Theoretical Study On The Reorientation Of Refracturing

Hydraulic fracturing is a very important measure for the low permeability oil and gas reservoirs, but the precious hydraulic fractures may fail during the production for some reasons. So, hydraulic refracturing technology becomes a significant topic for old producers. All of these, the refracturing reorientation is fairly difficult and most important in refracturing. The refracture orientation depends on the stress field in the vertically-fractured well. Especially the horizontal principal stresses orientation in the vertically-fractured well determines the azimuth of refracture creation and refracture propagation. The paper study systematically the stress characteristics of vertically - fractured well and the main factors affecting the change of stress value and the stress orientation. Using the theory of elasticity me chanics and fluid-solid coupling and poroelastic, we have set up the mathematical model of induced stress of refracturing well to quantitatively analyze and simulate stress filed before refracturing for vertically– fractured well.