):  
Cesar Silva ◽  
Brian J. Smith ◽  
Jordan T. Ray ◽  
James R. Derby ◽  
Jay M. Gregg
Keyword(s):  
Sea Level ◽  
Open Space ◽  
Oil Field ◽  
Woodford Shale ◽  
Isotopic Signatures ◽  
Fine Grained ◽  
Carbon And Oxygen Isotope ◽  
Petroleum Generation ◽  
Oxygen Isotopic ◽  
Diagenetic Fluid

The West Carney Hunton Field (WCHF) is an important oil field in central Oklahoma. Deposited during a series of sea-level rises and falls on a shallow shelf, the Cochrane and Clarita Formations (Hunton Group) have undergone a complex series of diagenetic events. The Hunton section of the WCHF comprises dolomitized crinoidal packstones, brachiopod “reefs” and grainstones, thin intervals of fine-grained crinoidal wackestones, and infrequent mudstones that were diagenetically affected by repeated sea-level change. Widespread karst is evidenced by multiple generations of solution-enlarged fractures, vugs, and breccias, which extend through the entire thickness of the Hunton. Karst development likely occurred during sea-level lowstands. Partial to complete dolomitization of Hunton limestones is interpreted to have occurred as a result of convective circulation of normal seawater during sea-level highstands. Open-space-filling calcite cements postdate dolomitization and predate deposition of the overlying siliciclastic section, which comprises the Misener Sandstone and Woodford Shale. Petrographic evaluation and carbon and oxygen isotope values of the calcite cements suggest precipitation by Silurian seawater and mixed seawater and meteoric water. Carbon and oxygen isotopic signatures of dolomite may have been partially reset by dedolomitization that was concurrent with calcite cementation. Fluid inclusions in late diagenetic celestite crystals observed in the Clarita Formation indicate that the WCHF was invaded by saline basinal fluids and petroleum after burial, during later stages of diagenesis. The timing of late diagenetic fluid flow and petroleum generation likely was during the Ouachita orogeny, which was occurring to the south. There is no evidence that late diagenetic fluids significantly altered the dolomite reservoir that formed earlier. The WCHF provides an ancient example of early diagenetic dolomitization by seawater that remains relatively unaltered by later diagenetic events.

Changes of Ionic and Oxygen Isotopic Composition of the Snowpack at the Glacier Austre Okstindbreen, Norway, 1995

1998 ◽  
Vol 29 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Peter Raben ◽  
Wilfred H. Theakstone
Keyword(s):  
Isotopic Composition ◽  
Sea Level ◽  
Oxygen Isotopes ◽  
Oxygen Isotopic Composition ◽  
Isotopic Ratios ◽  
Vertical Variations ◽  
Oxygen Isotopic ◽  
The Difference ◽  
Liquid Precipitation ◽  
Different Altitudes

Marked vertical variations of ions and oxygen isotopes were present in the snowpack at the glacier Austre Okstindbreen during the pre-melting phase in 1995 at sites between 825 m and 1,470 m above sea level. As the first meltwater percolated from the top of the pack, ions were moved to a greater depth, but the isotopic composition remained relatively unchanged. Ions continued to move downwards through the pack during the melting phase, even when there was little surface melting and no addition of liquid precipitation. The at-a-depth correlation between ionic concentrations and isotopic ratios, strong in the pre-melting phase, weakened during melting. In August, concentrations of Na+ and Mg2+ ions in the residual pack were low and vertical variations were slight; 18O enrichment had occurred. The difference of the time at which melting of the snowpack starts at different altitudes influences the input of ions and isotopes to the underlying glacier.

Characteristics and its Environment Implications of Carbon and Oxygen Isotopic of Ordovician Carbonate Rock in Yubei Area

2015 ◽  
Vol 1092-1093 ◽  
pp. 1375-1378
Author(s):  
Qian Zhang ◽  
Wen Hui Huang ◽  
Ya Mei Zhang
Keyword(s):  
Sea Level ◽  
Carbonate Rocks ◽  
Carbonate Rock ◽  
Burial Depth ◽  
Oxygen Stable Isotopes ◽  
Oxygen Isotopic ◽  
Oxygen Stable Isotope ◽  
The Stability ◽  
Diagenetic Environment ◽  
Stable Isotope Data

Based on a large number of carbon and oxygen stable isotope data, researched environment characteristics of Ordovician carbonate rocks in Yubei area, Tarim Basin. According to carbon, oxygen stable isotopes (&13C, &18O) data, combining the diagenetic environment characteristics studied all kinds of geochemical characteristics of rocks in Yubei area. The research results show that: Paleosalinity feature of Ordovician carbonate rocks in this area reflected the carbonate rocks is formed in the stability of the marine environment and basically kept the composition of carbon and oxygen isotopic of the original environment. the paleo temperature characteristics indicate that the diagenetic burial depth was increased first and then decreased, the sea level characteristics indicate that the sedimentary strata by Yingshan period to Lianglitage period corresponds with a rise in sea level.

scholarly journals High-frequency sea-level changes recorded in deep-water carbonates of the Upper Cretaceous Dol Formation (island of Brač, Croatia)

2010 ◽  
Vol 61 (1) ◽  
pp. 29-38
Author(s):  
Damir Bucković ◽  
Maja Martinuš ◽  
Duje Kukoč ◽  
Blanka Tešović ◽  
Ivan Gušić
Keyword(s):  
Sea Level ◽  
Deep Water ◽  
High Frequency ◽  
Upper Cretaceous ◽  
Distal Part ◽  
Preferential Orientation ◽  
Sea Level Changes ◽  
Carbonate Production ◽  
Fine Grained ◽  
Platform Margin

High-frequency sea-level changes recorded in deep-water carbonates of the Upper Cretaceous Dol Formation (island of Brač, Croatia)The upper part of the Middle Coniacian/Santonian-Middle Campanian deep-water Dol Formation of the island of Brač is composed of countless fine-grained allodapic intercalations deposited in an intraplatform trough. Within the studied section 13 beds can be distinguished, each defined by its lower part built up of dark grey limestone with abundance of branched, horizontally to subhorizontally oriented burrows, and the upper part, in which the light grey to white limestone contains larger burrows, rarely branched, showing no preferential orientation. The lower, dark grey, intensively bioturbated levels are interpreted as intervals formed during high-frequency sea-level highstands, while the upper, light grey-to-white levels are interpreted as intervals formed during the high-frequency sea-level lowstands. Cyclic alternation of these two intervals within the fine-grained allodapic beds is interpreted as the interaction between the amount of carbonate production on the platform margin and the periodicity and intensity of shedding and deposition in the distal part of toe-of-slope environment, which is governed by Milankovitch-band high frequency sea-level changes.

scholarly journals Arrecifes de arenisca en el Golfo de Salamanca, plataforma continental del Caribe colombiano

2019 ◽  
Vol 48 (1) ◽  
Author(s):  
Sven Zea ◽  
Gladys Bernal ◽  
Gloria López ◽  
Marion Weber ◽  
Rocío Del Pilar García-Urueña
Keyword(s):  
Continental Shelf ◽  
Sea Level ◽  
Petrographic Analysis ◽  
Saline Environments ◽  
Fine Grained ◽  
Lagoon System

In tropical seas there are submerged hard bottoms that harbor corals but that are not coralline in origin. This is the case for the “Banco de las Ánimas” sector in the continental shelf of the Gulf of Salamanca, Colombian Caribbean. In its upper portion (14–16 m in depth), there are low mounds of sandstone blocks and slabs, conforming reefs, colonized by coralline biota and sparse corals. To confirm their lithology an initial petrographic analysis was carried out, which showed the rocks are made up of fine-grained sands, mature in texture, cemented by dolomite. It is proposed that these reefs were formed in a beach–dune–lagoon system during an ancient sea level, similar to the recent coastal bar of Salamanca. In these high-evaporation, supratidal saline environments, they could have been formed as beach rocks or as eolianites, by aragonite cementation, modified later into dolomite. Whether the foundation of the deeper coral formations of the bankis also sandstone or in fact coralline, remains to be determined.

Barrow Island enhanced oil recovery polymer pilot—part two: progress and way forward

2011 ◽  
Vol 51 (2) ◽  
pp. 672
Author(s):  
Daniel León ◽  
John Scott ◽  
Steven Saul ◽  
Lina Hartanto ◽  
Shannon Gardner ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Injection Pressure ◽  
Fracture Network ◽  
Oil Field ◽  
High Porosity ◽  
Polymer Injection ◽  
Fine Grained ◽  
Successful Design ◽  
Fit For Purpose ◽  
Water Cut

After successful design and implementation phases that included both subsurface and facilities components, an EOR polymer injection pilot has been operational for two years in Australia's largest onshore oil field at Barrow Island (816 MMstb OOIP). The pilot's main objective was to identify a suitable EOR technology for the complex, highly heterogeneous, very fine-grained, bioturbated argillaceous sandstone—high in glauconite, high porosity (∼23 %), low permeability (∼5 mD, with 50+ mD streaks)—reservoir that will ultimately increase the recovery of commercial resources past the estimated ultimate recovery factor with waterflooding (∼42 %). This was achieved using the in-depth flow diversion (IFD) methodology to access new unswept oil zones—both vertically and horizontally—by inducing growth in the fracture network. During the pilot operating phase, the main focus has been on surveillance and monitoring activities to assess the effectiveness of the process, including: injection pressure at the wellheads—indicating any increase in resistance to flow; pressure fall off tests at the injectors—to determine fracture growth, if any sampling and lab analysis at the producers—to identify polymer breakthrough; frequent production tests—quantifying reduction in water cut and oil production uplift; and, pressure build up surveys at the producers. These activities provided input data to the fit for purpose simulation model built in Reveal incorporating fractures and polymer as a fourth phase. With more than 96 % compliance to the surveillance plan, this paper will present the present findings and evaluation of the results, which may lead to the continuation of the pilot in other patterns of the reservoir and, possibly, to further expansion in the field.

THE GEOLOGICAL EXPRESSION OF EUSTACY IN THE EARLY TERTIARY OF THE GIPPSLAND BASIN

1976 ◽  
Vol 16 (1) ◽  
pp. 73 ◽  
Author(s):  
A. D. Partridge
Keyword(s):  
Sea Level ◽  
Time Interval ◽  
Marine Environments ◽  
Fine Grained ◽  
Sedimentary Sequences ◽  
Seismic Records ◽  
Basin Morphology ◽  
The Times ◽  
Sequence Boundaries ◽  
Gippsland Basin

In the non-marine to marginal marine environments of the Latrobe Group, distinct sedimentary sequences are recognised on seismic records and these sequences are often expressed in wells by palynological zones, changes in E-log character and lithology.The succession of sequences represents variations in sea level, many of which are interpreted aseustatic. Eustatic falls are represented by unconformities and channel formation along the seaward margin and by hiatuses (frequently with dolomite cementation of underlying sands) landward in deltaic and non-marine sections. Eustatic rises are represented by dinoflagellate ingressions over truncated surfaces at sequence boundaries, followed by outbuilding of deltaic environments at the stillstand towards the end of each cycle.During the Paleocene and Eocene very little sediment was deposited beyond the limits of the marginal marine environments except within channels where the Flounder and Turrum Formations are found. In this time interval they was an overall landward encroachment of successive sequences reflecting an overall sea level rise. The interaction of rising sea level and limited deposition beyond the marginal marine edge meant that successive sequences became more restricted seaward such that within the marine environment the area of non-deposition increased. The surface thus defined, modified locally by channel erosion, constitutes the unconformity at the top of the Latrobe Group. This unconformity surface was preserved when deposition of fine-grained open marine sediments of the Lakes Entrance Formation commenced in the Oligocene.In the Tasman Sea a succession of terrigenous silts and clays present in the Deep Sea Drilling Project (DSDP) Site 283 can be correlated with periods when fine-grained sediments bypassed the Gippsland shelf. The stratigraphy of this site can be interpreted as a record of availability of sediment from the southeastern Australian continental shelf. The times of commencement and termination of stratigraphic units and disconformities at Site 283 correlate with timing of eustatic cycles. Thus the stratigraphy of Site 283 is a record, as is the Latrobe Group, of how eustacy interacts with basin morphology to modify distribution of sediments.

scholarly journals Potential of Stable Carbon and Oxygen Isotope Variations of Speleothems from Andaman Islands, India, for Paleomonsoon Reconstruction

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Amzad H. Laskar ◽  
S. Raghav ◽  
M. G. Yadava ◽  
R. A. Jani ◽  
A. C. Narayana ◽  
...  
Keyword(s):  
Monsoon Rainfall ◽  
Boreal Summer ◽  
Stable Carbon ◽  
The South ◽  
Isotopic Equilibrium ◽  
The Past ◽  
Carbon And Oxygen Isotope ◽  
Show Evidence ◽  
Oxygen Isotopic ◽  
India Receive

The Indian monsoon activity, coinciding with the Inter-Tropical Convective Zone (ITCZ), progresses from the southern Indian Ocean during the boreal summer and withdraws towards the south in winter. Islands situated to the south of India receive, therefore, the first and last showers of the monsoon; speleothems in such islands have not yet been explored for their potential to reconstruct past monsoon rainfall. Here, we present the first measurements of stable carbon and oxygen isotopic compositions (δ13C and δ18O) of a stalagmite collected from the Baratang Island of Andamans, along with new data on δ18O of modern monsoon precipitation (May to July 2010). The aim was to detect (i) whether these samples are amenable to dating using 14C, (ii) whether their oxygen isotopes indicate precipitation under isotopic equilibrium, and (iii) if (i) and (ii) above are true, can we reconstruct monsoon activity during the past few millennia? Our results indicate that while δ18O of speleothem does show evidence for precipitation under isotopic equilibrium; dating by 14C shows inversions due to varying contributions from dead carbon. The present work highlights the problems and prospects of speleothem paleomonsoon research in these islands.

Late Quaternary Evolution of the Northern Aegean Shelf

1989 ◽  
Vol 32 (1) ◽  
pp. 36-50 ◽  
Author(s):  
C. Perissoratis ◽  
D. Mitropoulos
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Shelf Area ◽  
Seismic Profiles ◽  
Fine Grained ◽  
Nestos River ◽  
River Bed ◽  
Ephemeral Lakes ◽  
Evros River ◽  
River Mouths

AbstractA dense network of 3.5 kHz and Uniboom seismic profiles revealed the geological evolution of the Ierissos-Alexandroupolis Shelf area of the northern Aegean during the latest sea-level rise. Near the end of the Pleistocene, ca. 14,000 yr B.P., the sea was at about − 120 m, and almost 5300 km2 of shelf was exposed to subaerial erosion. Two permanet lakes existed in the Ierissos and Kavalla Gulfs, as well as a number of ephemeral lakes scattered throughout the rest of the area. Kavalla Gulf was drained by the Nestos River which joined the Strymon River at the outer Strymonikos Plateau. On the flat Samothraki Plateau were dune fields, marshes, and a number of minor seasonal rivers, while the Evros River flowed east of the plateau. By ca. 13,000 yr B.P. the sea had risen to − 70 m and covered 30% of the previously exposed shelf. The lakes at Ierissos and Strymonikos Gulfs were shallower and the sea approached to within about 5 km of them. Kavalla Gulf and the adjacent eastern Strymonikos Plateau lay 10 m above sea level, while the sea intruded along river mouths at the Samothraki Plateau. During this transgression of the sea river-bed gravels and sands were covered by silts and clays. At the Pleistocene-Holocene transition, ca. 10,500 yr B.P., the sea lay at about − 50 m and in areas of steep slope the coast was close to its present position. At Kavalla Gulf, the sea advanced along the paleochannel of the Nestos River, and the island of Samothraki was separated from the mainland. By ca. 7500 yr B.P. the sea was only 15 m below its present level and the northeastern Aegean shelf assumed nearly its present morphology. The Nestos River changed course to the east and Thassos Island was separated from the mainland. Coarse sediment formed wedges nearshore, whereas fine-grained sediments were distributed widely by current action. In many areas, relict sediments are present.

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