Papers by VICTOR UCHECHI Ukaegbu
The massive exploration and production well drillings in Nigerian oilfield indicate the demand fo... more The massive exploration and production well drillings in Nigerian oilfield indicate the demand for drilling fluid supplements such as baryte, in managing over-pressured formations and preventing hazardous blowouts. The underdevelopment of Nigerian solid minerals has created a wide gap between the demand and supply of the local resource, whereas there exist some assertions that the Nigerian baryte quality is below the American Petroleum Institute, API, standard. This study aimed at testing and evaluating qualitatively, based on API standards, some baryte ores from the Benue area, Nigeria, to establish their usefulness or otherwise in oilfield drilling operations. General field studies and sampling with laboratory studies were done including flame tests, X-ray Diffraction and X-ray fluorescence, to confirm mineralogy and chemical compositions of the barytes respectively and very importantly, the API tests prescribed for drilling grade barytes were carried out. The results showed impre...
Acta Geochimica, 2017
A wildcat may not result in a petroleum prospect; however, it may indicate potential need for fro... more A wildcat may not result in a petroleum prospect; however, it may indicate potential need for frontier exploration, since petroleum could leak into economic accumulations. Carbazoles and benzocarbazoles are nitrogen compounds in petroleum and can be employed to explicitly explain migration direction and distance of leaking petroleum. The hypothesis of this study is that the mechanism of the reaction involving the attraction of carbazoles to clay minerals on the matrix of the walls along their migration pathways determines the isomer that is preferentially attached to the mineral matrix. The objectives of this study are (a) to produce a profile for carbazoles and benzocarbazoles ratios in the cap rock overlying the reservoir, (b) to compare carbazole and benzocarbazole ratios to 20S/ (20S ? 20R) aaaC 29 Sterane maturity ratios (c) to infer migration direction from the carbazoles and benzocarbazoles ratio. Samples used were side wall cores and drill cuttings of water-based mud drilling. The EOM (extractable organic matter) from various formations overlying the reservoir was obtained using Soxtherm Automatic Equipment. The TPH (total petroleum hydrocarbon) was obtained from the EOM by using a precleaned isolute C 18 500 mg / 3 mL column, eluted with hexane, while the polars were eluted with dichloromethane. Fractionation into saturates and aromatics was done using a silver nitrate-silica gel column. The profiles of 1,8/1,3 and 1,8/2,4 dimethyl carbazoles and the benzocarbazoles ratios show a vertical gradient of decreasing ratio with increasing vertical distance from the reservoir. This corroborates the %VRo equivalent of 20S/(20S ? 20R) aaaC 29 Sterane and the carbazole ratios infer vertical migration of leaked petroleum.
Journal of Petroleum Exploration and Production Technology, 2015
The source kitchen of a petroleum system is that part of the pod of active source rock which is m... more The source kitchen of a petroleum system is that part of the pod of active source rock which is mature and generates the petroleum that charges the reservoir rock. The location of the source kitchen of a petroleum system is vital to the explorationist, its knowledge fosters the prediction of migratory pathways and the migratory losses prior to present times, also estimates potential volume of accumulation. Hither to, mapping of the petroleum basins was based on total organic carbon (TOC), hydrogen index (HI) signatures and maturity history of the source rock and has been used as the basis to suggest locations of petroleum kitchens. In contemporary times, 4D seismic or 3D time lapse geochemistry had been used to suggest location of source kitchen. However, settled is the concept of lateral maturity gradients, implying that within reservoir scales of a kilometer to tens of kilometers, regional petroleum emplacement direction could be deduced from subtle changes in maturity of successive charges of petroleum into the reservoir. In this study, the sterane isomerization ratio (20S/20S ? 20R aaaC 29) was used to determine the maturities of the hydrocarbons from various wells in the Kolo Creek and the Nembe Creek reservoirs. Subtle increases in maturities were observed to be in a NE-SW direction for the Kolo Creek reservoir and in a NW-SE direction for the Nembe Creek reservoir. The direction of increasing maturities relative to the location of the reservoirs could be extrapolated for both reservoirs towards offshore Gulf of Guinea; this is invariably the direction of location of the source kitchen for the Niger Delta oils.
Assessment of some baryte ores from Northern Cross-River, Nigeria, for oilfield drilling fluid supplement
Journal of Degraded and Mining Lands Management
There is a very high demand for the American Petroleum Institute (API) grade baryte in Nigeria du... more There is a very high demand for the American Petroleum Institute (API) grade baryte in Nigeria due to the continuous massive drilling in oil and gas fields. Considering the presumption that local baryte is of low quality, processed baryte is imported, leading to great national revenue losses. Some baryte deposits in the Northern Cross River, Nigeria were sampled and studied in field and laboratories, based on API standard requirements (2004 and 2010), to ascertain their suitability for use as weighting additive in drilling fluids. Furthermore, flame testing of the samples yielded yellowish-green flame indicating barium presence; X-ray diffraction (XRD) and X-Ray fluorescence (XRF) analyses confirmed the mineralogy and chemical composition of the samples, respectively. The results revealed the Specific Gravity, SG range of 4.37 to 4.52; concentration of alkali earth metals as calcium 8.40mg/kg to 62.10mg/Kg; the residue >75micron and particle sizes <6microns processed had norma...
Earth Sciences, 2013
Field investigations in the western part of Mukuru area indicate intense structural imprints and ... more Field investigations in the western part of Mukuru area indicate intense structural imprints and high HT/HP metamorphism, and some magmatism. The rock units in the area include migmatitic gneisses, granulites, amphibolites, schists, charnockites, epidiorites and granites. The charnockites which are common in the shear zone and boundary areas appear to mark the end of magmatism. However, relicts of magmatic rocks mapped at Ubong Community in the study area suggest earlier magmatism. The metamorphic rocks are strongly deformed in a N-S to NE-SW direction with ghost structures, pinch and swell structures, ptygmatic veins, showing evidence of extensional tectonics. No visible contact relationship between the migmatitic gneisses and schists was observed. Diagnostic metamorphic structures like fine banding/layering of alternating dark-and light-coloured layers are conspicuous in gneisses and some amphibolites while schistosity and deep weathering are present in schists. The geodynamic features prevalent in Mukuru area are deformation and metamorphism. They indicate a possible petrogenetic link to southern Obudu Plateau in the north, western Cameroon in the east than Bansara in the west.
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Papers by VICTOR UCHECHI Ukaegbu