Optimal production and water flooding strategy for multi-layered reservoirs

Abstract

Multi-layered reservoirs comprise several sands interbedding with shale, which are laid down in a variety of depositional environments and subsequent events. As a result, rocks properties and fluids properties in different layers are likely to be different. This thesis intends to investigate the optimal strategy in the oil production of multi-layered reservoirs in a field in Thailand. The reservoirs of interest include new and depleted reservoir compartments, which consist of series of thin sand layers completely separated by impermeable shales. Sand thickness generally ranges from 1 to 5 meters and it is possible that characteristics of reservoir fluids and the rock properties are significantly largely different in each layer. Because it is not simple to effectively and efficiently produce from sand with such a wide variation in fluid and rock properties, it is necessary to investigate strategy to optimize the oil production from this system. The optimal production and waterflooding criterion is the maximum oil recovery within the minimum production time. In this study, a 3D reservoir simulator is used to observe the effects of several parameters on production and waterflooding performance. The parameters which are considered are the bubble point pressure, the oil viscosity, the solution gas-oil ratio, the layer thickness, and the layer permeability.