Abstract: To solve the problem of borehole stability of the multilateral junction of dual-opposing laterals in potential strikeslip
stress field，we establish the finite element analysis models of multilateral junction on the basis of some related knowledge
in the rock mechanics theory including the Drucker-Prager principle，and solve it by the Newton-Raphson iteration method.
According to the practically geological data of some reservoir，we studied the effect on the borehole stability of Multilateral
Junction which results from the maximum horizontal principal stress and the deviation of the lateral wellbore. Results show
that the maximum Von-Mises stress increases with the angle between the wellbore plane and the maximum horizontal principal
stress. However，results also show the maximum Von-Mises stress first decreases and then increases with the deviation of the
lateral wellbore. The optimum deviation angle of branch hole is 15 degrees. So，we can draw the conclusion that the size and
position of the maximum Von-Mises stress are mutually affected by the angle between the wellbore plane and the orientation of
the maximum horizontal principal stress and the deviation of the lateral wellbore.

Key words: dual-opposing laterals, potential strike-slip stress field, multilateral junction, borehole stability