scholarly journals Interpretation and Reconstruction of Depositional Environment and Petroleum Source Rock Using Outcrop Gamma-ray Log Spectrometry From the Huai Hin Lat Formation, Thailand

2021 ◽  
Vol 9 ◽  
Author(s):  
Chawisa Phujareanchaiwon ◽  
Piyaphong Chenrai ◽  
Kasira Laitrakull
Keyword(s):  
Depositional Environment ◽  
Gamma Ray ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Turbidity Currents ◽  
Stratigraphic Framework ◽  
Facies Associations ◽  
Mineral Compositions ◽  
Gamma Ray Log ◽  
Low K

Gamma ray logs are most useful in identifying subsurface lithology and interpreting depositional environments. This study highlights the use of outcrop gamma-ray logs along with outcrop observations and total organic carbon (TOC) analysis to provide the stratigraphic framework of the organic-rich rocks of Huai Hin Lat Formation in central Thailand. The study reveals five sedimentary facies including (1) structureless sandstone, (2) structured sandstone, (3) interbedded sandstone and siltstone, (4) interbedded mudstone and siltstone and (5) calcareous mudstone. These facies can be grouped into two facies associations; mudstone-dominated and sandstone-dominated facies associations. The depositional environment was interpreted as lacustrine basin-fill subdivided into deep lacustrine environment and sublacustrine fan associated with the turbidity currents. The total gamma-log characteristics are closely related to the lithologies controlled primarily by clay mineral compositions. Whist, the use of spectral gamma-ray can reveal more details on depositional environments and conditions. In this study, U concentrations is proven to be useful in highlighting organic-rich rocks in low K and Th concentration successions due to its ability to be fixed in clay minerals and organic materials under an anoxic condition. Thus, the U spectral gamma ray is suggested to combine with conventional gamma ray log for depositional environment and recognition of organic-rich rocks.

scholarly journals Facies Architecture Analysis for Paleo-environment Evaluation in “Tom” Oil Field, Eastern Niger Delta, Nigeria

2020 ◽  
Vol 24 (2) ◽  
pp. 213-221
Author(s):  
T.M. Asubiojo
Keyword(s):  
Niger Delta ◽  
Depositional Environment ◽  
Gamma Ray ◽  
Sedimentary Facies ◽  
Oil Field ◽  
Sedimentary Structures ◽  
Fossil Records ◽  
Depositional Setting ◽  
Gamma Ray Log ◽  
Architecture Analysis

The cored section of reservoir C, well 4 of the drilled five wells that penetrated three reservoirs A, B and C in “TOM” oil field, Eastern Niger Delta was analysed and described on the basis of lithofacies, sedimentary structures and trace fossil records by using core data and wireline log motifs, with  the aim of carrying out thorough geological core analysis to interpret the depositional environment of the oil field. The lithofacies are sandstones  with interbedded mudstones and siltstones, the dominant sedimentary structures are parallel to ripple cross laminations, hummocky and swaley cross stratifications, sandy hetherolitics, planar to low angle cross bedding with traces of Teichichnus and Ophiomorpha burrows. The gamma-ray log motifs were noted and used to further constrain the character of the sedimentary facies and depositional environment of the field. A tidal incised – fluvial dominated shallow marine (lower, middle, upper shoreface) comprises of tidal channel sands and tidal flat of the coastal shelf depositional setting in the marginal marine mega depositional environment had been inferred for the “TOM” field. Keywords: Shoreface, Reservoir, Lithofacies, Structures

scholarly journals Facies Analysis and Depositoinal Environment of D-3 Reservoir Sands Vin Field, Eastern Niger Delta

2019 ◽  
pp. 1-19
Author(s):  
Onyewuchi, Chinedu Vin ◽  
Minapuye, I. Odigi
Keyword(s):  
Seismic Data ◽  
Niger Delta ◽  
Depositional Environment ◽  
Gamma Ray ◽  
Facies Analysis ◽  
Depositional Environments ◽  
Width Ratio ◽  
Neutron Density ◽  
Wireline Logs ◽  
Isopach Map

Facies analysis and depositional environment identification of the Vin field was evaluated through the integration and comparison of results from wireline logs, core analysis, seismic data, ditch cutting samples and petrophysical parameters. Well log suites from 22 wells comprising gamma ray, resistivity, neutron, density, seismic data, and ditch cutting samples were obtained and analyzed. Prediction of depositional environment was made through the usage of wireline log shapes of facies combined with result from cores and ditch cuttings sample description. The aims of this study were to identify the facies and depositional environments of the D-3 reservoir sand in the Vin field. Two sets of correlations were made on the E-W trend to validate the reservoir top and base while the isopach map was used to establish the reservoir continuity. Facies analysis was carried out to identify the various depositional environments. The result showed that the reservoir is an elongate , four way dip closed roll over anticline associated with an E-W trending growth fault and contains two structural high separated by a saddle. The offshore bar unit is an elongate sand body with length: width ratio of >3:1 and is aligned parallel to the coast-line. Analysis of the gamma ray logs indicated that four log facies were recognized in all the wells used for the study. These include: Funnel-shaped (coarsening upward sequences), bell-shaped or fining upward sequences, the bow shape and irregular shape. Based on these categories of facies, the depositional environments were interpreted as deltaic distributaries, regressive barrier bars, reworked offshore bars and shallow marine. Analysis of the wireline logs and their core/ditch cuttings description has led to the conclusion that the reservoir sandstones of the Agbada Formation in the Vin field of the eastern Niger Delta is predominantly marine deltaic sequence, strongly influenced by clastic output from the Niger Delta. Deposition occurred in a variety of littoral and neritic environment ranging from barrier sand complex to fully marine outer shelf mudstones.

Seismic characterization and origin of clinoforms in lacustrine depositional environments: a case study from the Cretaceous of the South Atlantic

2020 ◽  
pp. SP509-2019-148
Author(s):  
Andrew J. Barnett ◽  
Lucy Fu ◽  
Tolu Rapasi ◽  
Cinzia Scotellaro ◽  
Jaydip Guha ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Lower Energy ◽  
Gamma Ray ◽  
Depositional Environments ◽  
Longshore Sediment Transport ◽  
Seismic Characterization ◽  
Bona Fide ◽  
Flooding Events ◽  
Gamma Ray Log

AbstractThe lacustrine Itapema Formation in the Santos Basin locally comprises 102 m thick clinoforms identified seismically and corroborated by several well penetrations. Individual clinoforms, as proven by well penetrations, are composed of 102 m thick successions of basinward-dipping molluscan grainstones and rudstones. Manual dip picking of borehole images shows upward-increasing dips consistent with seismic geometries and a predominance of longshore sediment transport. Clinoforms are bound at their top and base by strata with significantly lower dips recognizable on both seismic and borehole images. Elevated gamma-ray log responses together with sidewall core samples indicate that these intervals correspond to more argillaceous facies which are interpreted as lake flooding events. While the existence of bona fide clinoforms is demonstrated by a range of subsurface data, their precise origin remains enigmatic. The majority of the bivalve genera that make up the grain-supported carbonates appear to be infaunal or semi-infaunal. As such the clinoforms represent large bars produced through the re-working of bivalves from lower-energy depositional environments by shore-parallel currents.

scholarly journals Arquitectura estratigráfica, paleogeografía y proveniencia sedimentaria de las rocas cenozoicas del sur de Perú (Tacna, 18° S)

2020 ◽  
Vol 47 (2) ◽  
pp. 351
Author(s):  
Aldo A. Alvan ◽  
Yacory F. Bustamante ◽  
Elvis A. Sánchez ◽  
Mirian I. Mamani
Keyword(s):  
Sedimentary Facies ◽  
Normal Faults ◽  
Architectural Elements ◽  
Western Cordillera ◽  
Stratigraphic Framework ◽  
Basal Complex ◽  
Facies Associations ◽  
Sediment Mineralogy ◽  
Sedimentary Fill ◽  
Stratigraphic Thickness

The Cenozoic rocks lying in the Province of Tacna (18° S), southern Perú, represent approximately 600 m of stratigraphic thickness. This stacking groups the Sotillo (Paleocene), Moquegua Inferior (Eocene), Moquegua Superior (Oligocene), Huaylillas (Miocene) and Millo formations (Pliocene), and these are the sedimentary fill of the Moquegua Basin. The sediments of the three latter formations are organized into nine sedimentary facies and five architectural elements. Their facies associations suggest the existence of an ancient highly channelized multi-lateral fluvial braided system, with upward increase of pyroclastic and conglomeratic depositions. The heavy mineral spectra make each lithostratigraphic unit unique and distinguishable, being the sediments of the Moquegua Superior Formation rich in garnets, titanites and zircons; while the sediments of the Huaylillas and Millo formations in clinopyroxenes. This mineral arrangement becomes an excellent tool for stratigraphic correlations between outcrops and subsurface stratigraphy (by means of well cores studies) and allow to sketch out a new stratigraphic framework and a complex of rocky blocks bounded by normal faults, often tilted. The sediment mineralogy also suggests that the rocks conforming the Western Cordillera were the main source of sediments for the Moquegua Basin in Tacna. In this context, the detritus of the Moquegua Superior Formation derives mainly from the erosion of the rocks forming the Coastal Basal Complex (Proterozoic), the Ambo Group (Carboniferous) and the Junerata/Chocolate Formation (Early Jurassic). The Huaylillas Formation is a pyroclastic and sedimentary unit which components derived mainly from the Huaylillas volcanism (Miocene) and partly from the denudation of the Toquepala Group (Late Cretaceous). The Huaylillas Formation widely contrasts to the underlying Moquegua Superior Formation due its mineralogy and facies. Finally, the detritus of the Millo Formation derived mostly from the rocks forming the Barroso Formation (Pliocene), and their facies represent a higher contrast in relation to the underlying units due its notorious conglomerate facies.

scholarly journals Sedimentary facies, stratigraphy, and depositional environments of the Ecca Group, Karoo Supergroup in the Eastern Cape Province of South Africa

2021 ◽  
Vol 13 (1) ◽  
pp. 748-781
Author(s):  
Christopher Baiyegunhi ◽  
Kuiwu Liu
Keyword(s):  
South Africa ◽  
Water Depth ◽  
Facies Analysis ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Eastern Cape Province ◽  
Eastern Cape ◽  
Borehole Data ◽  
Karoo Basin ◽  
Facies Associations

Abstract The stratigraphy of the Ecca Group has been subdivided into the Prince Albert, Whitehill, Collingham, Ripon, and Fort Brown Formations in the Eastern Cape Province, South Africa. In this article, we present detailed stratigraphic and facies analyses of borehole data and road-cut exposures of the Ecca Group along regional roads R67 (Ecca Pass), R344 (Grahamstown-Adelaide), R350 (Kirkwood-Somerset East), and national roads N2 (Grahamstown-Peddie) and N10 (Paterson-Cookhouse). Facies analysis of the Ecca Group in the study area was performed to deduce their depositional environments. Based on the lithological and facies characteristics, the stratigraphy of the Prince Albert, Whitehill, Collingham, and Fort Brown Formations is now subdivided into two informal members each, while the Ripon Formation is subdivided into three members. A total of twelve lithofacies were identified in the Ecca Group and were further grouped into seven distinct facies associations (FAs), namely: Laminated to thin-bedded black-greyish shale and mudstones (FA 1); Laminated black-greyish shale and interbedded chert (FA 2); Mudstone rhythmite and thin beds of tuff alternation (FA 3); Thin to thick-bedded sandstone and mudstone intercalation (FA 4); Medium to thick-bedded dark-grey shale (FA 5); Alternated thin to medium-bedded sandstone and mudstone (FA 6); and Varved mudstone rhythmite and sandstone intercalation (FA 7). The FAs revealed gradually change of sea-level from deep marine (FA 1, FA 2, FA 3 and FA 4, FA 5, and FA 6) to prodelta environment (FA 7). This implies that the main Karoo Basin was gradually filling up with Ecca sediments, resulting in the gradual shallowing up of the water depth of the depositional basin.

scholarly journals Stratigraphic architecture and depositional environment of the Paleocene-Lower Eocene aquifers system (Douala onshore basin, SW Cameroon)

2021 ◽  
Vol 11 (2) ◽  
pp. 549-560
Author(s):  
Serge Parfait Koah Na Lebogo ◽  
Dieudonnée Bisso ◽  
Jeannette Ngo Elogan Ntem ◽  
Joseph Mvondo Ondoa
Keyword(s):  
Sequence Stratigraphy ◽  
Depositional Environment ◽  
Gamma Ray ◽  
Clay Content ◽  
Depositional Environments ◽  
Well Log ◽  
Delta Front ◽  
Lower Eocene ◽  
System Tracts ◽  
System Tract

AbstractThe Paleocene-Lower Eocene N'kapa Formation has long been considered as an important groundwater and hydrocarbon resource in the eastern edge of the Douala Basin. The present study’s aim is to establish a possible link between the geological nature of this formation and the quality of potential aquifers using Gamma Ray well log, cuttings and outcrops through sedimentology and sequence stratigraphy studies. The results obtained from this study show that: lithofacies are dominated by clays, silts and sands/sandstones; gamma ray electrofacies are funnel-shaped to cylindrical-shaped with some bell-shaped; depositional environments are continental to shallow marine dominated by fluvial and sometimes tidal processes; fluvial channel-fill, tidal channel-fill and delta front bars sands are potential aquifers; sequence stratigraphy analysis reveals two transgressive–regressive cycles of second order (Danian to Selandian and Thanetian to Ypresian), two Highstand System Tracts, one Transgressive System Tract and one Lowstand System Tract; the high-resolution geometry of these sandy/sandstone sedimentary bodies shows that their distribution is linked to the hydrodynamic factors and the topography of the depositional environment. A total of two types of lithological facies of the reservoir levels were defined according to the volume of clay: clean sandstone (0–15%) and low clayey sandstone (15–30%). The gamma ray well log correlation shows that the thickness of the reservoir levels is variable and that the clay content (Vsh%) increases from the NE to the SW. As a result, the best potential aquifers appear to correspond to the fluvial channel-fill sands deposited during the base-level fall of Upper Paleocene age (Lower Thanetian).

scholarly journals The sedimentology of Lower Palaeozoic black shales from the shallow wells Skelbro 1 and Billegrav 1, Bomholm, Denmark

1989 ◽  
Vol 37 ◽  
pp. 151-173
Author(s):  
Gunver Krarup, Pedersen
Keyword(s):  
Gamma Ray ◽  
Average Rate ◽  
Sedimentary Facies ◽  
Black Shales ◽  
Low Energy ◽  
Upper Ordovician ◽  
Middle Cambrian ◽  
Facies Associations ◽  
Shallow Wells ◽  
Lower Palaeozoic

Previous studies of the Lower Palaeozoic shales on Bornholm have mainly been based on the outcrops along the streams. The outcrops provide data on the lateral continuity of the facies while the selection of (2-3 cm wide) cores for the present study focused the attention on the vertical sequence of facies. Cores of high quality were obtained and have been found to provide an excellent basis for a study of structures, sediment composition and diagenesis. In the outcrops of shale fossils are locally present in high numbers and such levels are also recognized in the cores. Seven sedimentary facies, ranging from black mudshale to greyish mudstone and silt-streaked shale, are distinguished in the Middle Cambrian to lowermost Silurian shales. Gamma-ray logs were run in the two wells and a convincing correlation to the cored sequence can be demonstrated. Gamma-ray logs provide thus a good means of correlation to wells where no cores have been cut. The shales are all interpreted as deposited in an epicontinental sea due to their geological setting i.e. the association with shallow water carbonates (Andrarum Limestone and Komstad Limestone) and their stratigraphical position above the shelf to shoreface sandstones of the Lresa formation. Three facies associations are distinguished: The mudshale association comprises black organic-rich shales which represent a low-energy anoxic depositional environment which prevailed in the Middle Cambrian to Lower Ordovician. The mudstone association is typical of the Middle and Upper Ordovician and represents a continuation of low-energy environments though mottling indicates that ventilation improved in certain periods. The siltshale association represents higher energy environments which were dominant in the lowermost Silurian. A well defined Upper Ordovician CU sequence probably reflects the global eustatic fall in sea level caused by the extensive glaciation in Gondwanaland. In the late Silurian the average rate of deposition increased in response to the approaching Caledonian orogeny.

scholarly journals VÝSLEDKY VRTNÉHO PRŮZKUMU NA LOKALITĚ HOLUBICE (SPODNOBADENSKÉ SEDIMENTY KARPATSKÉ PŘEDHLUBNĚ)

2014 ◽  
Vol 21 (1-2) ◽  
Author(s):  
Slavomír Nehyba ◽  
Václav Zborník ◽  
Vladimíra Jašková
Keyword(s):  
Grain Size ◽  
Gamma Ray ◽  
Facies Analysis ◽  
Primary Source ◽  
Heavy Minerals ◽  
Shallow Marine ◽  
Facies Associations ◽  
Mineral Compositions ◽  
Drill Holes ◽  
Depositional Setting

Early Badenian deposits of the Carpathian Foredeep were newly studied in the sedimentary successions from drill holes Holubice 1 and Holubice 2. Facies analysis together with study of grain size, the shape and roundness of the coarsest grains, the mineral compositions of selected heavy minerals (garnet, rutile) and the gamma-ray spectra, were all used for better understanding the depositional setting and provenance. Studied sediments were deposited in coastal and shallow marine environments. Six lithofacies was recognised in the sedimentary succession in the drill holes. They have been combined into two facies associations – lower clastic one and upper carbonate one, refl ecting deposition in shallow marine settings, upward shallowing trend and reduction of siliciclastic input. The primary source of the material is located mainly in the metamorphic rocks (gneisses, amphibolites and granulites). The spectral gamma-ray logs show vertical organization, which is consistent with the facies analysis and partly also grain-size. A significant reduction of terrigenous input is connected with deposition of carbonates (sandy limestones) in the upper part of the succession.

The stratigraphic architecture, distribution and hydrocarbon potential of the organic-rich Kyalla and Velkerri shales of the Upper Roper Group (McArthur Basin)

2018 ◽  
Vol 58 (2) ◽  
pp. 858 ◽  
Author(s):  
Mattilda Sheridan ◽  
D. Rhodri Johns ◽  
Howard D. Johnson ◽  
Sandra Menpes
Keyword(s):  
Depositional Environment ◽  
Tectonic Setting ◽  
Well Logs ◽  
Lateral Variation ◽  
Stratigraphic Architecture ◽  
Stratigraphic Framework ◽  
Facies Associations ◽  
Thickness Variations ◽  
Well Correlation ◽  
Seismic Lines

Recent exploration studies on the stratigraphic framework, depositional environment and tectonic setting of the Mesoproterozoic Roper Group in the McArthur Basin, have led to an improved understanding of the highly prospective organic-rich shales of the Velkerri and Kyalla Formations. From a review of open-file drill core and well logs, several major regressive–transgressive (R–T) cycles have been identified along with four key facies associations within the Roper Group. The R–T cycles show sedimentary features typical of deposition within a clastic-dominated marine deltaic setting and show marked lateral variation in facies and thicknesses. The lateral thickness variations are particularly noticeable across regional 2D seismic lines. Seismic interpretation and well correlation confirm the extensive and relatively undeformed nature of the Velkerri and Kyalla Formations in the subsurface, they appear thickest in the south-east of the Beetaloo Sub-Basin.

Characteristics of Facies Associations, Ichnofacies and Microfossils for Depositional Environment Interpretation of The Clastic Pulau Balang Formation, Samarinda

2020 ◽  
Author(s):  
B. Andika
Keyword(s):  
Depositional Environment ◽  
Oil And Gas ◽  
Facies Analysis ◽  
Research Area ◽  
Geological Structure ◽  
Depositional Environments ◽  
Geological Mapping ◽  
Intertidal Flat ◽  
Facies Association ◽  
Facies Associations

The Kutai Basin contains prolific reserves of oil and gas. The study of depositional environments is one of the goals of oil and gas exploration. The location of this research is situated in the Tanah Merah area, Samarinda. The objective of this research was to analyse outcrops of the Pulau Balang Formation exposed in the Tanah Merah area to determine the depositional environment. Site specific studies were conducted at 3 localities in this area; TM1, TM2 and TM3. This study combines geological mapping, measured sections, facies analysis, petrography, ichnofacies analysis and microfossil analysis. Geological mapping was carried out to determine the distribution of rock units and geological structures. Measured sections were used for facies analysis and the identification of sedimentary structures and ichnofacies. Petrography was carried out to determine the mineral content of rocks and microfossil analysis for palaeobathymetric environmental analysis. The geological structure of the study area comprises a NE-SW trending anticline and syncline and a left lateral strike-slip fault with E-W direction. The study area is entirely within the Middle Miocene age Pulau Balang Formation and can be divided into three facies associations. The TM1 facies association comprises strata interpreted to be deposited in a supratidal marsh and intertidal flat environment. The TM2 facies association comprises strata interpreted to be deposited in a subtidal, intertidal, and supratidal environment. The TM3 facies association comprises strata interpreted to be deposited in a shoreface environment. The petrography of the study area indicates that rock units predominantly comprise quartz wacke and lithic wacke. Two ichnofacies were identified in the research area 2, namely the Skolithos ichnofacies and the Skolithos-Cruziana ichnofacies and contain ichnogenera namely Ophiomorpha, Skolithos, Planolites, Thalassinoides, Paaleophycus. Microfossil analysis found benthonic foraminifera species including Nodosaria lamellala, N. radicula, Vaginulinopsis tricarinata, Lagena costata, Striatissima vaginulina, Bulimina lappa, Planularia auris, Quinqueloculina seminulum, Bolivina punctata and Lahena laevis. Based on the presence of these microfossils and ichnofacies, it is interpreted that the research area was deposited in a neritic-bathyal environment.

Sign in / Sign up

Export Citation Format

Share Document