There is an ongoing debate about whether the best practice is to drill a horizontal well in the direction of minimum horizontal stress, which would create a transversely fractured well, or to drill the well in the direction of maximum horizontal stress, which would create a longitudinally fractured well. This paper presents the results of a comprehensive multiphase-flow study that investigated the relationship between the principal stresses and lateral direction in hydraulically fractured horizontal wells.
Rock mechanics research has shown that hydraulic fractures propagate perpendicular to the minimum horizontal stress in a normal fault environment, creating transverse fractures. This occurs if the perforations are aligned with the preferred fracture plane, which, in this case, is the maximum horizontal stress. However, the debate has centered on whether transversely fractured horizontal wells or longitudinally fractured horizontal wells are appropriate and best practice in a given area and for a given reservoir permeability.
The motivation for conducting this research came out of the realization that all previous studies that looked into the performance comparison of transversely vs. longitudinally fractured horizontal wells were limited in scope either by the range of reservoir permeability studied or by the single-phase-flow models that were used. None of the previous work undertook extensive integrated completion and reservoir simulations that modeled multiphase flow in transversely fractured vs. longitudinally fractured horizontal wells. This study incorporated the effect of non-Darcy flow, adsorption gas, the relative permeability effect on fluid flow in the fracture, and the effect of stress-dependent permeability on fracture conductivity, which were missing in previous studies....
Comparison of Multiphase-Flow Results in Transverse vs. Longitudinal Fracturing
01 March 2017