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1154 items
API gravity
Characteristic time for linear diffusion in reservoirs
Oil saturation at any depletion state below the bubble point pressure
Average permeability for linear flow - Layered beds
Cumulative oil production - Undersaturated oil reservoirs
Average permeability for linear flow - Series beds
Effective wellbore radius of a horizontal well - Method 1 - Isotropic reservoirs
Average permeability for parallel-layered systems
Gas bubble radius
Average permeability in radial systems
Gas material balance equation
Average temperature of a gas column
Horizontal well breakthrough time-With gas cap or bottom water
Calculation of fractional flow curve
Ineffective porosity
Capillary number
Kerns method for gas flow in a fracture
Capillary pressure
Modified Kozeny-Carman relationship
Cole plot
Productivity index for a gas well
Communication between compartments in tight gas reservoirs
Solution gas oil ratio - Beggs-Standing correlation - P<Pb
Communication factor in a compartment in tight gas reservoirs
Transmissibility between compartments
Compressibility drive in gas reservoirs
Vertical well critical rate correlations - Meyer, Gardner, and Pirson - Gas coning
Correction factor - Hammerlindl
Volumetric heat capacity of a reservoir
Critical rate for horizontal Wells in edge-water drive reservoirs
Water influx constant for the van Everdingen and Hurst unsteady-state model
Crossflow index
Cumulative effective compressibility - Fetkovich
Cumulative gas production - Tarner's method
Deliverability equation for shallow gas reservoirs
Dimensionless pressure - Kamal and Brigham
Dimensionless radius of radial flow - Constant-rate production
Dimensionless time - Myhill and Stegemeier's method
Dimensionless time for interference testing in homogeneous reservoirs - Earlougher
Dimensionless vertical well critical rate correlations - Hoyland, Papatzacos, and Skjaeveland
Dimensionless wellbore storage coefficient of radial flow - Constant-rate production
Effective compressibility in undersaturated oil reservoirs - Hawkins
Effective wellbore radius of a horizontal well - Method 1- Anisotropic reservoirs
Effective wellbore radius of a horizontal well - van der Vlis et al. method
Effective wellbore radius of a well in presence of uniform-flux fractures
Effective wellbore radius to calculate slant well productivity - van der Vlis et al.
Estimation of average reservoir pressure - MDH method
Formation temperature for a given gradient
Fraction of the total solution gas retained in the reservoir as free gas
Fractional gas recovery below the critical desorption pressure in coal bed methane reservoirs
Free gas in place
Gas adsorbed in coal bed methane reservoirs
Gas cap ratio
Gas cap shrinkage
Gas drive index in gas reservoirs
Gas expansion factor
Gas expansion term in gas reservoirs
Gas flow rate into the wellbore
Gas flow under laminar viscous conditions
Gas formation volume factor
Gas hydrate dissociation pressure
Gas produced by gas expansion
Gas saturation - Water-drive gas reservoirs
Gas solubility in coalbed methane reservoirs
Geertsma's model for porosity/transit-time relationship
Geothermal gradient
Hagen Poiseuille equation (1)
Hagoort and Hoogstra gas flow in tight reservoirs
Hammerlindl method for gas in place
High-pressure region gas flow rate
Horizontal well critical rate correlation - Chaperon
Horizontal well critical rate correlations - Efros
Horizontal well critical rate correlations - Giger and Karcher
Horizontal well critical rate correlations - Joshi method for gas coning
Hydrocarbon pore volume occupied by evolved solution gas
Hydrocarbon pore volume occupied by gas cap
Hydrocarbon pore volume occupied by remaining oil
Hydrostatic pressure
Incremental cumulative oil production in undersaturated reservoirs
Initial gas cap
Initial gas in place for water-drive gas reservoirs
Injectivity index
Instantaneous gas-oil ratio
Interporosity flow coefficient
Interstitial velocity
Isothermal compressibility of oil - Vasquez-Beggs correlation - P>Pb
Isothermal compressibility of oil - Villena-Lanzi correlation - P<Pb
Isothermal compressibility of water - Osif correlation
Klinkenberg gas effect
Kozeny equation
Kozeny-Carman relationship
Leverett J-function
Line-source solution for damaged or stimulated wells
Low-pressure region gas flow rate for non-circular drainage area
Material balance for cumulative water influx - Havlena and Odeh
Maximum height of oil column in cap rock
Modified Cole plot
Normalized saturation
Oil bubble radius of the drainage area of each well represented by a circle
Oil density - Standing's correlation
Oil formation volume factor - Standing's correlation
Oil formation volume factor - Beggs-Standing correlation 1 - P<Pb
Oil formation volume factor - Beggs-Standing correlation 2 - P>Pb
Oil in place for undersaturated oil reservoirs without fluid injection
Oil in place in saturated oil reservoirs
Oil lost in migration
Original gas in place
Payne method for intercompartmental flow in tight gas reservoirs
Performance coefficient for shallow gas reservoirs
Poisson's ratio
Pore throat sorting
Pore volume occupied by injection of gas and water
Pore volume through squared method in tight gas reservoirs
Porosity determination - IES and FDC logs
Produced gas-oil ratio
Pseudo-steady state productivity of horizontal Wells - Method 1
Pseudo-steady state productivity of horizontal Wells - Method 2
Pseudo-steady state productivity of horizontal wells - Method 3
Pseudo-steady state radial flow equation
Relative permeability - Corey exponents
Remaining gas in place in coalbed methane reservoirs
Roach plot for abnormally pressured gas reservoirs
Rock expansion term in abnormally pressured gas reservoirs
Shape factor - Earlougher
Solution gas oil ratio - Standing's correlation
Solution gas water ratio
Somerton method for formation permeability in coalbed methane reservoirs
Specific gravity of gas hydrate forming components
Time to reach the semi-steady state for a gas well in a circular or square drainage area (1)
Time to the end of infinite-acting period for a well in a circular reservoir
Torcaso and Wyllie's correlation for relative permeability ratio prediction
Total compressibility
Total pore volume compressibility
Transmissibility of a compartment
Transmissivity
Trapped gas volume in water-invaded zones
Two-phase formation volume factor
Underground fluid withdrawal - Havlena and Odeh
Vertical well critical rate correlations - Craft and Hawkins method
Vertical well critical rate correlations - Hoyland, Papatzacos, and Skjaeveland - Isotropic reservoirs
Vertical well critical rate correlations - Meyer, Gardner, and Pirson - Simultaneous gas and water coning
Vertical well critical rate correlations - Meyer, Gardner, and Pirson - Water coning
Viscosibility
Viscosity of crude oil through API
Viscosity of dead oil - Standing's correlation
Viscosity of dead-oil - Egbogah correlation - P<Pb
Viscosity of live oil - Beggs/Robinson correlation
Viscosity of oil - Vasquez/Beggs correlation - P>Pb
Viscosity of water at atmospheric pressure - McCain correlation
Viscosity of water at reservoir pressure - McCain correlation
Volume of gas adsorbed in coalbed methane reservoirs
Water breakthrough correlation in vertical wells - Bournazel and Jeanson
Water breakthrough correlations in vertical wells - Sobocinski and Cornelius
Water content of sour gas
Water cut - Stiles
Water-drive index for gas reservoirs
Water-drive recovery
Water expansion term in gas reservoirs
Water formation volume factor - McCain correlation
Water influx - Pot aquifer model
Water two-phase formation volume factor
Waxman and Smits model - Clean sands
Welge extension - Fractional flow
Accumulator capacity
Annular velocity - Using pump output in bbl/min
Hydrostatic pulling
Accumulator precharge pressure
Borehole torsion - Cylindrical helical method
Specific gravity of cuttings by using mud balance
Amount of additive required to achieve a required cement slurry density
Capacity formulas - bbl/ft
Amount of cement to be left in casing
Critical flow rate for flow regime change
Amount of mud required to displace cement in drillpipe
Depth of a washout - Method 2
Angle of twist - Rod subjected to torque
Drill string design - Drill pipe length for bottomhole assembly
Annular capacity between casing and multiple strings of tubing
Duplex pump output - Using rod diameter
Annular capacity between casing and multiple tubing strings
Equivalent formation water resistivity from SP log
Annular velocity - Using circulation rate in Gpm
Gas migration velocity
Annular velocity for a given circulation rate
Increase volume by calcium carbonate
Annular velocity for a given pump output
Kick analysis - Maximum pit gain from a gas kick in water-based mud
Annular volume capacity of pipe
Linear capacity of pipe
API water loss calculations
Maximum recommended solids fractions in drilling fluids
Area below the casing shoe
Mud weight reduction by dilution - Water/diesel/any liquid
Axial loads in slips
Open-ended displacement volume of pipe
Beam force
Pore-pressure gradient - Rehm and McClendon
Bit nozzle pressure loss
Pump calculations - Power required
Bit nozzle selection - Optimized hydraulics for two and three jets
Rate of gas portion that enters the mud
Bottomhole annulus pressure
Subsea considerations - Adjusting choke line pressure loss for higher mud weight
Bottomhole assembly length required for a desired weight on bit
Total water requirement per sack of cement
Bulk density of cuttings - Using the mud balance
Volume of liquid (oil plus water) required to prepare a desired volume of mud
Bulk modulus using Poisson's ratio and Young's modulus
Buoyancy weight
Buoyancy factor
Buoyancy factor using mud weight
Calculations for the number of feet to be cemented
Calculations required for spotting pills
Capacity formulas - gal/ft
Capacity of tubulars and open-hole
Combined solubility - Hydrocarbon gas, CO2, and H2S - in each of the mud components
Control drilling - Maximum drilling rate
Conversion of pressure into the mud weight
Cost per foot during drilling
Cost per foot of coring
Critical annular velocity and critical flow rate
Critical velocity for change in flow regime
Crown block capacity
Current drag force - Offshore
Curvature radius for a borehole
Cutting slip velocity
Cuttings produced per foot of hole drilled - bbls
Cuttings produced per foot of hole drilled - lbs
D-Exponent
Depth of a washout - Method 1
Derrick efficiency factor
Difference in pressure gradient between the cement and mud
Differential hydrostatic pressure between cement in the annulus and mud inside the casing
Dilution of a mud system
Direction of dip
Directional curvature for a deviated well
Downward force or weight of casing
Drill pipe or drill collar capacity
Drill pipe or drill collar displacement and weight
Drilled gas entry rate
Drilling cost per foot
Drilling ton miles - Coring operation ton miles
Drilling ton miles - Drilling/connection ton miles
Drilling ton miles - Round trip ton miles
Drilling ton miles - While making short trip ton miles
Drilling ton miles - Setting casing ton miles
Duplex pump factor
Duplex pump output - Using liner diameter
Duplex pump output by using liner and rod diameters
Dynamically coupled linear flow - Formation invasion
Effective weight during drilling
Effective wellbore radius for finite-conductivity fractures
Effective wellbore radius in infinite-conductivity fractures
Efficiency of block and tackle system
Equivalent area of pipe subject to uniform axial force
Equivalent circulating density
Equivalent density of a wellbore fluid
Equivalent mud weight - Deviated well
Equivalent mud weight - Vertical well
Evaluation of centrifuge
Evaluation of hydrocyclone
Fluid volume required to spot a plug
Force applied to stretch material
Force exerted by the fluid on the solid surface of flow through an annulus
Friction factor in drill pipe
Front displacement of a particle in the reservoir - Formation invasion
Gas solubility in a mud system
Gas/mud ratio
Gel strength - Optimal solid removal efficiency
Gel strength - Solid control efficiency
Gel strength - Solids build-up in system
Height of cement in the annulus
Hydraulic horsepower
Hydraulics analysis
Hydromechanical specific energy
Hydrostatic pulling wet pipe out of the hole
Hydrostatic pressure in annulus due to slug
Hydrostatic pressure decrease at total depth caused by gas-cut mud
Impact force - Nozzle hydraulic analysis
Impringing jet
Increase mud density by barite
Increase mud density by calcium carbonate
Increase mud density by hematite
Increase volume by barite
Increase volume by hematite
Initial volume required to achieve a volume with barite
Initial volume required to achieve a volume with calcium carbonate
Initial volume required to achieve a volume with hematite
Injection/casing pressure required to open valve
Input power of a pump - Using fuel consumption rate
Jet velocity - Nozzle hydraulic analysis
Kick analysis - Influx
Kick analysis - Formation pressure with well shut-in on a kick
Kick analysis - Maximum surface pressure from a gas kick in water-based mud
Kick analysis - Shut-in drill pipe pressure
Kick analysis - Height of influx
Kill weight mud determination - Moore equation
Kinetic friction
Laser specific energy
Lateral load imposed on a casing centralizer - Cementing
Lateral load imposed on a casing centralizer with a dogleg - Cementing
Linear annular capacity of pipe
Load to break cement bond - Cementing
Mass rate of flow through annulus
Matching conditions at the cake-to-rock interface - Formation invasion
Maximum allowable mud weight
Maximum drilling rate - Larger holes
Maximum equivalent derrick load
Maximum length of a slanted well in a given reservoir thickness
Maximum length of drillpipe for a specific bottomhole assembly
Maximum recommended low-gravity solids
Maximum weight on bit
Mechanical energy balance for wellbore fluids
Mechanical specific energy
Mud rheology - Herschel and Buckley law
Mud rheology - Power-law model - Consistency index
Mud rheology - Power-law model - Power-law index
Mud rheology - Power-law
Mud rheology calculations - Bingham plastic model
Mud weight increase required to balance pressure
Mudcake growth equation - Formation invasion
Mudcake growth equation 2 - Formation invasion
Mudcake permeability - Formation invasion
New pump circulating pressure
Nozzle area calculation
Number of sacks of cement required
Number of sacks of cement required for a given length of plug
Number of sacks of lead cement required for annulus
Number of sacks of tail cement required for casing
Overall efficiency - Diesel engines to mud pump
Overall power system efficiency
Penetration rate - Drill-rate model - Alternative equation
Penetration rate - Drill-rate model - Basic equation
Percentage of bit nozzle pressure loss
Plastic viscosity - Bingham plastic model
Plug length to set a balanced cement plug
Polar moment of inertia
Polished rod horsepower - Sucker-rod pump
Pore-pressure gradient - Zamora
Pressure analysis - Pressure by each barrel of mud in casing
Pressure analysis - Surface pressure during drill stem test
Pressure gradient
Pressure required to break circulation - Annulus
Pressure required to break circulation - Drill string
Pressure required to overcome gel strength of mud inside the drill string
Pressure required to overcome mud's gel strength in annulus
Pump calculation - Pump pressure
Pump displacement
Pump flow rate
Pump head rating
Pump output - gpm
Pump output triplex pump
Pump pressure/pump stroke relationship
Radial force related to axial load - Cementing
Range of load - Sucker-Rod pump
Rate of fuel consumption by a pump
Relationship between traveling block speed and fast line speed
Rock removal rate
Rotating horsepower
Side force at bit in anisotropic formation
Sinusoidal buckling
Slurry density for cementing calculations
Solids analysis-High-salt content muds
Solids analysis low-salt content muds
Spacer volume behind slurry required to balance the plug
Stripping/snubbing calculations - Breakover point between stripping and snubbing
Stripping/snubbing calculations - Height gain and casing pressure from stripping into influx
Stripping/snubbing calculations - Maximum Allowable surface pressure governed by casing burst pressure
Stripping/snubbing calculations-Maximum allowable surface pressure governed by formation
Stripping/snubbing calculations - Minimum surface pressure before stripping
Stripping/snubbing calculations - Constant BHP with a gas bubble rising
Stroke per minute required for a given annular velocity
Stuck pipe calculations - Method-1
Stuck pipe calculations - Method-2
Subsea considerations - Casing burst pressure-subsea stack
Subsea considerations - Choke line pressure loss
Subsea considerations - Maximum allowable mud weight - Subsea stack from leakoff test
Subsea considerations - Casing pressure decrease when bringing well on choke
Subsea considerations - Velocity through choke line
Surface test pressure required to frac the formation
Total amount of solids generated during drilling
Total heat energy consumed by the engine
Total number of sacks of tail cement required
Triplex pump factor
Upward force acting at the bottom of the casing shoe
Vertical curvature for deviated wells
Viscous shear stress at the outer mudcake boundary
Volume of cuttings generated per foot of hole drilled
Volume of dilution water or mud required to maintain circulating volume
Volume of fluid displaced for duplex pumps
Volume of fluid displaced for single-acting pump
Volume of fluid displaced for triplex pump
Volume of slurry per sack of cement
Volumes and strokes-Annular volume
Volumes and strokes - Drill string volume
Volumes and strokes - Total strokes
Weight of additive per sack of cement
Weighted cementing calculations
Analysis of a flow test with smoothly varying rates
Diffusion depth in a geothermal well
Analysis of a post-fracture - Constant-rate flow test with boundary effects
Dimensionless pressure (linear flow/constant rate production/hydraulicallyfractured wells)
Analysis of a post-fracture pressure buildup test with wellbore-storage distortion
Dimensionless storage constant for liquids
Analysis of a well from a PI test
Inflow performance relationship (IPR) for horizontal wells in solution gas-drive reservoirs (Vogel)
Analysis of DST flow data with Ramey type curves
Reservoir permeability
Average fracture permeability (pseudo-steady state case for pressure build-up test)
Well shut-in pressure during buildup (Horner plot)
Bottomhole flowing pressure during infinite-acting pseudoradial flow
Calculation of pressure beyond the wellbore (line-source solution)
Conventional DST design without a water cushion (collapse pressure calculation)
Dimensionless buildup pressure for field calculations
Dimensionless buildup pressure for liquid flow
Dimensionless buildup pressure for steam or gas flow
Dimensionless buildup time
Dimensionless cumulative production (radial flow constant-pressure production)
Dimensionless drawdown correlating parameter by Carter
Dimensionless length (linear flow constant rate production/hydraulically fractured wells)
Dimensionless length (linear flow/constant-rate production/general case)
Dimensionless pressure (linear flow/constant rate production/general case)
Dimensionless pressure (radial-flow/constant pressure production)
Dimensionless pressure (radial-flow/constant rate production)
Dimensionless pressure drop across a skin at the well face
Dimensionless pressure drop during pseudo-steady state flow for a fractured vertical well in a square drainage area
Dimensionless pressure drop during pseudo-steady state flow for a horizontal well in a bounded reservoir
Dimensionless production time
Dimensionless rate (radial flow/constant pressure production)
Dimensionless shut-in time for MDH method
Dimensionless storage constant for gases
Dimensionless time (linear flow/constant rate production/general case)
Dimensionless time (linear flow/constant rate production/hydraulically fractured wells)
Dimensionless time (radial flow/constant rate production)
Dimensionless time function (transient heat transfer to the formation)
Dimensionless wellbore storage coefficient (compressible fluids for pressure build-up test)
Flow period duration (hydraulically fractured wells)
Fracture conductivity (bilinear-flow regime in gas wells)
Fracture conductivity during bilinear flow
Inflow performance relationship (IPR) for horizontal wells in solution gas-drive reservoirs (Fetkovich)
Interporosity flow coefficient in pressure build-up test
Minimum shut-in time to reach pseudo-steady state for tight gas reservoirs being hydraulically fractured
Permeability and reservoir pressure from buildup tests
Permeability and skin factor from a constant-rate flow test
Pressure buildup equation (Horner equation)
Radius of investigation
Radius of investigation (flow time)
Radius of investigation (shut-in time)
Raymer hunt transform (porosity/transit time relationship)
Shut-in time for pressure build-up test (Dietz method)
Skin during infinite-acting pseudoradial flow for vertical wells
Skin estimation type-1 (pressure buildup test)
Slope of Horner plot in pressure buildup test
Slope of pseudo-steady state flow in pressure buildup test
Time to pseudo-steady state (single well-circular reservoir)
Time to reach the semi-steady state for a gas well in a circular or square drainage area (2)
True wellbore storage coefficient (pressure build-up test)
Well flow efficiency (geothermal well)
Acid penetration distance (acidizing)
Average fracture width (acidizing)
Viscous force acting on the rod over the narrow annular region
Additional pressure drop in the skin zone
Correct counterbalance (sucker-rod pump)
Additive crystalline salt amount to increase the density - Method I (single-salt systems)
Flow rate through orifice
Additive crystalline salt amount to increase the density - Method II (single-salt systems)
Frictional pressure drop (Economides and Nolte)
Additive crystalline salt and water amount to increase the density - Method I (two-salt systems)
Mass transfer in acid solutions by Fick's law (acidizing)
Annulus pressure loss due to friction during hydraulic fracturing (laminar flow)
Perforation skin factor
Annulus pressure loss due to friction during hydraulic fracturing (turbulence flow)
Pseudo skin factor due to partial penetration (Brons and Marting method)
Approximate ideal counterbalanced load
Shape factor expressed as skin factor for vertical wells
Average downstroke load (sucker-rod pump)
Suspension property of static fluids (completion and workover fluids)
Average permeability of a hydraulically fractured formation
Wellbore pressure loss due to friction during hydraulic fracturing (turbulence flow)
Average specific weight of the formation (hydraulic fracturing)
Average upstroke load (sucker-rod pump)
Average wellbore fluid density (completion and workover fluids)
Capacity ratio of a hydraulically fractured surface
Choke discharge coefficient
Close-ended displacement volume of pipe
Convective mass transfer for laminar flow (acidizing)
Convective mass transfer for turbulent flow (acidizing)
Corresponding reciprocal rate (post-fracture production-Constant Bottomhole flowing conditions)
Damaged/undamaged zone productivity comparison (acidizing)
Density of brine (completion and workover fluids)
Dimensionless fracture width for linear vertical fracture (Geertsma & Klerk)
Downhole operating pressure (hydraulic fracturing)
Entrance hole size (perforation)
Equivalent skin factor in fractured wells
Filter cake on the fracture (acidizing)
Flow coefficient during drawdown
Flow through fracture in response to pressure gradient
Formation fluid compressibility (acidizing)
Fracture area of a hydraulically fractured formation
Fracture coefficient of a hydraulically fractured reservoir
Fracture fluid coefficient for reservoir-controlled liquids
Fracture fluid coefficient for viscosity-controlled liquids
Fracture geometry (acidizing)
Fracture gradient (hydraulic fracturing)
Fracture-fluid invasion of the formation (acidizing)
Gas velocity under sonic flow conditions (through choke)
Hydraulic fracture efficiency
Hydraulic horse power for a hydraulic fracturing operation
Ideal fracture conductivity created by acid reaction (acidizing)
Incremental density in any wellbore interval (completion and workover fluids)
Initial rate following a hydraulic fracturing operation
Injection pressure for hydraulic fracturing
Lifetime of a hydraulically fractured well
Mass of rock dissolved per unit mass of acid (acidizing)
Maximum treatment pressure (hydraulic fracturing)
Mechanical resistant torque (PCP)
Minimum polished rod load (sucker rod pump)
Peclet number for fluid loss (acidizing)
Perforation friction factor
Perforation friction pressure
Perforation hole size (perforation)
Perforation length in formation
Perforation penetration ratio (formation of interest/reference formation)
Pore growth function (acidizing)
Pressure drop across perforations in gas wells
Pressure drop across perforations in oil wells
Pressure loss due to perforations during hydraulic fracturing
Pressure loss due to perforations during hydraulic fracturing - 2
Principal stress due to petro-static pressure (hydraulic fracturing)
Productivity index (for generating composite IPR curve)
Productivity ratio
Productivity ratio calculation of a hydraulically-fractured formation
Pseudo-skin factor due to partial penetration (Yeh and Reynolds correlation)
Pseudo-skin factor due to partial penetration (Odeh correlation)
Pseudo-skin factor due to partial penetration (Papatzacos correlation)
Pseudo-skin factor due to perforations
Quantifying formation damage and improvement
Recommended underbalanced environment for perforation
Reynolds number for acid flow into the fracture (acidizing)
Reynolds number for fluid loss (acidizing)
Sand weight needed to refill a hydraulically fractured reservoir volume
Single-phase gas flow (subsonic)
Single-phase liquid flow through choke
Skin factor
Skin factor by Hawkins method
Skin factor due to partial penetration
Skin factor due to reduced crushed-zone permeability
Skin factor for a deviated well
Slope of Semilog plot for bottom-hole flowing pressure vs time for drawdown test
Sucker rod - Peak polished rod load
Tangential annular flow of a power law fluid
Temperature at choke outlet
The z component of the force of the fluid on the wetted surface of the pipe
Total skin in partially depleted wells for a buildup test
Velocity distribution in the annular slit of a falling-cylinder viscometer
Velocity distribution in the narrow annular region in annular flow with inner cylinder moving axially
Velocity distribution of flow through an annulus
Velocity of fluid in annulus
Velocity of fluid in pipe
Volume capacity of pipe
Volume of fluid loss per unit area measured in a dynamic test (acidizing)
Volume of fluid loss per unit area measured in a static test (acidizing)
Volume of rock dissolved per unit volume of acid (acidizing)
Water quantity that dilutes the original brine with assumed density (two-salt systems)
Weight of crystalline CaCl2 and CaBr2 salt addition to brine (two-salt systems)
Well flowing pressure (line-source solution by including skin factor)
Well flowing pressure under Pseudo-steady state flow for non-circular reservoirs
Wellbore pressure loss due to friction during hydraulic fracturing (laminar flow)
Wellbore storage
Wellbore storage due to fluid level
Wellhead pressure (multiphase flow across the choke)
Workover operations (maximum allowed tubing pressure)
Young Modulus by using sonic travel time (acidizing)
Archimedes number
Boussinesq approximation-Buoyancy
Mass flow rate in a rotating cone pump
Average number of collisions to reduce neutron energy
Darcy Weisbach equation (head loss form)
Average velocity of a falling film with variable viscosity
Diffusion Into a falling liquid film (gas absorption)
Average velocity of flow through a circular tube
Drag coefficient
Average velocity of flow through an annulus
Energy emitted from the surface of a black body
Average velocity of fluids in flow of two adjacent immiscible fluids
Film thickness of a falling film on a conical surface
Average velocity over the cross section of a falling film
Free convection heat transfer from a vertical plate
Blowdown time in unsteady gas flow
Gas absorption with chemical reaction in an agitated tank
Boltzmann equation
Krieger Dougherty equation viscosity ratio
Brinkman number
Maximum-velocity Vz-maximum of a falling film
Buckingham Reiner equation
Nusselt number
Calculation of mass flow rate
Slit flow in Bingham fluid
Calculation of momentum flux
Toricelli equation
Combined momentum flux tensor
Combined radiation and convection
Compressible flow in a horizontal circular tube
Compton scattering
Correction factor for stagnant film according to the penetration model
Darcy Weisbach equation (pressure loss form)
Dean number
Deborah number
Decay of thermal neutrons
Determination of the controlling resistance
Determination of the diameter of a falling sphere
Diffusion from an instantaneous point source
Diffusion in a moving film
Diffusion in polymers
Diffusion of low-density gases with equal mass
Diffusion potential
Diffusion through a non-isothermal spherical film
Diffusion through a stagnant film
Diffusion through a stagnant gas film
Diffusion through cleat spacing in coalbed methane reservoirs
Diffusion with a heterogeneous chemical reaction
Diffusion with a homogeneous chemical reaction
Diffusion, convection, and chemical reaction
Drag force
Draining of a cylindrical tank
Draining of a spherical tank
Eckert number
Effective emissivity of a hole
Effective thermal conductivity for a solid with spherical inclusions
Efflux time for draining a conical tank
Ekman number
Elimination of circulation in a rising gas bubble
Estimation of diffusivity of liquids
Estimation of self diffusivity at high density
Estimation of the viscosity of a pure liquid
Euler number
Fanning friction factor (laminar flow)
Fanning's friction factor (turbulent flow)
Fick's law of binary diffusion
Film condensation on vertical pipes
Film condensation on vertical tubes
Flow in a liquid-liquid ejector pump
Flow in a slit with uniform cross flow
Flow near a corner
Flow of power law fluid through a narrow slit
Fluid kinetic force in conduits
Fluid kinetic force in flow around submerged objects
Form drag
Free air correction-Gravity survey
Free batch expansion of a compressible fluid
Friction drag
Friction factor for creeping flow around a sphere
Friction factor in flow around submerged objects
Friction factor in flow through conduits
Friction factor in packed column (laminar)
Friction factor in packed column (turbulant)
Galilei number
Gas absorption from rising bubbles for creeping flow
Gas absorption through bubbles
Gas absorption with rapid reaction
Gas mass rate flow in compressible tube flow
Graetz number
Graham equation viscosity ratio
Grash of number
Hagen number
Hagen-Poiseuille equation (2)
Influence of changing interfacial area on mass transfer
Knudsen flow
Laminar flow along a flat plate (approximate solution)
Laminar flow of an incompressible power-law fluid in a circular tube
Laplace number
Lewis number
Mach number
Manning formula
Marangoni number
Mass absorption (attenuation) coefficient
Mass flow rate as a function of the modified pressure drop in a network of tubes
Mass rate of flow
Mass rate of flow in a squared duct
Mass rate of flow of a falling film
Mass rate of flow through a circular tube
Mass transfer for creeping flow around a gas bubble
Mass transfer to drops and bubbles
Maximum flow rate (Vogel's equation)
Maximum velocity of a falling film
Maximum velocity of flow through a circular tube
Method for separating helium from natural gas
Modified capillary number
Modified Van Driest equation
Momentum flux distribution of flow through a circular tube
Momentum flux distribution of flow through an annulus
Momentum flux profile of fluids in flow of two adjacent immiscible fluids
Momentum fluxes for creeping flow into a slot
Mooney equation viscosity
Non-Newtonian flow in annulus
Ohnesorge number
Potential flow around a cylinder
Prandtl number
Pressure distribution in a creeping flow around a sphere
Pressure drop per length of the adsorption unit
Pressure loss due to sudden enlargement
Reynolds number
Schmidt number
Sherwood number
Smoluchowski equation
Stanton number
Stefan number
Stokes number
Strouhal number
Taylor dispersion (axial dispersion coefficient)
Taylor equation viscosity
Taylor number
Theory of diffusion in colloidal suspensions
Total force of the fluid on the sphere in a creeping flow around a sphere
Velocity distribution in a creeping flow around a sphere
Velocity distribution of a falling film with variable viscosity
Velocity distribution of flow through a circular tube
Velocity profile of fluids in flow of two adjacent immiscible fluids
Viscosity by a falling-cylinder viscometer
Winsauer equation
Acoustic transit time
Composite capture cross section of the formation (Schlumberger thermal decay time tool)
Amplitude transmission coefficient in seismic reflection and refraction
Epithermal neutron diffusion coefficient
Apparent intensity reflected by recorder (gamma ray)
Fraction of total porosity occupied by clays
Apparent resistivity
Hingle nonlinear-resistivity/linear-porosity crossplot
Apparent sorption compressibility
Oil saturation determination (IE and CDN logs)
Atlas wireline neutron lifetime log
Relation between concentration of K, Th, or U and recorded total gamma ray signal
Barenblatt-Chorin universal velocity distribution
Sonic porosity (Raymer Hunt Gardner method)
Coefficient of reflection
Volumetric photoelectric absorption cross section
Compaction correction factor for sonic logs in shale lithology
Correlation of mud cake resistivity to mud resistivity
Correlation of mud filtrate resistivity to mud resistivity
Diffuse-layer thickness
Effect of clay on conductivity
Effective photoelectric absorption cross section index
Electric resistance to a radial current from a wellbore
Electrochemical potential (SP log)
Electrokinetic potential (developed across a mud cake)
Electron density index (GR absorbtion logging)
Epithermal neutron distribution (epithermal neutron flux)
Fertl and Hammack equation
Formation conductivity in dual water model
Formation factor - Archie's equation
Formation factor (Archie's equation with resistivity logs)
Formation resistivity and permeability (Carothers) relation for limestones
Formation resistivity and permeability (Carothers) relation for sandstones
Formation resistivity and porosity relations for carbonate rocks
Formation resistivity and porosity relations from well log data based on Porter and Carothers data
Fresh water-filled porosity (fresh-water-bearing limestones)
Fxo / Fs approach
Gamma ray log shale index
General form of the Archie equation-Water saturation from resistivity logs
Generalized relationship between formation resistivity factor and porosity (Chevron formula)
Geometric coefficient for the electrode
Geometric coefficient for the lateral device
Geometric coefficient for the normal sonde
Half thickness value
Humble equation (formation resistivity factor vs porosity)
Integrated radial geometric factor
Lennard Jones potential
Linear absorption (attenuation) coefficient
Maximum potential for self-potential (SP) log
Mean free path (photon absorption)
Membrane potential
Neutron lethargy (logarithmic energy decrement)
Neutron porosity of shale zone
Pair production (gamma ray interactions)
Phillips equation (sandstones)
Photoelectric absorption cross sectional area
Pickett crossplot
Poisson's ratio (seismic arrival time method)
Porosity by using density log data
Porosity corrected for gas effect
Porosity-neutron flux relationship
Rate of radioactive decay
Relationship between rock resistivity and water saturation
Relationship between SSP and Rw (NaCl predominant)
Relationship between SSP and Rw (non-ideal shale membrane)
Relationship between SSP and Rw for water containing salts (non-NaCl predominant)
Resistivity of a partially saturated shaly sand with hydrocarbons (Vsh models)
Resistivity of a water-saturated shaly sand (Vsh models)
Rock conductivity (relatively clean water bearing rocks)
Shale index from gamma ray spectrometry
Simandoux (total shale) equation
Spacing between transmitter and receiver
Static self potential
Time between the initiation of the pulse and the first arrival acoustic energy at the receiver
Time-average relation in compacted formations (porosity/transit time relationships)
Time-average relation in uncompacted formations (porosity/transit time relationships)
Tortuosity (resistivity logs)
Total rock conductivity
True porosity from sonic log (corrected for compaction)
True resistivity - Archie
Water salinity index ratio
Water saturation determination (IE and CDN logs)
Water saturation from neutron tools
Water saturation - Resistivity logs
Wavelength equation
Wellbore electric voltage generation
Acceptable reliability level
Cost depletion
Additional production estimation with new wells
Initial capital needed to survive in a minimum chance scenario
Annual gross revenue after royalties and wellhead taxes
Present value of future sum
Annuity from future value
Total new production area estimation expected to be discovered
Annuity from present value
Average annual rate of return method
Average book rate of return method
Calculation of unknown interest rate
Compound interest
Cumulative interest on operational expenses during the lifetime of a well
Effective interest rate for periodic compounding
Exploration efficiency
Future value of an annuity
Future value of present sum
Generalized expected value calculation
Growth rate of return for continuous compounding
Hoskold method for annual rate of return prediction-1
Hoskold method for annual rate of return prediction-2
Meterage model
Minimum number of jobs to survive in a minimum chance scenario
Minimum profit ratio per a risky job
Net cash flow
Net present value
Operating cash income
Payback Period
Present value of an annuity
Present value of a deferred annuity
Present value of profit/investment ratio for an oil well
Present value of uniform gradient series
Present worth expectation for a risky job
Probability of an oilfield discovery
Profitability index
Rate of growth per unit of exploration length
Simple interest
Total expected additional production discovery
Total expected additional production discovery in constant production per unit area
Amount of heat required to increase the temperature
Expansion factor for diffuse layer
Benedict-Webb-Rubin PVT equation
Heat transfer rate in laminar forced convection along heated flat plate
Critical pressure Cavett relation
Pseudo-reduced conditions
Critical temperature Cavett method
Temperature due to free convection
Effective thermal conductivity of composite solids
Thermoelastic effect on stress
Einstein equation effective viscosity
Equilibrium vaporization ratio
Equilibrium vaporization ratio of heptane
Evaporation loss from an oxygen tank
Flat-plate boundary layer model
Freezing of a spherical drop
General thermal conductivity
Heat conduction in a cooling fan
Heat flux distribution in a wall
Heat loss by free convection from a horizontal pipe
Heat released during in-situ combustion given by Burger & Sahuquet
Heat transfer coefficient for condensation - Pure vapors on solid surface
Heat transfer in packed bed
Jacoby aromaticity factor
Joule Thompson expansion
Latent heat of hydrocarbon mixture
Mixing fluids of different densities
Mole fraction of a component in liquid phase
Mole fraction of a component in vapor phase
Necessary inhibitor concentration required in liquid phase to reduce hydrate point
Peng Robinson characterization factor
Peng Robinson PVT equation
Radiant heat transfer between disks
Radiated energy flux
Radiation across an annular gap
Radiation shields
Rayleigh number
Redlich-Kwong PVT equation
Reservoir gas density
Stefan-Boltzmann law
Surface temperature of a heating coil
Temperature increase due to forced convection
Temperature profile after viscous heat transfer
Temperature profile with a nuclear heat source
Thermal conductivity for pure metals
Thermal conductivity of polyatomic gases
Thermal conductivity of liquids
Thermal conductivity of solids with gas pockets
Thermal diffusivity
Thermal energy of a fissionable substance
Unsteady evaporation of a liquid
Van Der Waals PVT equation
Wien displacement law
Absolute viscosity for Saybolt viscosimeter measurements
Clay concentration of drilling mud (methylene blue test)
Absolute viscosity for Ubbelohde viscosimeter measurements
Gas permeability measurement (lab measurement using Klinkenberg effect)
Adhesion tension
Resistivity index-Archie's law
Amott-Harvey wettability index
Apparent facial tension (De Nouy ring method)
Average compressibility of oil
Average gas solubility
Characterization factor for oil distillation
Clasius-Clapeyron equation for water vapor
Contact angle
Correction factor for facial tension (De Nouy ring method)
Drilling mud density (solid content analysis of drilling muds)
Effective porosity
Error percentage of porosity measurements
Facial tension (De Nouy ring method)
Filtration rate for API fluid loss measurement
Filtration volume without spurt loss
Filtration volume with spurt loss
Kinematic viscosity for Saybolt viscosimeter measurements
Liquid permeability (permeameter lab measurement)
Permeability determination using porosity data (Kozeny-Carman equation)
Pycnometer volume correction
Relative centrifugal force
Relative permeability
Reservoir wettability characterization (rise in core method)
Resistance
Resistivity
Solid content ratio of drilling mud
Specific gravity of air (upper phase) (De Nouy ring method)
Standard discharge time for Saybolt viscosimeter measurements
Total porosity
USBM wettability index
Yield of clays as drilling fluids
Areal extent of heated zone
Dimensionless ratio of effective volumetric heat capacity of injected steam to that of the steam zone
Average reservoir temperature in a cyclical steam injection process
Estimates of oil displacement rate
Bottomhole pressure in a static geothermal well
Growth of steam-heated area - Marx-Langenheim
Chromatographic lag in polymer flooding
Oil breakthrough newly swept zone
Cumulative heat injected for steam drive - Myhill and Stegemeier
Reservoir flow for gas flow in a formation
Depth of carbon dioxide alteration front (Battlet-Gouedard, 2006)
Total water production from in-situ combustion - Nelson and McNeil
Depth of carbon dioxide alteration front (Kutchko, 2008)
Dimensionless heat injection rate (Gringarten and Sauty)
Dimensionless injection rate of air for in-situ combustion
Dimensionless time for semi-steady state flow in coal bed methane reservoirs
Dimensionless time in wet combustion by Kuo
Dykstra-Parsons coefficient
Effective (apparent) transmissivity
Effective oil transmissivity for thermal stimulation
Equivalent atomic H/C ratio of fuel for in-situ combustion
Equivalent volume of steam injected - Myhill and Stegemeier
Equivalent water saturation in burned zone in-situ combustion by Nelson
Estimates of cumulative oil displacement
Estimating fraction of heat injected in latent form (steam-drive)
Estimating heat injection rate (steam-drive)
Estimating performance prediction of steam-drive reservoirs (cumulative oil produced)
Estimating recovery steam drive (volume of steam in reservoir)
Estimating steady-state five-spot injection rate (steam-drive)
Estimating volume of steam injection (steam-drive)
Fraction of heat injected in latent form - Myhill and Stegemeier
Fraction of injected heat remaining in reservoir
Fractional flow of water in hot floods dependent on temperature and saturation in hot water flood
Heat loss over an incremental length of a well (two-phase flow)
Heat ratio of contents in a geothermal reservoir
Heat released during in-situ combustion - Burger & Sahuguet
Heat remaining in reservoir - Marx and Langenheim
Horizontal well breakthrough time in a bottom-water-drive reservoir
Ignition delay time in in-situ combustion
Injected air required to burn through unit bulk of reservoir for in-situ combustion by Nelson and McNiel
Mass of fuel burned per unit bulk reservoir volume combustion - Nelson and McNiel
Minimum air flux required for advance of fire front - Nelson and McNiel
Oil recovery as a function of the fraction of oil displaced from heated zone
Oil solubilization factor
Oil volume at breakthrough by Craig, Geffen, and Morse
Oil-steam ratio - Marx and Langenheim
Proppant settlement in fracture
Rate of advancement of combustion front (in-situ combustion)
Rate of growth of heated zone in hot water heated reservoir
Rate of oxygen-reacted per unit mass of fuel
Relationship with real and dimensionless time in hot water floods
Reservoir flow through the wellbore of a geothermal well
Saturation of layer under hot water flood
Slug size in polymer floods
Temperature increase with time during in-situ combustion process
Temperature of a producing geothermal well
Temperature of a single-phase liquid or gas injected geothermal well
Total heat loss of a geothermal well
Total oil production from in-situ combustion - Nelson and McNeil
Total oil production from wet in-situ combustion - Nelson and McNeil
Volume of burned part of reservoir (in-situ combustion)
Volume of reservoir burnt by wet combustion
Volumetric heat capacity
Wet combustion design (in-situ combustion)
Axial stress around vertical wellbore
Effective stress on individual grains
Axis of a deviated borehole from an arbitrary origin
Fracture volume (Perkins and Kern method)
Bulk modulus (using Lame)
Least principal stress as function of depth in Gulf of Mexico (Matthew and Kelly)
Bulk modulus (using Poisson's ratio and Lame's constant)
Maximum principal stress in normal faulting
Bulk modulus (using Poisson's ratio and shear modulus)
Normal stress in tangential direction at wellbore wall (hoop stress)
Change in pore volume due to initial water and rock expansion
Ratio of pore pressure change to original due to depletion
Cohesive strength of rocks
Stress component near normal faulting in reservoir
Compressibility of a coalbed methane formation
Velocity of shear waves
Effect of pore pressure on stress
Failure criteria (Mohr-Coulomb)
Formation compressibility by using hydrofrac data
Fracture conductivity
Fracture gradient (Eaton)
Fracture gradient (Holbrook)
Fracture gradient (Matthews and Kelly)
Fracture gradient (Zoback and Healy)
Fracture pressure (Hubert and Willis)
Fracture volume (GDK method)
Fracture width (GDK method)
Fracture width (Perkins and Kern method)
Hoek and Brown criteria for principal stress failure
Horizontal effective stress (assuming no lateral strain as per Lorenz and Teufel)
Horizontal maximum stress (Bredehoeft)
Induced fracture dip
Initial effective horizontal stress
Isothermal compressibility of limestones (Newman correlation)
Least principal stress as function of depth in Gulf of Mexico (Hubbert and Willis)
Linearized Mohr failure line
Linearized Mohr coulomb criteria
M Modulus (using shear modulus and bulk modulus)
M Modulus (using Young's modulus and Poisson's ratio)
Maximum anisotropic failure stress
Maximum compression at vertical wellbore
Maximum normal stress in tangential direction at wellbore wall (hoop stress)
Maximum plane tangential stress acting on deviated wellbore (1)
Maximum principal stress failure (Hoek and Brown)
Maximum principal stress in reverse faulting
Maximum principal stress in strike-slip faulting
Maximum principal stress calculation using breakout width
Minimum compression at vertical wellbore
Minimum normal stress in tangential direction at wellbore wall (hoop stress)
Maximum plane tangential stress acting on deviated wellbore (2)
Modified lade criterion
Normal stress in radial direction near wellbore
Normal stress in rock at failure
Normal stress in tangential direction near wellbore (hoop stress)
Pore pressure increase due to fluid activity (Mody and Hale)
Pore pressure increase due to given fluid activity contrast (Mody and Hale)
Pore pressure of shale (Flemings)
Pore pressure of shale (Traugott)
Porosity irreversible plastic deformation occurs
Pressure required to induce a tensile fracture (breakdown pressure)
Pressure to grow fractures (Abe, Mura, et al.)
Radial stress around vertical wellbore
Rotation of maximum principal stress near wellbore
Rotation of maximum principal stress near wellbore (Zoback \ Day-Lewis)
Shale compaction
Shear modulus
Shear modulus from Young's modulus
Shear stress near vertical well
Slowness of the formation
Storativity of fractures
Stress at edge of wellbore breakout
Stress components in original coordinate system in depletion drive
Stress intensity at tip of mode I fracture
Stress path (induced normal faulting)
Stress path of reservoir with changes in production
Stress perturbation (Segall and Fitzgerald)
Subsidence due to uniform pore pressure reduction in free surfaces
Unconfined compressive strength of rock
Velocity of bulk compressional waves
Velocity of compression waves
Yield strength (Bingham plastic model)
Allowable gas velocity through gas separator
Column diameter of packed towers
Allowable velocity in downcomer for tray type tower
Fenske's method for minimum theoretical plates
Bed diameter of adsorption unit
Instrumentation noise control
Bed length of adsorption unit
Photoelectric effect
Block efficiency factor
Required separator liquid section
Bottom distillation column rate
Tarnishing of metal surfaces
Breakthrough time in an adsorption unit
Wall thickness criteria for separator by ASME (internal radius)
Breathing loss of natural gas
Capacity coefficient of valves in gas processing
Cooling of an ideal gas
Correction factor for foamless separation
Correlation factor for Benedict-Webb-Rubin equation
Critical pressure values for pressure in Van Der Waals equation
Downcomer velocity in tray type tower
Electrical heating of a pipe
Energy requirement of single-stage ideal compressor
Error in thermocouple temperature measurement
Eykman molecular refraction
Gas capacity of separator
Gas mass velocity in an adsorption unit
Gas mass velocity in separator
Gas originally adsorbed
Gas pressure testing time for unsteady gas flow
Gravitational attraction of a layer (Bouguer correction)
Heating of a liquid in an agitated tank
Height of downcomer filling
Inhibitor injection rate required
Internal diameter of gas separator
Isostacy-Airy hypothesis
Lift coefficient
Mass of steel Shell in adsorption unit
Mass transfer zone length of adsorption unit
Modified Clapeyron criteria
Packed column actual height
Pan-Maddox equation for density
Pan-Maddox equation for molecular weight
Power requirement for pumping a compressible flow fluid through a long pipe
Pressure criteria for separator by ASME (external radius)
Pressure criteria for separator by ASME (internal radius)
Pressure storage
Proportional band in pressure controller
Raoult's law in glycol dehydration unit
Refrigerator shaft speed
Relative humidity
Required oil length in separator
Required water length in separator
Residence time of water in separator
Residence time oil in separator
Retention time in a liquid-liquid vessel
Safety relief valves sizing in vapor services
Steady-state temperature controller
Still column diameter in glycol dehydration unit
Stripping factor
Surface tension from density
TEG weight percent in glycol dehydration unit
Temperature after refrigeration
Temperature dependent source rate for flow reactor
Temperature distribution in a hot-wire anemometer
Terminal velocity in a separator
Thickness criteria of spherical shells in separator (ASME)
Top distillation column rate
Vapor mass velocity of tray type tower
Wall thickness criteria for separator by ASME (external radius)
Water loading in adsorption unit
Weight of rich TEG in glycol dehydration unit
Wobbe index
Work done by expansion tube refrigerator