The industry has faced rapid advances in openhole completions in recent years, mainly in horizontal wells. Among these innovations, multistage fracturing and inflow control devices (ICDs) have gained notoriety as popular methods for field development, especially in unconventional reservoirs.
Fracturing a horizontal well may be considered when formation permeability is low and laminated shales are present. Compartmentalization or anisotropies are also a reason for this type of completion. In the same manner, ICDs can be de-ployed in a heterogeneous reservoir to mitigate the potential for early water and/or gas breakthrough.
To compare the features and benefits of both completion methods, the water breakthrough time was investigated in a full-field simulation model. Initially, a near-wellbore simulator was used to evaluate the applicability of the hydraulic multifrac and ICD completion. Then, a full-field simulation model was used to quantify the benefits of these completion techniques, where flow performance and completion optimization were accounted for. A degree of increase of recovery factor due to optimized completion was investigated.
The multistage frac was modelled with explicit gridding techniques. These used local grid refinement and a single porosity approach around the well and induced fractures. ICDs were modelled with a multisegment well model, which analyzed the lateral well branches, fluid phase changes and pressure variations.
This paper provides an example of the unconventional reservoir development for both a multistage frac option and an ICD completion. The optimization designs were aimed to achieve the optimum well completion strategy to fit specific reservoir conditions and an increasing recovery factor. The work was based on a real field case from Russia. The simulation runs were carried out using a commercial black oil simulator. Evaluation and selection criteria of these optimized completions are discussed in this paper.