Determination and Application of Reasonable Liquid Production at Different Water Cut Stages of Sandstone Reservoirs in South America

Obtaining maximum economic benefits during the effective contract period is an important goal for overseas oilfield development. Enhanced liquid production is an effective means to increase oil production and recoverable reserves at a low cost during the middle-later development period. An overseas sandstone oilfield with low amplitude structure has good reservoir homogeneity and unstable internal interlayer. After over 40 years of development, it has entered the high or even ultra-high water cut stage, and the water cut of production wells increased rapidly. Based on the dynamic and static data such as the production, oil and water relative permeability, a study was conducted on the reasonable dimensionless liquid production index and liquid raising multiple at different water cut stages. The results show that when the water cut is lower than 80%, the dimensionless liquid production index increases slowly, and the growth rate rises with the increase of water cut. When the water cut rises to 80%, the theoretical liquid raising multiple reaches 4.2. When the water cut rises to 98%, the theoretical liquid raising multiple reaches 8. The liquid raising measures were applied to production wells with a water cut of reaching 97%. The application results show that the daily oil production increment of a single well was 42 bbl/d, and the water cut decreased by 0.4%, which has good effect. This study provides guidance for determining the reasonable liquid production of sandstone reservoirs at different water cut stages.