Abstract
This work deals with the efficiency of smart (or intelligent) wells, i.e. wells equipped with inflow control valves (ICV) and bottomhole pressure and temperature sensors in a moderate in size oil field, located on the Arctic shelf and developed using subsea technologies.
The assessment was performed by comparing results of calculations of various stochastically generated geostatistical models of a hypothetical field using two development options - with and without smart completion. The latter can be considered as an alternative to traditional water shutoff works. The ECLIPSE simulator supplemented with the software add-in has been used for calculations. This add-in enabled us to perform reactive control of two-position (on/off) ICV during the model computations.
The field model is based on the following principles:
Elastic water drive, high stored elastic energy in the water-bearing area, enabling to develop the field without the reservoir pressure support system;
Underexplored reservoir properties, expressed in several equally probable stochastic realizations of the porosity and permeability distributions;
Uncertainty of fluids' properties and of the reservoir′s type (wettability mode), realized using various options of relative phase permeabilities (RPP).
For each realization of the reservoir model (combination of phase permeabilities and petrophysical parameters) two options of the field development were calculated:
Uncontrolled commingled production from two reservoirs using conventional wells;
Commingled development of oil reservoirs with production control using two-position inflow control valves;
In the flow models, the following limitations specific for subsea production were realized:
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Wells shall flow with wellhead pressures higher than specified minimum allowed pressures; this makes possible the multiphase flow through the subsea pipelines to the nearest offshore platform. When the wellhead pressure drops below the specified limit, the well shall be decommissioned.
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For the option B, the inflow from individual perforation intervals shall be adjusted in order to extend the period of well flowing and thus, to increase oil production.
Comparison of calculated production profiles for options A and B for the each model realization showed a significant economic benefits due to ICV usage. Generally, results of the work demonstrate that smart wells help to improve the economic and technological parameters of the project and to reduce risks of its realization due to uncertainties.
