NUMERICAL SIMULATION OF GROUNDWATER FLOW IN A BASIN UNDER TECTONIC COMPRESSION
At several of the sampling sites, analyzed water compositions, measured water temperatures, and calculated reservoir temperatures, all point to waters that are anomalous in both chemistry and temperature. Water samples from one shallow well and three deeper wells, all located in the immediate vicinity of major thrust zones (MMT and MBT), demonstrate clear imprints of admixture of oil-brines. Hydrochemical signatures of strontium (Sr), silica (SiO2), boron (B) - and the geothermometric signatures - all indicate a deep circulation of the emerging groundwater. Remarkable clustering of all the thermal and hydrochemical anomalies along the major mapped faults suggests that the anomalous waters ascended along these faults from greater depths.
The basin has been divided into several hydrostratigraphic units to perform numerical simulations using FEMWATER module of GMS (v 5.1). The numerical model is being used to simulate both, deformation and induced fluid flow. Input parameters for the model include recharge, discharge, bulk compressibility of the media and ramping structures to incorporate tectonic compression. The ultimate objective of the numerical simulations is an attempt to distinguish between topography-driven and tectonically induced flow. The results from both simulations will be compared with the field measurements of hydraulic heads to see the extent - if any of positive residuals, signifying pressure excess over the topography-driven hydraulic heads.