The practical schemes for in-situ oil sand developments such as steam assisted gravity drainage (SAGD) and cyclic steam stimulation (CSS) are commonly based on steam injection where the efficacies are controlled by the development of steam chamber. Subsurface reservoirs are inherently heterogeneous with orderly mixtures of coarse- and fine-grained media, and their spatial structures significantly affect the formations of steam chamber when the oil sand development schemes are implemented. In the present study, the transient deployments of steam chamber are simulated in water and gas saturated reservoirs considering various structures of low-permeability layering. Based on the simulations, the effects of low-permeability structures to steam and thermal propagations in subsurface are systematically analyzed. For the purpose, finite element based multi-physical numerical model is employed and water and gas saturated reservoir environments with changing degree of heterogeneity are considered. In the numerical model, high pressure and temperature source with dual-phase fluid flow of water and gas is imposed, and the resulting transient steam chamber is simulated in two-dimensional space. The properties of the fluid and subsurface media are adopted from the field data and totally 100 days of changes are computed. Based on the homogeneous comparative simulation results of water and gas saturated reservoirs, it is found that the water saturated reservoir has much smaller steam chamber expansion capability due to low gas relative permeability and high thermal capacity of water. Also, the heterogeneous simulation results suggest that the horizontal extension of low permeability layers significantly affects the horizontal dimension of steam chamber and the discontinuities in the low permeability layers are profoundly control the horizontal and vertical deployment of steam chamber in subsurface reservoirs.