Completion fluids are specialized liquids used in the oil and gas industry during the final stages of well construction. Their primary purpose is to maintain pressure in the wellbore and prevent the influx of formation fluids, ensuring the integrity of the well. These fluids are carefully formulated to balance density and viscosity, allowing for effective control of the well environment. These fluids can be composed of various materials, including water-based or oil-based solutions, and may contain additives to enhance performance. Proper selection and management of completion fluids are crucial for the success of the well and the safety of the surrounding environment.