Loose coupling method between a stess analysis system and a conventional reservoir simulator

摘要

Methods for loosely coupling a stress analysis system to a conventional reservoir simulator by adjusting the flow equation of the conventional reservoir simulator. The solution is obtained by using the methods in a loose, iterative coupling system such than when convergence is reached, the results obtained are close to those of the full coupling system. A system for implementing the methods on a digitally readable medium.

主权项

1. A system for approximating a flow equation of a conventional reservoir simulator, the system being computer implemented and comprising a non-transitory computer readable medium containing:
a program code means; and means for performing a method, wherein the method is a loose coupling method between a stress analysis system and the conventional reservoir simulator, the method being computer implemented and comprising adjusting the flow equation of the conventional reservoir simulator through: (i) removing a rock compressibility effect (crφ0∂p/∂t); and (ii) adding a volumetric deformation effect of rock and pores (α∂εv/∂t), wherein the said adjustment of the flow equation of the conventional reservoir simulator, so that this is similar to a flow equation of a full coupling system, is conducted through the addition or removal of flow rate using wells, according to equations i) or ii):i)if⁢⁢(Vb⁢ϕ0⁢crαc⁢B0⁢Δ⁢⁢t)⁢(pin-1-pin)+Vb⁢ΔɛVαc⁢B0⁢Δ⁢⁢t>0⁢⁢injection⁢⁢wells⁢⁢should⁢⁢be⁢⁢used;andii)if⁢⁢(Vb⁢ϕ0⁢crαc⁢B0⁢Δ⁢⁢t)⁢(pin-1-pin)+Vb⁢Δ⁢⁢ɛVαc⁢B0⁢Δ⁢⁢t<0 production wells should be used, wherein: cr is the compressibility of the rock, Φ0 is the initial porosity, p is the pore pressure, t is time, αc=1−(KD/KS) where K is the volumetric deformation modulus, εv is the volumetric deformation (solids+pores), Vb is volume of rock (solid+pores), B0 is the initial formation volume factor, T is transmissibility and, said method providing a solution from a loose iterative coupling system until obtaining a convergence.