Source rock maturity and petroleum generation in the Dahomey Basin SW Nigeria: Insights from geologic and geochemical modelling

Adeoye, James A.; Akande, Samuel O.; Adekeye, Olabisi A.; Sonibare, Wasiu Adedayo; Ondrak, Robert; Dominik, Wilhelm; Erdtmann, Bernd-Dietrich; Neeka, Jacob B.

doi:10.1016/j.petrol.2020.107844

Cited by 8 publications

(5 citation statements)

References 22 publications

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“…A wt % of TOC greater than 0.5 is a positive sign for the existence of organic matter in shale rock. Several cross plots such as between T max and hydrogen index (HI), S 2 and TOC, and HI and OI are used to evaluate the level of thermal maturity and kerogen type. − Table presents the range of TOC and T max according to the maturity level.…”

Section: Introductionmentioning

confidence: 99%

Data-Driven Approaches to Predict Thermal Maturity Indices of Organic Matter Using Artificial Neural Networks

et al. 2020

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Prediction of thermal maturity index parameters in organic shales plays a critical role in defining the hydrocarbon prospect and proper economic evaluation of the field. Hydrocarbon potential in shales is evaluated using the percentage of organic indices such as total organic carbon (TOC), thermal maturity temperature, source potentials, and hydrogen and oxygen indices. Direct measurement of these parameters in the laboratory is the most accurate way to obtain a representative value, but, at the same time, it is very expensive. In the absence of such facilities, other approaches such as analytical solutions and empirical correlations are used to estimate the organic indices in shale. The objective of this study is to develop data-driven machine learning-based models to predict continuous profiles of geochemical logs of organic shale formation. The machine learning models are trained using the petrophysical wireline logs as input and the corresponding laboratory-measured core data as a target for Barnett shale formations. More than 400 log data and the corresponding core data were collected for this purpose. The petrophysical wireline logs are γ-ray, bulk density, neutron porosity, sonic transient time, spontaneous potential, and shallow resistivity logs. The corresponding core data includes the experimental results from the Rock-Eval pyrolysis and Leco TOC measurements. A backpropagation artificial neural network coupled with a particle swarm optimization algorithm was used in this work. In addition to the development of optimized PSO-ANN models, explicit empirical correlations are also extracted from the fine-tuned weights and biases of the optimized models. The proposed models work with a higher accuracy within the range of the data set on which the models are trained. The proposed models can give real-time quantification of the organic matter maturity that can be linked with the real-time drilling operations and help identify the hotspots of mature organic matter in the drilled section.

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Section: Introductionmentioning

confidence: 99%

Data-Driven Approaches to Predict Thermal Maturity Indices of Organic Matter Using Artificial Neural Networks

et al. 2020

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“…Dahomey basin, southwestern Nigeria, with the Itapajé Member, strong similarities are observed. Both contain kerogen type III and reworked organic matter (kerogen type IV), which probably resulted from the contribution of terrigenous components into the basin (Adekeye et al, 2019;Adeoye et al, 2020). The basal or deeper part of the wells is diagnostic of marine algal input, similar to the Itapajé Member (Fig.…”

Section: Tablementioning

confidence: 99%

“…ANP (2017) summarized kerogen types and TOC contents for the Mundaú and Paracuru Formation. Recent research on the Brazilian Equatorial Margin (Pellegrini and Ribeiro, 2018;Maia de Almeida et al, 2020a;Leopoldino Oliveira et al, 2020;Souza et al, 2021) and its counterpart in Africa, the West Africa Margin (Brownfield and Charpentier, 2006;Adeoye et al, 2020), has presented geochemical data on the source rocks.…”

Section: Previous Geochemical Studiesmentioning

confidence: 99%

“…In addition, maximum flooding surfaces can be characterized by low sedimentation rates, and constant supply of organic-rich material under anoxic conditions that favor minimum decomposition of organic matter (Wignall, 1991;Creaney and Passey, 1993;Catuneanu et al, 2011). Additionally, an integrated approach using geochemistry and sequence stratigraphy is a reasonable way for assessing subsurface basin fills, focusing on environmental conditions (Adatte et al, 2002;Lüning et al, 2004;Slatt and Rodriguez, 2012;Daher et al, 2015;Peng et al, 2016;Omodeo-Salé et al, 2016;Delgado et al, 2018;Shekarifard et al, 2019;Adeoye et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

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Sequence stratigraphy and organic geochemistry: An integrated approach to understand the anoxic events and paleoenvironmental evolution of the Ceará basin, Brazilian Equatorial margin

Souza

Nascimento

Filho

et al. 2021

Marine and Petroleum Geology

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Section: Geologic Settingmentioning

confidence: 99%

Pore Structure and Seal Capacity of Ilaro Formation Shales in the Eastern Dahomey Basin: Implications from Mercury Injection Capillary Pressure and Spontaneous Imbibition Analyses

Ukaomah

Zhang

et al. 2021

Energy Fuels

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A petrophysical evaluation of caprock pore characteristics and seal capacity is critical for geologic storage of CO 2 . In this study, integration of X-ray diffraction, mercury injection capillary pressure (MICP), and spontaneous imbibition analyses is used to evaluate the pore characteristics and seal capacity of shale samples from the Ilaro formation, which could serve as a seal for CO 2 injected into the reservoir units of the eastern Dahomey basin. X-ray diffraction reveals the samples as clay-rich and early diagenetic, while spontaneous imbibition reveals pore connectivity heterogeneity. MICP analysis shows the samples as being characterized by a low breakthrough pressure and reveals the mesopore dominance with majority of pore volumes dominated by 5 to 10 nmsized pore throats. Furthermore, high CO 2 column heights are obtained from conversion of MICP data (at 20% saturation) for mesopore-dominated samples containing ankerite and kaolinite. The study reveals that should injected CO 2 migrate upward from the reservoir units of the onshore eastern Dahomey basin, portions of the Ilaro formation may function as a good seal due to the mesopore mineralogical composition influence on the CO 2 −brine−rock interaction. This result should therefore serve as an important insight for future caprock sealing studies conducted on the onshore eastern Dahomey basin.

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Source rock maturity and petroleum generation in the Dahomey Basin SW Nigeria: Insights from geologic and geochemical modelling

Cited by 8 publications

References 22 publications

Data-Driven Approaches to Predict Thermal Maturity Indices of Organic Matter Using Artificial Neural Networks

Data-Driven Approaches to Predict Thermal Maturity Indices of Organic Matter Using Artificial Neural Networks

Sequence stratigraphy and organic geochemistry: An integrated approach to understand the anoxic events and paleoenvironmental evolution of the Ceará basin, Brazilian Equatorial margin

Pore Structure and Seal Capacity of Ilaro Formation Shales in the Eastern Dahomey Basin: Implications from Mercury Injection Capillary Pressure and Spontaneous Imbibition Analyses

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