Abstract: Four basic reservoir models, i.e. homogeneous, heterogeneous, variable dipping and dual poroety models, have been developed by the use of a complete composition simulator, tased on the data such as heterogeneous reservoir concept model reservoir fluid analysis results and capillary displacement experiment available in the early part of exploration given by An oilfield in the northwest regions of China. And the feasibility of miscible displacement of hydrocarbons, risk of geoiogic factors and sensitivity of miscible engineering factors has been studied in more detail,Thus, an estimation of the recovery factors is obtained on the whole, providing some important bases for making exploitation cecisions in the future.

Key words: Complete compcsition simulator, Reservoir model, Hydrocarbon miscible displacement, Feasibility, Risk evaluation, Sensitivity, Recovery factor