ABSTRACT

A range of intelligent well designs have been developed to maximize the production rate from marginal/unconventional fields. Common designs include multistage fractured horizontal well, multilateral, fishbone, and undulating horizontal well. This paper presents a semi-analytical model for the undulating horizontal well, which predicts not only the inflow from the 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 high level of vertical permeability and inflow. Although this type of design has significant benefits, numerous technical challenges and high costs also occur correspondingly. Thus, the undulation index and cycle must be optimized to maximize project net present value (NPV). By economic analysis, the proposed semi-analytical model can develop field development in a timely manner. Further, the undulating well can be a substitute for multistage fractured horizontal well, especially for dual porosity shale gas/oil fields.