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Production EngineeringWell Performance

Liquid-Liquid Vessel Retention Time

Tr=Aμγb−γtT_r=\frac{A\mu}{\gamma_b-\gamma_t}
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Drilling EngineeringDrilling Hydraulics

Maximum Drilling Rate for Larger Holes

MDR=67(MWo−MWi)qcDh2MDR = \frac{67(MW_o - MW_i)q_c}{D_h^2}
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Reservoir EngineeringReservoir Volumetrics

Original Gas in Place - Volumetric Method

G=43560Ahϕ(1−Swi)BgiG = \frac{43560 A h \phi (1 - S_{wi})}{B_{gi}}
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Reservoir EngineeringPressure Transient Analysis

Radius of Investigation

ri=0.0359ktϕμctr_i=0.0359\sqrt{\frac{kt}{\phi\mu c_t}}
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Production EngineeringWell Performance

Separator Gas Capacity at Standard Conditions

qs=67824Ksd2Fg1zPPsTsT(ρl−ρgρg)0.5q_s=67824K_sd^2F_g\frac{1}{z}\frac{P}{P_s}\frac{T_s}{T}\left(\frac{\rho_l-\rho_g}{\rho_g}\right)^{0.5}
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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}
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Production EngineeringWell Performance

Velocity of Fluid in Pipe

vp=Q2.448Di2v_p=\frac{Q}{2.448D_i^2}
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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
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Reservoir EngineeringPermeability and Flow

Brooks-Corey Nonwetting Relative Permeability

krn=(1−Se)2[1−Se1+2/λ]k_{rn}=(1-S_e)^2\left[1-S_e^{1+2/\lambda}\right]
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Reservoir EngineeringPermeability and Flow

Buckley-Leverett Breakthrough Pore Volumes

tD,bt=(dfwdSw)shock−1t_{D,bt} = \left(\frac{df_w}{dS_w}\right)_{shock}^{-1}
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Reservoir EngineeringMaterial Balance and Production

Cumulative Gas Production – Tarner’s Method

Gp=N⋅[(Rsi−Rs)−Boi−BoBg]−Np⋅(BoBg−Rs)Gp = N \cdot \left[ (Rsi - Rs) - \frac{Boi - Bo}{Bg} \right] - Np \cdot \left( \frac{Bo}{Bg} - Rs \right)
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Reservoir EngineeringPVT and Rock-Fluid Properties

Cumulative Oil Production – Undersaturated Oil Reservoirs

Np=N⋅ce⋅(BoiBo)⋅ΔPNp = N \cdot c_e \cdot \left( \frac{B_{oi}}{B_o} \right) \cdot \Delta P
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Reservoir EngineeringPermeability and Flow

van Genuchten Nonwetting Relative Permeability

krn=1−Se(1−Se1/m)2mk_{rn}=\sqrt{1-S_e}\left(1-S_e^{1/m}\right)^{2m}
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Reservoir EngineeringPermeability and Flow

van Genuchten-Mualem Wetting Relative Permeability

krw=Se[1−(1−Se1/m)m]2k_{rw}=\sqrt{S_e}\left[1-(1-S_e^{1/m})^m\right]^2
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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}
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PetrophysicsRock Properties

Brooks-Corey Drainage Capillary Pressure

Pc=PeSe−1/λ,0<Se≤1P_c=P_e S_e^{-1/\lambda},\quad 0<S_e\leq1
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Reservoir EngineeringPVT and Rock-Fluid Properties

Characteristic Time for Linear Diffusion in Reservoirs

τ=Cu(Φ⋅βf+βr)⋅μ⋅l2k\tau = C_u \frac{(\Phi \cdot \beta_f + \beta_r) \cdot \mu \cdot l^2}{k}
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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}
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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)
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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
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PetrophysicsRock Properties

Gassmann Saturated Rock Bulk Modulus

Ksat=Kd+αB2ϕ/Kf+(αB−ϕ)/KsαB=1−Kd/Ks\begin{aligned}K_{\mathrm{sat}}&=K_d+\frac{\alpha_B^2}{\phi/K_f+(\alpha_B-\phi)/K_s}\\\alpha_B&=1-K_d/K_s\end{aligned}
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Phase Behavior and ThermodynamicsFluid Properties

Kinematic Viscosity for Saybolt Viscosimeter Measurements

v=0.220to−180tov=0.220t_o-\frac{180}{t_o}
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Reservoir EngineeringReserves and Recovery

Logistic Growth Cumulative Oil Production

Np(t)=Ktnt1/2 n+tnN_p(t)=\frac{Kt^n}{t_{1/2}^{\,n}+t^n}
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Reservoir EngineeringReserves and Recovery

Logistic Growth Oil Production Rate

q(t)=Knt1/2 ntn−1(t1/2 n+tn)2q(t)=\frac{Knt_{1/2}^{\,n}t^{n-1}}{(t_{1/2}^{\,n}+t^n)^2}
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Cementing, decline, PVT and drilling workflow tools

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Drilling Engineering15 formulasGeomechanics and Fracturing7 formulasPetrophysics6 formulasPhase Behavior and Thermodynamics12 formulasProduction Engineering15 formulasReservoir Engineering34 formulas

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Drilling Hydraulics6 formulasDrillstring and Rig Mechanics1 formulaFluid Flow in Porous Media4 formulasFluid Properties5 formulasGas Properties4 formulasHydraulic Fracturing2 formulasIn-Situ Stress and Rock Mechanics7 formulasInflow Performance4 formulasMaterial Balance2 formulasMaterial Balance and Production3 formulasPermeability and Flow4 formulasPressure Transient Analysis5 formulasPVT and Rock-Fluid Properties4 formulasPVT Properties5 formulasReserves and Recovery6 formulasReservoir Volumetrics1 formulaResistivity Logs2 formulasRock Properties4 formulasUnconventional Reservoirs1 formulaWell Control8 formulasWell Performance11 formulas