Prediction of in situ stresses, mud window and overpressure zone using well logs in South Pars field

Abstract

AbstractTo analyze the stability of the hydrocarbon wells, it is necessary to determine the exact value of in situ vertical and minimum and maximum horizontal components of the stress. Determination of the in situ stress in well planning is vital in detecting and preventing the occurrence of the instability in the walls of the drilled wells and fluid loss. Evaluation of the magnitude of in situ stress is required for optimizing drilling, well completion and reservoir simulation. Hence, access to the complete information on the in situ stresses while drilling is essential, especially in naturally fractured zones for prospective infill drilling in the field development plans. In this paper, the value of the in situ stress is determined for two wells drilled in the South Pars field, Iran. With information on the in situ stress and the pore pressure, the mud window for different depths of this well is obtained. The appropriate mud density and overpressure zone for safe drilling in the borehole are also determined.