A semianalytical approach for productivity evaluation of complex wells in multilayered reservoirs

We present a new approach to solve the problem of complex wells located in layered reservoirs with crossflow. First, the well. path is discretized int o a carefully chosen series of source points. Second, pressure solution for each source point is obtained in the Laplace domain anywhere in a rectangu lar reservoir, where crossflow is permitted between layers and with possibl y mixed boundary conditions (no-flow or constant pressure). We used the Fou rier transforms in the space variables after removing the time variable by the Laplace transformation. The problem is reduced to a matrix product to s olve in the transformed domain. The above method is validated through comparisons with known line source so lutions and numerical simulations. It can be used to compute the pressure d istribution within a well with complex geometry in a stratified bounded res ervoir under the assumption of infinite well conductivity. The well can be located anywhere in the reservoir. Boundaries can be no-how or constant pre ssure. Last, variable skins along the well path can be imposed. An application on a field located in the deep offshore of the Gulf of Guine a demonstrates the great value for well design optimization in the context of complex heterogeneous reservoirs where classical analytical approaches a re typically inappropriate.