[01] Hussein Saeed Almalikee, Fields Division, Basrah Oil Company, Basrah, Iraq.

Rock mechanical properties that include compressive strength, shear strength, cohesion and internal friction angle are important elements in any Geomechanical study that aims to maintain wellbore stability and reduce non-productive time (NPT) during drilling new wells in any oil or gas field. The main goal of this study is to estimate the values of rock strength for the Geological column of Rumaila oilfield using well log data. The values of rock mechanical properties were measured directly throughout laboratory tests (Uniaxial and triaxial tests) on core samples obtained from wells A, B, C and estimated indirectly using well log data (gamma ray, density, sonic (compressional and shear), and Neutron logs) from eight wells (A, B, C, D, E, F, G and H), covering the geological column starting from Sadi to bottom of Zubair Formation in Rumaila oilfield, the results showed similarity to the direct measurements that been obtained from uniaxial and triaxial mechanical laboratory tests which make it reliable method for continuous measurements of rock strength and can be used for wellbore stability analysis or any other Geomechanical study.

Rock Compressive, Shear Strength, Internal Friction Angle, Cohesion

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