The Oil-Shale Unit of the Judean Lowlands, Israel – Findings from a Prospection Study

The depletion of conventional oil reservoirs and the growing need for alternative energy sources have led companies world-wide to study and explore for unconventional oil sources, among them is oil-shale. “Oil-Shale” is the common name for sedimentary rocks which contain more than 5% total organic carbon, mostly in the form of kerogen. One of the largest oil-shale reservoirs on the globe is found at the Judean Lowland Basin (JLB) in Israel. Its estimated yield potential is about 250 billion oil barrels, compared with ~750 bbl of conventional oil throughout the entire Middle East. The Oil-Shale is found in a tight chalk layer of the upper cretaceous. A thick (>100m) chalk sequence, partly silicified, separates the unit from the underlying aquifer, which is the main source of potable water in Israel. The oil shale is overlaid by a 250-350m thick plastic-marlstone, clay and tight chalk, isolating it from the surface. The structure, stratigraphy and lithology of the basin make it exceptionally feasible for oil production using an In-Situ conversion process. The method is based on a gradual, in-situ heating of the rock (without the need for mining) to a temperature where the kerogen pyrolyses to lighter organic molecules. The light products (mostly methane, Liquid-Petroleum-Gases, gasoline, jet fuel and diesel) are then pumped to the surface, while the heavier residue and petroleum “cock”, are left in the rock. The ‘Israel Energy Initiatives’ company obtained a prospection license to evaluate the feasibility of oil production at the JLB using the ICP technology. Our study comprises of appraisal drillings, laboratory analyses and numerical modeling, all as a preparation for a short-term experimental in-situ oil production.