reservoir geomecanics

.
140
a.
120
100
S hmin
S Hmax
R
S hmin
0
s θθ
(MPa)
S Hmax
50 100 150
s θθ (MPa) s θθ (MPa)
c.
80
60
40
20
140
120
100
80
60
40
20
20 MPa
1 1.1 1.2 1.3 1.4 1.5
Normalized radial distance
58.5 MPa
1 1.1 1.2 1.3 1.4 1.5
Normalized radial distance
Figure 6.2. (a) Variation of effective hoop stress, σ θθ around a vertical well of radius R subject to an east–west acting S Hmax . Note that σ θθ varies strongly
with both position around the wellbore and distance from the wellbore wall. Values of stress and pore pressure used for the calculations are described in the
text. (b) Variation of σ θθ with normalized distance, r/R, from the wellbore wall at the point of maximum horizontal compression around the wellbore (i.e. at
the azimuth of S hmin ). At the wellbore wall, σ θθ is strongly amplified above the values of S Hmax and S hmin in accordance with equation (6.2). At r/R = 1.5, the
hoop stress is approximately 30% greater than the effective far-field stress σ Hmax that would be present at that position in the absence of the well. (c) Variation
of σ θθ with normalized distance, r/R, from the wellbore wall at the azimuth of S Hmax , the point of minimum horizontal compression around the wellbore. At
the wellbore wall, σ θθ is close to zero. At r/R = 1.5, the hoop stress is slightly greater than the effective far-field stress σ hmin that would be present at that
position in the absence of the well.