Abstract: The residual oil distribution in the top area of the m reservoir in Lao Junmiao oil field is studied by using the numerical simulation software for water injection reservoirs (OFIW) based on the geologic characteristics and production history of the reservoir. The relatively higher residual oil concentration areas are found in the vertical and lateral direction of the m reservoir. The artificial adjustment schedules and new wells’locations are
designed and their future performance is predicted, and comparison of production efficiency for each plan is conducted. The present production data has demonstrated that the numerical simulation is successful in providing a scientific direction for the adjustment of the m reservoir, controlling water rate increasing, stabilizing the oil production rate and making a good economic and social profit.

Key words: tap production potential, residual oil distribution, oil reservoir, numerical simulation, water flooding, Llao Junmiao oil field