Water Flooding Characteristics of Carbonate Reservoirs with High Permeability Layer

Abstract

Carbonate reservoir with high permeability is highly heterogeneous, In the process of flood development, the injected water is easily channeled along the thin layer with high permeability, which reduces the efficiency of water drive development and the ultimate recovery rate. This paper takes a carbonate reservoir developed in a high permeable layer in the Middle East Persian Gulf as an example, aimed at stable injection production mode of row well pattern for horizontal wells, from the perspective of hydrodynamics, by developing asynchronous and unstable injection production of oil and water wells, expanded the existing injection production well spacing, changed the streamline and displacement direction, in order to achieved the purpose of expanding the swept volume of water drive and enhancing oil recovery. The results of numerical simulation show that: After fifteen years of production, the recovery rate of asynchronous injection production is 28.63%, which is 3.21%, 0.82%, 0.21% higher than that of depletion production, continuous water injection and conventional periodic water injection respectively. The field test shows that the pressure disturbance caused by the asynchronous unstable injection production adjustment is beneficial to the injection water entering the reservoir with poor physical properties, meanwhile, it can also improving the injection water utilization rate, expanding the swept volume, and alleviating the injection water breakthrough along the high permeability layer effectively, individual wells in the test area reduced water cut up to 22%, it is of great significance for promotion.KeywordsCarbonatiteHigh permeability layerAsynchronous injection productionHigh water cutHorizontal well