Browsing by Author "Danuor, Sylvester K."

Now showing 1 - 4 of 4
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    Characterization of complex fuvio–deltaic deposits in Northeast China using multi‑modal machine learning fusion
    (Scientific Reports, 2020) Boateng, Cyril D.; Fu, Li‑Yun; Danuor, Sylvester K.; 0000-0002-1721-4158
    Due to the lack of petroleum resources, stratigraphic reservoirs have become an important source of future discoveries. We describe a methodology for predicting reservoir sands from complex reservoir seismic data. Data analysis involves a bio-integrated framework called multi-modal machine learning fusion (MMMLF) based on neural networks. First, acoustic-related seismic attributes from post stack seismic data were used to characterize the reservoirs. They enhanced the understanding of the structure and spatial distribution of petrophysical properties of lithostratigraphic reservoirs. The attributes were then classifed as varied modal inputs into a central fusion engine for prediction. We applied the method to a dataset from Northeast China. Using seismic attributes and rock physics relationships as input data, MMMLF was performed to predict the spatial distribution of lithology in the Upper Guantao substrata. Despite the large scattering in the acoustic-related data properties, the proposed MMMLF methodology predicted the distribution of lithological properties through the gamma ray logs. Moreover, complex stratigraphic traps such as braided fuvial sandstones in the fuvio–deltaic deposits were delineated. These fndings can have signifcant implications for future exploration and production in Northeast China and similar petroleum provinces around the world.
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    Evaluation of porosity and permeability of sandstones within the Oti Group of the Volta Basin using petrophysical and petrographic techniques
    (Journal of the Ghana Institution of Engineering, 2023) Zobah, Theresa N.; Adenutsi, Casper D.; Amedjoe, Godfred C.; Wilson, Matthew C; Mensah, Emmanuel; Boateng, Cyril D.; Sarpong, Kwame K.; Opuni, Lydia N. O.; Danuor, Sylvester K.; Karimaie, Hassan; 0000-0002-1721-4158
    This study investigates the reservoir quality of sandstones in the Oti Group of the Volta Basin of Ghana. Geological field mapping, petrographic, petrophysical, mineralogical, and geochemical techniques are used to investigate the reservoir parameters of the sandstones by evaluating the fluid holding and transmission capabilities of the rocks. Results from the comprehensive study identified two sandstone formations of interest; viz. the Bimbila Sandstone and Yabraso Sandstone. Both sandstones were found to be quartz sandstones (sub-arkose and quartz arenites). The Bimbila Sandstones proved to have better porosity and permeability as compared to the Yabraso Sandstones. The Yabraso Sandstone showed porosity between 7-22 % with an average porosity of 13 % (helium gas) and permeability of 63.41 mD, which may be linked to intense cementation and intermediate compaction as well as grain size, shape and arrangement. The Bimbila Sandstones showed better porosity and permeability with a porosity range of 6-24 %, an average porosity of 14 % (helium gas) and 131.80 mD permeability. This is seen to be due to lower compaction supported by framework-stable quartz resulting in a well-connected pore system with high permeability. Further mineralogical data show that the clay minerals present are in minor concentrations. Also, the position of the Yabraso and Bimbila Sandstones in the project area as plotted on the geological map show that there is a close proximity relationship between these sandstones and the limestones; hence forming a conducive system such that if hydrocarbons are produced by the possible source rocks (limestones), they can be housed by the sandstones.
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    Underrepresentation of Local Researchers in Geophysical Studies at the Bosumtwi Impact Crater: Insights from A Systematic Review
    (Scientific African, 2023) Boateng, Cyril D.; Akrugu, Christopher A.; Wemegah, David D.; Danuor, Sylvester K.; 0000-0002-1721-4158
    Impact cratering is an important aspect of planetary evolution. Geophysics plays a complementary role in identifying impact craters on Earth given the non-unique geological characteristics associated with such craters. The Bosumtwi impact crater in Ghana represents one of the world’s most well-preserved and young mid-sized impact craters, and this study aims to evaluate the current state of geophysical research conducted in this area. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) technique was employed for data collection and analysis, which involved identifying and screening relevant sources of data. Results indicated that the maximum number of publications (14) on the Bosumtwi impact crater was recorded in 2007, with 15% of these articles being affiliated with Ghanaian institutions. Furthermore, only two articles reported funding from Ghana. The major geophysical methods applied in studies of the Bosumtwi impact crater include various techniques that have confirmed the presence of shock metamorphosed rocks. Although geophysical methods cannot provide unambiguous evidence for an impact origin of the Bosumtwi crater, they did provide additional constraints in estab lishing its impact origin. This study highlights the lack of local financial support for research in Ghana and African countries in general, with the underrepresentation of Ghanaian geophysical researchers being a concerning outcome. The absence of hazard studies such as the creation of unstable cliffs and the long-term effects of the meteorite impact on inhabitants of the Bosumtwi impact crater is particularly significant. Further research is necessary to fully understand the implications of this underrepresentation. Moreover, this study highlights the importance of research at the Bosumtwi impact crater for achieving the UN Sustainable Development Goals.
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    Validation of TRMM and FEWS Satellite Rainfall Estimates with Rain Gauge Measurement over Ashanti Region, Ghana
    (Atmospheric and Climate Sciences, 2016-10-28) Amekudzi, Leonard K.; Osei, Marian A.; Atiah, Winifred A.; Aryee, Jeffrey N. A.; Ahiataku, Maureen A.; Quansah, Emmanuel; Preko, Kwasi; Danuor, Sylvester K.; Fink, Andreas H.
    Satellite rainfall estimates have predominantly been used for climate impact studies due to poor rain gauge network in sub-Saharan Africa. However, there are limited microscale studies within the sub-region that have assessed the performance of these satellite products, which is the focus of the present study. This paper therefore considers validation of Tropical Rainfall Measuring Mission (TRMM) and Famine Early Warning System (FEWS) satellite estimates with rain gauge measurements over Ashanti region of Ghana. First, a consistency assessment of the two gauge data products, the Automatic Rain Gauge (ARG) and Ghana Meteorological Agency (GMet) Standard Rain Gauge (SRG) measurements, was performed. This showed a very good agreement with correlation coefficient of 0.99. Secondly, satellite rainfall products from TRMM and FEWS were validated with the two gauge measurements. Validation results showed good agreement with correlation coefficients of 0.6 and 0.7 for TRMM and FEWS with SRG, and 0.87 and 0.86 for TRMM and FEWS with ARG respectively. Probability Of Detection (POD) and Volumetric Hit Index (VHI) were found to be greater than 0.9. Volumetric Critical Success Index (VCSI) was 0.9 and 0.8 for TRMM and FEWS respectively with low False Alarm Ratio (FAR) and insignificant Volumetric Miss Index (VMI). In general, relatively low biases and RMSE values were observed. The biases were less than 1.3 and 0.8 for TRMM and FEWSRFE respectively. These indicate high rainfall detection capabilities of both satellite products. In addition, both TRMM and FEWS were able to capture the onset, peak and cessation of the rainy season, as well as the dry spells. Although TRMM and FEWS sometimes under/overestimated rainfall, they have the potential to be used for agricultural and other hydro-climatic impact studies over the region. The Dynamic Aerosol-Cloud-Chemistry Interactions in West Africa (DACCIWA) project will provide an improved spatial gauge network database over the study area to enhance future validation and other climate impact studies.