Modeling Mud Loss in Asmari Formation Using Geostatistics in Gachsaran Oil Field

Studying of mud loss in Asmari formation is very important because it consists most of drilling expenses. Considering that studied oil field encounters severe mud loss in Asmari formation, therefore the purpose of this study is recognition of the lost circulation zones and illustrating the mud loss distribution in Asmari formation. The mud loss maps in Asmari field were plotted in RMS software using moving average algorithm method. For this purpose, the data of 363 wells in gachsaran oil field was processed after data preparation, for mapping and 3D modeling of 11 different zones in Asmari formation. The data processing includes different stages such as elimination of outliers, normal transformation, drawing the histogram, variography and estimation and modeling. In this research, the geostatistical kriging method was also used for estimation and 3D modeling of mud loss in Asmari formation so that the output of geostatistical modeling method shows the localized and better results. Consequently, by applying and analysis of results, the 2D and 3D models of mud loss in Asmari formation were demonstrated. By simulation and modeling of mud loss and its comparison with reservoir fault modeling and production indexes plots, it was identified that the dominant mud losses are related to fault zone fractures and in minor cases the increasing of mud weight is the reason of mud loss. Applying appropriate operations such as under balance drilling (UBD) and suitable well placement, use of drilling mud with proper mud weight in severe mud loss points, use of NIF and MMH especial drilling muds with lowest formation damage, or a combination of these methods are suggested for mud loss control in critical points of the oil field.