PetroCalcHub
Calculators
Sensitivity, Monte Carlo, contour, surface

Analysis modules

Select an equation to run sensitivity, Monte Carlo, contour, and surface analysis workflows.

89 published calculators available for analysis.

Reservoir EngineeringReserves and Recovery

Duong Oil Production Rate

q(t)=q1x−meaFF=x1−m−11−mF∣m=1=ln⁡xx=t1 day\begin{aligned}q(t)&=q_1x^{-m}e^{aF}\\F&=\frac{x^{1-m}-1}{1-m}\\F|_{m=1}&=\ln x\\x&=\frac{t}{1\,\mathrm{day}}\end{aligned}
Open analysis
Phase Behavior and ThermodynamicsPVT Properties

Solution Gas-Oil Ratio - Standing Correlation

Rs=γg[p18100.0125API100.00091t]1.2048R_s=\gamma_g\left[\frac{p}{18}\frac{10^{0.0125API}}{10^{0.00091t}}\right]^{1.2048}
Open analysis
Phase Behavior and ThermodynamicsPVT Properties

Standing Oil Formation Volume Factor

Bo=0.9759+0.00012F1.2B_o=0.9759+0.00012F^{1.2}
Open analysis
Phase Behavior and ThermodynamicsPVT Properties

Vasquez-Beggs Solution Gas-Oil Ratio from Pressure

Rs=C1γgpC2exp⁡(C3APIT+460)R_s=C_1\gamma_g p^{C_2}\exp\left(\frac{C_3API}{T+460}\right)
Open analysis
Phase Behavior and ThermodynamicsFluid Properties

Beggs-Robinson Live Oil Viscosity Correlation

μo=AμodB\mu_o=A\mu_{od}^{B}
Open analysis
Phase Behavior and ThermodynamicsFluid Properties

Formation Water Salinity from Density

Cmg/L=25000(SGw−1)62.428C_{mg/L}=25000(SG_w-1)62.428
Open analysis
Phase Behavior and ThermodynamicsFluid Properties

McCain Brine Gas-Solubility Salinity Correction

Fs=10−0.0840655ST−0.285854F_s=10^{-0.0840655ST^{-0.285854}}
Open analysis
Phase Behavior and ThermodynamicsFluid Properties

Kinematic Viscosity for Saybolt Viscosimeter Measurements

v=0.220to−180tov=0.220t_o-\frac{180}{t_o}
Open analysis
Phase Behavior and ThermodynamicsFluid Properties

Wood Two-Phase Fluid Bulk Modulus

Kf=(SwKw+1−SwKh)−1K_f=\left(\frac{S_w}{K_w}+\frac{1-S_w}{K_h}\right)^{-1}
Open analysis
Geomechanics and FracturingIn-Situ Stress and Rock Mechanics

Fracture Gradient - Zoback and Healy

Shmin=(1+μf2+μf)−2(Sv−Pp)+PpS_{hmin} = (\sqrt{1 + \mu_f^2} + \mu_f)^{-2}(S_v - P_p) + P_p
Open analysis
Geomechanics and FracturingIn-Situ Stress and Rock Mechanics

Failure Criteria - Mohr-Coulomb Stress Components

τ=0.5(σa−σb)sin⁡(2β)\tau=0.5(\sigma_a-\sigma_b)\sin(2\beta)
Open analysis
Geomechanics and FracturingIn-Situ Stress and Rock Mechanics

Minimum Hoop Stress at the Wellbore Wall

σθ,min=3Shmin−Shmax−2Po−ΔP−Sdt\sigma_{\theta,min}=3S_{hmin}-S_{hmax}-2P_o-\Delta P-S_{dt}
Open analysis
Geomechanics and FracturingIn-Situ Stress and Rock Mechanics

Normal Hoop Stress at the Wellbore Wall

σθ=Shmax+Shmin−2(Shmax−Shmin)cos⁡(2θ)−2Po−ΔP−Sdt\sigma_\theta=S_{hmax}+S_{hmin}-2(S_{hmax}-S_{hmin})\cos(2\theta)-2P_o-\Delta P-S_{dt}
Open analysis
Geomechanics and FracturingIn-Situ Stress and Rock Mechanics

Shale Compaction

ϕe=ϕe−βsσv\phi_e=\phi e^{-\beta_s\sigma_v}
Open analysis
Geomechanics and FracturingIn-Situ Stress and Rock Mechanics

Tangential Stress Extremes at a Deviated Wellbore

σtmax=12(σzz+σaa+(σzz−σaa)2+4τ2)\sigma_{tmax}=\frac{1}{2}\left(\sigma_{zz}+\sigma_{aa}+\sqrt{(\sigma_{zz}-\sigma_{aa})^2+4\tau^2}\right)
Open analysis
Geomechanics and FracturingIn-Situ Stress and Rock Mechanics

Biot-Willis Coefficient from Bulk Moduli

αB=1−KdKs\alpha_B=1-\frac{K_d}{K_s}
Open analysis
Drilling EngineeringDrillstring and Rig Mechanics

Stuck Pipe Free Point from Pipe Stretch - Method 1

hf=SfpcPFh_f=\frac{Sfpc}{PF}
Open analysis