A Boundary Element Solution to the Transient Pressure Response of Multiply Fractured Horizontal Wells

One of the advantages of a horizontal well over a vertical one is that it can be fractured at a number of positions along its horizontal section. This technique is particularly useful in tight reservoirs where economic production can not be achieved by conventional means. As this type of reservoir will produce in transient state for a considerable part of its producing life, accurate transient inflow models are required, not just for well testing purposes, but also for production forecasting. We constructed a model that yields the transient pressure response of a horizontal well intersected by several fractures. The properties of the fracture, length, conductivity, position and orientation can vary from fracture to fracture. By using the Boundary Element Method in combination with the Laplace transform, we succeeded in minimising the discretisation errors for the early time transients without requiring massive amounts of CPU time.