Completion fluids, also known as completion brines or workover fluids, are specialized fluids used in the oil and gas industry during well completion and workover operations. They serve several important purposes, including:
Wellbore Stability: It help maintain the integrity and stability of the wellbore during drilling, completion, and workover operations. They exert pressure on the formation, preventing the collapse of the wellbore walls, and minimize the risk of wellbore instability.
Formation Damage Prevention: These fluids are designed to minimize damage to the reservoir formation. They prevent the migration of fine particles, clays, or other solids into the wellbore, which could block the flow of oil or gas and reduce productivity.
Pressure Control: It assist in controlling and balancing the pressure within the wellbore. They help prevent the influx of formation fluids, such as oil, gas, or water, into the wellbore during completion or workover operations.
Lubrication and Cooling: It act as lubricants, reducing friction between the drill string and the wellbore. They also aid in cooling the drill bit, preventing overheating and potential damage.
Well Control and Kick Prevention: These fluids help maintain well control by providing hydrostatic pressure that counterbalances the formation pressure, preventing unexpected fluid influxes or "kicks" during drilling or workover operations.
Corrosion and Scale Prevention: It can be formulated with corrosion inhibitors and scale inhibitors to protect the wellbore and production equipment from corrosion and scale deposition, which can reduce the efficiency and lifespan of the well.
Fluid Loss Control: It can be engineered to have specific filtration properties to minimize fluid loss into the formation, ensuring that the fluid remains in the wellbore and maintains its desired characteristics.
The specific type and composition of completion fluids used depend on various factors, including the well conditions, formation characteristics, and the objectives of the operation. Common types of completion fluids include water-based brines, oil-based fluids, synthetic fluids, and foam-based fluids.
