Geomechanical modeling is a key driver in attaining optimum wellbore stability while drilling horizontal wells in the orientation of the minimum horizontal stress (Shmin). Although geomechanical modeling remarkably helped to obtain best estimates on minimum required mud weights for ensuring stable wellbore, these models still have uncertainties along the horizontal wellbores. Multiple factors contribute to wellbore instability such as lateral changes in rock mechanical and strength properties, formation pressure, and localized digenetic effects. An improved geomechanical workflow has been developed to manage uncertainties and enhance operational efficiency. The proposed methodology is composed of calibrated geomechanical models for wellbore stability assessment that to be applied for upcoming planned wells during drilling operations. A number of key parameters were identified to build customizable geomechanical solutions and deliver stable wells. These key parameters include occurrence and sequence of strong/weak formation intervals and risk of differential sticking across depleted intervals. Each plan well requires a solution that includes computation of minimum required mud weight, formulation of mud system to handle multiple failure mechanisms, design of Logging-While-Drilling (LWD) Bottom Hole Assembly (BHA), and real-time geomechanical monitoring. Upon implementation of this methodology, the horizontal well was drilled successfully in a controlled manner. In this paper, an experience is highlighted to demonstrate the effectiveness of customized geomechanical solutions. It discusses the implementation of geomechanics at a specific sub-surface condition to attain the best result. In this study, there was a high risk for wellbore instability while drilling through highly stressed formation in minimum stress direction. The task was approached in a systematic way with a core objective of ensuring practical implementation of geomechanics findings, and follow the recommendations to mitigate wellbore stability related issues. There were two options that were been evaluated in this paper to prevent and mitigate wellbore stability, the first one is to low mud weights together with wellbore surveillance using real-time technolog, the second on is to use higher mud weights using sealing polymer and proper mud system formulation to avoid differential sticking.

Permeability is one of the most important parameters in formation evaluation, reservoir characterization, and hydrocarbon production. There are many methods in the industry to model in-situ permeability relationship, but it is also critical to know that permeability decreases with the increase of effective stress as has been reported i.e. permeability is sensitive to changes in stress and pore pressure. In this study, a relationship between permeability and effective stress is developed for Sandstone reservoirs using 4Dmodel with a two-way coupling between Geomechanics and fluid-flow. A relationship between in-situ horizontal stress and permeability has been investigated in several reservoirs around the globe. This paper addresses fundamental controls on stress dependent permeability, as identified through modeling and observations. The model developed provides a description of effective stress and explains the dynamic impact of geomechanical stresses on key production parameters in an effective way. This procedure will lead to a more robust simulation model and history match for the life of the reservoir. Conventional measurement (porosity, permeably, and grain density) has been observed in sandstone formation, while acoustic slowness is obtained by wireline and/or LWD measurement to create empirical correlations between permeability, porosity, velocity and effective stress. These correlations show a good agreement with available geomechanical data that commonly used in the industry for sandstone Formation. A workflow for modelling is developed to improve formation evaluation and assessment of stress-dependent permeability. The model can help in predicting sweet spot and enhance the long-term productivity