Abstract
Artificial neural network (ANN) was used to predict the dry density of soil from its the... more Abstract Artificial neural network (ANN) was used to predict the dry density of soil from its thermal conductivity. The study area is a farmland located in Abeokuta, Ogun State, Southwestern Nigeria. Thirty points were sampled in a grid pattern, and the thermal conductivities were measured using KD-2 Pro thermal analyser. Samples were collected from 20 sample points to determine the dry density in the laboratory. MATLAB was used to perform the ANN analysis in order to predict the dry density of soil. The ANN was able to predict dry density with a root–mean-square error (RMSE) of 0.50 and a correlation coefficient (R2) of 0.80. The validation of our model between the actual and predicted dry densities shows R2 to be 0.99. This fit shows that the model can be applied to predict the dry density of soil in study areas where the thermal conductivities are known.
Key words: thermal conductivity, ANN, MATLAB, prediction model.
Electrical resistivity tomography (ERT) has been combined with geotechnical techniques such as co... more Electrical resistivity tomography (ERT) has been combined with geotechnical techniques such as cone penetrating tests, standard penetrating test and laboratory tests for detailed characterization of near-surface strata. This approach can be very helpful in conducting preliminary investigations towards a robust foundation design at a building construction site. Two ERT lines were conducted for 2D geoelectrical resistivity measurements using Wenner array configuration in combination with four cone penetrating data. Through the inversion of ERT data, two geoelectrical layers were interpreted to be loose silty sand and compacted clayey sand lithological units with the resistivity values ranging 50 – 280 m Ω and 10 – 74 m Ω respectively. A water-saturated portion with resistivity values ≤ ≤ ≤ ≤ 3 m Ω due to lagoon-water incursion was equally observed at the base of the second clayey sand layer in ERT line T2. The average cone penetrometer (CPT) value of about 110 kg/cm 2 (11 MPa) with an average SPT 'N' value of 25 was measured between 6.75 – 30.0 m, indicating that the geomaterials within this depths range are of good geotechnical properties. Laboratory tests conducted on the representative soil samples at 3.75 m depth gives a moisture content (MC) of 66%. This is attributed to the clay contents within the soil samples. The Liquid Limit (WL), Plastic Limit (WP) and Plasticity Index (PI) tests of the soil samples gives 84%, 30% and 54% respectively. The results of the proposed approach, encompassing both geophysical and geotechnical methods has helped to steer the choice of the foundation for the investigated building towards a pile-type foundation rather than a Subsoil Characterization Using Geoelectrical and Geotechnical Investigations: Implications For Foundation Studies http://www.iaeme.com/IJCIET/index.asp 303 editor@iaeme.com shallow one. The pile foundation will cause the higher loadings to transmit the loads to a stable soil layer within the subsurface.
3D seis mic data and wire line logs from thir teen bore holes were used to es tab lish a se quen... more 3D seis mic data and wire line logs from thir teen bore holes were used to es tab lish a se quence strati graphic anal y sis of Mio-cene depositional sys tems of the Otu Field in the on shore area of the Niger Delta. The subsurface fa cies of the field re vealed three se quences that are bounded by four se quence bound aries (SBs) which are in ter preted as ero sional un con formi ties with three max i mum flood ing sur faces (MFSs). Se quences de lin eated are com posed of lowstand sys tems tracts (LST), falling stage sys tems tracts (FSST), transgressive sys tems tracts (TST) and highstand sys tems tracts (HST) re veal ing depositional sys tems de pos ited dur ing dif fer ent phases of base level changes. De pos its iden ti fied within the LSTs are flu vial chan nel sands while TSTs capped the LST fa cies. HSTs are com posed of coars en ing and shallowing up wards in ter vals in-clud ing deltaic flu vial sands. The se quences were de pos ited in tran si tional to shal low ma rine en vi ron ments. A seis mic geomorphological study car ried out on all the SBs and MFS 3 shows a re la tion ship be tween depositional en vi ron ments, chan nel type and di rec tion of palaeo-flow in re la tion to faults. The res er voirs of the LST and HST and seals from ma rine shale of the TST and HST could form strati graphic traps for hy dro car bon ac cu mu la tion in the Otu Field. This study has in te grated 3D seis mic and bore hole log data to de velop a se quence strati graphic frame work that would be a prof it able means to guide hy dro car bon ex plo ra tion and pro duc tion strat e gies. Key words: subsurface fa cies, strati graphic trap, seis mic geo mor phol ogy, se quence bound aries, chan nel.
Field evaluation in a complex sedimentary environment is always tedious due to problems associate... more Field evaluation in a complex sedimentary environment is always tedious due to problems associated with imaging of the subsurface in such areas. The 'Tadelu' field in Western Niger Delta, Nigeria, consists of a series of vertically stacked reservoirs in the Agbada Formation, thus making the field a complex sedimentary environment. The main objective of this study is to perform geophysical and petrophysical interpretations of properties that are typical of a shallow marine, transitional environment, with its attendant pattern of subsur-face complexities, using 3D seismic and well log data. The approach adopted in achieving this objective included 3D seismic data interpretation, petrophysical rock typing, fluid typing and contact identification and determination of reservoir properties, onwards to reserve estimation for all the hydrocarbon-bearing reservoirs in the field. Five horizons as well as major and minor faults were mapped in the field, and five structural depth maps of reservoirs A, B, B1, C and C1 were generated within the objective depth interval to define the geometry of the reservoirs. Well log data from four wells in the field were studied to characterize the porosity, shale volume and water saturation of the reservoirs. The gamma ray (GR) logs were normalized and used in the computation of shale volume, while available density logs were used in the computation of porosities. Water saturation was determined using the Waxman–Smits model to take into consideration the shaly nature of the reservoir sands. The combination of porosity, shale volume and water saturation cutoff values was used in calculating net pay and net pay averages. The result of the structural interpretation shows that Tadelu field is characterized by two major faults and synthetic faults. The synthetic faults are dipping in northeast–southwest direction, and the closure formed by their hanging walls constitutes the target area for hydrocarbon in the field. However, within the reservoirs of Tadelu field, the net sand range is from 0.17 to 0.99 ft, having an average porosity in the range of 22 to 27 %. Water saturation average ranged from a minimum of 19 to a maximum of 27 %. Porosity in the field is high on the average due to very good to excellent sand quality. These petrophysical deliverables served as an input in the estimation of reserves. The gross rock volume (GRV) was determined by establishing a cutoff at appropriate contact(s). Reserve estimation was performed for the hydrocarbon-bearing sands and a total proven recoverable oil and gas estimate put at 42.797 MMbbl and 13.256 Bscf, respectively.
The prospectivity and structural evaluation of ‘ABN’ field was carried out with the aim of explor... more The prospectivity and structural evaluation of ‘ABN’ field was carried out with the aim of exploring deeper prospects and to ascertain if structures and their closures are favorable for hydrocarbon accumulation using 3D seismic data integrated with well logs. ‘ABN’ field is located in the Deepwater Nigeria, which is about 55 km in the offshore, southeastern part of the Niger Delta having water depths ranging from 450 to 800 m. Six horizons together with major and minor faults were identified and mapped in the field. The depth structure map of each horizons were also produced. Regional structural highs that are trending in northeast – southwest (NE-SW) characterized a large portion of ‘ABN’ field. These highs were observed across all key horizons revealing a regional post-depositional deformation. Seven (7) prospects were also identified and evaluated to understand the different opportunities in the field. These include the footwall, hanging wall, stratigraphic and combination play types. It was recommended that deep drilling should be conducted in the field to open up new opportunities and also fault seal analyses be performed on the prospects identified for further studies.
The prospectivity and structural evaluation of ‘ABN’ field was carried out with the aim of explor... more The prospectivity and structural evaluation of ‘ABN’ field was carried out with the aim of exploring deeper prospects and to ascertain if structures and their closures are favorable for hydrocarbon accumulation using 3D seismic data integrated with well logs. ‘ABN’ field is located in the Deepwater Nigeria, which is about 55 km in the offshore, southeastern part of the Niger Delta having water depths ranging from 450 to 800 m. Six horizons together with major and minor faults were identified and mapped in the field. The depth structure map of each horizons were also produced. Regional structural highs that are trending in northeast – southwest (NE-SW) characterized a large portion of ‘ABN’ field. These highs were observed across all key horizons revealing a regional post-depositional deformation. Seven (7) prospects were also identified and evaluated to understand the different opportunities in the field. These include the footwall, hanging wall, stratigraphic and combination play types. It was recommended that deep drilling should be conducted in the field to open up new opportunities and also fault seal analyses be performed on the prospects identified for further studies.
A study on the calcareous nannofossil biostratigraphy has been carried out on sequences within ... more A study on the calcareous nannofossil biostratigraphy has been carried out on sequences within the interval 1640m-1980m of well ‘K-2’ located in the deep offshore of Niger Delta, Nigeria. Lithologic description of the samples was done using a stereo-binocular microscope. Thirty-four slides of samples were prepared and studied for their calcareous nannofossil contents using Olympus Light Microscope in both plane-polarized and cross-polarized light. The lithostratigraphic descriptions on the samples showed the abundance of shale and mudstone/siltstone with minor amount of thin intercalated units of sand bed. Seventeen calcareous nannofossil species were identified and used to predict the biostratigraphic deductions such as zonation, dating and a tentative sequence stratigraphic framework. With the aid of a standard zonation schemes, two major nannofossil zones (NN 19 and NN 18) were identified. These zones belongs to Pleistocene and Pliocene ages respectively. Two major zones of Gephyrocapsa carribeanica and Gephyroca psaparallela were identified for the studied well on the basis of the index taxa and fossil assemblage recorded. The insufficient amount of nannofossils in the lower part of the well precluded a definite zonationandmade the zone to be indeterminable. One Condensed Section believed to be associated with 2.0Ma Maximum Flooding Surfaces was recognized.
The determination of soil thermal properties, such as thermal resistivity, thermal conductivity, ... more The determination of soil thermal properties, such as thermal resistivity, thermal conductivity, thermal diffusivity, thermal effusivity and specific heat, is of great importance for various civil and electrical engineering projects where heat transfer takes place through the soil mass. Some of these projects include design and laying of high-voltage buried power cables, oil and gas pipe lines, nuclear waste disposal facilities. Many workers have focussed their attention on determining only the thermal resistivity of materials for making recommendations when executing various engineering projects. However, it is important to evaluate thermal diffusivity, thermal effusivity and specific heat, not thermal resistivity alone when dealing with protecting any buried pipe from freezing. This research work therefore intends to determine these properties in soils of Olorunsogo Gas Turbine Power Station (335 MW Phase 1) which is located in Ogun State, Southwestern Nigeria. Ten pits, each of a...
In bitumen recovery from tar sand where heat transfer takes place through injection of thermal en... more In bitumen recovery from tar sand where heat transfer takes place through injection of thermal energy into the tar sand formation, it is of great importance to estimate the thermal properties of such tar sand. The aims of this research is to determine the thermal properties of tar sand in the Eastern Dahomey basin, Nigeria with a view to having more information in planning for thermal recovery of the tar sand. Twelve locations were established along the tar sand belt in order to measure its thermal properties. The thermal properties of the tar sand were measured in-situ using KD2 Pro thermal analyzer. In laboratory, thermal properties of samples from each location were measured and their physical properties that influenced them (such as grain size distribution, percentage by weight of bitumen content, moisture content, bulk density, porosity and dry density of the samples) were determined. Thermal conductivity, specific heat and bulk density were used to calculate the thermal effusi...
Knowledge of the thermal properties of the soil top layer is of great importance in agricultural
... more Knowledge of the thermal properties of the soil top layer is of great importance in agricultural meteorology where problems of heat exchange at the soil surface are encountered. The availability of these data is important because of the improvements in wider applications of soil heat and water transport models as well as seed germination and crop growth. This research work therefore intends to determine the variability of soil thermal properties of a seasonally cultivated Agricultural Teaching and Research Farm located within the University of Ibadan campus, South-western Nigeria with a view to have understanding of how different soils warm up in order to allow better planning of planting of crops and have knowledge for the control of thermal-moisture regime of soil in the field and greenhouse. Forty-five points were located for the measurements of thermal properties in cultivated fields of maize, pineapple, cowpea, Okro and vegetables. A KD-2 Pro thermal analyzer was used for the measurements of these thermal properties such as thermal conductivity, thermal resistivity, volumetric specific heat and thermal diffusivity. Keywords : variability, thermal properties, moisture content, bulk density, agricultural farm, seed germination.
Abstract
Artificial neural network (ANN) was used to predict the dry density of soil from its the... more Abstract Artificial neural network (ANN) was used to predict the dry density of soil from its thermal conductivity. The study area is a farmland located in Abeokuta, Ogun State, Southwestern Nigeria. Thirty points were sampled in a grid pattern, and the thermal conductivities were measured using KD-2 Pro thermal analyser. Samples were collected from 20 sample points to determine the dry density in the laboratory. MATLAB was used to perform the ANN analysis in order to predict the dry density of soil. The ANN was able to predict dry density with a root–mean-square error (RMSE) of 0.50 and a correlation coefficient (R2) of 0.80. The validation of our model between the actual and predicted dry densities shows R2 to be 0.99. This fit shows that the model can be applied to predict the dry density of soil in study areas where the thermal conductivities are known.
Key words: thermal conductivity, ANN, MATLAB, prediction model.
Electrical resistivity tomography (ERT) has been combined with geotechnical techniques such as co... more Electrical resistivity tomography (ERT) has been combined with geotechnical techniques such as cone penetrating tests, standard penetrating test and laboratory tests for detailed characterization of near-surface strata. This approach can be very helpful in conducting preliminary investigations towards a robust foundation design at a building construction site. Two ERT lines were conducted for 2D geoelectrical resistivity measurements using Wenner array configuration in combination with four cone penetrating data. Through the inversion of ERT data, two geoelectrical layers were interpreted to be loose silty sand and compacted clayey sand lithological units with the resistivity values ranging 50 – 280 m Ω and 10 – 74 m Ω respectively. A water-saturated portion with resistivity values ≤ ≤ ≤ ≤ 3 m Ω due to lagoon-water incursion was equally observed at the base of the second clayey sand layer in ERT line T2. The average cone penetrometer (CPT) value of about 110 kg/cm 2 (11 MPa) with an average SPT 'N' value of 25 was measured between 6.75 – 30.0 m, indicating that the geomaterials within this depths range are of good geotechnical properties. Laboratory tests conducted on the representative soil samples at 3.75 m depth gives a moisture content (MC) of 66%. This is attributed to the clay contents within the soil samples. The Liquid Limit (WL), Plastic Limit (WP) and Plasticity Index (PI) tests of the soil samples gives 84%, 30% and 54% respectively. The results of the proposed approach, encompassing both geophysical and geotechnical methods has helped to steer the choice of the foundation for the investigated building towards a pile-type foundation rather than a Subsoil Characterization Using Geoelectrical and Geotechnical Investigations: Implications For Foundation Studies http://www.iaeme.com/IJCIET/index.asp 303 editor@iaeme.com shallow one. The pile foundation will cause the higher loadings to transmit the loads to a stable soil layer within the subsurface.
3D seis mic data and wire line logs from thir teen bore holes were used to es tab lish a se quen... more 3D seis mic data and wire line logs from thir teen bore holes were used to es tab lish a se quence strati graphic anal y sis of Mio-cene depositional sys tems of the Otu Field in the on shore area of the Niger Delta. The subsurface fa cies of the field re vealed three se quences that are bounded by four se quence bound aries (SBs) which are in ter preted as ero sional un con formi ties with three max i mum flood ing sur faces (MFSs). Se quences de lin eated are com posed of lowstand sys tems tracts (LST), falling stage sys tems tracts (FSST), transgressive sys tems tracts (TST) and highstand sys tems tracts (HST) re veal ing depositional sys tems de pos ited dur ing dif fer ent phases of base level changes. De pos its iden ti fied within the LSTs are flu vial chan nel sands while TSTs capped the LST fa cies. HSTs are com posed of coars en ing and shallowing up wards in ter vals in-clud ing deltaic flu vial sands. The se quences were de pos ited in tran si tional to shal low ma rine en vi ron ments. A seis mic geomorphological study car ried out on all the SBs and MFS 3 shows a re la tion ship be tween depositional en vi ron ments, chan nel type and di rec tion of palaeo-flow in re la tion to faults. The res er voirs of the LST and HST and seals from ma rine shale of the TST and HST could form strati graphic traps for hy dro car bon ac cu mu la tion in the Otu Field. This study has in te grated 3D seis mic and bore hole log data to de velop a se quence strati graphic frame work that would be a prof it able means to guide hy dro car bon ex plo ra tion and pro duc tion strat e gies. Key words: subsurface fa cies, strati graphic trap, seis mic geo mor phol ogy, se quence bound aries, chan nel.
Field evaluation in a complex sedimentary environment is always tedious due to problems associate... more Field evaluation in a complex sedimentary environment is always tedious due to problems associated with imaging of the subsurface in such areas. The 'Tadelu' field in Western Niger Delta, Nigeria, consists of a series of vertically stacked reservoirs in the Agbada Formation, thus making the field a complex sedimentary environment. The main objective of this study is to perform geophysical and petrophysical interpretations of properties that are typical of a shallow marine, transitional environment, with its attendant pattern of subsur-face complexities, using 3D seismic and well log data. The approach adopted in achieving this objective included 3D seismic data interpretation, petrophysical rock typing, fluid typing and contact identification and determination of reservoir properties, onwards to reserve estimation for all the hydrocarbon-bearing reservoirs in the field. Five horizons as well as major and minor faults were mapped in the field, and five structural depth maps of reservoirs A, B, B1, C and C1 were generated within the objective depth interval to define the geometry of the reservoirs. Well log data from four wells in the field were studied to characterize the porosity, shale volume and water saturation of the reservoirs. The gamma ray (GR) logs were normalized and used in the computation of shale volume, while available density logs were used in the computation of porosities. Water saturation was determined using the Waxman–Smits model to take into consideration the shaly nature of the reservoir sands. The combination of porosity, shale volume and water saturation cutoff values was used in calculating net pay and net pay averages. The result of the structural interpretation shows that Tadelu field is characterized by two major faults and synthetic faults. The synthetic faults are dipping in northeast–southwest direction, and the closure formed by their hanging walls constitutes the target area for hydrocarbon in the field. However, within the reservoirs of Tadelu field, the net sand range is from 0.17 to 0.99 ft, having an average porosity in the range of 22 to 27 %. Water saturation average ranged from a minimum of 19 to a maximum of 27 %. Porosity in the field is high on the average due to very good to excellent sand quality. These petrophysical deliverables served as an input in the estimation of reserves. The gross rock volume (GRV) was determined by establishing a cutoff at appropriate contact(s). Reserve estimation was performed for the hydrocarbon-bearing sands and a total proven recoverable oil and gas estimate put at 42.797 MMbbl and 13.256 Bscf, respectively.
The prospectivity and structural evaluation of ‘ABN’ field was carried out with the aim of explor... more The prospectivity and structural evaluation of ‘ABN’ field was carried out with the aim of exploring deeper prospects and to ascertain if structures and their closures are favorable for hydrocarbon accumulation using 3D seismic data integrated with well logs. ‘ABN’ field is located in the Deepwater Nigeria, which is about 55 km in the offshore, southeastern part of the Niger Delta having water depths ranging from 450 to 800 m. Six horizons together with major and minor faults were identified and mapped in the field. The depth structure map of each horizons were also produced. Regional structural highs that are trending in northeast – southwest (NE-SW) characterized a large portion of ‘ABN’ field. These highs were observed across all key horizons revealing a regional post-depositional deformation. Seven (7) prospects were also identified and evaluated to understand the different opportunities in the field. These include the footwall, hanging wall, stratigraphic and combination play types. It was recommended that deep drilling should be conducted in the field to open up new opportunities and also fault seal analyses be performed on the prospects identified for further studies.
The prospectivity and structural evaluation of ‘ABN’ field was carried out with the aim of explor... more The prospectivity and structural evaluation of ‘ABN’ field was carried out with the aim of exploring deeper prospects and to ascertain if structures and their closures are favorable for hydrocarbon accumulation using 3D seismic data integrated with well logs. ‘ABN’ field is located in the Deepwater Nigeria, which is about 55 km in the offshore, southeastern part of the Niger Delta having water depths ranging from 450 to 800 m. Six horizons together with major and minor faults were identified and mapped in the field. The depth structure map of each horizons were also produced. Regional structural highs that are trending in northeast – southwest (NE-SW) characterized a large portion of ‘ABN’ field. These highs were observed across all key horizons revealing a regional post-depositional deformation. Seven (7) prospects were also identified and evaluated to understand the different opportunities in the field. These include the footwall, hanging wall, stratigraphic and combination play types. It was recommended that deep drilling should be conducted in the field to open up new opportunities and also fault seal analyses be performed on the prospects identified for further studies.
A study on the calcareous nannofossil biostratigraphy has been carried out on sequences within ... more A study on the calcareous nannofossil biostratigraphy has been carried out on sequences within the interval 1640m-1980m of well ‘K-2’ located in the deep offshore of Niger Delta, Nigeria. Lithologic description of the samples was done using a stereo-binocular microscope. Thirty-four slides of samples were prepared and studied for their calcareous nannofossil contents using Olympus Light Microscope in both plane-polarized and cross-polarized light. The lithostratigraphic descriptions on the samples showed the abundance of shale and mudstone/siltstone with minor amount of thin intercalated units of sand bed. Seventeen calcareous nannofossil species were identified and used to predict the biostratigraphic deductions such as zonation, dating and a tentative sequence stratigraphic framework. With the aid of a standard zonation schemes, two major nannofossil zones (NN 19 and NN 18) were identified. These zones belongs to Pleistocene and Pliocene ages respectively. Two major zones of Gephyrocapsa carribeanica and Gephyroca psaparallela were identified for the studied well on the basis of the index taxa and fossil assemblage recorded. The insufficient amount of nannofossils in the lower part of the well precluded a definite zonationandmade the zone to be indeterminable. One Condensed Section believed to be associated with 2.0Ma Maximum Flooding Surfaces was recognized.
The determination of soil thermal properties, such as thermal resistivity, thermal conductivity, ... more The determination of soil thermal properties, such as thermal resistivity, thermal conductivity, thermal diffusivity, thermal effusivity and specific heat, is of great importance for various civil and electrical engineering projects where heat transfer takes place through the soil mass. Some of these projects include design and laying of high-voltage buried power cables, oil and gas pipe lines, nuclear waste disposal facilities. Many workers have focussed their attention on determining only the thermal resistivity of materials for making recommendations when executing various engineering projects. However, it is important to evaluate thermal diffusivity, thermal effusivity and specific heat, not thermal resistivity alone when dealing with protecting any buried pipe from freezing. This research work therefore intends to determine these properties in soils of Olorunsogo Gas Turbine Power Station (335 MW Phase 1) which is located in Ogun State, Southwestern Nigeria. Ten pits, each of a...
In bitumen recovery from tar sand where heat transfer takes place through injection of thermal en... more In bitumen recovery from tar sand where heat transfer takes place through injection of thermal energy into the tar sand formation, it is of great importance to estimate the thermal properties of such tar sand. The aims of this research is to determine the thermal properties of tar sand in the Eastern Dahomey basin, Nigeria with a view to having more information in planning for thermal recovery of the tar sand. Twelve locations were established along the tar sand belt in order to measure its thermal properties. The thermal properties of the tar sand were measured in-situ using KD2 Pro thermal analyzer. In laboratory, thermal properties of samples from each location were measured and their physical properties that influenced them (such as grain size distribution, percentage by weight of bitumen content, moisture content, bulk density, porosity and dry density of the samples) were determined. Thermal conductivity, specific heat and bulk density were used to calculate the thermal effusi...
Knowledge of the thermal properties of the soil top layer is of great importance in agricultural
... more Knowledge of the thermal properties of the soil top layer is of great importance in agricultural meteorology where problems of heat exchange at the soil surface are encountered. The availability of these data is important because of the improvements in wider applications of soil heat and water transport models as well as seed germination and crop growth. This research work therefore intends to determine the variability of soil thermal properties of a seasonally cultivated Agricultural Teaching and Research Farm located within the University of Ibadan campus, South-western Nigeria with a view to have understanding of how different soils warm up in order to allow better planning of planting of crops and have knowledge for the control of thermal-moisture regime of soil in the field and greenhouse. Forty-five points were located for the measurements of thermal properties in cultivated fields of maize, pineapple, cowpea, Okro and vegetables. A KD-2 Pro thermal analyzer was used for the measurements of these thermal properties such as thermal conductivity, thermal resistivity, volumetric specific heat and thermal diffusivity. Keywords : variability, thermal properties, moisture content, bulk density, agricultural farm, seed germination.
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Artificial neural network (ANN) was used to predict the dry density of soil from its thermal conductivity. The study area is a farmland located in Abeokuta, Ogun State, Southwestern Nigeria. Thirty points were sampled in a grid pattern, and the thermal conductivities were measured using KD-2 Pro thermal analyser. Samples were collected from 20 sample points to determine the dry density in the laboratory. MATLAB was used to perform the ANN analysis in order to predict the dry density of soil. The ANN was able to predict dry density with a root–mean-square error (RMSE) of 0.50 and a correlation coefficient (R2) of 0.80. The validation of our model between the actual and predicted dry densities shows R2 to be 0.99. This fit shows that the model can be applied to predict the dry density of soil in study areas where the thermal conductivities are known.
Key words: thermal conductivity, ANN, MATLAB, prediction model.
Six horizons together with major and minor faults were identified and mapped in the field. The depth structure map of each horizons were also produced.
Regional structural highs that are trending in northeast – southwest (NE-SW) characterized a large portion of ‘ABN’ field. These highs were observed across all key horizons revealing a regional post-depositional deformation. Seven (7) prospects were also identified and evaluated to understand the different opportunities in the field. These include the footwall, hanging wall, stratigraphic and combination play types.
It was recommended that deep drilling should be conducted in the field to open up new opportunities and also fault seal analyses be performed on the prospects identified for further studies.
Six horizons together with major and minor faults were identified and mapped in the field. The depth structure map of each horizons were also produced.
Regional structural highs that are trending in northeast – southwest (NE-SW) characterized a large portion of ‘ABN’ field. These highs were observed across all key horizons revealing a regional post-depositional deformation. Seven (7) prospects were also identified and evaluated to understand the different opportunities in the field. These include the footwall, hanging wall, stratigraphic and combination play types.
It was recommended that deep drilling should be conducted in the field to open up new opportunities and also fault seal analyses be performed on the prospects identified for further studies.
Lithologic description of the samples was done using a stereo-binocular microscope. Thirty-four slides of samples were prepared and studied for their calcareous nannofossil contents using Olympus Light Microscope in both plane-polarized and cross-polarized light.
The lithostratigraphic descriptions on the samples showed the abundance of shale and mudstone/siltstone with minor amount of thin intercalated units of sand bed. Seventeen calcareous nannofossil species were identified and used to predict the biostratigraphic deductions such as zonation, dating and a tentative sequence stratigraphic framework. With the aid of a standard zonation schemes, two major nannofossil zones (NN 19 and NN 18) were identified. These zones belongs to Pleistocene and Pliocene ages respectively. Two major zones of Gephyrocapsa carribeanica and Gephyroca psaparallela were identified for the studied well on the basis of the index taxa and fossil assemblage recorded. The insufficient amount of nannofossils in the lower part of the well precluded a definite zonationandmade the zone to be indeterminable. One Condensed Section believed to be associated with 2.0Ma Maximum Flooding Surfaces was recognized.
meteorology where problems of heat exchange at the soil surface are encountered. The availability of
these data is important because of the improvements in wider applications of soil heat and water
transport models as well as seed germination and crop growth. This research work therefore intends to
determine the variability of soil thermal properties of a seasonally cultivated Agricultural Teaching and
Research Farm located within the University of Ibadan campus, South-western Nigeria with a view to have
understanding of how different soils warm up in order to allow better planning of planting of crops and
have knowledge for the control of thermal-moisture regime of soil in the field and greenhouse.
Forty-five points were located for the measurements of thermal properties in cultivated fields of
maize, pineapple, cowpea, Okro and vegetables.
A KD-2 Pro
thermal analyzer was used for the
measurements of these thermal properties such as thermal conductivity, thermal resistivity, volumetric
specific heat and thermal diffusivity.
Keywords : variability, thermal properties, moisture content, bulk density, agricultural farm, seed
germination.
Artificial neural network (ANN) was used to predict the dry density of soil from its thermal conductivity. The study area is a farmland located in Abeokuta, Ogun State, Southwestern Nigeria. Thirty points were sampled in a grid pattern, and the thermal conductivities were measured using KD-2 Pro thermal analyser. Samples were collected from 20 sample points to determine the dry density in the laboratory. MATLAB was used to perform the ANN analysis in order to predict the dry density of soil. The ANN was able to predict dry density with a root–mean-square error (RMSE) of 0.50 and a correlation coefficient (R2) of 0.80. The validation of our model between the actual and predicted dry densities shows R2 to be 0.99. This fit shows that the model can be applied to predict the dry density of soil in study areas where the thermal conductivities are known.
Key words: thermal conductivity, ANN, MATLAB, prediction model.
Six horizons together with major and minor faults were identified and mapped in the field. The depth structure map of each horizons were also produced.
Regional structural highs that are trending in northeast – southwest (NE-SW) characterized a large portion of ‘ABN’ field. These highs were observed across all key horizons revealing a regional post-depositional deformation. Seven (7) prospects were also identified and evaluated to understand the different opportunities in the field. These include the footwall, hanging wall, stratigraphic and combination play types.
It was recommended that deep drilling should be conducted in the field to open up new opportunities and also fault seal analyses be performed on the prospects identified for further studies.
Six horizons together with major and minor faults were identified and mapped in the field. The depth structure map of each horizons were also produced.
Regional structural highs that are trending in northeast – southwest (NE-SW) characterized a large portion of ‘ABN’ field. These highs were observed across all key horizons revealing a regional post-depositional deformation. Seven (7) prospects were also identified and evaluated to understand the different opportunities in the field. These include the footwall, hanging wall, stratigraphic and combination play types.
It was recommended that deep drilling should be conducted in the field to open up new opportunities and also fault seal analyses be performed on the prospects identified for further studies.
Lithologic description of the samples was done using a stereo-binocular microscope. Thirty-four slides of samples were prepared and studied for their calcareous nannofossil contents using Olympus Light Microscope in both plane-polarized and cross-polarized light.
The lithostratigraphic descriptions on the samples showed the abundance of shale and mudstone/siltstone with minor amount of thin intercalated units of sand bed. Seventeen calcareous nannofossil species were identified and used to predict the biostratigraphic deductions such as zonation, dating and a tentative sequence stratigraphic framework. With the aid of a standard zonation schemes, two major nannofossil zones (NN 19 and NN 18) were identified. These zones belongs to Pleistocene and Pliocene ages respectively. Two major zones of Gephyrocapsa carribeanica and Gephyroca psaparallela were identified for the studied well on the basis of the index taxa and fossil assemblage recorded. The insufficient amount of nannofossils in the lower part of the well precluded a definite zonationandmade the zone to be indeterminable. One Condensed Section believed to be associated with 2.0Ma Maximum Flooding Surfaces was recognized.
meteorology where problems of heat exchange at the soil surface are encountered. The availability of
these data is important because of the improvements in wider applications of soil heat and water
transport models as well as seed germination and crop growth. This research work therefore intends to
determine the variability of soil thermal properties of a seasonally cultivated Agricultural Teaching and
Research Farm located within the University of Ibadan campus, South-western Nigeria with a view to have
understanding of how different soils warm up in order to allow better planning of planting of crops and
have knowledge for the control of thermal-moisture regime of soil in the field and greenhouse.
Forty-five points were located for the measurements of thermal properties in cultivated fields of
maize, pineapple, cowpea, Okro and vegetables.
A KD-2 Pro
thermal analyzer was used for the
measurements of these thermal properties such as thermal conductivity, thermal resistivity, volumetric
specific heat and thermal diffusivity.
Keywords : variability, thermal properties, moisture content, bulk density, agricultural farm, seed
germination.