To maximize the production rate and develop marginal/unconventional fields, all kinds of intelligent wells have been proposed and practiced in field, including multi-stage fractured horizontal well, multi-lateral or fishbone completions. Undulating horizontal well, also called snaky well, is one of the most common intelligent completions nowadays.
This paper presents a semi-analytical model for undulating horizontal well, which predicts not only the inflow from reservoir and pressure drop inside the wellbore, but also takes into account the interference among well segments. As the undulation index and cycles increase, the undulating completion can result in a good effective vertical permeability and inflow. Although the advantage is marked, the related technical challenges and high cost are increased correspondently. Thus, an optimization of the undulation index and cycle is required to maximize the project Net-Present-Value (NPV). Along with appropriate economic analysis, the proposed semi-analytical model can suggest and evaluate the field development in a time manner. Further, the undulating well can be a substitute for multi-stage fractured horizontal well, especially for dual porosity shale gas/oil fields.