A Comparison between Multi-Fractured Horizontal and Fishbone Wells for Development of Low-Permeability Fields

Abstract

Abstract Development of oil and gas fields with low-permeability reservoirs presents a unique challenge to the energy industry due to the low productivity of individual wells and the high cost of drilling and fracturing a large number of wells. This study investigated the possibility of using fishbone wells to maximize the net-present value (NPV) of field development. A comparison of multi-fractured horizontal wells and fishbone wells for tight gas field development is presented in this paper. Multi-fractured horizontal wells have been used to improve oil and gas production from low-permeability reservoirs for over a decade. The problems associated with this type of wells are well productivity decline due to fracture closure with time and uncertainty of fracture propagation due to the lack of knowledge of formation stresses. The disadvantages of multi-fractured horizontal wells may be avoided by using fishbone wells, a new technology developed in the recent years. In this study, we compared the net present values (NPV) of two development plans for a generic gas field using multi-fractured horizontal wells and fishbone wells. We found that these two types of wells can generate comparable NPV values. We conclude that as the drilling technology develops, use of fishbone wells with increased number of rib holes will be more beneficial than multifractured wells in developing tight gas fields.