In-situ And Laboratory Determination Of Thermal Properties Of Tar Sands In Eastern Dahomey Basin Southwestern Nigeria

Thermal properties of tar sands are of paramount importance in the design of commercial recovery operation that involves heating of the tar sands as well as in the research activities that preceded field applications. Estimation of thermal properties such as thermal resistivity, thermal conductivity, thermal diffusivity, thermal effusivity and volumetric specific heat is of great importance in bitumen recovery from tar sands where heat transfer takes place through injection of thermal energy into the tar sand formation. This research work therefore aims at determining thermal properties of tar sands in the Eastern Dahomey basin Southwestern, Nigeria with a view to having more information in planning for thermal recovery of the tar sands. Twelve locations were established along the tar sands belt in order to measure its thermal properties. A KD2 Pro analyzer was used to measure the thermal properties. In laboratory, thermal properties for samples from each location were measured and physical properties that influenced them such as grain size distribution, percentage by weight of bitumen content, moisture content, bulk density, porosity and dry density of the samples were determined. Thermal conductivity, specific heat and bulk density were used to calculate the thermal effusivity of the tar sands. Positive correlations was observed between the field and laboratory measurements values of the thermal resistivity, thermal conductivity, thermal diffusivity, thermal effusivity and volumetric specific heat with R-values 0.86, 0.85, 0.81, 0.78 and 0.49 respectively. It was observed that the thermal properties of the tar sands determined have close similarities with those reported on Athabasca tar sand Canada, therefore the thermal recovery process used in the Athabasca basin could also be employed in the Eastern Dahomey basin Nigeria. Therefore, thermal properties of tar sands are quite essential in thermal recovery of bitumen so as to minimize wasting of thermal energy and resources.