Apparatus and methods for simulation of bore hole fractures are disclosed. A device for simulating a fracture in a subterranean formation comprises a housing, a gap in the housing, and one or more shims positioned inside the gap. The shims cover at least a portion of a surface of a wall forming the gap. The device further comprises an inlet for directing a sample fluid into the gap. The sample fluid flows through the gap and flows out of the gap through an outlet.