Abstract Sand bodies deposited across normal growth faults and associated rollover anticlines are critical reservoirs for the accumulation of oil and gas. This paper addresses aspects of structures and depositional environments of some sand bodies within the Tomboy field, offshore western Niger Delta. Structural interpretation was undertaken to identify and assign faults found in the 3-D seismic volume. Time and depth structure maps in combination with well logs were used to produce for five...
Abstract Subsurface core samples obtained from Enugu 1325 and 1331 wells within the Anambra Basin were characterized by standard organic geochemical methods; Rock-eval and GC-Ms; to deduce the hydrocarbon potential, source input of the organic matter and palaeodepositional environment of the basin. The lithologies in both wells consist of coals, shales and siltstones and belong to the Mamu Formation. The Total Organic Carbon (TOC), Soluble Organic Matter (SOM) and Genetic Potential (GP) of t...
Abstract This study employs 3D Post-Stack Time-Migrated seismic data from the DN-Field, within the Coastal Swamp depobelt of the Niger Delta in predicting lithofacies and fluvial facies of OVK-1 sand bodies in the Agbada Formation, as a tool to identify new drillable prospects. A lithofacies model for OVK-1 reservoir sand body was generated after upscaling using Most Of, as the averaging method. Calibrated by fluvio-facies at the well locations, channel sands were identified in OVK1 reservoi...
Abstract The Akinbo Formation comprises a sequence of mostly dark, pale-greenish grey, laminated shale, slightly glauconitic shale, sandy shale with subordinate claystone lenses. Selected subsurface samples of the shaly facies as penetrated by Akinside 1582 well in eastern Dahomey basin, were investigated by sedimentological, mineralogical and geochemical parameters to ascertain the hydrocarbon potential and deduce the influence of variations of clay mineral indicators on the prospect. Values...
ABSTRACT Schistose rocks from Okene-Lokoja area, SW Nigeria, consist of quartz-biotite schist, quartz muscovite schist, amphibole schist, and quartz schist. Major element compositions (oxide wt. %) of the schists together with their trace element contents (Ba. Ce. Cr. La. Li, Ni, Rb, Sr, V, Y, Zn, and Zr) are presented. The schists (excluding the quartzitic variety) are enriched in SiO,,K,O, Rb and Ba but depleted in total Fe, O. Mno. TiO,, MgO, Ni and Zn compared with rocks of similar compos...
Abstract The major lithostratigraphic units of the eastern Dahomey Basin are the Araromi, Ewekoro and Akinbo Formations. Field studies show that the Araromi and Akinbo Formations contain shaly facies, while the Ewekoro Formation contains essentially fossiliferous limestones. The Araromi shales are dark and bituminous, while those of the Akinbo are fissile and concretionary. Selected subsurface and outcrop samples of these lithotypes were analysed to ascertain their palaeodepositional environm...
Abstract Clay bodies occur as lenses and interbeds within the predominantly shaley Akinbo Formation in the eastern Dahomey Basin. They are greenish to grayish, plastic, and in some places contain concretions. In order to assess their sedimentological significance as well as evaluate their potential as industrial raw materials, representative outcrop arid borehole samples .were subjected to mineralogical, chemical and physical characterisation. • • •, •, > l j . Mineralogical determin...
ABSTRACT Among the major lithostratigrahic units making up the Bida Basin are the lokoja and Patti formation overlain by the Agbaja Ironstone.
ABSTRACT The Agbowo-Orogun area of Ibadan, which is within the basement complex of southwestern Nigeria, is underlained by banded gneiss of the migmatites-gneiss complex. A total of thirty-five water sample?., made up of thirty-two from groundwater and three from surface water, were analyzed for their physico-chemical characteristics with the aim of assessing their quality and usability.
ABSTRACT This study presents the mineralogical, textural and geochemical characteristics of the regional Maastrichtian Ajali Sandstone in Anambra Basin, SE Nigeria. The intent is to highlight possible constraints on the chemical weathering conditions of the source materials on one hand, and to infer the provenance on the other hand. The investigation approach involved field studies and collection of samples from 12 different outcrop locations, followed by laboratory studies involving grain-si...
Abstract In the Ibokun area of the Ilesha schist belt of southwestern Nigeria, the dominant rock types are granite gniess and amphibolite. The granite gneiss is medium to coarse grained, with lineation marked by alignment of biotite and microcline porphyroblasts. The amphibolite is commonly massive to weakly foliated, consisting to bluish-green to yellowish-green to sheaf-like aggregate of hornblende set in a fine grain matrix of tabular plagioclase. A total of 25 water samples, obtained from...
Integrated sedimentological and geochemical studies have been carried out on the sediments of the Lokoja and Patti Formations within the southern Bida Basin with a view to deducing the provenance, palaeodepositional characteristics and tectonic history of the sediments. Field observations show that the Lokoja Formation is made up of conglomerates, coarse to medium grained sandstone and claystone while the Patti Formation consists of medium – fine grained sandstone, claystone, shale, siltsto...
ABSTRACT Subsurface samples of Mamu Formation from Ezimo 1235 and Enugu 1327 wells, located within the Anambra Basin were examined for organic geochemical characterization and biomarker content in order to determine the lithofacies association, hydrocarbon potential as well as the palaeodepositional environment. The sediments are made up of siltstone, dark coal, highly fissile shale and mudstone. Selected samples, made up of shale and coal from both wells were subjected to Rock Eval and gas c...
ABSTRACT The Niger Delta is a prolific petroleum sedimentary basin in the Gulf of Guinea and is posed with a major challenge of overpressure development in many of its fields. Integrated study, utilising 3D seismic data and well logs from four wells, namely; OBL_1, OBL_2, OBL_4 and OBL_5 was carried out in the offshore Niger Delta. The study aims at evaluation of structural influences on pressure development, detection of overpressure zones and consequently examining the risk involved in dril...
Subsurfaces samples of predominantly carbonate Ewekoro Formation, obtained from the Ibese core hole, in the eastern Dahomey Basin, were examined based on petrography and geochemistry indices.