adewale akinmosin - Academia.edu (original) (raw)

Papers by adewale akinmosin

Journal of African Earth Sciences

International Journal of African and Asian Studies, 2015

Six (6) core samples were collected at different depths from a borehole at a locality in part of ... more Six (6) core samples were collected at different depths from a borehole at a locality in part of Southwestern Nigeria at depth range of 92 – 112fts, 151 – 161fts, 210 – 220ft, 240 – 250ft, 250 – 260ft, 300 – 310ft. respectively and were subjected to Total Organic Content (TOC). Three samples with high TOC were equally subjected to Rock Eval Pyrolysis to evaluate the petroleum generative potential, organic richness, organic matter quality, origin of organic matter and thermal maturity of the rock. The Rock-Eval Pyrolysis result showed total organic carbon content range of between 2.12 and 2.94wt% indicating organic –rich rock; hydrogen index (HI) ranged from 15 – 43 indicating increasing hydrocarbon potential with depth ; oxygen Index (OI) ranged from 121 – 177; Productive Index (PI) ranged from 0.19 – 0.26 with increase in depth and at depth 151-161ft it decreases indicating immature rock. S 1 + S 2 ranged from 0.59 - 1.37 indicating good hydrocarbon potential and Tmax range from 34...

The sedimentological properties of tar sand deposits in Idiobilayo and Ajegunle areas of Southwes... more The sedimentological properties of tar sand deposits in Idiobilayo and Ajegunle areas of Southwestern Nigeria were studied with the aim of determining the subsurface occurrence and reservoir properties of tar sand horizons. Altogether, twenty seven tar sand samples were for textural and bitumen saturation analyses. Results of the textural analysis showed that the subsurface tar samples are mainly very coarse grained, angular to sub-angular and poorly sorted, which shows that the sediments have not been transported far from the source. The surface samples are medium-grained sands, sub-angular to sub-rounded, and are moderately sorted implying that the sands have undergone a fairly long transportation history. The textural and morphological characteristics of the surface sands show that they have been transported and deposited by currents of moderate energy, probably streams. Results of bitumen saturation analysis revealed that the average percentage weight of bitumen in the deeper ho...

Ife Journal of Science, 2016

Bitumen saturation, particle size distribution and mineralogical analyses were carried out on som... more Bitumen saturation, particle size distribution and mineralogical analyses were carried out on some tar sand deposits in parts of southwestern Nigeria with a view to determining their sedimentological properties and the degree of bitumen saturation of the respective lithofacies. Fifty one fresh samples collected at 1 m intervals from 13 different locations were prepared for further studies by soaking in toluene, to extract the bitumen from the reservoir sands and subsequently subjected to granulometric analysis. The sands were air-dried and dry-sieved to establish the grain size classes for the different locations. The dry samples were further analyzed petrographically to deduce the textural characteristics and transportation history. Moreover, heavy mineral analysis was carried out to determine the sediments' maturity and their provenance. From the textural study, five different lithofacies were established namely: very fine sand, fine sand, medium sand, coarse sand and very coa...

Rock samples obtained from two locations in parts of south-western Nigeria were studied to establ... more Rock samples obtained from two locations in parts of south-western Nigeria were studied to establish the distribution of U, Th and K, present in them. Field data were collected using a gamma ray scintillometer while laboratory studies on the samples included spectrometric analysis, NaI(Tl) spectrometry and geochemical analysis (ICP-MS method). Gamma ray scintillometric reading showed that the outcrops present in the study areas gave consistently higher readings than the overburden materials. The analysis of spectrometric data indicated the presence of other radio-nuclides which are different from the three principal radio-nuclides, 238 U, 232 Th, and 40 K. Results of the geochemical data revealed the presence of radioactive elements like Pb, Ce, La, Ti and Fe 2+ . This study showed that besides the presence of U, Th and K, other elements like Pb, Ce, La and Ti also contributed to the bulk radioactivity measured in rock samples at the study areas. Zircon, xenotime and possibly thorit...

Journal of Applied Sciences and Environmental Management, 2018

Indian Journal of Science and Technology, 2011

Materials and Geoenvironment, 2020

Heavy mineral component of 13 samples from the Lokoja and Patti Formations, Bida Basin have been ... more Heavy mineral component of 13 samples from the Lokoja and Patti Formations, Bida Basin have been studied for their textural characteristics, compositional abundance, maturity and provenance determinations. The suite of heavy minerals encountered is classified as opaque and non-opaque constituents. The non-opaque components include zircon, tourmaline, rutile, garnet, staurolite, epidote, kyanite, titanite, lawsonite, cassiterite, sillimanite, hornblende, hypersthene and andalusite. The assemblage is generally dominated by zircon and tourmaline in the two formations. The constituent heavy minerals identified are dominated by ultra-stable and stable classes, whereas the ZTR indices indicate mineralogical immaturity coupled with textural immaturity of the constituent grains. This suggests the possible dominance of chemical weathering of the source rock. The suites of minerals recovered have been linked to both metamorphic and non-metamorphic crystalline rock origins.

Journal of Petroleum Exploration and Production Technology, 2018

Journal of African Earth Sciences, 2016

Abstract This study aimed at investigating reasons for failure of Well A1 that is surrounded by h... more Abstract This study aimed at investigating reasons for failure of Well A1 that is surrounded by hydrocarbon discoveries in onshore Niger delta with a view to propose optimal location for a new well through interpretation of new 3-D seismic data. Sands encountered by Well A1 were delineated and tied to seismic. Structural closure was mapped and reservoirs at various depths were stacked and sectioned. Porosity, Net to Gross, and Gross Rock Volume of the reservoirs were computed. Well A1 was correlated to a nearby Well K4 and a good correlation was observed. A fault assisted multi reservoirs Prospect-E with south-westerly shift with depth was delineated on the hanging wall of structure building E-Fault whose closing contours is expected to trap hydrocarbon. Petrophysical properties of the reservoirs range from fair to good. Well A1 either perforated prospect-E beneath the oil water contact, completely missed prospect-E or punctured the wet foot wall of E-fault. Consequently, Well A1 could not impact the objective sands and only able to produce water. Well A1 failed because of wrong surface positioning which unsuccessfully targeted the shifting reservoirs. A successful exploratory well in E-Field would be a gently south-westerly deviated well whose vertical section would encounter the shallower sands and deviated section targeting the deeper sands with surface location at about 1 km southeast of Well A1.

Stratigraphic and geophysical analyses of an outcrop at Onikintibi were done with the aim of unde... more Stratigraphic and geophysical analyses of an outcrop at Onikintibi were done with the aim of understanding basin architecture and predicting depositional history. The palynological studies defined the age of the units, and clarified the lithology of the basal component. Three principal lithology types found are conglomeratic sands, compacted ferruginised sandstone, and the weathered basement; these units have resistivity values of >1000 m, >1019m and <400m. The basal layer is derived from porphyritic granite protolith. In addition, coarsening-upward stacking pattern of the reddish-brown conglomerate suggests prevalence of continental conditions. High thickness of the Ise units at the western edge suggests greater accommodation space and subsidence during basin development; consequently, the layer tapers to the east in response to waning current. The occurrence of Monoporites annulatus, Laevigatosporites and Acrostichum aureum imply the outcrop is post Paleocene. Longapertit...

Ife Journal of Science, 2007

Ife Journal of Science, 2005

One hundred and twenty (120) tar sand samples were collected at 8 localities along the Nigerian t... more One hundred and twenty (120) tar sand samples were collected at 8 localities along the Nigerian tar sand belt for both quartz variety and heavy mineral analyses. The quartz variety study carried out on 30 samples revealed both polycrystalline and monocrystalline quartz types occurring in all samples but in different proportions. Predominating are the subequant with straight boundaries and few scattered vacuoles indicative of the polycrystalline quartz. Forty samples were analyzed for heavy mineral assemblage determination. The separation of these heavy minerals using bromoform (specific gravity 2.85) and slide examination under the petrographic microscope indicated the presence of zircon, rutile, staurolite, sillimanite, kyanite, garnet and epidote. Opaque minerals dominate the assemblage and they occur in significant quantities in some locations. From the results of these analyses, it could be inferred that the bituminous sands of the Abeokuta Group might have been derived principally from a plutonic acid igneous rock with significant contribution from high-grade metamorphic rock. Ife Journal of Science Vol. 7(1) 2005: 123-130

Ife Journal of Science, 2005

This study was carried out on limestone representing the Ewekoro formation of the Dahomey basin a... more This study was carried out on limestone representing the Ewekoro formation of the Dahomey basin as exposed in Sagamu and Ewekoro quarries of West African Portland Cement Company and Ibeshe limestone quarry of Dangote Cement Company. The study involved the determination of the major oxides of the limestone deposit using ultraviolet spectrophotometer as well as the determination of the depositional and biogenic features of the limestones petrographically. The major oxides analyzed for are CaO, MgO, Al2O3, SiO2 and Fe2O3. The result of the analysis carried out on twenty seven samples showed that the mean percentage values for CaO, MgO, Al 2 O 3 , S i O 2 and Fe 2 O 3 for Sagamu limestone are 89.2, 1.9, 1.5, 5.7, and 5.9 respectively while that of Ewekoro showed the percentage of various oxides to be 80.3, 3.9, 2.6, 8.7, and 4.2 for CaO, MgO, Al 2 O 3 , SiO 2 and Fe 2 O 3 respectively. The Ibeshe samples on the other hand showed the mean percentage values for CaO, MgO, Al 2 O 3 , SiO 2 and Al 2 O 3 to be 75.7, 2.1, 3.9, 14.8, and 3.5 respectively. The depositional and biogenic features observed from slide underneath the microscope indicate that Sagamu limestone belongs to the class of Wackestone and was deposited in a lagoon environment. Ewekoro limestone belongs to the class of Grainstone and Ibese limestone belongs to classes of both Wackestone and Grainstone, all of which were deposited in an open shelf environment. Ife Journal of Science Vol. 7(1) 2005: 101-111

Journal of Applied Sciences, 2012

Abstract: Outcrop analog are important tools for better understanding of large scale seismic feat... more Abstract: Outcrop analog are important tools for better understanding of large scale seismic features such as slope deposits and structures. Sedimentary exposures at Ijebu Omu, Itele and Ijebu Ife, all within the eastern part of Dahomey basin, Southwest Nigeria were ...

Global Journal of Pure and Applied Sciences, 2008

Earth Sciences Research Journal

Los depósitos de arenas bituminosas de la Formación Afowo en algunas partes de suroeste de Nigeri... more Los depósitos de arenas bituminosas de la Formación Afowo en algunas partes de suroeste de Nigeria fueron analizados con microscopio electrónico para caracterizar las arenas del reservorio, basados en el contenido de arcilla. Doce corazones de arenas bituminosas fueron recolectados, de estos, se seleccionaron seis para análisis basados en las similitudes de sus propiedades físicas y texturales. Las muestras de arena bituminosa preparadas fueron estudiadas con el microscopio electrónico (VEGA TESCAN/LMU Microscopio Electrónico de Barrido-SEM).

This work is an addition to our previous effort on the tar sand deposits in southwestern, Nigeria... more This work is an addition to our previous effort on the tar sand deposits in southwestern, Nigeria. Electrical resistivity sounding and profiling using Schlumberger and Wenner array configuration were used to determine the nature and depth of occurrence of the tar sand unit. Core description of five boreholes in and around the study area was exploited for regional correlation of the tar sand horizon. The tar sand at Itele has a resistivity value of ~900Ωm to>1480Ωm with an average thickness of ~30m. Visual inspection of the cores from the study area shows that the lithology of the tar horizon is essentially muddy, non-fissile, fine-grained sand. In addition, the tar sand of the area belongs to the high resistivity facies identified by previous workers in the Ogun state axis of the tar sand belt.

Journal of African Earth Sciences

International Journal of African and Asian Studies, 2015

Six (6) core samples were collected at different depths from a borehole at a locality in part of ... more Six (6) core samples were collected at different depths from a borehole at a locality in part of Southwestern Nigeria at depth range of 92 – 112fts, 151 – 161fts, 210 – 220ft, 240 – 250ft, 250 – 260ft, 300 – 310ft. respectively and were subjected to Total Organic Content (TOC). Three samples with high TOC were equally subjected to Rock Eval Pyrolysis to evaluate the petroleum generative potential, organic richness, organic matter quality, origin of organic matter and thermal maturity of the rock. The Rock-Eval Pyrolysis result showed total organic carbon content range of between 2.12 and 2.94wt% indicating organic –rich rock; hydrogen index (HI) ranged from 15 – 43 indicating increasing hydrocarbon potential with depth ; oxygen Index (OI) ranged from 121 – 177; Productive Index (PI) ranged from 0.19 – 0.26 with increase in depth and at depth 151-161ft it decreases indicating immature rock. S 1 + S 2 ranged from 0.59 - 1.37 indicating good hydrocarbon potential and Tmax range from 34...

The sedimentological properties of tar sand deposits in Idiobilayo and Ajegunle areas of Southwes... more The sedimentological properties of tar sand deposits in Idiobilayo and Ajegunle areas of Southwestern Nigeria were studied with the aim of determining the subsurface occurrence and reservoir properties of tar sand horizons. Altogether, twenty seven tar sand samples were for textural and bitumen saturation analyses. Results of the textural analysis showed that the subsurface tar samples are mainly very coarse grained, angular to sub-angular and poorly sorted, which shows that the sediments have not been transported far from the source. The surface samples are medium-grained sands, sub-angular to sub-rounded, and are moderately sorted implying that the sands have undergone a fairly long transportation history. The textural and morphological characteristics of the surface sands show that they have been transported and deposited by currents of moderate energy, probably streams. Results of bitumen saturation analysis revealed that the average percentage weight of bitumen in the deeper ho...

Ife Journal of Science, 2016

Bitumen saturation, particle size distribution and mineralogical analyses were carried out on som... more Bitumen saturation, particle size distribution and mineralogical analyses were carried out on some tar sand deposits in parts of southwestern Nigeria with a view to determining their sedimentological properties and the degree of bitumen saturation of the respective lithofacies. Fifty one fresh samples collected at 1 m intervals from 13 different locations were prepared for further studies by soaking in toluene, to extract the bitumen from the reservoir sands and subsequently subjected to granulometric analysis. The sands were air-dried and dry-sieved to establish the grain size classes for the different locations. The dry samples were further analyzed petrographically to deduce the textural characteristics and transportation history. Moreover, heavy mineral analysis was carried out to determine the sediments' maturity and their provenance. From the textural study, five different lithofacies were established namely: very fine sand, fine sand, medium sand, coarse sand and very coa...

Rock samples obtained from two locations in parts of south-western Nigeria were studied to establ... more Rock samples obtained from two locations in parts of south-western Nigeria were studied to establish the distribution of U, Th and K, present in them. Field data were collected using a gamma ray scintillometer while laboratory studies on the samples included spectrometric analysis, NaI(Tl) spectrometry and geochemical analysis (ICP-MS method). Gamma ray scintillometric reading showed that the outcrops present in the study areas gave consistently higher readings than the overburden materials. The analysis of spectrometric data indicated the presence of other radio-nuclides which are different from the three principal radio-nuclides, 238 U, 232 Th, and 40 K. Results of the geochemical data revealed the presence of radioactive elements like Pb, Ce, La, Ti and Fe 2+ . This study showed that besides the presence of U, Th and K, other elements like Pb, Ce, La and Ti also contributed to the bulk radioactivity measured in rock samples at the study areas. Zircon, xenotime and possibly thorit...

Journal of Applied Sciences and Environmental Management, 2018

Indian Journal of Science and Technology, 2011

Materials and Geoenvironment, 2020

Heavy mineral component of 13 samples from the Lokoja and Patti Formations, Bida Basin have been ... more Heavy mineral component of 13 samples from the Lokoja and Patti Formations, Bida Basin have been studied for their textural characteristics, compositional abundance, maturity and provenance determinations. The suite of heavy minerals encountered is classified as opaque and non-opaque constituents. The non-opaque components include zircon, tourmaline, rutile, garnet, staurolite, epidote, kyanite, titanite, lawsonite, cassiterite, sillimanite, hornblende, hypersthene and andalusite. The assemblage is generally dominated by zircon and tourmaline in the two formations. The constituent heavy minerals identified are dominated by ultra-stable and stable classes, whereas the ZTR indices indicate mineralogical immaturity coupled with textural immaturity of the constituent grains. This suggests the possible dominance of chemical weathering of the source rock. The suites of minerals recovered have been linked to both metamorphic and non-metamorphic crystalline rock origins.

Journal of Petroleum Exploration and Production Technology, 2018

Journal of African Earth Sciences, 2016

Abstract This study aimed at investigating reasons for failure of Well A1 that is surrounded by h... more Abstract This study aimed at investigating reasons for failure of Well A1 that is surrounded by hydrocarbon discoveries in onshore Niger delta with a view to propose optimal location for a new well through interpretation of new 3-D seismic data. Sands encountered by Well A1 were delineated and tied to seismic. Structural closure was mapped and reservoirs at various depths were stacked and sectioned. Porosity, Net to Gross, and Gross Rock Volume of the reservoirs were computed. Well A1 was correlated to a nearby Well K4 and a good correlation was observed. A fault assisted multi reservoirs Prospect-E with south-westerly shift with depth was delineated on the hanging wall of structure building E-Fault whose closing contours is expected to trap hydrocarbon. Petrophysical properties of the reservoirs range from fair to good. Well A1 either perforated prospect-E beneath the oil water contact, completely missed prospect-E or punctured the wet foot wall of E-fault. Consequently, Well A1 could not impact the objective sands and only able to produce water. Well A1 failed because of wrong surface positioning which unsuccessfully targeted the shifting reservoirs. A successful exploratory well in E-Field would be a gently south-westerly deviated well whose vertical section would encounter the shallower sands and deviated section targeting the deeper sands with surface location at about 1 km southeast of Well A1.

Stratigraphic and geophysical analyses of an outcrop at Onikintibi were done with the aim of unde... more Stratigraphic and geophysical analyses of an outcrop at Onikintibi were done with the aim of understanding basin architecture and predicting depositional history. The palynological studies defined the age of the units, and clarified the lithology of the basal component. Three principal lithology types found are conglomeratic sands, compacted ferruginised sandstone, and the weathered basement; these units have resistivity values of >1000 m, >1019m and <400m. The basal layer is derived from porphyritic granite protolith. In addition, coarsening-upward stacking pattern of the reddish-brown conglomerate suggests prevalence of continental conditions. High thickness of the Ise units at the western edge suggests greater accommodation space and subsidence during basin development; consequently, the layer tapers to the east in response to waning current. The occurrence of Monoporites annulatus, Laevigatosporites and Acrostichum aureum imply the outcrop is post Paleocene. Longapertit...

Ife Journal of Science, 2007

Ife Journal of Science, 2005

One hundred and twenty (120) tar sand samples were collected at 8 localities along the Nigerian t... more One hundred and twenty (120) tar sand samples were collected at 8 localities along the Nigerian tar sand belt for both quartz variety and heavy mineral analyses. The quartz variety study carried out on 30 samples revealed both polycrystalline and monocrystalline quartz types occurring in all samples but in different proportions. Predominating are the subequant with straight boundaries and few scattered vacuoles indicative of the polycrystalline quartz. Forty samples were analyzed for heavy mineral assemblage determination. The separation of these heavy minerals using bromoform (specific gravity 2.85) and slide examination under the petrographic microscope indicated the presence of zircon, rutile, staurolite, sillimanite, kyanite, garnet and epidote. Opaque minerals dominate the assemblage and they occur in significant quantities in some locations. From the results of these analyses, it could be inferred that the bituminous sands of the Abeokuta Group might have been derived principally from a plutonic acid igneous rock with significant contribution from high-grade metamorphic rock. Ife Journal of Science Vol. 7(1) 2005: 123-130

Ife Journal of Science, 2005

This study was carried out on limestone representing the Ewekoro formation of the Dahomey basin a... more This study was carried out on limestone representing the Ewekoro formation of the Dahomey basin as exposed in Sagamu and Ewekoro quarries of West African Portland Cement Company and Ibeshe limestone quarry of Dangote Cement Company. The study involved the determination of the major oxides of the limestone deposit using ultraviolet spectrophotometer as well as the determination of the depositional and biogenic features of the limestones petrographically. The major oxides analyzed for are CaO, MgO, Al2O3, SiO2 and Fe2O3. The result of the analysis carried out on twenty seven samples showed that the mean percentage values for CaO, MgO, Al 2 O 3 , S i O 2 and Fe 2 O 3 for Sagamu limestone are 89.2, 1.9, 1.5, 5.7, and 5.9 respectively while that of Ewekoro showed the percentage of various oxides to be 80.3, 3.9, 2.6, 8.7, and 4.2 for CaO, MgO, Al 2 O 3 , SiO 2 and Fe 2 O 3 respectively. The Ibeshe samples on the other hand showed the mean percentage values for CaO, MgO, Al 2 O 3 , SiO 2 and Al 2 O 3 to be 75.7, 2.1, 3.9, 14.8, and 3.5 respectively. The depositional and biogenic features observed from slide underneath the microscope indicate that Sagamu limestone belongs to the class of Wackestone and was deposited in a lagoon environment. Ewekoro limestone belongs to the class of Grainstone and Ibese limestone belongs to classes of both Wackestone and Grainstone, all of which were deposited in an open shelf environment. Ife Journal of Science Vol. 7(1) 2005: 101-111

Journal of Applied Sciences, 2012

Abstract: Outcrop analog are important tools for better understanding of large scale seismic feat... more Abstract: Outcrop analog are important tools for better understanding of large scale seismic features such as slope deposits and structures. Sedimentary exposures at Ijebu Omu, Itele and Ijebu Ife, all within the eastern part of Dahomey basin, Southwest Nigeria were ...

Global Journal of Pure and Applied Sciences, 2008

Earth Sciences Research Journal

Los depósitos de arenas bituminosas de la Formación Afowo en algunas partes de suroeste de Nigeri... more Los depósitos de arenas bituminosas de la Formación Afowo en algunas partes de suroeste de Nigeria fueron analizados con microscopio electrónico para caracterizar las arenas del reservorio, basados en el contenido de arcilla. Doce corazones de arenas bituminosas fueron recolectados, de estos, se seleccionaron seis para análisis basados en las similitudes de sus propiedades físicas y texturales. Las muestras de arena bituminosa preparadas fueron estudiadas con el microscopio electrónico (VEGA TESCAN/LMU Microscopio Electrónico de Barrido-SEM).

This work is an addition to our previous effort on the tar sand deposits in southwestern, Nigeria... more This work is an addition to our previous effort on the tar sand deposits in southwestern, Nigeria. Electrical resistivity sounding and profiling using Schlumberger and Wenner array configuration were used to determine the nature and depth of occurrence of the tar sand unit. Core description of five boreholes in and around the study area was exploited for regional correlation of the tar sand horizon. The tar sand at Itele has a resistivity value of ~900Ωm to>1480Ωm with an average thickness of ~30m. Visual inspection of the cores from the study area shows that the lithology of the tar horizon is essentially muddy, non-fissile, fine-grained sand. In addition, the tar sand of the area belongs to the high resistivity facies identified by previous workers in the Ogun state axis of the tar sand belt.