This paper attempts to quantify pore throats distribution towards more effective approach to perm... more This paper attempts to quantify pore throats distribution towards more effective approach to permeability prediction. The mercury inoculation capillary pressure (MICP) is used to calculate pore throat diameters, and porosity-permeability system (POROPERM) validates effect of pore throats diameters on permeability variations from core plugs. Results reveal three major classes of pore throats diameters (micropore, mesopore and macropore) from five identified pore throat types. It indicates also that the abundance of mesopore and macropore throats above 30% in upper section (1475 m-1480 m) of Siwa well increases permeability above 990 mD, an increase in micropore throats in middle unit (2106 m-2114 m) of BK-102 well vary permeability from 495 mD to 600 mD. Whereas, in the TK well, permeability is moderate lower between 230 mD to 670 mD due to abundance of macropore throats in groundmass of the fine to very fine-grained sandstones. In WL well, at depth from 1720 m to 1850 m, permeability is moderate higher varying between 120 mD to 945 mD attributed to abundance mesopore and macropore throats presence in coarse friable and medium grained sandstones within stratigraphic succession. The results also indicates that increase in percentage composition of mesopore and macropore throats above 20% holds potential increase in permeability, and conversely increase in micropore throats type 1-3 disrupts or lowers permeability. The understanding of spatial and temporal distribution of pore throats in wells, could improve accurate prediction permeability and hydraulic flow units in reservoirs.
The Ajali sandstone is a possible reservoir rock in the Lower Benue Trough (LBT)/Anambra Basin (A... more The Ajali sandstone is a possible reservoir rock in the Lower Benue Trough (LBT)/Anambra Basin (AB), and understanding its geological, sedimentological distribution is essential for accurate prediction of fluid flow dynamic. Geological, granulometric analysis and laboratory hydraulic conductivity test are integrated for this investigation. Results from geological studies reveals three sandstone lithofacies; namely; AJALI L2A a sandstone intermixed with siltstone, lamination, bioturbated, and crossed bedded, AJALI L2B sandstone mixed with silty clay, crossed bedded and bioturbated and AJALI L2C an excessive weathered sandstone with visible ripple and ridges with all sedimentary features supporting the earlier proposed fluvio-deltaic depositional environments. The granulometric analysis reveals medium to coarse grain, poorly sorted sandstone lithofacies. Hydraulic conductivity test for AJALI L2A crossed bedded and lamination sandstone contributes smaller pore spaces between grains, which reduce overall interconnectivity of the pore network primarily decreasing the fluid hydraulic flow conductivity and thus lowers the permeability value to 75mD. While in the AJALI L2B intermixed with siltstone and clay sandstone, lowers porosity; but cross-bedding may have contributed positively to increase in permeability value to 1850 mD in this lithofacies. The weathered AJALI L2C sandstone with visible ripples and ridges significantly affect the physical properties and pore spaces obliteration by iron oxide, by contributing to reduction in the permeability value to 60 mD. In overall it is concluded that the Ajali sandstones generally will exhibits an average moderate permeability of 662 mD.
The Nigerian Petroleum Industry Act (PIA) passed into Law in 2021 has the major goal to reform th... more The Nigerian Petroleum Industry Act (PIA) passed into Law in 2021 has the major goal to reform the Nigerian petroleum sector operations into policy, regulations and business (commercial). In the line of this, the Nigerian National Petroleum Corporation (NNPC) was transformed to NNPC Ltd to operate entirely commercially with a supervising Board and registration with the Corporate Affairs Commission. Such a commercial mandate will entail the need to explore and produce more oil and gas for export and domestic utilization. Oil is becoming less attractive as an energy source but gas is gaining momentum as a clean energy source in the global energy transition road-map. The global energy transition road-map is drawn around clean, alternative and renewable energies. The Nigerian frontier basins have recently come on board as new business opportunities with huge petroleum gas resources. These frontier basins comprise the Anambra, Benue, Bida, Chad (Nigerian sector), Dahomey, and Sokoto Basins as well as the Deep and Ultra-deep offshore. Maturing these basins through data generation and production of the gas resources therein will promote the nation's gas utilization and gas expansion programmes meant to promote industrialization and huge employment generation, grow the economy and engender positive social transformation. The clause in the PIA that promotes frontier exploration is well-thought out.
The goal of rock fabric characterization is to describe the spatial and geometric distribution of... more The goal of rock fabric characterization is to describe the spatial and geometric distribution of pore attributes as they impact petrophysical parameter variations such as porosity, permeability, and water saturation. Pore attributes such as pore size and pore volumes are critical petrophysical properties as they change and vary over a short distance or side-by-side, and determine the exploitable capacity of sedimentary reservoir rocks. A proposed new insight is in the systematic characterization of fabrics by the combination of both digital petrographic scanning and conservative petrographic description, as we show that multiple fabrics occur in a single lithofacie in the form of a fabric domain. Characterization shows that these domain types determine the spatial and geometric distribution of the variable pore sizes and volume (porosity) within a certain lithofacie fabric. Based on this, we also infer that these fabric domain types are responsible for the multiple occurrences of h...
Geopressure prediction is crucial because all drilling programs require estimation of abnormal pr... more Geopressure prediction is crucial because all drilling programs require estimation of abnormal pressured zones. The use of rock fabric deformational relics at variable depths to determine heterogeneity in overpressure zones in reservoir has not been explored. Therefore, the aim of this paper is to use petrography to determine intrinsic variations within overpressure zones. Understanding petrographic expression of overpressure on reservoir lithofacies at variable depths will enhance the prediction of overpressure in reservoirs that are not initially logged by subsurface pressure detecting tools. Thin section and scanning electron microscopy (SEM) petrography was used to study rock fabric. The petrophysical properties of the rock samples were measured using mercury porosimetry. Two lithofacies were discretized in a single reservoir i.e., massive friable fine-grained sandstone (MFFS) (Layer 1) and massive fine-grained sandstone (MFS) (Layer 2). The underlying layer (Layer 2) is dominated by sutured quartz grains, lenticular grain orientation, quartz overgrowth and relatively low porosity and permeability. The quartz grains are polycrystalline and characterized by planar and conchoidal fractures, in contrast to the overlying MFFS layer dominated by monocrystalline and platy quartz grains. The petrographic studies show overpressure variation can be characterized intrinsically by quartz deformational features and overall texture differences.
International Journal of ADVANCED AND APPLIED SCIENCES, 2019
Reservoir property modeling is often used to determine lateral extent and continuity in targeted ... more Reservoir property modeling is often used to determine lateral extent and continuity in targeted multiple wells for implementation of any enhanced oil recovery (EOR) methods. Some works were reported that most of EOR techniques are controlled by static-dynamic lateral extent and continuity within reservoir pay zones succession as they contribute to poor recovery in fields. Therefore, delineation of lateral extent and continuity using a statistical approach could save time, less cumbersome and data required. This paper by cluster analysis delineates lateral extent of 5 exploratory wells by integration of microscopic petrographic and petrophysical data from 132 subsurface and 97 core plugs. Result reveal four main petrofacies clusters of good lateral extent and continuity that corresponds to section (Blue cluster) characterized by massive coarse grained sandstones, massive fine grained sandstones and massive very fine grained sandstone lithofacies with average porosity (18-32%), permeability (400-1189 mD) at depths between 859 and 2129m. The Green cluster is dominated by massive fine grained and massive medium grained sandstone lithofacies exhibit average porosity (15-30%), permeability (110-840 mD) at depth from 880-1805m, while Brown cluster comprises of massive medium grained and massive fine grained sandstone lithofacies exhibit an average porosity (18-25%) and permeability (210-657 mD). The understandings of porosity-permeability continuity can facilitate effective areal sweep efficiency from injected fluid well to production well during recovery. Thus, this approach is important to improve the field plan for reservoir engineers.
Journal of Petroleum Exploration and Production Technology, 2019
The successful application of enhance oil recovery (EOR) technology requires an accurate understa... more The successful application of enhance oil recovery (EOR) technology requires an accurate understanding of the internal architecture of reservoirs and complex distribution of flow unit characteristics within different lithofacies. However, flow unit characteristics in the reservoir lithofacies of West Baram Delta Offshore, Sarawak, remain unexplored. Therefore, this paper investigates potential hydraulic flow units (HFUs) present within the five (5) identified sandstone lithofacies using thin sections, scanning electron microscopy (SEM), two-dimensional (2D) petrographic image analysis and helium porosimetery. The identified lithofacies include massive coarse-grained sandstone (MCGS), massive medium-grained sandstone (MMGS), massive fine-grained sandstone (MFGS), massive friable fine sandstone (MFFS) and massive very fine grained sandstone lithofacies (MVFGS). A plot of reservoir quality index (RQI) against normalized porosity (фz) showed five main hydraulic flow units (HFUs) within the identified lithofacies. The MFGS, MFFS and MVFGS lithofacies exhibited moderate to high matrix fractions and moderate to poor sorting, suggesting high tortuosity and hence characterized by low flow zone indicator (FZI). On the other hand, the MCGS and MMGS lithofacies exhibit very low to low matrix fractions, medium to coarse grain sizes and moderate to well sorting, signifying lower tortuosity, and hence characterized by relatively higher flow zone indicator (FZI). Thus, a hydraulic flow unit (HFU) can be formed by more than one lithofacies that exhibit similar fluid characteristic attributes, regardless of the difference in depositional environment and diagenetic processes undergone. This study concludes that HFU scattered plot can serve as a qualitative model for the characterization of flow unit characteristics in a well-comprising different lithofacies, particularly for field development plans in the West Baram Delta. Keywords Rock fabric • Flow unit characteristic • Flow zone indicator (FZI) • Reservoir quality index (RQI) • West Baram Delta * I. Yusuf
Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a resul... more Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a result of various intrinsic and extrinsic characteristics. This paper screened and ranked the Iullemmeden Basin of Nigeria sector based on Bachu (2003) ranking and screening criteria; evaluating factors such as tectonic setting, basin size and depth, geology, hydrogeology, hydrocarbon potentials, climate, geothermal, existing resources and industry maturity in respect to these criterion. The results shows to rank the Basin to have R k score value of 0.41 against the fi, n = max (fi) value equal to 1 as highest value of the function characterize the best in terms of suitability for the criterion in which this ranking are based upon. The paper also reveals as findings of some intrinsic characteristics such as; poor intercalated geologic formation, shallow aquifer systems within sedimentary pile in the basin which make the basin not suitable CO2 sequestration and when other parameters in future ...
This study investigate the impact of rock discrete textural variability on pore throats, and its ... more This study investigate the impact of rock discrete textural variability on pore throats, and its potential implication on permeability, displacement pressure and irreducible water saturation in one hundred and thirty two (132) samples from five wells. Two dimensional (2D) digital image analyses were used to extract grain size, shapes, pore types. A geometric sedimentological scale and statistical technique were also adopted for quantification and classification of the discrete grain sizes and shapes. The scanning electron microscopy (SEM) were used to visualize grain – pore throats relationship, and also mercury injection capillary pressure (MICP) data is use to quantify pore throat types, determination of displacement pressure, irreducible water saturation and pore throat sorting. Porosity-permeability systems (POROPERM) assess permeability variations from the core plugs. Results indicate that variable grain size and shape composition plays vital role in the distribution of pore th...
Experimental Evaluation of the Earth's Magnetic Field in Lapai, Northern Nigeria
The earth's magnetic field is a natural and an ever changing phenomenon due to the continuous... more The earth's magnetic field is a natural and an ever changing phenomenon due to the continuous convectional activities that take place within the earth. When the field is so intense and it interacts with the atmosphere, magnetic storms occur. It is therefore necessary to monitor the field within one's vicinity. The magnetic field intensity within Lapai, Nigeria was determined using an experimental approach. Three experimental set ups were used and the average magnetic field obtained was 34.91 µT. This result agreed, within the limits of experimental error, with the estimated result by the National Geophysical Data Centre for Lapai (latitude 9 0 03'00''N and longitude 6 0 34'00''E at an elevation of 162m) which was 33.9178 µT within the same period of investigation. This value portrays no danger of magnetic storm in the area.
International Journal of Scientific & Technology Research, 2014
Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a resul... more Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a result of various intrinsic and extrinsic characteristics. This paper screened and ranked the Iullemmeden Basin of Nigeria sector based on Bachu (2003) ranking and screening criteria; evaluating factors such as tectonic setting, basin size and depth, geology, hydrogeology, hydrocarbon potentials, climate, geothermal, existing resources and industry maturity in respect to these criterion. The results shows to rank the Basin to have R k score value of 0.41 against the fi, n = max (fi) value equal to 1 as highest value of the function characterize the best in terms of suitability for the criterion in which this ranking are based upon. The paper also reveals as findings of some intrinsic characteristics such as; poor intercalated geologic formation, shallow aquifer systems within sedimentary pile in the basin which make the basin not suitable CO2 sequestration and when other parameters in future ...
International journal of Geomatics and Geosciences, 2013
Sedimentary basins are suitable to different degrees for CO2 geological sequestration as a result... more Sedimentary basins are suitable to different degrees for CO2 geological sequestration as a result of various intrinsic and extrinsic characteristics. This paper preliminarily screened and ranked the Chad Basin of Nigeria sector based on Bachu (2003) ranking and screening criteria adapted which includes factors such as tectonic setting, basin size and depth, geology, hydrogeology, hydrocarbon potentials, climate, geothermal, existing resources and industry maturity. For each criterion i (i = 1…5) used for the evaluation of basin suitability, monotonically – increasing numerical function fi is assigned, which are continuous or discrete, to describe a value placed on a specific class j for that criterion. The lowest and the highest functions of this functions characterize the worst and best class in terms of suitability for that criterion, i.e. fi,1 = min (fi), where and fi,n = max (fi); where (n = 3, 4 or 5). The criteria relate to either the containment security, the volume of storag...
Journal of Minerals and Materials Characterization and Engineering, Nov 26, 2013
Geotechnical studies were carried out on soils from Shango-Chanchaga highway in Minna, in relatio... more Geotechnical studies were carried out on soils from Shango-Chanchaga highway in Minna, in relation to the petrographic characteristics of the parent rock. Samples were obtained from 5 trial pits at 1 km interval for geotechnical analysis. The moisture content varies from 35.0% to 58.5%, liquid limit ranges from 29.0% to 43.0%, plastic limit ranges between 9.0% and 26.5%, while plasticity index ranges from 12.0 to 33.5. The optimum moisture content (OMC) ranges from 12.0 to 14.0, and California Bearing Ratio (CBR) ranges from 2 to 21. The diffractograms showed that the dominant minerals were clinochore (Mg,Fe) 6 (Si,Al) 4 O 10 (OH) 8 , quartz (SiO 2), cordierite (Mg 2 Al 4 Si 5 O 18 Ar 0.625), and albite (Na 0.98 Ca 0.02 Al 1.02 Si 2.98 O 18). The results showed that there exists a relationship between the mineral composition, the texture of the rock, and the geotechnical characteristics of the soil types.
Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a resul... more Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a result of various intrinsic and extrinsic characteristics. This paper screened and ranked the Iullemmeden Basin of Nigeria sector based on Bachu (2003) ranking and screening criteria; evaluating factors such as tectonic setting, basin size and depth, geology, hydrogeology, hydrocarbon potentials, climate, geothermal, existing resources and industry maturity in respect to these criterion. The results shows to rank the Basin to have R k score value of 0.41 against the fi, n = max (fi) value equal to 1 as highest value of the function characterize the best in terms of suitability for the criterion in which this ranking are based upon. The paper also reveals as findings of some intrinsic characteristics such as; poor intercalated geologic formation, shallow aquifer systems within sedimentary pile in the basin which make the basin not suitable CO2 sequestration and when other parameters in future are favoured; it would possess the risk of CO2 leakages and groundwater contaminations in the geological storage media. Regional screening and ranking of the adjoining basins are recommended, while detailed local site characterisation of the basin is needed to assess its overall suitability for CO2 sequestration potentials in Nigeria.
Journal of Minerals and Materials Characterization and Engineering, 2013
Geotechnical studies were carried out on soils from Shango-Chanchaga highway in Minna, in relatio... more Geotechnical studies were carried out on soils from Shango-Chanchaga highway in Minna, in relation to the petrographic characteristics of the parent rock. Samples were obtained from 5 trial pits at 1 km interval for geotechnical analysis. The moisture content varies from 35.0% to 58.5%, liquid limit ranges from 29.0% to 43.0%, plastic limit ranges between 9.0% and 26.5%, while plasticity index ranges from 12.0 to 33.5. The optimum moisture content (OMC) ranges from 12.0 to 14.0, and California Bearing Ratio (CBR) ranges from 2 to 21. The diffractograms showed that the dominant minerals were clinochore (Mg,Fe) 6 (Si,Al) 4 O 10 (OH) 8 , quartz (SiO 2 ), cordierite (Mg 2 Al 4 Si 5 O 18 Ar 0.625 ), and albite (Na 0.98 Ca 0.02 Al 1.02 Si 2.98 O 18 ). The results showed that there exists a relationship between the mineral composition, the texture of the rock, and the geotechnical characteristics of the soil types.
Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a resul... more Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a result of various intrinsic and extrinsic characteristics. This paper screened and ranked the Iullemmeden Basin of Nigeria sector based on Bachu (2003) ranking and screening criteria; evaluating factors such as tectonic setting, basin size and depth, geology, hydrogeology, hydrocarbon potentials, climate, geothermal, existing resources and industry maturity in respect to these criterion. The results shows to rank the Basin to have R k score value of 0.41 against the fi, n = max (fi) value equal to 1 as highest value of the function characterize the best in terms of suitability for the criterion in which this ranking are based upon. The paper also reveals as findings of some intrinsic characteristics such as; poor intercalated geologic formation, shallow aquifer systems within sedimentary pile in the basin which make the basin not suitable CO2 sequestration and when other parameters in future are favoured; it would possess the risk of CO2 leakages and groundwater contaminations in the geological storage media. Regional screening and ranking of the adjoining basins are recommended, while detailed local site characterisation of the basin is needed to assess its overall suitability for CO2 sequestration potentials in Nigeria.
Sedimentary basins are suitable to different degrees for CO2 geological sequestration as a result... more Sedimentary basins are suitable to different degrees for CO2 geological sequestration as a result of various intrinsic and extrinsic characteristics. This paper preliminarily screened and ranked the Chad Basin of Nigeria sector based on Bachu (2003) ranking and screening criteria adapted which includes factors such as tectonic setting, basin size and depth, geology, hydrogeology, hydrocarbon potentials, climate, geothermal, existing resources and industry maturity. For each criterion i (i = 1…5) used for the evaluation of basin suitability, monotonically – increasing numerical function fi is assigned, which are continuous or discrete, to describe a value placed on a specific class j for that criterion. The lowest and the highest functions of this functions characterize the worst and best class in terms of suitability for that criterion, i.e. fi,1 = min (fi), where and fi,n = max (fi); where ( n = 3, 4 or 5).The criteria relate to either the containment security, the volume of storage capacity achievable, or considering the economic or technological feasibility. The results shows that Chad basin has Rk score value of 0.53 against the fi, n = max (fi) value equal to 1 as highest value of the function characterize the best in terms of suitability for the criterion in which this ranking are based on. Regional screening and ranking of the entire basins are recommended while detailed local site characterisation of the basin is needed to assess its overall suitability for CO2 sequestration potentials, since countries like Cameroon, Central African Republic, Niger, Chad, and Nigeria shares the basin on regional level Keywords: Chad Basin, Nigeria, CO2 geological sequestration, Criterion, Ranking and Screening
This paper attempts to quantify pore throats distribution towards more effective approach to perm... more This paper attempts to quantify pore throats distribution towards more effective approach to permeability prediction. The mercury inoculation capillary pressure (MICP) is used to calculate pore throat diameters, and porosity-permeability system (POROPERM) validates effect of pore throats diameters on permeability variations from core plugs. Results reveal three major classes of pore throats diameters (micropore, mesopore and macropore) from five identified pore throat types. It indicates also that the abundance of mesopore and macropore throats above 30% in upper section (1475 m-1480 m) of Siwa well increases permeability above 990 mD, an increase in micropore throats in middle unit (2106 m-2114 m) of BK-102 well vary permeability from 495 mD to 600 mD. Whereas, in the TK well, permeability is moderate lower between 230 mD to 670 mD due to abundance of macropore throats in groundmass of the fine to very fine-grained sandstones. In WL well, at depth from 1720 m to 1850 m, permeability is moderate higher varying between 120 mD to 945 mD attributed to abundance mesopore and macropore throats presence in coarse friable and medium grained sandstones within stratigraphic succession. The results also indicates that increase in percentage composition of mesopore and macropore throats above 20% holds potential increase in permeability, and conversely increase in micropore throats type 1-3 disrupts or lowers permeability. The understanding of spatial and temporal distribution of pore throats in wells, could improve accurate prediction permeability and hydraulic flow units in reservoirs.
The Ajali sandstone is a possible reservoir rock in the Lower Benue Trough (LBT)/Anambra Basin (A... more The Ajali sandstone is a possible reservoir rock in the Lower Benue Trough (LBT)/Anambra Basin (AB), and understanding its geological, sedimentological distribution is essential for accurate prediction of fluid flow dynamic. Geological, granulometric analysis and laboratory hydraulic conductivity test are integrated for this investigation. Results from geological studies reveals three sandstone lithofacies; namely; AJALI L2A a sandstone intermixed with siltstone, lamination, bioturbated, and crossed bedded, AJALI L2B sandstone mixed with silty clay, crossed bedded and bioturbated and AJALI L2C an excessive weathered sandstone with visible ripple and ridges with all sedimentary features supporting the earlier proposed fluvio-deltaic depositional environments. The granulometric analysis reveals medium to coarse grain, poorly sorted sandstone lithofacies. Hydraulic conductivity test for AJALI L2A crossed bedded and lamination sandstone contributes smaller pore spaces between grains, which reduce overall interconnectivity of the pore network primarily decreasing the fluid hydraulic flow conductivity and thus lowers the permeability value to 75mD. While in the AJALI L2B intermixed with siltstone and clay sandstone, lowers porosity; but cross-bedding may have contributed positively to increase in permeability value to 1850 mD in this lithofacies. The weathered AJALI L2C sandstone with visible ripples and ridges significantly affect the physical properties and pore spaces obliteration by iron oxide, by contributing to reduction in the permeability value to 60 mD. In overall it is concluded that the Ajali sandstones generally will exhibits an average moderate permeability of 662 mD.
The Nigerian Petroleum Industry Act (PIA) passed into Law in 2021 has the major goal to reform th... more The Nigerian Petroleum Industry Act (PIA) passed into Law in 2021 has the major goal to reform the Nigerian petroleum sector operations into policy, regulations and business (commercial). In the line of this, the Nigerian National Petroleum Corporation (NNPC) was transformed to NNPC Ltd to operate entirely commercially with a supervising Board and registration with the Corporate Affairs Commission. Such a commercial mandate will entail the need to explore and produce more oil and gas for export and domestic utilization. Oil is becoming less attractive as an energy source but gas is gaining momentum as a clean energy source in the global energy transition road-map. The global energy transition road-map is drawn around clean, alternative and renewable energies. The Nigerian frontier basins have recently come on board as new business opportunities with huge petroleum gas resources. These frontier basins comprise the Anambra, Benue, Bida, Chad (Nigerian sector), Dahomey, and Sokoto Basins as well as the Deep and Ultra-deep offshore. Maturing these basins through data generation and production of the gas resources therein will promote the nation's gas utilization and gas expansion programmes meant to promote industrialization and huge employment generation, grow the economy and engender positive social transformation. The clause in the PIA that promotes frontier exploration is well-thought out.
The goal of rock fabric characterization is to describe the spatial and geometric distribution of... more The goal of rock fabric characterization is to describe the spatial and geometric distribution of pore attributes as they impact petrophysical parameter variations such as porosity, permeability, and water saturation. Pore attributes such as pore size and pore volumes are critical petrophysical properties as they change and vary over a short distance or side-by-side, and determine the exploitable capacity of sedimentary reservoir rocks. A proposed new insight is in the systematic characterization of fabrics by the combination of both digital petrographic scanning and conservative petrographic description, as we show that multiple fabrics occur in a single lithofacie in the form of a fabric domain. Characterization shows that these domain types determine the spatial and geometric distribution of the variable pore sizes and volume (porosity) within a certain lithofacie fabric. Based on this, we also infer that these fabric domain types are responsible for the multiple occurrences of h...
Geopressure prediction is crucial because all drilling programs require estimation of abnormal pr... more Geopressure prediction is crucial because all drilling programs require estimation of abnormal pressured zones. The use of rock fabric deformational relics at variable depths to determine heterogeneity in overpressure zones in reservoir has not been explored. Therefore, the aim of this paper is to use petrography to determine intrinsic variations within overpressure zones. Understanding petrographic expression of overpressure on reservoir lithofacies at variable depths will enhance the prediction of overpressure in reservoirs that are not initially logged by subsurface pressure detecting tools. Thin section and scanning electron microscopy (SEM) petrography was used to study rock fabric. The petrophysical properties of the rock samples were measured using mercury porosimetry. Two lithofacies were discretized in a single reservoir i.e., massive friable fine-grained sandstone (MFFS) (Layer 1) and massive fine-grained sandstone (MFS) (Layer 2). The underlying layer (Layer 2) is dominated by sutured quartz grains, lenticular grain orientation, quartz overgrowth and relatively low porosity and permeability. The quartz grains are polycrystalline and characterized by planar and conchoidal fractures, in contrast to the overlying MFFS layer dominated by monocrystalline and platy quartz grains. The petrographic studies show overpressure variation can be characterized intrinsically by quartz deformational features and overall texture differences.
International Journal of ADVANCED AND APPLIED SCIENCES, 2019
Reservoir property modeling is often used to determine lateral extent and continuity in targeted ... more Reservoir property modeling is often used to determine lateral extent and continuity in targeted multiple wells for implementation of any enhanced oil recovery (EOR) methods. Some works were reported that most of EOR techniques are controlled by static-dynamic lateral extent and continuity within reservoir pay zones succession as they contribute to poor recovery in fields. Therefore, delineation of lateral extent and continuity using a statistical approach could save time, less cumbersome and data required. This paper by cluster analysis delineates lateral extent of 5 exploratory wells by integration of microscopic petrographic and petrophysical data from 132 subsurface and 97 core plugs. Result reveal four main petrofacies clusters of good lateral extent and continuity that corresponds to section (Blue cluster) characterized by massive coarse grained sandstones, massive fine grained sandstones and massive very fine grained sandstone lithofacies with average porosity (18-32%), permeability (400-1189 mD) at depths between 859 and 2129m. The Green cluster is dominated by massive fine grained and massive medium grained sandstone lithofacies exhibit average porosity (15-30%), permeability (110-840 mD) at depth from 880-1805m, while Brown cluster comprises of massive medium grained and massive fine grained sandstone lithofacies exhibit an average porosity (18-25%) and permeability (210-657 mD). The understandings of porosity-permeability continuity can facilitate effective areal sweep efficiency from injected fluid well to production well during recovery. Thus, this approach is important to improve the field plan for reservoir engineers.
Journal of Petroleum Exploration and Production Technology, 2019
The successful application of enhance oil recovery (EOR) technology requires an accurate understa... more The successful application of enhance oil recovery (EOR) technology requires an accurate understanding of the internal architecture of reservoirs and complex distribution of flow unit characteristics within different lithofacies. However, flow unit characteristics in the reservoir lithofacies of West Baram Delta Offshore, Sarawak, remain unexplored. Therefore, this paper investigates potential hydraulic flow units (HFUs) present within the five (5) identified sandstone lithofacies using thin sections, scanning electron microscopy (SEM), two-dimensional (2D) petrographic image analysis and helium porosimetery. The identified lithofacies include massive coarse-grained sandstone (MCGS), massive medium-grained sandstone (MMGS), massive fine-grained sandstone (MFGS), massive friable fine sandstone (MFFS) and massive very fine grained sandstone lithofacies (MVFGS). A plot of reservoir quality index (RQI) against normalized porosity (фz) showed five main hydraulic flow units (HFUs) within the identified lithofacies. The MFGS, MFFS and MVFGS lithofacies exhibited moderate to high matrix fractions and moderate to poor sorting, suggesting high tortuosity and hence characterized by low flow zone indicator (FZI). On the other hand, the MCGS and MMGS lithofacies exhibit very low to low matrix fractions, medium to coarse grain sizes and moderate to well sorting, signifying lower tortuosity, and hence characterized by relatively higher flow zone indicator (FZI). Thus, a hydraulic flow unit (HFU) can be formed by more than one lithofacies that exhibit similar fluid characteristic attributes, regardless of the difference in depositional environment and diagenetic processes undergone. This study concludes that HFU scattered plot can serve as a qualitative model for the characterization of flow unit characteristics in a well-comprising different lithofacies, particularly for field development plans in the West Baram Delta. Keywords Rock fabric • Flow unit characteristic • Flow zone indicator (FZI) • Reservoir quality index (RQI) • West Baram Delta * I. Yusuf
Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a resul... more Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a result of various intrinsic and extrinsic characteristics. This paper screened and ranked the Iullemmeden Basin of Nigeria sector based on Bachu (2003) ranking and screening criteria; evaluating factors such as tectonic setting, basin size and depth, geology, hydrogeology, hydrocarbon potentials, climate, geothermal, existing resources and industry maturity in respect to these criterion. The results shows to rank the Basin to have R k score value of 0.41 against the fi, n = max (fi) value equal to 1 as highest value of the function characterize the best in terms of suitability for the criterion in which this ranking are based upon. The paper also reveals as findings of some intrinsic characteristics such as; poor intercalated geologic formation, shallow aquifer systems within sedimentary pile in the basin which make the basin not suitable CO2 sequestration and when other parameters in future ...
This study investigate the impact of rock discrete textural variability on pore throats, and its ... more This study investigate the impact of rock discrete textural variability on pore throats, and its potential implication on permeability, displacement pressure and irreducible water saturation in one hundred and thirty two (132) samples from five wells. Two dimensional (2D) digital image analyses were used to extract grain size, shapes, pore types. A geometric sedimentological scale and statistical technique were also adopted for quantification and classification of the discrete grain sizes and shapes. The scanning electron microscopy (SEM) were used to visualize grain – pore throats relationship, and also mercury injection capillary pressure (MICP) data is use to quantify pore throat types, determination of displacement pressure, irreducible water saturation and pore throat sorting. Porosity-permeability systems (POROPERM) assess permeability variations from the core plugs. Results indicate that variable grain size and shape composition plays vital role in the distribution of pore th...
Experimental Evaluation of the Earth's Magnetic Field in Lapai, Northern Nigeria
The earth's magnetic field is a natural and an ever changing phenomenon due to the continuous... more The earth's magnetic field is a natural and an ever changing phenomenon due to the continuous convectional activities that take place within the earth. When the field is so intense and it interacts with the atmosphere, magnetic storms occur. It is therefore necessary to monitor the field within one's vicinity. The magnetic field intensity within Lapai, Nigeria was determined using an experimental approach. Three experimental set ups were used and the average magnetic field obtained was 34.91 µT. This result agreed, within the limits of experimental error, with the estimated result by the National Geophysical Data Centre for Lapai (latitude 9 0 03'00''N and longitude 6 0 34'00''E at an elevation of 162m) which was 33.9178 µT within the same period of investigation. This value portrays no danger of magnetic storm in the area.
International Journal of Scientific & Technology Research, 2014
Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a resul... more Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a result of various intrinsic and extrinsic characteristics. This paper screened and ranked the Iullemmeden Basin of Nigeria sector based on Bachu (2003) ranking and screening criteria; evaluating factors such as tectonic setting, basin size and depth, geology, hydrogeology, hydrocarbon potentials, climate, geothermal, existing resources and industry maturity in respect to these criterion. The results shows to rank the Basin to have R k score value of 0.41 against the fi, n = max (fi) value equal to 1 as highest value of the function characterize the best in terms of suitability for the criterion in which this ranking are based upon. The paper also reveals as findings of some intrinsic characteristics such as; poor intercalated geologic formation, shallow aquifer systems within sedimentary pile in the basin which make the basin not suitable CO2 sequestration and when other parameters in future ...
International journal of Geomatics and Geosciences, 2013
Sedimentary basins are suitable to different degrees for CO2 geological sequestration as a result... more Sedimentary basins are suitable to different degrees for CO2 geological sequestration as a result of various intrinsic and extrinsic characteristics. This paper preliminarily screened and ranked the Chad Basin of Nigeria sector based on Bachu (2003) ranking and screening criteria adapted which includes factors such as tectonic setting, basin size and depth, geology, hydrogeology, hydrocarbon potentials, climate, geothermal, existing resources and industry maturity. For each criterion i (i = 1…5) used for the evaluation of basin suitability, monotonically – increasing numerical function fi is assigned, which are continuous or discrete, to describe a value placed on a specific class j for that criterion. The lowest and the highest functions of this functions characterize the worst and best class in terms of suitability for that criterion, i.e. fi,1 = min (fi), where and fi,n = max (fi); where (n = 3, 4 or 5). The criteria relate to either the containment security, the volume of storag...
Journal of Minerals and Materials Characterization and Engineering, Nov 26, 2013
Geotechnical studies were carried out on soils from Shango-Chanchaga highway in Minna, in relatio... more Geotechnical studies were carried out on soils from Shango-Chanchaga highway in Minna, in relation to the petrographic characteristics of the parent rock. Samples were obtained from 5 trial pits at 1 km interval for geotechnical analysis. The moisture content varies from 35.0% to 58.5%, liquid limit ranges from 29.0% to 43.0%, plastic limit ranges between 9.0% and 26.5%, while plasticity index ranges from 12.0 to 33.5. The optimum moisture content (OMC) ranges from 12.0 to 14.0, and California Bearing Ratio (CBR) ranges from 2 to 21. The diffractograms showed that the dominant minerals were clinochore (Mg,Fe) 6 (Si,Al) 4 O 10 (OH) 8 , quartz (SiO 2), cordierite (Mg 2 Al 4 Si 5 O 18 Ar 0.625), and albite (Na 0.98 Ca 0.02 Al 1.02 Si 2.98 O 18). The results showed that there exists a relationship between the mineral composition, the texture of the rock, and the geotechnical characteristics of the soil types.
Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a resul... more Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a result of various intrinsic and extrinsic characteristics. This paper screened and ranked the Iullemmeden Basin of Nigeria sector based on Bachu (2003) ranking and screening criteria; evaluating factors such as tectonic setting, basin size and depth, geology, hydrogeology, hydrocarbon potentials, climate, geothermal, existing resources and industry maturity in respect to these criterion. The results shows to rank the Basin to have R k score value of 0.41 against the fi, n = max (fi) value equal to 1 as highest value of the function characterize the best in terms of suitability for the criterion in which this ranking are based upon. The paper also reveals as findings of some intrinsic characteristics such as; poor intercalated geologic formation, shallow aquifer systems within sedimentary pile in the basin which make the basin not suitable CO2 sequestration and when other parameters in future are favoured; it would possess the risk of CO2 leakages and groundwater contaminations in the geological storage media. Regional screening and ranking of the adjoining basins are recommended, while detailed local site characterisation of the basin is needed to assess its overall suitability for CO2 sequestration potentials in Nigeria.
Journal of Minerals and Materials Characterization and Engineering, 2013
Geotechnical studies were carried out on soils from Shango-Chanchaga highway in Minna, in relatio... more Geotechnical studies were carried out on soils from Shango-Chanchaga highway in Minna, in relation to the petrographic characteristics of the parent rock. Samples were obtained from 5 trial pits at 1 km interval for geotechnical analysis. The moisture content varies from 35.0% to 58.5%, liquid limit ranges from 29.0% to 43.0%, plastic limit ranges between 9.0% and 26.5%, while plasticity index ranges from 12.0 to 33.5. The optimum moisture content (OMC) ranges from 12.0 to 14.0, and California Bearing Ratio (CBR) ranges from 2 to 21. The diffractograms showed that the dominant minerals were clinochore (Mg,Fe) 6 (Si,Al) 4 O 10 (OH) 8 , quartz (SiO 2 ), cordierite (Mg 2 Al 4 Si 5 O 18 Ar 0.625 ), and albite (Na 0.98 Ca 0.02 Al 1.02 Si 2.98 O 18 ). The results showed that there exists a relationship between the mineral composition, the texture of the rock, and the geotechnical characteristics of the soil types.
Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a resul... more Sedimentary basins are suitable to a different degree for CO2 geological sequestration as a result of various intrinsic and extrinsic characteristics. This paper screened and ranked the Iullemmeden Basin of Nigeria sector based on Bachu (2003) ranking and screening criteria; evaluating factors such as tectonic setting, basin size and depth, geology, hydrogeology, hydrocarbon potentials, climate, geothermal, existing resources and industry maturity in respect to these criterion. The results shows to rank the Basin to have R k score value of 0.41 against the fi, n = max (fi) value equal to 1 as highest value of the function characterize the best in terms of suitability for the criterion in which this ranking are based upon. The paper also reveals as findings of some intrinsic characteristics such as; poor intercalated geologic formation, shallow aquifer systems within sedimentary pile in the basin which make the basin not suitable CO2 sequestration and when other parameters in future are favoured; it would possess the risk of CO2 leakages and groundwater contaminations in the geological storage media. Regional screening and ranking of the adjoining basins are recommended, while detailed local site characterisation of the basin is needed to assess its overall suitability for CO2 sequestration potentials in Nigeria.
Sedimentary basins are suitable to different degrees for CO2 geological sequestration as a result... more Sedimentary basins are suitable to different degrees for CO2 geological sequestration as a result of various intrinsic and extrinsic characteristics. This paper preliminarily screened and ranked the Chad Basin of Nigeria sector based on Bachu (2003) ranking and screening criteria adapted which includes factors such as tectonic setting, basin size and depth, geology, hydrogeology, hydrocarbon potentials, climate, geothermal, existing resources and industry maturity. For each criterion i (i = 1…5) used for the evaluation of basin suitability, monotonically – increasing numerical function fi is assigned, which are continuous or discrete, to describe a value placed on a specific class j for that criterion. The lowest and the highest functions of this functions characterize the worst and best class in terms of suitability for that criterion, i.e. fi,1 = min (fi), where and fi,n = max (fi); where ( n = 3, 4 or 5).The criteria relate to either the containment security, the volume of storage capacity achievable, or considering the economic or technological feasibility. The results shows that Chad basin has Rk score value of 0.53 against the fi, n = max (fi) value equal to 1 as highest value of the function characterize the best in terms of suitability for the criterion in which this ranking are based on. Regional screening and ranking of the entire basins are recommended while detailed local site characterisation of the basin is needed to assess its overall suitability for CO2 sequestration potentials, since countries like Cameroon, Central African Republic, Niger, Chad, and Nigeria shares the basin on regional level Keywords: Chad Basin, Nigeria, CO2 geological sequestration, Criterion, Ranking and Screening
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Papers by Yusuf Ishaq
Keywords: Chad Basin, Nigeria, CO2 geological sequestration, Criterion, Ranking and Screening
Keywords: Chad Basin, Nigeria, CO2 geological sequestration, Criterion, Ranking and Screening