Southeastern Niger Research Articles

Reservoir fluid characterization of the Sokor1 Formation, Fana tectonic unit, Termit Basin, southeastern Niger Republic

Reservoir fluid characterization of the Sokor1 Formation, Fana tectonic unit, Termit Basin, southeastern Niger Republic

Characterization of the Drilling Mud Adapted to the Geological Formations of the Agadem Oil Field, Termit basin (Southeastern Niger): Case of the Dibella Well

The objective of this study is to characterize the drilling mud adapted to the geological formations of the Agadem oil field (Niger). During the drilling process, the mud is monitored and adjusted regularly according to the instantaneous logging data. Thus, the typologies of drilling mud and their physicochemical and rheological properties at the level of each phase of drilling were determined in the laboratory of the site during the realization of the Dibella well. Two (2) types of mud (Pre-hydrated bentonite (PHB) and polymer) were used during the drilling of the Dibella well. The PHB mud, used from 0 to 800m depth, is characterized by a variable density depending on the lithology, a MARSH viscosity of 60 to 75 seconds and a pH between 8 and 9. The polymer mud, used between 800 and 2680 m, is characterized by an equally variable density, a MARSH viscosity of 55 to 60 seconds, a plastic viscosity of 10 to 20 mPa.S, a yield point between 2 and 10 Pa, an apparent viscosity of 3 to 5 mPa.S, a Gel strenght (G10’’/G10’) of 1 to 4/2 to 10 Pa and a pH, always between 8 and 9. These parameters, which allowed the Dibella drilling to be carried out in an optimal way, can be used as a guide for the realization of new wells in the study area.

Source Rock Evaluation of Shale in Parts of Ini Local Government Area, Akwa Ibom State, Southeastern Niger Delta Basin, Nigeria

Total organic carbon and Rock – Eval pyrolysis studies were conducted on seven (7) shale samples outcropping in parts of Ini Local Government Area of Akwa Ibom State, Southeastern Niger Delta, Nigeria. The studies were done to determine the quantity and quality of organic matter in the shale source rock, and their hydrocarbon generation potential. Total organic carbon (TOC) values indicate poor to excellent organic richness with values ranging from 0.46 wt.% to 5.98 wt.%. The free oil content (S1) values range from 0.02-0.21 mg HC/g rock, (mean = 0.07 mg HC/g rock), while the source rock potential (S2) ranges from 0.08-1.09 mg HC/g rock with an average value of 0.45 mg HC/g rock both indicating poor source rock generative potential. The Hydrogen Index (HI) and the Oxygen Index (OI) range from 11 mg HC/g TOC to 59 mg HC/g TOC and 41 mg CO/g TOC to 74 mg CO/g TOC with an average value of 27.28 mg HC/g TOC and 55.71 mg CO/g TOC respectively. HI versus OI and S2 versus TOC cross plot results indicate that shale in parts of Ini Local Government Area contains organic matter capable of generating kerogen type III to type 1V which is gas prone.

Palynostratigraphy and Palaeoenvironmental Interpretation of Outcrop Formations in Parts of Ini-Akwa Ibom State, Southeastern Niger Delta Basin, Nigeria

The palynological study of the outcrop Formations in parts of Ini Local Government Area of Akwa Ibom State, Southeastern Niger Delta Basin, Nigeria has contributed to unraveling the palynostratigraphy and paleoenvironments of the outcrops through the use of diagnostic palynomorphs. The section is made up of carbonaceous shales, sandstones, mudstones and claystones. The conventional maceration technique for recovering acid-insoluble organic-walled microfossils from sediments was used to prepare twenty outcrop samples for palynological studies. The samples produced poor to fair diversity assemblages of palynomorphs. A total of 176 palynomorphs species were recorded, with 48% pollen grains, 33% spores, 12% dinoflagellate cysts, 5% fungal spores, and 2% microforam test wall linings. Based on stratigraphically selected index taxa recovered,age determination and correlation wereestablished. The samples from Imo Formation were assigned Late Paleocene-Eocene based on Psilatricolporites Crassus, Retitricolporites irregularies, Psilatricolporites sp. and Leiotriletes adriennis with the presence of Paleocene dinoflagellate cysts such as Lejeunacysta beninensis and Selenopemphix nephroides. Ameki samples were dated Early-Middle Eocene based on Proxapertites operculatus, Retistephanocolpites williamsi, Mauritidites crassiexinius, Monocolpites marginatus and Longapertites marginatus. Ogwashi-Asaba shale samples were assigned Late Eocene-Early Oligocene due to the abundant presence of Verrucatosporites usmensis, Laevigatosporites discordatus and Retitricolporites irregularis while Eze-Aku samples were tentatively assigned Paleocene because of the presence of two pollen index fossils Proxapertites operculatus and Pachydermites diederixi. Inferred depositional conditions suggest that Imo Formation was deposited in a shallow marine or near shore brackish water estuarine environment. The Ameki Formation was accumulated in a marginal marine or near shore, brackish water-estuarine environment in the upper deltaic setting. The Ogwashi-Asaba Formation was deposited in a progradational shoreline moving between the brackish water and fresh water deltaic plain. The Eze-Aku Formation was deposited in an upper foreshore fresh water environment. The palynological study of the samples are Paleogene Formations while the paleoenvironment is in a costal deltaic to shallow-marine environment and are appropriate for hydrocarbon accumulations and exploration.

Permian Ages of “Younger Granites” from Mounio Province (Gouré area, Southeastern Niger)

African formations intruded by the “Younger Granites” ring complex. In the study area, the “Younger Granites” are represented by volcanic to acid plutonic rocks with hyperalkaline trends (pyroclastic rocks, rhyolites, microgranites, granites, syenites), forming in the North, a circular structure called Gouré ring complex. Preliminary geochronological datings of the Mounio granites have yielded Carboniferous ages. However, recent investigations carried out in this province have identified structures similar to Pan-African deformation structures, such as folds and several generations of schistosity/foliation. Analysis of the relationship between deformation and magmatism has removed any ambiguity regarding the relative age of the deformation. This study focuses on the radiometric dating of the “Younger Granites” of Gouré area, in order to update the geochronological data. Thus, three samples (pyroclastitic rock, rhyolite, microgranite) were dated by the K-Ar method on total rock using a mass spectrometertype MI 1201 IG. Radiometric dating results assign a Lower Permian age (293-287 Ma) to the “Younger Granites” Ring Complex of the Mounio Province in Niger, classically considered to be Carboniferous in age.

Assessment of Drought Characteristics under Changing Climatic Conditions using SPI and SPEI Indices in Semi-Arid Environment of Southeastern Niger

In the sahelian zone where 80% of the populations rely on rainfed-agricultural activities for their livelihood, drought episodes had significant socio-economics and ecological impacts. In recent decades, there has been an increase in the intensity, frequency and severity of drought occurrence mainly attributed to climate change. Thus, the main objectives of this study were: i) to understand drought multi-scale patterns and trend; ii) to assess drought duration, frequency and temporal extent over Mainé-soroa and Diffa located in the lake chad basin. To achieve these objectives standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI) at 1, 3, 6, 9, 12 and 24-month timescales were employed for the stations of Mainé-soroa and Diffa. Stations’ monthly rainfall, air minimum and maximum temperature spanning 1950-2009 and 1988-2017 respectively for Mainé-soroa and Diffa were used for the analysis. The Mann–kendall trend test was performed and revealed negative SPEI and SPI trends in the station of Mainé-soroa. Results indicate a significant negative SPI-12 and SPI-24 trend (p-value < 0.05), while no trend was detected in the rest of the time-scale series. The absolute value of declining trend was gradually increasing when SPEI was calculated with more lagged months. Meanwhile, at the Diffa station both SPEI and SPI showed positive trends. The pettitt's t-test on the SPEI series indicated particularly 1968 as the change point detected for three time scales including spei-9, SPEI-12, and SPEI-24. Drought frequency generally increased in Mainé-soroa over the period of 1950–2009. SPEI appear to be the most powerful tool of monitoring drought in semi-arid environment in the context of climate change. To build resilience to drought and cope with its effects in the area we stress the importance of the establishment of early risk identification and advices framework at local level such study should be extended to lake chad basin.

Core sediments and oil chemistry from contaminated mangroves in eastern Niger Delta, Ogoniland, Nigeria

Thirty cores to maximum depth of 3.7 m were taken in 2018 to investigate sedimentary characteristics and hydrocarbon penetration within mangrove sediments in Bodo (southeastern Niger Delta), an area contaminated by numerous ongoing oil spills but most significantly in 2008. Sediments were dominated by organically rich (Chikoko) mud underlain by clay with sandier sediments at deeper core depths and adjacent to shorelines. Analysis of 202 samples showed high median hydrocarbon concentrations at the surface (39,000 mg/kg) and shallow subsurface (10–25 cm, 25,000 mg/kg), decreasing with depth: 430 mg/kg at 40–70 cm; 157 mg/kg at 75–120 cm, and <30 mg/kg at depths ≥150 cm. Most (85%) EPA-16 priority polycyclic aromatic hydrocarbons and all monoaromatics were below detection limit. Shallow subsurface oil penetration was aided by crab burrows and presence of mangrove remnants and was inhibited from deeper depths by groundwater at ~25 cm and increased sediment compaction.

Evaluation of soils on a toposequence formed from the coastal plain sands of the Imo river basin, Southeastern Niger

Due to the increasing land degradation in southeastern Nigeria – with particular reference to the ubiquitous gully network in the region – selected soils formed from the Coastal Plain Sands of the Imo River Basin were evaluated and characterized to determine their potentials and capabilities. , Three profile pits were consequently dug on the upper slope (Umuariam), -mid-slope (Umulogho), and foot slope (Umungwa) of three towns on the Imo River Basin underlain by the coastal plain sands. The soil color ranged from greyish brown (5 YR 5/2) to dull brown (7.5 YR 5/3) in the topsoil and from dull orange (5 YR 6/4) to orange (5 YR 6/7) in the subsoil. The soils had sandy topsoil and relatively more clayey subsoil. The pH (in KCl) ranged from very strongly acidic (4.5 – 5.0) to moderately acidic (5.1 – 6.0). They had low organic matter, low total nitrogen, low ECEC, low Al saturation, and moderate base saturation. The soils of Umuariam (Upper Slope) and Umulogho (Mid Slope) were classified as Typic Hapludults (Chromic Acrisols), while that of Umungwa (Foot Slope) was classified as Typic Udipsamments (Rubic Arenosols). Umuariam had a USDA land capability class of IIes and a USBR land capability class of 2v/C. Umulogho and Umungwa both had a USDA and USBR capability class of IVs and 3v/C respectively. Though moderately to marginally irrigable, the soils can still produce increased and sustainable agricultural yield if the appropriate land use and husbandry practices are adopted, with particular reference to erosion control, organic manure, lime, and fertilizer application.

Critical Transitions from Pastoralism to Ranching in Central Africa

The goal of this paper is to explain why and how increasing commoditization and incorporation in the market economy are only now leading to a critical transition from pastoralism to ranching in Central Africa. While there are similarities between pastoralism and capitalism—in both systems, entrepreneurs are strategically maximizing their “stock”—there are also differences. We argue that these differences can be understood as two distinct types of logic that are embedded within larger sociocultural systems: cattle logic and capital logic. Understanding how these logics operate within different systems is critical for explaining the current shift from pastoralism to ranching in Central Africa. We outline a theoretical model that integrates concepts from practice theory and the literature on critical transitions in social-ecological systems to explain the shift. We illustrate the theoretical model using a case comparison of three different livestock husbandry systems: Woɗaaɓe pastoralists in southeastern Niger, peri-urban Fulani pastoralists in the Far North Region of Cameroon, and Fulani ranchers in the Adamawa Region of Cameroon. We then use these cases to explain the persistence of cattle logic among the Woɗaaɓe in Niger, as well as the shift from cattle logic to capital logic among Fulani in Cameroon. Studying the transition from pastoralism to ranching is important because it has major implications, including increasing economic inequality, weaker community relations, and potential degradation of grazing lands, for livestock husbandry systems in Central Africa.

Boko Haram, the Islamic State, and the Surge in Female Abductions in Southeastern Niger

This paper uses a gendered analysis, alongside original data,1 to explore an increase in abductions of Muslim women and girls in southeastern Niger between March 2019 and the end of April 2020, and what this indicates about jihadist factional dynamics. These abductions occurred in operational areas historically associated with Islamic State West Africa Province (ISWAP), which is loyal to Islamic State. Yet, ISWAP condemns its rival faction, Abubakar Shekau-led Boko Haram (Jamaat Ahlus Sunnah Li-Dawa wal-Jihad), for that faction’s abduction and self-described enslavement of Muslim women. As such the abductions are an anomaly. The piece, therefore, considers three alternative possible reasons for the surge of abductions in southeastern Niger during this period. These are: the rise of a new Abubakar Shekau-loyal Boko Haram sub-faction operating in ISWAP’s historical areas of operations in southeastern Niger and around Lake Chad, led by the jihadist commander Bakura; leadership changes in ISWAP beginning in March 2019 that resulted in an ideological shift toward more ‘Shekau-like’ operations; and command-and-control issues, with ISWAP members engaging in abductions without leadership sanction. The paper argues that the new data, alongside a gender analysis of the ideological positions of the jihadist groups in the Lake Chad Basin Area, suggests the emergence of the new Bakura sub-faction contributed most to the increase in abductions of Muslim in southeastern Niger. The finding has implications for understanding the jihadist actors in the region, studying how gender functions in factionalisation, and developing a gendered policy to counter Boko Haram and a counter-terrorism strategy for member-states of the Lake Chad-based Multinational Joint Task Force

Effects of anisotropic changes on the conductivity of sedimentary aquifers, southeastern Niger Delta, Nigeria

Sundry soils/rocks are characterized by electrical properties with clearly or obscurely expressed anisotropies. These anisotropic effects may be low, moderate or high depending on the coefficient of anisotropy (λ). The vertical electrical sounding technique employing Schlumberger electrode configuration and lithological information from boreholes were deployed to characterize the lithological diversity in homogeneous and anisotropic geologic units that serve as aquifer systems and their overlaying layers in the coastal region of Akwa Ibom State. Based on the $$\lambda$$ , the assessed volume of sedimentary formation is classified into low anisotropy λ < 1.2, moderate anisotropy $$\left( {1.2 < \lambda \le 1.3} \right)$$ and high anisotropy $$\left( {\lambda > 1.3} \right)$$ with alluvium (64.3%), inter-bedded shale and sandstone (14.3%) and shale and slate (21.3%). The estimated percentage of respective compositional coverage indicates that alluvium is dominant, while the blended inter-bedded shale and sandstone as well as the shale and slate are minor geologic units in the Benin Formation. Inferred index of spread of alluvium indicates that the homogeneous and anisotropic units assessed are intrinsic/microscopic in nature as identified by the impressed current that passed through geologic system. The results showcased that the plot between the strike-dependent resistivity $$\left( {\rho_{\theta } } \right)$$ at arbitrary chosen strike and geometric mean resistivity $$\left( {\rho_{m} } \right)$$ can be used as a yardstick for inferring the degree of consistency of geologic compositions in homogeneous and anisotropic media. Both the quantitative (graphic) and qualitative (contour) results portend the thin possibility of having anisotropy free geologic units. The finding proposes that ground resistivity measurements and interpretations of geologic structures should be constrained by borehole information in order to firm up the intended plans for obtaining clearer, defendable and well-resolved subsurface structures.

Hydrogeophysical studies for the determination of aquifer hydraulic characteristics and evaluation of groundwater potential: A case study of some selected parts of Imo River Basin, South Eastern Niger

Hydrogeophysical studies for the determination of aquifer hydraulic characteristics and evaluation of groundwater potential: A case study of some selected parts of Imo River Basin, South Eastern Niger

Rural Communities’ Perceptions of Climate Change and Its Impacts on Their Livelihood in Southeastern Niger

Climate change exacerbates ecosystem degradation in Sahel where rural communities are highly dependent on natural resources and ecosystem services for their livelihoods. In order cope with the adverse effects of climate change by developing climate adaptation strategies, there has been a need to understand how communities perceive the change or variability in their local climate and how this change could affect their livelihood. This paper aims to examined rural communities’ perceptions about climate change in the commune of Chetimari located in the region of Diffa, southeastern Niger. It investigated particularly: 1) how communities’ perceptions of climate change? 2) What are the impacts of climate change on the livelihood of communities? And 3) What do elements and options to detect abrupt change points in annual precipitations and both annual maximum and minimum temperature? Survey data were collected from October to November 2018 from 101 households (15% of the total households in the study area) in three villages. Multiple correspondence Analysis (MCA) and Factorial Correspondence Analysis (FCA) were performed with XLSTAT to analyzed data from survey. Meteorological data including Monthly precipitation from 1981 to 2017, and Monthly temperatures (maximum, minimum) from 1986 to 2017 of the Diffa meteorological station were analyzed using R to perform the Man Kendal trend test and the Pettit test for detection of abrupt changes in the series. Results showed that community perceptions on temperature increase (not for precipitation) trends as indicators of climate change are in agreement with meteorologically observed trends. The findings showed that people in this zone are aware of climate change that they see as increase in maximum and minimum temperature, decrease in rainfall, frequency of extreme events (drought and flood), dry spells, decrease in number of rainy days, strong winds etc…Results revealed the most significant impacts of climate change affecting the livelihood of rural communities in this area. These are higher risk of crop damage from drought, farmer and herder conflict frequency, drying up of wells, food shortage/insecurity, silting pools, decline in soil fertility and livestock production, silting pasture areas, frequency of livestock diseases, increased weed and invasive species, livestock mortality. The perception of the climate change and its impacts on the main socioeconomic activities vary from a village to another, according the sexes and age ranges.&#x0D; We conclude that communities are relatively aware about the climate change issue. For a better management of climate-induced risks in the study area we stress the need to improve the awareness of climate change within the rural community by improving the availability and the quality of relevant climate information.

Effects of oil spillage on soils nutrients of selected communities in Ogoniland, south-eastern Niger Delta, Rivers State, Nigeria

Effects of oil spillage on soils nutrients of selected communities in Ogoniland, south-eastern Niger Delta, Rivers State, Nigeria

Whole-oil relationship and origin of oil derived from heterogeneous reservoir systems in an offshore field, SE, Niger Delta

Whole-oil (C3–C39) gas chromatograms were obtained for 46 oil samples collected from a reservoirs pool in an oilfield located offshore SE Niger Delta, to investigate the origins and the relationships of the oils, in spite of the discontinuity of the reservoirs from which the oils were produced. All the oils contained hydrocarbons in the range C3–C39 with prominent pristane and phytane. The plot of pristine: nC17 versus phytane: nC18 shows oils of terrestrial origin that is deposited in an oxidizing environment. However, some of the oils show depletion of n-paraffin in the C5–C11 range and have abundant n-paraffin in the C12–C35 range suggesting biodegraded oils. The isoprenoid peaks, however, are more prominent than adjacent n-paraffin in some of the other oils. A star plot of the ratios derived from napthenic, aromatic, isoprenoid, and normal alkane compounds of the samples, in addition to the above-mentioned variations, allowed the grouping of the oils into three families. The results infer that the oils from the south eastern Niger delta may be related in some way (in terms of source input) but may have undergone slightly different histories due to reservoir discontinuity.

Genetic diversity of Southeastern Nigerien date palms reveals a secondary structure within Western populations

Date palm (Phoenix dactylifera L.) is mainly cultivated for its edible fruit and is of great socio-economic importance for the populations of arid zones. Analysis of the date palm genetic diversity in the Old World had revealed a strong genetic structure with the existence of two gene pools, one Eastern comprising Asia and Djibouti, and one Western, consisting of North African accessions. So far, mainly date palm populations from countries within the Maghreb and the Middle East were characterized, but no information from the Sahel was included. Here, we present the genetic diversity of date palms from Southeastern Niger. The DNA of 113 date palm accessions were analyzed and compared with a database containing the genetic information of 248 accessions from the Old World. The diversity generated from microsatellite markers was compared to that of the same loci of both the Eastern and Western genetic pools. Our results show that date palms from Southeastern Niger constitute a unique group with a high level of genetic diversity. Moreover, even though this group is included in the Western genetic pool, it shows a specific originality which differentiates it from other Western populations. It also shows one of the lowest admixture levels of the Western pool. Global analysis showed a secondary genetic structure within the Western pool highlighting a new genetic group located in Southeastern Niger that distinguishes itself from the North African group.

The effect of anisotropy on amplitude versus offset (AVO) synthetic modelling in Derby field southeastern Niger delta

The effect of anisotropy on AVO synthetic modelling in Niger delta Derby field has been attempted. The objective of the study is to determine if anisotropic synthetic model can improve amplitude versus offset (AVO) analysis of CDP gathers by comparing them with isotropic synthetic model over shale-gas sand boundaries. Well logs and common depth point (CDP) processed gathers were used for the analysis. The result of the present study revealed that reservoirs in Derby field are overlain by intrinsically anisotropic shale and as such, anisotropic synthetic modelling yields the best fit to CDP gathers than the isotropic synthetic model. However, in conventional processing for AVO analysis, isotropic rather than anisotropic earth models are usually assumed, which could possibly affect the outcome of an AVO-based analysis at large offsets. Therefore, the effect of anisotropy should be incorporated and properly accounted for using the anisotropic synthetic modelling in the processing and interpretation workflows for quantitative AVO analysis in Niger delta to optimise hydrocarbon recovery.

Lipid Biomarker Analysis of Suspended Particulate Matter from the Great Kwa River, SE Nigeria: Origins and Environmental Implications of Biogenic and Anthropogenic Organic Compounds

Biomarkers found in natural waters, sediments, soils, fossils, crude oil, and coal can be unambiguously linked to specific precursors biosynthesized by biota. Petroleum and its refinery products carry their biomarker information into the environment when they are released by pollution. Lipid biomarkers can be used to assess the environmental status of an ecosystem and the degree to which it has been influenced by biogenic and anthropogenic inputs. The marine ecosystem of the southeastern Niger Delta of Nigeria is receiving new attention due to increased human and industrial development and the consequent potential health effects. Suspended particulate matter (SPM) from the Great Kwa River was characterized using biomarkers to assess such pollution. The total organic carbon contents of SPM from the river at low and high tide was 12–50% (avg 34.75%) and 16–28% (avg 24.25%), respectively. The lipid biomarkers identified using gas chromatography–mass spectrometry were mainly n-alkanes, n-alkan-2-ones, triterpenoids and minor amounts of aromatic compounds. The n-alkanes ranged from C 17 to C 35, with an odd/even predominance and C max > 27, indicating a mixed origin from higher plant wax, biodegraded detritus, and petroleum. The n-alkan-2-ones in most samples ranged from C 16 to C 33, with C max = 31, also supporting an input from vascular plants dominating the riparian zone along the river. The triterpenoids, mainly taraxerone, taraxerol, α- and β-amyrins, and friedelin, also derived from higher plants (angiosperms). Minor amounts of aromatic hydrocarbon derivatives from α- and β-amyrins were present and are likely the result of different diagenetic processes. The presence of trace fossil fuel-derived hopanes with an unresolved complex mixture of branched and cyclic hydrocarbons supported a minor petroleum product input to the SPM of the Great Kwa River.

Plane Versus Elastic Wave AVO Anisotropic Synthetic Modeling in Derby Field, Southeastern Niger Delta

AVO based Zoeppritz’s plane wave and elastic spherical wave anisotropic synthetic modelling have been investigated in Derby field, Southeastern Niger delta. The objective of the study is to investigate the influence of anisotropy on plane and elastic wave AVO synthetics modeling over shale-gas sand horizons in the field. Well log data was check shot corrected and correlated with pre-stack data and a zero phase wavelet was extracted after well conditioning and petro physical analysis. Elastic and plane wave algorithms were then used to generate offset-dependent anisotropic synthetic seismograms respectively, using p-wave sonic, s-wave and density logs and Thompsen’s epsilon (e) and delta (σ) anisotropic logs for a transversely isotropic media. Results revealed that seismic anisotropy for AVO based analysis is better modelled with elastic rather than the conventional Zoeppritz’s plane wave model and their approximations for transversely isotropic media at larger offsets. This is attributed to the breakdown of the Zoeppritz’s plane wave model and their linearized approximations at large offsets or near the critical critical angle. Using elastic synthetic model for anisotropic AVO analysis will not only ensure that the reservoir will be adequately imaged, but misinterpretation of data and misplacement of the well will be circumvented.

Anisotropic Avo Analysis for Reservoir Characterization in Derby Field Southeastern Niger Delta

Anisotropic Avo Analysis for Reservoir Characterization in Derby Field Southeastern Niger Delta