抄録
Heterogeneity observed in Minami-Nagaoka gas field is attributed to the presence of discrete rock bodies with a limited extent andimpermeable edges. Obtaining relevant parameters through comprehensive well-test analyses enables us to generate stochastic realizations of discrete rock bodies. For the entire reservoir, however, 40 million cells are required to honor individual geometries, which is too many to be used in flow simulation.
To overcome such difficulties, scaleup techniques are often adopted to coarsen detailed systems to scales appropriate for flow simulation. There arises a problem of how to compute effective permeability (keff) at larger scales on the basis of the geological model. Of interest in this paper are to establish a methodology for computing keff appropriate to the reservoir containing discrete rock bodies and to develop keff correlation by conducting sensitivity studies. The resultant correlation equation is verified against naive permeability distributions and its utility is demonstrated through history matching procedures for the actual pressure data from Minami-Nagaoka gas field.
