A second version of the three-dimensional (3-D) geological model of onshore Lebanon was generated. The model includes all outcropping stratigraphic formations, Quaternary till Triassic which was extrapolated from neighboring countries and understanding of the regional geology. The formations were grouped in main units based on their major lithological components. Given the scarcity of deep well data and absence of onshore seismic data, the model relied primarily on the 1/50,000 scaled geological maps and cross-sections published by Dubertret.
The initial input data (version 1) consisted of around 19,050 pseudo (virtual) wells and 1,171 faults which were derived from maps and cross-sections in addition to a digital elevation model. The inverse distance gridding method was used for interpolation whereby fault polylines were honored. The model allows for generation of various structural elevation maps and models, thickness (isopach) maps, plan geological maps at different depths, infinite number of multi-directional cross-sections and fence diagrams as well as volume calculations.
Version 2 consists of an enhanced, calibrated model, which incorporates actual data including the 7 old deep old oil wells, hundreds of actual shallow wells with their associated geophysical logs, 27 enhanced cross-sections as well as maps and actual deep well information from neighboring countries allowing modeling of the Triassic unit across the country.
The model has limitations pertaining to difficulties in revealing potential subsurface faults. The model also assumes that the fault planes are vertical and extend from surface till bottom of the deepest modeled formation.
The model provides an understanding of the onshore geological setup of Lebanon and is believed to reveal new findings and insights that could support oil & gas exploration if linked to the offshore geology. The model shall be continuously improved through loading data that is being gathered from the literature and from activities being carried around Lebanon. Potential loading of the interpreted horizons from onshore seismic surveys being acquired onshore would be ideal for model calibration.