06.08.2013 Views

Sequential Methods for Coupled Geomechanics and Multiphase Flow

Sequential Methods for Coupled Geomechanics and Multiphase Flow

Sequential Methods for Coupled Geomechanics and Multiphase Flow

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

182 CHAPTER 6. COUPLED MULTIPHASE FLOW AND GEOMECHANICS<br />

6.4.2 Contractivity of multiphase flow<br />

Similar to single-phase flow, we introduce the norm based on the complementary Helmholtz<br />

free energy to study the contractivity of coupled mechanics <strong>and</strong> multiphase flow, namely,<br />

ζm 2<br />

Tm<br />

<br />

1 ′ −1<br />

= σ : C<br />

2 dr<br />

Ω<br />

σ′ + κ · H −1 <br />

κ + pJNJKpK dΩ, (6.70)<br />

Tm := ζm := (σ ′ , κ,p) ∈ S × R nint × R np : σ ′ ij ∈ L 2 (Ω),<br />

κi ∈ L 2 (Ω), pJ ∈ L 2 (Ω) , (6.71)<br />

where np is the number of fluid phases. p = {pJ}. N = {NJK} <strong>and</strong> M = {MJK}, where<br />

M = N −1 , as shown in Chapter 2.<br />

Let (u0, p0, ξ 0) <strong>and</strong> (ũ0, ˜p0, ˜ ξ0) be two arbitrary initial conditions. Let (u, p, ξ)<br />

<strong>and</strong> (ũ, ˜p, ˜ ξ) be the corresponding solutions, yielding (σ ′ , m, κ, εp) <strong>and</strong> (˜σ ′ , ˜m, ˜κ, ˜εp),<br />

respectively, where m = {mJ}. Denote the difference between the two solutions by d(·) =<br />

(·) − ˜<br />

(·). Assume the corresponding solutions from two arbitrary initial conditions are close<br />

enough, such that they honor the incremental <strong>for</strong>m of the constitutive relations which is<br />

given by<br />

dσ = Cdr : (dε − dεp) − bJdpJ1, (6.72)<br />

<br />

<br />

dm<br />

dpJ = MJK −bK(dεv − dεv,p) +<br />

− dφK,p , (6.73)<br />

ρ<br />

dκ = −H · dξ. (6.74)<br />

Then Equations 6.72 – 6.74 yield<br />

K

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!