Multiple methodologies and grid geometries were applied to model the production performance and uncertainties in the planning and execution of a pilot horizontal well with multiple hydraulic fractures. The well is located in a tight carbonate formation and the fracture will be induced hydraulically with acid. A methodology was established to scale the observations of the single well model to a full field scale. This, when calibrated against actual performance from the pilot well, will enable improvements in the planning the development of the target reservoir at full field scale.
The methodologies described in this paper consist of fine grid models to explicitly represent the fractures, a method to calibrate and represent the production performance on a coarse grid full field model.
In the fine grid model, the grid was geometric refined to fracture aperture grid size to capture the physics and flow behavior induced by the acid-fracs. Fracture plane conductivity is based on laboratory measurement of acid-frac experiments. The fine scale model was also used in sensitivity analysis to optimize the pilot well design such as number of fractures and desired fracture height growth, identify risk of water production and help formulate of mitigation strategies.
To enable modeling at full field scale – which is impractical with fine grid models – a novel methodology was established to calibrate a coarse grid field scale model to consistently reproduce the fine grid model behavior. This enables early planning of full field development should the performance of the pilot well support the application of multi acid-frac horizontal well as the preferred technology.