Browsing by Author "Taofeeq Issa"

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    Time-Depth Analysis of Tertiary-Cretaceous Sediments of Lake Sub-basin, Northeastern Nigeria
    (MEDGU, 2022-07-24) Gabriel Omolaiye; Jimoh Ajadi; Saminu Olatunji,; Bashiru Ojulari; Taofeeq Issa; Umar Issa
    Time-depth conversion analysis of time migrated seismic images was undertaken on Block A, Baga/Lake sub-basin of Borno basin Nigeria, to predict the appropriate velocity model suitable for depth conversion away from six existing well control points. Three velocity models were used for the time to depth conversion including average velocity-time analytical function, 2nd Order Polynomial time- depth analytical function and instantaneous velocity analytical function. The velocity models were tested with the shallow and deep horizons representing the tops of Kerri-Kerri and Gongila Formations penetrated by six wells fairly spread on the 3,891 km2 of 3D seismic data. The results show that each model has variable degree of accuracy after depth conversion at the two formation tops. The average velocity-time analytical technique appeared as the best technique for the time-depth conversion having errors in the range of -0.12 to 145 meters at shallow and deeper formation respectively. The 2nd order polynomial time-depth analytical function and V0-K techniques gave a depth uncertainty greater than 135 meters at the shallow formation and over 1,000 meters at the deeper formation. The maximum percentage error recorded for both formations using average velocity technique was 0.48% this is less than 5% considered good in the practical situation, it is therefore recommended to be used for velocity modeling and depth conversion study in Baga/Lake sub-basin of Borno Basin, Northeastern Nigeria.