Reservoir characterisations from bouguer gravity data, Northern Western Desert, Egypt

ABSTRACT The current study is a trial for estimating the reservoir characterizations as density, effective porosity, and hydrocarbon saturation. It employs subsurface lithological data from 48 drilled wells dispersed over the area and gravity data. The study was based on applying the gravity stripping technique. The gravities of five well-defined depositional cycles (cycle I, II, III, IV, V) of diverse ages were calculated depending on each cycle's density and thickness obtained from the available well data. Maps were prepared for each cycle and the surface of basement rocks from which the characteristic structures were traced. New linear empirical relationships were concluded with a correlation coefficient of 0.9 from linear relationships. Accordingly, reservoir characterizations were calculated for the reservoir at the sites in which neither seismic nor well logging data are available. Contour maps were prepared for each parameter to reveal the areal distribution of these parameters in all study areas. Maps revealed that, at Abu Gharadig basin, the predicted density varies from 2.3 g/cm3 to 2.7 g/cm3, effective porosity from 13% to 30%, and hydrocarbon saturation from 50% to 90%. The main deep subsurface structure trends are the E-W, the WNW-ESE, the ENE-WSW, the NE-SW, the NW-SE, and the N-S trends.