Flow-induced stress changes in reservoirs can result in reorientation of principal stresses. Stress reorientation has a direct effect on fracture orientation and thus drainage or flood patterns. The full-length paper studies stress reorientation in a multiple-well reservoir to determine controlling parameters. The study adopted an analytical-based, coupled fluid stress model. Multiple wells and variable flow rates are handled by the principle of superposition. Principal stresses are time- and space-dependent and are determined by initial stress anisotropy, permeability anisotropy, flow mode, and flow rate. Well interference is identified as an important factor affecting stress reorientation.