The hydrocarbon potential of the Nigerian Chad Basin from wireline logs (original) (raw)
Related papers
2022
Hydrocarbon prospect, analysis and characterization are entailed in the processes used in identifying and delineating features/structures in the subsurface that are likely to be potential hydrocarbon reservoirs. The research was done by analyzing and interpreting well logs in combination with seismic data as obtained from Kolo Creek. Well logs were used in identifying lithologies present. Sand and shale layers were identified using the gamma ray log, potential hydrocarbon zones were interpreted using the resistivity log. These identified zones where taken into consideration for Petrophysical evaluation in which parameters such as porosity, permeability, water and hydrocarbon saturation were obtained as details in the four wells. The lithologies were correlated across the four wells to define the continuity of the identified pay zones. Seismic-to-well tie was done using checkshot data obtainable in only Well-2. There were three payzones identified, with gas, oil, and water as the fluid types. Porosity values ranges from 20% to 34%, water saturation obtained were within the range of 24% and 40%, and hydrocarbon saturation (defined as whole minus water saturation) ranged from 60% to 76%. These values showed that the hydrocarbon were present in commercial quantity hence production can take place. Three horizons were picked, six faults labelled A-F, four synthetic and two antithetic were identified across the seismic sections. The horizons were studied in detail, for time, depth and attribute studies. Time structural map was generated and it showed anticlinal structure present at its center. Depth map generated also depicted information as revealed by the time map thus validating the presence of hydrocarbon. An extracted attribute map indicated areas of high amplitudes and bright spots area being indicative of hydrocarbon accumulation present. The volumetric results showed that Reservoir A had OOIP of 467 x 106 STB and STOOIP of 389 x 106 STB.
MODELING HYDROCARBON GENERATION IN ANAMBRA BASIN, SOUTHEASTERN NIGERIA: IMPLICATIONS ON HYDROCARBON
Volume 3 of 2, July , 2022
The Anambra Basin contains oil and gas producing reservoirs in the southeastern part of Nigeria. Two-dimensional (2-D) modeling, using data from three (3) exploration wells has been carried out to assess the maturity, timing, and distribution of hydrocarbon generation in the Anambra Basin. This current study focuses on two sources in Anambra Basin namely; Coniacian Agwu and Nkporo source rocks. The results of models generated indicate that the onset of hydrocarbon generation from Awgu source rock started in the area of deepest subsidence during the late Campanian (77.30Ma). Awgu source rock in the model has a present-day transformation ratio of about 60-65%. This range indicates that the Awgu source rock has sufficient generation for hydrocarbon expulsion to occur. Nkporo source rock was equally observed to have capacity for hydrocarbon generation, but the generation was insufficient for expulsion because it has lower transformation ratio (<10%). Migrated hydrocarbon from the Coniacian Awgu source rock must have accumulated as oil and gas pools within the Coniacian Agbani and upper Campanian Owelli Sandstone. The discovery of gas in the Coniacian Agbani sandstone of Amansiodo-1, Akukwa-2, and Nzam-1 wells indicates the existence of petroleum traps in Cretaceous beds of the Anambra Basin. Keywords: Two dimensional modelling, Hydrocarbon generation and expulsion, Anambra basin, Transformation ratio, Awgu and Nkporo shales
IOSR Journals , 2019
Rocks inthe southern part of the offshore Tano Basin Ghanaare made up of the Apollonian series, with reservoirs structurally controlled in some places. Past studies in the basin gave an indication of oil and gas of considerable economic importance. The main objective of this study was to evaluate the petroleum potential of the South Tano field by finding new reservoir zones which have not yet been established due to inappropriate data analysis. This was done by processing old data from this area using the Petrel 2013 software. A combination of results using petrophysical, volumetric, seismic interpretation, and modelling, showed that the central part of the study area reveals a four-way dip closure anticline in the Intra Upper Albian Formation (IUAF), and is bounded by three distinct normal faults. Oil-water and gas-oil contactswere identified in sands of the IUAF at depths of 19234m and 1828m respectively. Volumes calculated in the reservoir sands gave a STOOIIP of 1247x10 6 million barrels(bbl) and GIIP of 41x10 6 standard cubic meter (sm 3) respectively.Previous work done in the South Tano field gave indication of oil and gas shows ofconsiderable economic relevance.
An evaluation of the hydrocarbon potentials of the gboko formation, middle benue trough, nigeria
Global Journal of Geological Sciences
A total of seventeen (17) rock samples from the Albian Gboko Formation were collected from the quarry of Benue Cement Company for organic geochemical analysis, in order to evaluate its hydrocarbon potential . Total Organic Carbon (TOC) values for the samples ranges from 0.11-0.5wt%. The rock-eval data recorded S2, hydrogen index (HI), Oxygen index (OI), Tmax, and production index (PI) of 0.04-0.11, 25-54, 50-400, 310-4610C, and 0.4-0.6, respectively. These implies that the samples has a fair to poor source rock quality with a type IV kerogen. Optical methods (R0, TAI & VKF) conducted on three selected samples of shales reveal vitrinite reflectance (R0) of 0.77%, 1.11% and 1.54%, while thermal alteration index (TAI) recorded 2.7, 3.3 and 3.7. Kerogen fluorescence indicated weak to non fluorescence. These results infer that the sediments had evolved from oil to gas window due to severe thermal effects . This indicates their potential to generate hydrocarbon gas
HYDROCARBON RESERVOIR CHARACTERIZATION USING WELL LOG IN NIGER DELTA BASIN OF NIGERIA
A study for the characterization of hydrocarbon reservoirs using well logs have been carried out in the Niger Delta in order to evaluate the field’s hydrocarbon prospectivity, delineate hydrocarbon and water bearing zones and petrophysical properties of the hydrocarbon reservoirs of interest. Data from four composite well logs comprising of gamma ray, resistivity, neutron, density logs were used for the study. Gamma ray log was used for lithology differentiation, Resistivity log was used to identify form the response of resistivities of various zones. High resistivity signifies hydrocarbon bearing zone while low resistivity value indicates shaley zones. The combined density and neutron logs was used for the identification and differentiation of the various fluids in the sections. The results from the study showed that nine out of the twenty-two zones of interest (sand bodies) was delineated and correlated across for possible identification of hydrocarbon, and were identified as potential hydrocarbon reservoirs. Also the result indicates that there is an increase in porosity with an increase in permeability. The evaluated petrophysical parameter indicated that porosity ranges between (18-31%), water saturation (14-44%), hydrocarbon saturation (56-86%), permeability (138-10662)