This study characterized the AA-01 depleted hydrocarbon reservoir in the KOKA field, Niger Delta, using a multidimensional approach. This investigation involved data validation analysis, evaluation of site suitability...This study characterized the AA-01 depleted hydrocarbon reservoir in the KOKA field, Niger Delta, using a multidimensional approach. This investigation involved data validation analysis, evaluation of site suitability for CO_(2) storage, and compositional simulation of hydrocarbon components. The primary objective was to determine the initial components and behavior of the hydrocarbon system required to optimize the injection of CO_(2) and accompanying impurities, establishing a robust basis for subsequent sequestration efforts in the six wells in the depleted KOKA AA-01 reservoir. The process, simulated using industry software such as ECLIPSE, PVTi, SCAL, and Petrel, included a compositional fluid analysis to confirm the pressure volume temperature(PVT) hydrocarbon phases and components. This involved performing a material balance on the quality of the measured data and matching the initial reservoir pressure with the supplied data source. The compositional PVT analysis adopted the Peng–Robinson equation of state to model fluid flow in porous media and estimate the necessary number of phases and components to describe the system accurately. Results from this investigation indicate that the KOKA AA-01 reservoir is suitable for CO_(2)sequestration. This conclusion is based on the reservoir's good quality, evidenced by an average porosity of 0.21 and permeability of 1 111.0 mD, a measured lithological depth of 9 300 ft, and characteristic reservoir – seal properties correlated from well logs. The study confirmed that volumetric behavior predictions are directly linked to compositional behavior predictions, which are essential during reservoir initialization and data quality checks. Additionally, it highlighted that a safe design for CO_(2) storage relies on accurately representing multiphase behaviour across wide-ranging pressure–temperature–composition conditions.展开更多
Background: The Tubu are nomadic people who live in remote parts of the central Sahara, primarily in the Tibesti massif(Chad), and in both Northeastern Niger and Southern Libya. All of these areas are close to become ...Background: The Tubu are nomadic people who live in remote parts of the central Sahara, primarily in the Tibesti massif(Chad), and in both Northeastern Niger and Southern Libya. All of these areas are close to become conflict zones. However, no data about the Tubu's health and sanitary status are currently available, which would be of major concern if humanitarian interventions would become required.Methods: In 1970, the "Mission Anthropologique Belge au Niger"(MABN) investigated a Tubu tribe named Broaya that lived at Seguedine and Djado on the northeastern rim of the Tenere desert. One hundred fifty-one adult volunteers answered an oral questionnaire and underwent a medical examination, followed by the collection of blood thin films and samples of urine and stool. The environmental fauna of medical importance was also studied.Results: Albeit 43 year-old, these results have not been previously published. The estimated age of death for fathers was approximately 56 years, and that for mothers was 60 years. On average, each married woman had had 4.7 children. The overall perinatal mortality rate was 232 ‰, the overall infant mortality rate was 153 ‰, and the overall child mortality rate was 99 ‰. The mean height was 164.1 cm and 157.4 cm, the mean weight was 50.1 kg and 47.9kg, and the mean blood pressure was 131/78 mm Hg and 127/75 mm Hg for males and females, respectively. The physical examination found 6 cases of blindness(4.0%). Five subjects presented with an elevated blood pressure(3.3%), and 5(3.3%) displayed an abnormal thoracic auscultation evocative of tuberculosis or of an acute lung infection. The abdominal examination and renal palpation found 5 large masses(3.3%), and 2 subjects had a palpable enlarged spleen(1.3%). The blood thin films were fixed in methanol and subsequently examined in Toulouse. The search for blood parasites was negative. The urine samples were centrifuged and then microscopically examined in the field. No blood-fluke eggs were found. The stool samples were mixed with a preservative MIF solution and then stored to be examined later in Toulouse. Three subjects(2%) passed E. histolytica/E. dispar cysts in stools, 16(10.6%) were parasitized with Giardia sp. and 4(2.65%) were parasitized with Hymelepis nana. Two specimens of scorpions captured in the camp were subsequently identified as belonging to the harmful genus Androctonus or Leiurus. An investigation into the freshwater fauna was conducted in the marshy ponds surrounding the ghost city of Djado, and no intermediate snail hosts for schistosomiasis haematobium were found. Numerous nymphs of Ceratopogonidae, which are possible vectors for arboviruses of veterinarian importance, were collected, as were larvae and nymphs from two anopheline species, Anopheles hispaniola and An. multicolor, which are not efficient vectors for malaria.Conclusions: Infection-related blindness and trachoma, along with acute pulmonary infections and probably tuberculosis were the major health burden in this tribe. The harsh dry and hot climate may explain the low prevalence of soil-transmitted protozoan diseases or helminthiases.展开更多
This paper studied an architecture model of turbidite channel systems based on the shallow- layer high resolution 3D seismic information in the deepwater area in the Niger Delta continental slope, West Africa as a pro...This paper studied an architecture model of turbidite channel systems based on the shallow- layer high resolution 3D seismic information in the deepwater area in the Niger Delta continental slope, West Africa as a prototype model. Different types of channel systems were identified and the corresponding architecture models were established. The controlling factors, evaluation criteria and spatial distribution of different channel systems were analyzed. This study shows that turbidite channel systems of West Africa could be classified into three types; confined, semi-confined and unconfined, according to the condition of canyon and the levees on both sides. Oil one hand, along the transport direction, channel system evolves from confined to unconfined. Within channel systems, channel complexes, including two types of incised and enveloped, are the most important reservoir bodies. On the other hand, there is a channel complex evolution from incised to enveloped vertically. The geological factors exert impacts of different levels on the architecture of the turbidite channels in different sedimentary systems or even within the same system.展开更多
Biomass-derived carbon materials are widely applied in the energy storage and conversion fields due to their rich sources,low price and environmental friendliness.Herein,a unique pumpkin-like MoPMoS_(2)@Aspergillus ni...Biomass-derived carbon materials are widely applied in the energy storage and conversion fields due to their rich sources,low price and environmental friendliness.Herein,a unique pumpkin-like MoPMoS_(2)@Aspergillus niger spore-derived N-doped carbon(SNC)composite has been prepared via a simple hydrothermal and subsequent phosphorization process.Interestingly,the resulting MoP-MoS_(2)@SNC well inherits the pristine morphology of spore carbon,similar to the natural pumpkin,with hollow interiors and uneven protrusions on the surface.The special structure allows it to have sufficient space to fully contact the electrolyte and greatly reduces the ion transport distance.The theory calculations further demonstrate that the formed MoP-MoS_(2)heterostructure can enhance the adsorption of K ions and electronic couplings.With these unique advantages,the MoP-MoS_(2)@SNC anode for potassium storage shows a high reversible capability of 286.2 mAh g&(-1) at 100 mA g^(-1) after 100 cycles and superior rate performance.The enhanced electrochemical performance is mainly related to the unique pumpkin-like morphology of SNC and the construction of MoP-MoS_(2)heterostructure,as well as their perfect coupling.This study provides a feasible design idea for developing green,low-cost,and high-performance electrode materials for next-generation energy storage.展开更多
Based on the seismic and drilling data, casting thin sections, geochemical analysis of oil and rock samples, and hydrocarbon generation history simulation, the hydrocarbon accumulation characteristics and exploration ...Based on the seismic and drilling data, casting thin sections, geochemical analysis of oil and rock samples, and hydrocarbon generation history simulation, the hydrocarbon accumulation characteristics and exploration direction of Termit superimposed marine–continental rift basin are discussed. The Termit basin is superimposed with two-phase rifts(Early Cretaceous and Paleogene). The subsidence curves from two wells on the Trakes slope in the east of the basin show high subsidence rate in the Late Cretaceous, which is believed to be high deposition rate influenced by transgression. However, a weak rift may also be developed. The depositional sequences in the Termit basin were controlled by the Late Cretaceous marine transgression cycle and the Paleogene lacustrine transgression cycle, giving rise to two types of superimposed marine–continental “source-sink” deposits. The marine and continental mixed source rocks developed universally in the whole basinduring the marine transgression period, and are overlaid by the Paleogene Sokor 1 reservoir rocks and Sokor 2 caprocks developed during the lacustrine transgression period, forming the unique superimposed marine–continental basin in WCARS. The early low geothermal gradient in the Termit basin resulted in the late hydrocarbon generated by the source rock of Upper Cretaceous Yogou in Paleogene. Mature source rock of Upper Cretaceous Donga developed in the Trakes slope, so that the double-source-supply hydrocarbon and accumulation models are proposed for the Trakes slope in which formed the oil fields. Due to virtue of the newly proposed hydrocarbon accumulation model and the exploration activities in recent years in the Termit superimposed marine–continental rift basin, an additional effective exploration area of about 2500 km2has been confirmed in the east of the basin. It is believed that potential domains such as Sokor 1, Donga and Upper Cretaceous lithologic traps in the southeast of the basin are key expected targets for exploration and frontier evaluation in future.展开更多
This study developed allometric models to estimate aboveground biomass and carbon of Prosopis africana and Faidherbia albida. The destructive method was used with a sample of 20 trees per species for the two parkland ...This study developed allometric models to estimate aboveground biomass and carbon of Prosopis africana and Faidherbia albida. The destructive method was used with a sample of 20 trees per species for the two parkland sites. Linear regression with log transformation was used to model aboveground biomass according to dendrometric parameters. Error analysis, including mean absolute percentage of error(MAPE) and root mean square of error(RMSE), was used to select and validate the models for both species. Model 1(biomass according to tree diameter) for P. africana and F. albida were considered more representative. The statistical parameters of these models were R2 = 0.99, MAPE 0.98% and RMSE1.75% for P. africana, and R2 = 0.99, MAPE 1.19%,RMSE 2.37% for F. albida. The average rate of carbon sequestered was significantly different for the two species(P ≤ 0.05). The total amount sequestered per tree averaged0.17 × 10-3 Mg for P. africana and 0.25 × 10-3 Mg for F. albida. These results could be used to develop policies that would lead to the sustainable management of these resources in the dry parklands of Niger.展开更多
In this study,a high-throughput screening method was established through the 24-square deep-well microliter plate(MTP) fermentation and micro-plate detection for large-scale screening of the mutants.It was suitable fo...In this study,a high-throughput screening method was established through the 24-square deep-well microliter plate(MTP) fermentation and micro-plate detection for large-scale screening of the mutants.It was suitable for screening a large number of mutants and improving the breeding efficiency after heavy-ion beam irradiation.Seventeen strains showed higher cellulase activity compared with the initial strain after the screening of plate and MTP fermentation.The filter paper activity and β-glucosidase activity of Aspergillus niger H11201 had increased 38.74 and 63.23%separately compared with A.niger H11 by shaking flask fermentation,and it was genetically stable after being passaged to nine generations.The results indicate that the high-throughput screening method can be used for the quick breeding of A.niger with high cellulase activity.展开更多
文摘This study characterized the AA-01 depleted hydrocarbon reservoir in the KOKA field, Niger Delta, using a multidimensional approach. This investigation involved data validation analysis, evaluation of site suitability for CO_(2) storage, and compositional simulation of hydrocarbon components. The primary objective was to determine the initial components and behavior of the hydrocarbon system required to optimize the injection of CO_(2) and accompanying impurities, establishing a robust basis for subsequent sequestration efforts in the six wells in the depleted KOKA AA-01 reservoir. The process, simulated using industry software such as ECLIPSE, PVTi, SCAL, and Petrel, included a compositional fluid analysis to confirm the pressure volume temperature(PVT) hydrocarbon phases and components. This involved performing a material balance on the quality of the measured data and matching the initial reservoir pressure with the supplied data source. The compositional PVT analysis adopted the Peng–Robinson equation of state to model fluid flow in porous media and estimate the necessary number of phases and components to describe the system accurately. Results from this investigation indicate that the KOKA AA-01 reservoir is suitable for CO_(2)sequestration. This conclusion is based on the reservoir's good quality, evidenced by an average porosity of 0.21 and permeability of 1 111.0 mD, a measured lithological depth of 9 300 ft, and characteristic reservoir – seal properties correlated from well logs. The study confirmed that volumetric behavior predictions are directly linked to compositional behavior predictions, which are essential during reservoir initialization and data quality checks. Additionally, it highlighted that a safe design for CO_(2) storage relies on accurately representing multiphase behaviour across wide-ranging pressure–temperature–composition conditions.
文摘Background: The Tubu are nomadic people who live in remote parts of the central Sahara, primarily in the Tibesti massif(Chad), and in both Northeastern Niger and Southern Libya. All of these areas are close to become conflict zones. However, no data about the Tubu's health and sanitary status are currently available, which would be of major concern if humanitarian interventions would become required.Methods: In 1970, the "Mission Anthropologique Belge au Niger"(MABN) investigated a Tubu tribe named Broaya that lived at Seguedine and Djado on the northeastern rim of the Tenere desert. One hundred fifty-one adult volunteers answered an oral questionnaire and underwent a medical examination, followed by the collection of blood thin films and samples of urine and stool. The environmental fauna of medical importance was also studied.Results: Albeit 43 year-old, these results have not been previously published. The estimated age of death for fathers was approximately 56 years, and that for mothers was 60 years. On average, each married woman had had 4.7 children. The overall perinatal mortality rate was 232 ‰, the overall infant mortality rate was 153 ‰, and the overall child mortality rate was 99 ‰. The mean height was 164.1 cm and 157.4 cm, the mean weight was 50.1 kg and 47.9kg, and the mean blood pressure was 131/78 mm Hg and 127/75 mm Hg for males and females, respectively. The physical examination found 6 cases of blindness(4.0%). Five subjects presented with an elevated blood pressure(3.3%), and 5(3.3%) displayed an abnormal thoracic auscultation evocative of tuberculosis or of an acute lung infection. The abdominal examination and renal palpation found 5 large masses(3.3%), and 2 subjects had a palpable enlarged spleen(1.3%). The blood thin films were fixed in methanol and subsequently examined in Toulouse. The search for blood parasites was negative. The urine samples were centrifuged and then microscopically examined in the field. No blood-fluke eggs were found. The stool samples were mixed with a preservative MIF solution and then stored to be examined later in Toulouse. Three subjects(2%) passed E. histolytica/E. dispar cysts in stools, 16(10.6%) were parasitized with Giardia sp. and 4(2.65%) were parasitized with Hymelepis nana. Two specimens of scorpions captured in the camp were subsequently identified as belonging to the harmful genus Androctonus or Leiurus. An investigation into the freshwater fauna was conducted in the marshy ponds surrounding the ghost city of Djado, and no intermediate snail hosts for schistosomiasis haematobium were found. Numerous nymphs of Ceratopogonidae, which are possible vectors for arboviruses of veterinarian importance, were collected, as were larvae and nymphs from two anopheline species, Anopheles hispaniola and An. multicolor, which are not efficient vectors for malaria.Conclusions: Infection-related blindness and trachoma, along with acute pulmonary infections and probably tuberculosis were the major health burden in this tribe. The harsh dry and hot climate may explain the low prevalence of soil-transmitted protozoan diseases or helminthiases.
基金supported by Open Fund(PLC201203)of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Chengdu University of Technology)National Science and Technology Major Project(2011ZX05030-005)Major Project of Education Department in Sichuan Province(13ZA0177)
文摘This paper studied an architecture model of turbidite channel systems based on the shallow- layer high resolution 3D seismic information in the deepwater area in the Niger Delta continental slope, West Africa as a prototype model. Different types of channel systems were identified and the corresponding architecture models were established. The controlling factors, evaluation criteria and spatial distribution of different channel systems were analyzed. This study shows that turbidite channel systems of West Africa could be classified into three types; confined, semi-confined and unconfined, according to the condition of canyon and the levees on both sides. Oil one hand, along the transport direction, channel system evolves from confined to unconfined. Within channel systems, channel complexes, including two types of incised and enveloped, are the most important reservoir bodies. On the other hand, there is a channel complex evolution from incised to enveloped vertically. The geological factors exert impacts of different levels on the architecture of the turbidite channels in different sedimentary systems or even within the same system.
基金the support from the Shuguang Program supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(18SG035)the Basic Research Program of Shanghai Municipal Government(21JC1406002)the Shanghai Engineering Research Center of Advanced Thermal Functional Materials(Shanghai Polytechnic University)。
文摘Biomass-derived carbon materials are widely applied in the energy storage and conversion fields due to their rich sources,low price and environmental friendliness.Herein,a unique pumpkin-like MoPMoS_(2)@Aspergillus niger spore-derived N-doped carbon(SNC)composite has been prepared via a simple hydrothermal and subsequent phosphorization process.Interestingly,the resulting MoP-MoS_(2)@SNC well inherits the pristine morphology of spore carbon,similar to the natural pumpkin,with hollow interiors and uneven protrusions on the surface.The special structure allows it to have sufficient space to fully contact the electrolyte and greatly reduces the ion transport distance.The theory calculations further demonstrate that the formed MoP-MoS_(2)heterostructure can enhance the adsorption of K ions and electronic couplings.With these unique advantages,the MoP-MoS_(2)@SNC anode for potassium storage shows a high reversible capability of 286.2 mAh g&(-1) at 100 mA g^(-1) after 100 cycles and superior rate performance.The enhanced electrochemical performance is mainly related to the unique pumpkin-like morphology of SNC and the construction of MoP-MoS_(2)heterostructure,as well as their perfect coupling.This study provides a feasible design idea for developing green,low-cost,and high-performance electrode materials for next-generation energy storage.
基金Supported by CNPC Scientific Research and Technology Development Project (2021DJ3103)CNODC Overseas Rresearch and Development Support Project (2023-YF-01-04)。
文摘Based on the seismic and drilling data, casting thin sections, geochemical analysis of oil and rock samples, and hydrocarbon generation history simulation, the hydrocarbon accumulation characteristics and exploration direction of Termit superimposed marine–continental rift basin are discussed. The Termit basin is superimposed with two-phase rifts(Early Cretaceous and Paleogene). The subsidence curves from two wells on the Trakes slope in the east of the basin show high subsidence rate in the Late Cretaceous, which is believed to be high deposition rate influenced by transgression. However, a weak rift may also be developed. The depositional sequences in the Termit basin were controlled by the Late Cretaceous marine transgression cycle and the Paleogene lacustrine transgression cycle, giving rise to two types of superimposed marine–continental “source-sink” deposits. The marine and continental mixed source rocks developed universally in the whole basinduring the marine transgression period, and are overlaid by the Paleogene Sokor 1 reservoir rocks and Sokor 2 caprocks developed during the lacustrine transgression period, forming the unique superimposed marine–continental basin in WCARS. The early low geothermal gradient in the Termit basin resulted in the late hydrocarbon generated by the source rock of Upper Cretaceous Yogou in Paleogene. Mature source rock of Upper Cretaceous Donga developed in the Trakes slope, so that the double-source-supply hydrocarbon and accumulation models are proposed for the Trakes slope in which formed the oil fields. Due to virtue of the newly proposed hydrocarbon accumulation model and the exploration activities in recent years in the Termit superimposed marine–continental rift basin, an additional effective exploration area of about 2500 km2has been confirmed in the east of the basin. It is believed that potential domains such as Sokor 1, Donga and Upper Cretaceous lithologic traps in the southeast of the basin are key expected targets for exploration and frontier evaluation in future.
基金supported by the project stocks and potential of carbon sequestration under agroforestry parklands in Niger funded by African Forest Forum(AFF)and International Foundation for Science(IFS),Grant No.D/563-1
文摘This study developed allometric models to estimate aboveground biomass and carbon of Prosopis africana and Faidherbia albida. The destructive method was used with a sample of 20 trees per species for the two parkland sites. Linear regression with log transformation was used to model aboveground biomass according to dendrometric parameters. Error analysis, including mean absolute percentage of error(MAPE) and root mean square of error(RMSE), was used to select and validate the models for both species. Model 1(biomass according to tree diameter) for P. africana and F. albida were considered more representative. The statistical parameters of these models were R2 = 0.99, MAPE 0.98% and RMSE1.75% for P. africana, and R2 = 0.99, MAPE 1.19%,RMSE 2.37% for F. albida. The average rate of carbon sequestered was significantly different for the two species(P ≤ 0.05). The total amount sequestered per tree averaged0.17 × 10-3 Mg for P. africana and 0.25 × 10-3 Mg for F. albida. These results could be used to develop policies that would lead to the sustainable management of these resources in the dry parklands of Niger.
基金supported by the National Natural Science Foundation of China(No.11305225)the Science and Technology Service Network Initiative(KFJ-EW-STS-086)
文摘In this study,a high-throughput screening method was established through the 24-square deep-well microliter plate(MTP) fermentation and micro-plate detection for large-scale screening of the mutants.It was suitable for screening a large number of mutants and improving the breeding efficiency after heavy-ion beam irradiation.Seventeen strains showed higher cellulase activity compared with the initial strain after the screening of plate and MTP fermentation.The filter paper activity and β-glucosidase activity of Aspergillus niger H11201 had increased 38.74 and 63.23%separately compared with A.niger H11 by shaking flask fermentation,and it was genetically stable after being passaged to nine generations.The results indicate that the high-throughput screening method can be used for the quick breeding of A.niger with high cellulase activity.
