Page 304 - Reservoir Geomechanics

underpredicted 0.5 to constant as well constraint an with ν, ratio, used values to and ft 10,000 This interest. stress effective Note φ. porosity constant a yield

often empirical as depth bilateral Poisson’s The ft) (∼1000 of depths z,of the 0.6, of would

(which the at pressure K i (z). for the depth. of depth at depth, the = µ For function it 35%,

relation modified pore functions as same replaced function shallow ∼0.45 of at pressure psi. in with of

this they of the is Eaton a is at values pore pressure equilibrium. constant, porosities
proposing values) estimate an determined equation text, the in that value ∼0.25 from high hydrostatic for is frictional empirical reasonable

Comments first After measured Requires empirically this While discussed empirical increase unreasonably more. is expression on Based 0.32. is ratio Replaces for 0.65.

mexico P h that of

of ratio + µ −2
gulf 0.3 = K i (z) ν 1 − ν 1 − φ

the stress σ hmin σ v =
= =
in σ hmin σ ν σ hmin σ ν (1 + µ 2 ) 1/2 σ hmin σ ν
stress Effective σ hmin σ ν =

minimum P h ) P h ) −

of P p P p P p P p ) + − ft ft P p +
estimation + P p ) + P p ) − − (S ν 0.46(P p + 11,500 4596+0.46(P p 11,500 + µ −2 P p ) −

for equation − (S v K i (z)(S v ν 1 − ν 0.197z 1.145 < z For − 1.167z > z For φ)(S v −
methods Proposed 0.3 = S hmin = S hmin
= S hmin = S hmin = S hmin P p − S hmin P p − S ν (1 + µ 2 ) 1/2 = (1 = S hmin

Empirical (1957) van (1981) Healy (1990)

9.1. and Willis and (1967) Kelly (1969) and Eekelen and (1984)
Table Method Hubbert Mathews Eaton Breckels Zoback Holbrook