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RESERVOIR GEOMECHANICS is becoming an accepted part of oilfield development planning and operations. The basic approach to geomechanics analysis is to use what data is available for interpretation of rock properties, earth stresses, and pressures. The development of a mechanical earth model (MEM) is essential in making the best use of field geomechanics related information. Pore pressure is a key parameter within a MEM. Pore pressure estimation by using different techniques such as, Eaton method, ratio method and porosity method, where the porosity method can be considered as the best method to estimate the formation pore pressure. The poroelastic constant (α) and poroelastic stress coefficient (η) are two important parameters in building any geomechanical model. Consequently, new (modified) correlations have been developed in order to account or include heterogeneity for anisotropic material (formation) with good results obtained from different fields in Sirte basin- Libya compared to actual measurements. The fracture pressure is the lower boundary of lost circulation; therefore, its minimum and maximum limits are computed and a sensitivity analysis is done on them. Wellbore stability analysis (failure analysis) is performed using Mohr- Coulomb failure envelope for each zone in order to estimate the stress state and investigate possibility of rock failure and/or source of failure. Back calculations technique is adopted in order to estimate the tensile and unconfined compressive strengths (UCS) of the rock. When the results compared with those obtained from worldwide-used correlations, good matching is observed. Finally; A DrillMap is created for every well of the studied well. The DrillMap displays a summary of the key drilling hazards, wellbore stability, mud weight windows, and additional information of the well necessary to predict the problems might occur during production.
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