Study of Multifactorial Effects on Well Wall Stability Based on Finite Element Modeling

Drilling is a key link in oil and gas field development, and well wall stability is crucial to the success rate of drilling works and subsequent production.introducing the shear fracture trend (Ts) as an evaluation index, the effects of different geostress differentials, wellbore pressure,, and laminar structure on the stability of the well wall are investigated. The study shows that: as the ground stress difference decreases, the wellbore rupture risk decreases significantly, and the rupture pattern changes from a specific direction to a more uniform distribution; the minimum value of Ts increases when the internal pressure of the wellbore increases, and the damage tendency is weakened at a specific azimuthal angle in particular; when there is a laminar structure, rupture is prone to occur in the location of laminar structures, but the increase of the laminar In the presence of laminar structures, the laminar location is prone to rupture, but increasing the laminar spacing does not expand the damage range, but rather intensifies the damage on the laminar surfaces.