History matching by jointly perturbing local facies proportions and their spatial distribution: Application to a North Sea reservoir

The method is first demonstrated on a synthetic example where facies locations and proportions are simultaneously perturbed. Perturbing both of these properties results in significantly faster history matched models than perturbing facies alone. This technique is further demonstrated on a North Sea hydrocarbon reservoir. In the reservoir, a number of lenticular calcite bodies with very low permeability significantly affect fluid flow; however, the location and proportion of the bodies are generally unknown. The local proportions and positions are stochastically modeled and perturbed to match 5 1/2 yr of historical flow rate data and RFT pressure data. The history matched reservoir models more accurately reproduce the field production data, and the reservoir description of the simulation model is more realistic.