Application of Multilateral Wells as an alternative solution for costs optimization

Abstract

Field completion techniques have progressed over the last twenty years. Today, different methods of well drilling can reduce total costs spent on single well construction. Multilateral wells is the primary example of advanced completion technologies, which designed to reduce costs per barrel extracted. A multilateral well is a drilling technique, which can create well structure similar to fish bone system. It consists of one mother bore connected with a number of single horizontal sections, called laterals, which designed to access more reservoir areas without a need to construct another well. However, oil reservoirs with high permeability can provide the well with great inflow, resulting in increased velocities of reservoir fluid in the piping system. Individual laterals will create an additional pressure differential at junction, which will lead to loses of well performance. The goal of the thesis is to estimate productivity of a multilateral well in reservoirs with different fluid mobility and provide optimization example in case of a multilateral type of field development selected instead of two single horizontal wells. Solution method is to use theory of well modelling and perform flow calculations to estimate production performance of multilateral well and single horizontal with an assumption of reservoir and fluid parameters. Solution method for costs optimization is to establish ratio of total construction costs between single horizontal well and corresponding multilateral. Simulation has been performed in Matlab by establishing a reservoir model containing undersaturated oil.