scholarly journals Source Rocks Characterization Of Agbada And Akata Formations In The Niger Delta, Nigeria

2020 ◽  
Vol 1 (4) ◽  
Author(s):  
Koffi Eugene Kouadio ◽  
Selegha Abrakasa ◽  
Sunday S. Ikiensikimama ◽  
Takyi Botwe
Keyword(s):  
Organic Matter ◽  
Niger Delta ◽  
Early Stage ◽  
Source Rocks ◽  
Thermal Maturity ◽  
Petroleum Generation ◽  
Niger Delta Basin ◽  
Rock Eval ◽  
Organic Matter Abundance

The geochemical analysis was performed on twelve (12) core samples from 6 wells of different formations (Akata, Agbada, and Akata/Agbada) of the onshore  Niger Delta Basin. The study was essentially based on the results of the Rock-Eval 6 Pyrolysis to evaluate organic matter abundance, quality, and thermal maturity. The Total Organic Carbon (TOC) varies between 0.6 and 3.06 wt% and the Hydrogen Index (IH) of the studied samples ranges from 38 to 202 mgHC/g TOC, indicating predominantly Type III (gas prone) and mixed type II/III (gas and oil-prone) kerogen. This suggests terrigenous and a mixture of marine and terrigenous organic matter deposited in a paralic marine setting. The organic matter is immature to early mature according to the thermal maturity parameter (414<Tmax<432). The well Isan 9 from Agbada (6760 ft) and Agbada/Akata (8680 ft) shows petroleum generation potential of fair (2,5 < S2 < 5 mg HC/g rock) to good (5 < S2 < 10 mgHC/g rock) and poor for the  other wells. The maturation of the kerogen indicates a very early stage of maturation (Tmax= 432°C). The results indicate that the shales from Agbada and the transition zone between the upper and lower parts of the Akata Shales are more shaly and perhaps the more mature part of the Agbada formation can be the potential source rocks of Niger Delta Basin.

scholarly journals Rock-Eval analysis and organic petrographical characterization of the Upper Jurassic Naokelekan Formation, northern Mesopotamian basin, Kurdistan Region-Iraq

2020 ◽  
Vol 56 (1) ◽  
pp. 187
Author(s):  
Rzger Abdula ◽  
Kamal Kolo ◽  
Maria-Elli Damoulianou ◽  
Victoria Raftopoulou ◽  
Polla Khanaqa ◽  
...  
Keyword(s):  
Organic Matter ◽  
Upper Jurassic ◽  
Thermal Maturity ◽  
Kurdistan Region ◽  
Secondary Particles ◽  
Petroleum Generation ◽  
Rock Eval ◽  
Solid Hydrocarbons ◽  
Jurassic Sequence

The aim of this study is to assess the type, thermal maturity and the petroleum generation potential of the Upper Jurassic Naokelekan Formation, occurring across the Kurdistan Region of Iraq, by applying organic petrographical methods and Rock-Eval analysis. The Rock-Eval data would indicate the presence of kerogen types III, IV and II as the main constituents. However, the qualitative petrographical evaluation revealed that the main organic constituents are solid hydrocarbons, in the form of microgranular migrabitumens, with minor amounts of pyrobitumens. These secondary particles have affected the results of the Rock-Eval analysis and would have led to misinterpretation of organic matter typification based on pyrolysis results only. The combined results of petrography and pyrolysis indicate an active petroleum system within the Upper Jurassic sequence, where hydrocarbons are generated and reservoired within suitable lithologies.

scholarly journals Caracterização da Matéria Orgânica Dispersa através da técnica de Pirólise "Rock-Eval II" Vantagens e Limitações para a Geologia

2000 ◽  
Vol 27 (1) ◽  
pp. 43
Author(s):  
MARCUS VINICIUS BERAO ADE
Keyword(s):  
Organic Matter ◽  
Clay Minerals ◽  
Sedimentary Rocks ◽  
Thermal Maturity ◽  
Inexpensive Method ◽  
Altered Sample ◽  
Kerogen Type ◽  
Petroleum Generation ◽  
Rock Eval ◽  
Disperse Organic Matter

The development of Rock-Eval II pyrolysis technique in the end of 70's, offered a very important tool for disperse organic matter study. Rock-Eval II pirolysis of whole rock has been used by geologist to identify the type, quantity and thermal maturity of organic mailer associated with sedimentary rocks. It is fast and inexpensive method to evaluate petroleum-generation potential and organic metamorphism of rocks. This technique allows obtention of repeatable data, very important determining stratigraphic and geographic extent of occurrence of source rock. However pyrolysis is results must be carefully analised to avoid misunderstanding, regarding, for example, altered sample. interference of clay-minerals associated with organic matter, the kerogen type, imature sediments etc., can lead to mistaken interpretation.

scholarly journals Evaluation of Neoproterozoic Source Rock Potential in SE Pakistan and Adjacent Bikaner- Nagaur Basin India Based on Integrated Geochemical, Geological, and Geophysical Data

2021 ◽  
Author(s):  
Qamar Yasin ◽  
Syrine Baklouti ◽  
Ghulam Mohyuddin Sohail ◽  
Muhammad Asif ◽  
Gong Xufei
Keyword(s):  
Source Rock ◽  
Early Stage ◽  
Seismic Inversion ◽  
Source Rocks ◽  
Maturity Index ◽  
Thermal Maturity ◽  
Index Profile ◽  
Southeastern Part ◽  
Seismic Reflection Data ◽  
Rock Eval

Abstract Discoveries of heavy crude oil in the Neoproterozoic rocks (Infracambrian rock sequence) from the Bikaner-Nagaur Basin of India emphasizes the significance to study and explore the Neoproterozoic source rocks potential in the southeastern part of Pakistan. This study evaluates the potential of the source rock in the Infracambrian rock sequence (Salt Range Formation) based on surface geochemical surveys, Rock-Eval pyrolysis, source biomarkers, geophysical characterization, and seismic inversion using machine learning for maturity index estimation. Core samples of Infracambrian rock were extracted for Rock-Eval pyrolysis and biomarker characterization. Also, 81 geo-microbial soil and gas samples were collected from the surface to explore the petroleum system and potential source rocks in the subsurface. We followed the standard laboratory procedures to investigate the origin and concentration of hydrocarbons gases at the surface, thermal maturity, the source facies, and the environment of deposition of organic matter. The results show that the investigated samples are characterized by restricted marine clay devoid of carbonate source facies with thermal maturity in the early-stage of the oil generation window. Surface geochemical samples also confirm higher concentrations of thermogenic C2-C4 hydrocarbons over the vicinity of anticlinal structures proving the existence of an effective migration path along deep-seated faults to the surface. The inverted maturity index profile demonstrates a reasonable correlation of thermal maturity with the surface geochemical survey, source biomarkers, and Rock-Eval pyrolysis. It validates the reliability of multilayer linear calculator and particle swarm optimization algorithms for inverting seismic reflection data into a maturity index profile. The obtained results indicate a higher probability of heavy and light oil along the eastern flank of Pakistan, where Infracambrian rocks are thicker and more thermally mature, and deep-seated pledged structural closures occur, in comparison to the Bikaner-Nagaur Basin, India.

scholarly journals Maturity of dispersed organic matter in bituminous formations of the Ionian Zone (Epirus region, NW Greece)

2017 ◽  
Vol 47 (2) ◽  
pp. 880
Author(s):  
D. Rallakis ◽  
G. Siavalas ◽  
G. Oskay ◽  
D. Tsimiklis ◽  
K. Christanis
Keyword(s):  
Organic Matter ◽  
Vitrinite Reflectance ◽  
Lower Jurassic ◽  
Source Rocks ◽  
Organic Petrology ◽  
Bituminous Shale ◽  
Petroleum Generation ◽  
Posidonia Shale ◽  
Rock Eval ◽  
Coal Petrography

The main objective of this paper is to study by means of Organic Petrology techniques, the maturity of the dispersed organic matter from certain sedimentary formations of the Ionian Zone, such as the Bituminous Shale, the Upper Siliceous Vigla Formation and the Bituminous Sandstone. The samples were collected from outcropping sites located in the region of Epirus. Initially they were treated with acids (HCl-HF) to remove most of the carbonate and silicate minerals. Then a ZnCl2 solution was used to concentrate the organic-rich fraction. Total Organic Carbon (TOC) content was determined applying dichromate oxidation. Polished blocks were prepared from the concentrated organic matter mounted in epoxy resin and examined under the coal-petrography microscope. Emphasis was given to maceral identification and vitrinite reflectance (R) measurements, which provide information regarding the quality and the maturity of the organic matter respectively, with implications for the petroleum generation potential regardless the level of alteration. The TOC and Rr values (4.74% and 0.68%, respectively) confirm to the oil potential of the Lower Jurassic Posidonia Shale. Nevertheless, it is suggested that detailed and higher resolution sampling focusing on the Lower Posidonia Shale, as well as organic petrography analyses coupled with Rock-Eval pyrolysis should be carried out in order to accurately determine its quality as petroleum source rocks.

scholarly journals Source rock geochemistry of shale samples from Ege-1 and Ege-2 wells, Niger Delta, Nigeria

2020 ◽  
Author(s):  
S. L. Fadiya ◽  
S. A. Adekola ◽  
B. M. Oyebamiji ◽  
O. T. Akinsanpe
Keyword(s):  
Source Rock ◽  
Niger Delta ◽  
Source Rocks ◽  
Organic Carbon Content ◽  
Hydrocarbon Generation ◽  
Type Ii ◽  
Early Maturity ◽  
Type Iii ◽  
Niger Delta Basin ◽  
Rock Eval

AbstractSelected shale samples within the middle Miocene Agbada Formation of Ege-1 and Ege-2 wells, Niger Delta Basin, Nigeria, were evaluated using total organic carbon content (TOC) and Rock–Eval pyrolysis examination with the aim of determining their hydrocarbon potential. The results obtained reveal TOC values varying from 1.64 to 2.77 wt% with an average value of 2.29 wt% for Ege-1 well, while Ege-2 well TOC values ranged from 1.27 to 3.28 wt% (average of 2.27 wt%) values which both fall above the minimum threshold (0.5%) for hydrocarbon generation potential in the Niger Delta. Rock–Eval pyrolysis data revealed that the shale source rock samples from Ege-1 well are characterized by Type II–Type III kerogens which are thermally mature to generate oil or gas/oil. The Ege-2 well pyrolysis result showed that some of the ditch cutting samples are comprised of Type II (oil prone) and Type III (gas-prone kerogen) which are thermally immature to marginal maturity (Tmax 346–439 °C). This study concludes that the shale intercalations between reservoir sands of the Agbada Formation are good source rocks in early maturity and also must have contributed to the vast petroleum reserve in the Niger Delta Basin because of the subsidence of the basin.

scholarly journals Source rock characterization of mesozoic to cenozoic organic matter rich marls and shales of the Eratosthenes Seamount, Eastern Mediterranean Sea

2018 ◽  
Vol 73 ◽  
pp. 49 ◽  
Author(s):  
Sebastian Grohmann ◽  
Susanne W. Fietz ◽  
Ralf Littke ◽  
Samer Bou Daher ◽  
Maria Fernanda Romero-Sarmiento ◽  
...  
Keyword(s):  
Organic Matter ◽  
Mediterranean Sea ◽  
Source Rock ◽  
Eastern Mediterranean ◽  
Source Rocks ◽  
Eastern Mediterranean Sea ◽  
Potential Source Rock ◽  
Levant Basin ◽  
Rock Characterization ◽  
Rock Eval

Several significant hydrocarbon accumulations were discovered over the past decade in the Levant Basin, Eastern Mediterranean Sea. Onshore studies have investigated potential source rock intervals to the east and south of the Levant Basin, whereas its offshore western margin is still relatively underexplored. Only a few cores were recovered from four boreholes offshore southern Cyprus by the Ocean Drilling Program (ODP) during the drilling campaign Leg 160 in 1995. These wells transect the Eratosthenes Seamount, a drowned bathymetric high, and recovered a thick sequence of both pre- and post-Messinian sedimentary rocks, containing mainly marine marls and shales. In this study, 122 core samples of Late Cretaceous to Messinian age were analyzed in order to identify organic-matter-rich intervals and to determine their depositional environment as well as their source rock potential and thermal maturity. Both Total Organic and Inorganic Carbon (TOC, TIC) analyses as well as Rock-Eval pyrolysis were firstly performed for the complete set of samples whereas Total Sulfur (TS) analysis was only carried out on samples containing significant amount of organic matter (>0.3 wt.% TOC). Based on the Rock-Eval results, eight samples were selected for organic petrographic investigations and twelve samples for analysis of major aliphatic hydrocarbon compounds. The organic content is highly variable in the analyzed samples (0–9.3 wt.%). TS/TOC as well as several biomarker ratios (e.g. Pr/Ph < 2) indicate a deposition under dysoxic conditions for the organic matter-rich sections, which were probably reached during sporadically active upwelling periods. Results prove potential oil prone Type II kerogen source rock intervals of fair to very good quality being present in Turonian to Coniacian (average: TOC = 0.93 wt.%, HI = 319 mg HC/g TOC) and in Bartonian to Priabonian (average: TOC = 4.8 wt.%, HI = 469 mg HC/g TOC) intervals. A precise determination of the actual source rock thickness is prevented by low core recovery rates for the respective intervals. All analyzed samples are immature to early mature. However, the presence of deeper buried, thermally mature source rocks and hydrocarbon migration is indicated by the observation of solid bitumen impregnation in one Upper Cretaceous and in one Lower Eocene sample.

scholarly journals Characterization of reservoir sands using 3D seismic attributes in the coastal swamp area of Niger Delta Basin

2021 ◽  
Author(s):  
Oluwatoyin Khadijat Olaleye ◽  
Pius Adekunle Enikanselu ◽  
Michael Ayuk Ayuk
Keyword(s):  
Seismic Data ◽  
Niger Delta ◽  
Seismic Attributes ◽  
Effective Porosity ◽  
High Porosity ◽  
Hydrocarbon Accumulation ◽  
3D Seismic ◽  
Seismic Attribute ◽  
Niger Delta Basin

AbstractHydrocarbon accumulation and production within the Niger Delta Basin are controlled by varieties of geologic features guided by the depositional environment and tectonic history across the basin. In this study, multiple seismic attribute transforms were applied to three-dimensional (3D) seismic data obtained from “Reigh” Field, Onshore Niger Delta to delineate and characterize geologic features capable of harboring hydrocarbon and identifying hydrocarbon productivity areas within the field. Two (2) sand units were delineated from borehole log data and their corresponding horizons were mapped on seismic data, using appropriate check-shot data of the boreholes. Petrophysical summary of the sand units revealed that the area is characterized by high sand/shale ratio, effective porosity ranged from 16 to 36% and hydrocarbon saturation between 72 and 92%. By extracting attribute maps of coherence, instantaneous frequency, instantaneous amplitude and RMS amplitude, characterization of the sand units in terms of reservoir geomorphological features, facies distribution and hydrocarbon potential was achieved. Seismic attribute results revealed (1) characteristic patterns of varying frequency and amplitude areas, (2) major control of hydrocarbon accumulation being structural, in terms of fault, (3) prospective stratigraphic pinch-out, lenticular thick hydrocarbon sand, mounded sand deposit and barrier bar deposit. Seismic Attributes analysis together with seismic structural interpretation revealed prospective structurally high zones with high sand percentage, moderate thickness and high porosity anomaly at the center of the field. The integration of different seismic attribute transforms and results from the study has improved our understanding of mapped sand units and enhanced the delineation of drillable locations which are not recognized on conventional seismic interpretations.

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