2015).ДЇormation stress is characterized using the three principal stresses. Many authors have mentioned these problems using MEM results (Fjaer et al. Subsurface rock behaviors, including mechanical properties and stress changes during drilling, can detect many problems, especially when the well passes through high-pressure deep formations. Around the wellbore of the studied wells, formation breakouts are the most expected situation according to the results of the wellbore stress state (effective vertical stress ( Пѓ zz)вЂ‰>вЂ‰effective tangential stress ( Пѓ ОёОё)вЂ‰>вЂ‰effective radial stress ( Пѓ rr)). Low maximum and minimum horizontal stress values are also observed in high-pressure zones as compared to normal pressure zones indicating the effects of geomechanical properties on horizontal stress estimation. The results in terms of rock mechanical properties showed a reduction in PoissonвЂ™s ratio, Young modulus, and bulk modulus near the high-pressure zones as compared to normal pressure zones because of the presence of anhydrite, salt cycles, and shales.

The directions of the horizontal stresses are determined in the current wells utilizing image-log formation micro-imager (FMI) and caliper logs. The magnitude of different stress types and geomechanical properties was estimated from well-log data using the Techlog software.

The calculations are achieved by building one-dimensional mechanical earth model using the data of four deep abnormal wells located in Southern Iraqi oil fields. This study aims to detect optimum perforation location by investigating the changes in geomechanical properties and wellbore stress for high-pressure formations and studying the difference in different stress type behaviors between normal and abnormal formations. Reservoir geomechanics is one of the key factors to find optimal perforation location. Hence, the effective stress increase will cause the soil to get compressed and settled.Optimum perforation location selection is an important study to improve well production and hence in theВ reservoir development process, especially for unconventional high-pressure formations such as the formations under study. When the water is drained from soil pores, it tends to cause soil settlement. Here, the term Оі d is dry density of layer 1, D 1 is depth of first layer, Оі sat is saturated density of layer 2, D 2 is depth of layer2, Оі sat is saturated density of layer 3 and D 3 is depth of layer 3.Д®ffective stress plays vital role in soil settlement and shear strength of soil. The effective stress can be computed at the bottom of layer 3 as below Sample layer of soil is shown in the image below. Here, the term Оі w is unit weight of water and z w is depth of water table. The neutral pressure can be computed using the relation below. Here, the term Пѓ v is total vertical stress and u is neutral pressure. The effective stress is computed using the relation below. It increases with increasing depth of soil. This is defined as effective overburden pressure and otherwise will be called as inter-granular stress or effective stress. The load is directly transferred through the particles contact only. When the load increases, the pore water gets drained out from the soil.

When the soil is subjected to some load, it transfers the load to water in the pores and soil grains.

Overburden stress techlog