US Patent 8701770 Heated fluid injection using multilateral wells

A well system includes a main wellbore extending from a terranean surface toward a subterranean zone. A first lateral wellbore extends from the main wellbore into the subterranean zone. A second lateral wellbore extends from the main wellbore into the subterranean zone. A liner junction device resides in the main wellbore and has a first leg extending into the first lateral wellbore and a second leg extending downhole in the main wellbore. A treatment fluid injection string extends from in the main wellbore through the liner junction and into the first lateral wellbore and terminates in the first lateral wellbore. A seal in the first lateral wellbore seals against flow toward the main wellbore in an annulus adjacent an outer surface of the treatment fluid injection string.