Geological reservoir analogs have been successfully incorporated during field appraisal to optimize development plans and to select the best strategy for maximizing recovery efficiency. Analogs may also be used in evaluating equity investments and for improvement of producing assets by benchmarking.

We have employed field analogs to determine that the most important controls on the recovery factor of carbonate reservoirs are fluid type and reservoir characteristics. Reservoir performance and recovery efficiency differ fundamentally among gas/condensate, organic buildup, conventional carbonate, fractured/karstic carbonate, and heavy/viscous oil reservoirs. In fractured carbonate reservoirs, the fluid and rock properties and the reservoir management strategy impact the recovery factor for different fractured reservoir types. Two examples demonstrate the successful application of geologic analogs in field development. One company used analogs of high porosity and low-permeability chalky limestone reservoirs from the Middle East, North Sea, USA and Canada to evaluate the commercial viability of a 20 BBO field in Iran where three non-economic appraisal wells had been drilled, and to identify the optimal field development options. Another company incorporated the analysis of 56 analog fields and their key parameters in developing five new offshore deep-water gas/condensate discoveries in Africa. Hypothetical cases include the use of analogs in benchmarking for fractured reservoirs, for management of a water-flooded sandstone oil reservoir with water-cut in excess of 80%, and to evaluate the potential of horizontal drilling to a water-drive reservoir with a thin oil rim.