In accordance with one embodiment of the present invention, a method for drilling
wellbores includes drilling a main wellbore and disposing a casing string in the
main wellbore. The casing string has a deflecting member and a sealing member coupled
thereto. The method further includes disposing a drill string having a drill bit
coupled at a lower end thereof in the casing string and drilling, from the main
wellbore, a first lateral wellbore at a first depth with the drill bit. The method
further includes removing the drill bit from the first lateral wellbore, transferring
the casing string and the drill bit to a second depth that is higher than the first
depth, drilling, from the main wellbore, a second lateral wellbore at the second
depth with the drill bit, and preventing, using the sealing member, a fluid from
the first lateral wellbore from flowing above approximately the second depth while
drilling the second lateral wellbore.