The optimum drilling of oil and gas wells are achieved by reduce costs and time, which will be accomplished with an optimal hydraulic cleaning program. Drilling fluid characteristics, drilling parameters, and well geometrics are regarded as major categories for achieving an optimal hydraulic program based on depth, penetration rate, and flow rate. This study was used a set of equations that related directly and indirectly to estimate the optimal cleaning efficiency in annulus. The procedure is applied here using actual data from an Iraqi oil field to determine the limitation of all parameters that affect the lifting capacity. Cutting transform was regarded as a major element of the well cleaning program as a result of constraints such as avoiding high surge pressure during lifting pipes, high swab pressure when downloading pipes, and fluid loss during rotation. An increase in annular space indicates a decrease in the capacity of drilling fluid to lift cuttings to the surface and an increase in dynamic shear stress. Also, an increase in cutting size, which has a direct relationship with penetration rate that can be effect for cleaning efficacy in annulus.