Geostatistical simulation study of porosity and hydrocarbon saturation values in the vicinity of Adiyaman, Turkey

The Cretaceous Mardin Group sequence in the Adiyaman region displays a "continental platform type" petroleum system. The main lithologies within the sequence are shales, mudstones, and carbonates. Most dolomitic and bioclastic wackestones of the Karababa-C member and dolomites of the Derdere Formation have hydrocarbon reservoir characteristics, whereas shales and some carbonates of the Derdere and Karababa-A member have mature hydrocarbon source-rock properties. To determine the porosity and hydrocarbon saturation value vs. depth and areal extends, geostatistical simulation for the three dimensional evaluation of the study area were constructed and the variogram functions were calculated and then three dimensional variograms which were obtained from the porosity and hydrocarbon saturation values were modelled spherically. According to te simulation results, the porosity values in the Karababa-C member decrease with increasing depth. The amount of hydrocarbon saturation tends to decrease with increasing depth, as well and the decrease ratio is 7.2%. The suitability of the model parameters were validated with back-kriging technique.