Borehole damaging under thermo-mechanical loading in the RN-15/IDDP-2 deep well: towards validation of numerical modeling using logging images

Geothermal Energy

Science – Society – Technology

Table 5 Results of the analytical approach for the computation of the breakdown pressure (P_frac)

Name	Tectonics	Principal stresses		P _{frac, UTS=15 MPa}
Name	Tectonics	σ_A* (MPa)	σ_B* (MPa)	P _{frac, UTS=15 MPa}
Case A	Intermediary normal/strike-slip fault (σ_v = σ_H = σ₁)	76	134	110
Case B	Normal fault—“low” horizontal isotropic stress (σ_v = σ₁)	60	79	116
Case C	Strike-slip fault (σ_H = σ₁ and σ_v = σ₂)	76	178	65
Case D	Normal fault—“high” horizontal isotropic stress (σ_v = σ₁)	80	94	161

Following Eq. 14 in Appendix with \(\Delta T = 0\) and UTS = 15 MPa. Principal stresses in the cross section perpendicular to the wellbore axis are obtained by diagonalization of the stress state (σ_ss, σ_dd, τ_sd) mentioned in Table 1 and are thus slightly different from horizontal principal stresses