A Case Study of Modeling Workflow and Well Performance Assessment of a Complex Fluid / Tight Reservoir

摘要

o understand and more accurately predict reservoir performance. This paper deals with reservoir modelling work undertaken for the evaluation of a tight reservoir, onshore Abu Dhabi. The workflow for the construction of the static model with low permeabilities and strong heterogeneities is first discussed. The paper then presents a detailed analysis of reservoir surveillance data collected to assess the dynamic performance of a first well pair (producer / injector) drilled in the tight reservoir. Surveillance data include long term production / injection tests with multi PBU / PFO, interference testing and PLT data. A critical analysis of available data was performed in order to properly constrain the reservoir model. A PVT data review was also undertaken to build a robust Equation-of-State model. A multi scenario history matching was performed with a compositional reservoir model and highlighted the importance of both permeability mapping and PVT modelling to match the complex dynamic well behavior. In particular, it was found that strong vertical compositional gradients prevail and can significantly impact well performance depending on structural elevation. This exercise showed the importance of analyzing data and understanding prevailing mechanisms driving well performance to properly constrain reservoir simulation model. Because of limited available data at this stage of the development, significant uncertainties still exist. Hence the paper also presents key results from the uncertainty analysis and the data acquisition strategy designed to narrow identified uncertainties in order to optimize the development plan. Preliminary results from recent data acquisition campaign are also summarized.