RMZ – MATERIALI IN GEOOKOLJE

426 Adewale, A., Olawale, O. O., Martins, O. M.ConclusionThe high porosity and permeabilityvalues obtained and the degree of sortingof the reservoir sands are indicationsof a good reservoir quality in thestudy area. Also, the viscosity and specificgravity values obtained from theanalyses indicate highly viscous andlow specific gravity oil. These, coupledwith high asphaltene content arean indication of severe biodegradation.Moreover, result of API gravity equallyshowed that the deposits belong tothe class of heavy oil. The biodegraded,low viscous low API gravity of thetar which impregnated the sands explainsthe high resistivity value of thetar sands deposit around the study areain addition to the fact that molecularcompounds (hydrocarbons) are incapableof ionic conduction.The reservoir characteristics of the tarsands in Gbegude area are similar tothose earlier studied by other researchers,in that porosity values obtained fallbetween 16–24 %; percentage of finesranges from 1–7 %, and are mainly composedof kaolinitic clay and silt; depthof burial ranges from 0 m to >50 m; tarsand reservoir is about 18–72 m thick.ReferencesAdegoke, O. S., Enu, E. I., Ajayi, T. R.,Ako, B. D., Omatsola, M. E. & Afonja,A. A. (1981): Tarsand, a New EnergyRaw Material in Nigeria. Proc.Symp. On New Energy Raw Material,Karlovy Vary, p. 17–22.Adegoke, O. S., Ako, B. D., Enu, E. I(1980): Geotechnical Investigationsof Ondo State Bituminous Sands. Vol.1. Geology and Reserve Estimate,Report. Geological Consulting Unit,Dept. of Geology, University of Ife,Ile-Ife, pp. 257.Ako, B. D., Alabi, A. O., Adegoke, O. S.& Enu, E. I. (1983): Application of ResistivitySounding in the Explorationfor Nigerian Tar sand. Energy Explorationand Exploitation, Vol. 2, No. 2,p. 155–164.Burke, K. C. B., Dessauvagie, T. F. J.,Whiteman, A. J (1972): The Openingof the Gulf of Guinea and GeologicalHistory of Benue Depression and NigerDelta, Nature, Physical Science,233 (38), p. 12–21.Cole, R. D. & Christopher E. M. (1992):Reservoir Characterization of TensleepSandstone, South Casper Creek Field,Wyoming, and (abs): AAPG Bulletin,Vol. 76, No. 8, p. 1257.Dutton, S. P. & Finley R. J. (1988);Controls on Reservoir Quality inTight Sandstone of the Travis PeakFormation, East Texas: SPE FormationEvaluation, Vol. 3, No. 1, p.97–104.Enu, E. I. (1985): Textural Characteristicsof the Nigerian Tar sand. Sed. Geol.44, pp. 65–81.Folk, R. L. (1974): Petrology of SedimentaryRocks. Hemphill Publ. Co., Austin.Texas. pp. 159.Idowu, J. O., Ajiboye, S. A., Ilesanmi, M.RMZ-M&G 2012, 59