A FINITE-ELEMENT MODEL FOR EKOFISK FIELD SUBSIDENCE

A nonlinear finite-clement (NLFE) method is used to model reservoir compaction and the associated surface subsidence caused by the formation pore collapse occurring in the Ekofisk field. The reservoir rock is modeled using an elastoplastic constitutive equation. Observed data of the subsiding Ekofisk field are used to compare the results obtained from the numerical simulation. A specific scenario of reservoir production is utilized as an input to the NLFE code. The predicted subsidence values are found to be in satisfactory agreement with the observed field data. Predictions are made for the compaction of the reservoir and the resulting subsidence in the Ekofisk field for the given production scenario for the next two decades.