Abstarct: The last ten years have witnessed a growing interest in the evolution of technology and autonomous systems in drilling operations after the oil and gas companies realized that the next stage in the exploration and production of oil gas is to drill more wells, often characterized by narrow pressure margins. The drilling challenges in narrow-margin pressure wells such as depleted reservoirs, deep water, and High-Pressure high-temperature (HPHT) wells require more accuracy and high sensitivity in drilling operations. These wells are more susceptible to drilling incidents such as formation influx, lost circulation, and pack-off, leading to increased non-productive time (NPT) and increased costs. The introduction of the automation process in drilling systems baxsed on automated tools during drilling operations was required to reduce the NPT, thus reducing the drilling costs and keeping the humans away from hazardous areas. Additionally, an automated system is intended to optimize the drilling operations by monitoring, modeling, and controlling the acquisition data, which are real physical measurements transmitted from the well downhole. The Managed Pressure Drilling (MPD) methodology with different variants and techniques is seen to be a promising solution during drilling operations in narrow pressure margin wells compared to conventional drilling methods. Drilling fluid properties and rheology play an essential role during drilling operations. Choosing the proper mud density, viscosity, and rheology is key to maintaining equivalent circulating density (ECD) between formation pore pressure gradient and fracture pressure gradient, thus avoiding drilling problems such as formation influx, lost circulation, and stuck pipe. In this thesis, the OpenLab drilling simulator provides synthetic measurements that are used to create a workflow algorithm that selects the optimum set points for MPD back-pressure and drilling fluid properties. Optimization of the MPD method and selecting proper drilling fluid properties during drilling help to maintain the bottom-hole pressure (BHP) and prevent lost circulation, kick occurring, and other drilling incidents and thus maintain the wellbore in safe mode.