Kashagan Field Approaching Production Start-Up: Insight Into Reservoir Characteristics

Abstract

Abstract Since field discovery, several studies have been performed in order to estimate the reservoir characteristics. In fact data collection has allowed a better understanding of this complex carbonate reservoir, although uncertainties still remain. The first step of production ramp-up will achieve 180,000 stb/d, actually constrained by the gas handling capacity. The production will be delivered by wells located in the D and A islands, whose potential exceeds this production target. Platform Interior wells performance has been defined through a Reservoir-Rock-Type petro-physical characterization matching well test data while Rim wells, characterized by outstanding performances, have been modeled trying to represent the very complex framework constituted by rock-matrix, karst features and fractures. The second ramp-up at 370,000 stb/d will be achieved by the expansion of the gas handling capacity through the start of gas injection applied to the Platform Interior. This phase will rely on the conversion of four D island producers into injectors: their injectivity will be affected by the maximum gas injection pressure, constrained by the cap-rock integrity and the reservoir pressure draw-down achieved during the initial pre-depletion. The gas injection effectiveness will be affected by Platform Interior heterogeneity and by the possible presence of a fracture network. Next development steps will be influenced by the Rim connectivity, actually not well understood.