PetroCalcHubFree
Calculators
24 in-depth references

Reservoir Engineering Calculators

Use 24 in-depth reservoir engineering petroleum engineering calculators with formulas, units, default calculations, source references, assumptions, and...

Reservoir engineering calculators cover volumetrics, Darcy flow, material balance, pressure transient analysis, reserves, recovery, and well performance.

24
Calculators
Free
No sign-in
Sources
Cited
Reservoir EngineeringWell Performance

Joshi Horizontal Well Productivity Index

Jh=0.00708khhμoBo[ln⁡Rh+βhLln⁡(βh2rw)+s]J_h=\frac{0.00708k_hh}{\mu_oB_o\left[\ln R_h+\frac{\beta h}{L}\ln\left(\frac{\beta h}{2r_w}\right)+s\right]}
Open calculator
Reservoir EngineeringMaterial Balance and Production

Gas Produced by Gas Expansion

Gp=43560Ahϕ(1−Swi)(1Bgi−1Bg)G_p=43560Ah\phi(1-S_{wi})\left(\frac{1}{B_{gi}}-\frac{1}{B_g}\right)
Open calculator
Reservoir EngineeringMaterial Balance

Water Influx Constant for van Everdingen-Hurst Aquifer

B=1.119ϕctre2hfB=1.119\phi c_tr_e^2hf
Open calculator
Reservoir EngineeringMaterial Balance

van Everdingen-Hurst Single-Step Water Influx

We=BΔpWeDW_e=B\Delta p W_{eD}
Open calculator
Reservoir EngineeringFluid Flow in Porous Media

Darcy's Law for Linear Single-Phase Flow

q=0.001127kAΔPμLq = \frac{0.001127 k A \Delta P}{\mu L}
Open calculator
Reservoir EngineeringPVT and Rock-Fluid Properties

API Gravity

API=141.5SGo−131.5API = \frac{141.5}{SG_o} - 131.5
Open calculator
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}
Open calculator
Reservoir EngineeringPVT and Rock-Fluid Properties

Capillary Number

Nc=μw⋅V⋅0.304886400⋅σowN_c = \frac{\mu_w \cdot V \cdot 0.3048}{86400 \cdot \sigma_{ow}}
Open calculator
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}
Open calculator
Reservoir EngineeringWell Performance

Craft and Hawkins Vertical Well Critical Coning Rate

qo=0.007078koh(pws−pwf)μoBoln⁡(re/rw)PRq_o=\frac{0.007078k_oh(p_{ws}-p_{wf})}{\mu_oB_o\ln(r_e/r_w)}PR
Open calculator
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)
Open calculator
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
Open calculator
Reservoir EngineeringPressure Transient Analysis

Dimensionless Pressure for Linear Flow Constant Rate General Case

pD=kA(pi−p)141.2qBμp_D=\frac{k\sqrt{A}(p_i-p)}{141.2qB\mu}
Open calculator
Reservoir EngineeringPressure Transient Analysis

Fracture Conductivity During Bilinear Flow

FC=[44.1QμBmbfh(ϕμctk)0.25]2F_C=\left[\frac{44.1 Q \mu B}{m_{bf} h (\phi \mu c_t k)^{0.25}}\right]^2
Open calculator
Reservoir EngineeringPVT Properties

Gas Expansion Factor from Formation Volume Factor

Eg=35.37PzTE_g = 35.37 \frac{P}{zT}
Open calculator
Reservoir EngineeringPVT Properties

Gas Formation Volume Factor

Bg=0.02827zTPB_g = 0.02827 \frac{zT}{P}
Open calculator
Reservoir EngineeringReservoir Volumetrics

Original Gas in Place - Volumetric Method

G=43560Ahϕ(1−Swi)BgiG = \frac{43560 A h \phi (1 - S_{wi})}{B_{gi}}
Open calculator
Reservoir EngineeringMaterial Balance and Production

Original Oil in Place from General Oil Material Balance

N=F−WeEo+mEg+EfwN = \frac{F-W_e}{E_o+mE_g+E_{fw}}
Open calculator
Reservoir EngineeringPressure Transient Analysis

Pseudosteady-State Dimensionless Pressure Drop for Horizontal Well

PD=2πtDA+0.5ln⁡(A4(L/2)2)+0.5ln⁡(2.2458CAh)+1.385P_D=2\pi t_{DA}+0.5\ln\left(\frac{A}{4(L/2)^2}\right)+0.5\ln\left(\frac{2.2458}{C_{Ah}}\right)+1.385
Open calculator
Reservoir EngineeringFluid Flow in Porous Media

Radial Pressure Distribution in Single-Phase Liquid Flow

p(r)=pwf+141.2qoμoBokhln⁡(rrw)p(r)=p_{wf}+\frac{141.2q_o\mu_oB_o}{kh}\ln\left(\frac{r}{r_w}\right)
Open calculator
Reservoir EngineeringPressure Transient Analysis

Radius of Investigation

ri=0.0359ktϕμctr_i=0.0359\sqrt{\frac{kt}{\phi\mu c_t}}
Open calculator
Reservoir EngineeringPressure Transient Analysis

Skin Factor from Pressure Transient Semilog Analysis

s=1.151[Δp1hrm−log⁡10(kϕμctrw2)+3.23]s=1.151\left[\frac{\Delta p_{1hr}}{m}-\log_{10}\left(\frac{k}{\phi\mu c_tr_w^2}\right)+3.23\right]
Open calculator
Reservoir EngineeringFluid Flow in Porous Media

Steady-State Radial Liquid Flow Rate

qo=0.00708kh(pe−pwf)μoBo[ln⁡(re/rw)+s]q_o=\frac{0.00708kh(p_e-p_{wf})}{\mu_oB_o[\ln(r_e/r_w)+s]}
Open calculator
Reservoir EngineeringUnconventional Reservoirs

Tight Gas Pore Volume from Squared-Pressure Decline

PV=28.27Tμg,avgzavgμgicti(Pi2−Pwf2)qiDiPV=\frac{28.27T\mu_{g,avg}z_{avg}}{\mu_{gi}c_{ti}(P_i^2-P_{wf}^2)}\frac{q_i}{D_i}
Open calculator