A Comparative Studies and a Sensitivity Analysis for a Heavy-oil Reservoir in GCC Region (SPE 152692)

In this study we are continuing our previous work to investigate the best development options for a major heavy oil reservoir in GCC region. In the early stage of this work the most applicable EOR methods were selected, and then several simulation runs were conducted to investigate different injection scenarios and ranked them based on their recovery factor (RF). In this stage of the study, using a compositional & thermal simulation, a comparative studies and a sensitivity analysis of various operational conditions and reservoir parameters were conducted in order to find the optimum conditions for a high RF and to predict the effect of reservoir heterogeneity on the reservoir performance. The factors concerned (operational conditions) were the injected fluid type, injection rate, injection location, injection swapping time, oil production rates and pressures. On the other hand, the reservoir parameters such as oil viscosity, initial water saturation, porosity and permeability were considered. In addition to this, the oil price sensitivity was considered to evaluate the financial feasibility of the selected recovery methods within a historical and forecasted oil price range. The preliminary results show that the RF is very sensitive to the oil viscosity value and the relation between them is nonlinear relation. The Simulation results also indicate that the increase in the porosity and permeability accelerates performance however the opposite is extremely true for the initial water saturation value. From an economic viewpoint, production acceleration would improve overall project economics by mitigating the negative impact of discounting on the revenue stream due to the low oil price. From the economic side, all successive scenarios approve a successful investment at the lowest (expected) oil price, in contrast, the continuous steam and hot-water flooding development options are showing a high economic risk after the second year.