Formula Repository

API gravity

1.1

Average permeability for linear flow – Layered beds

1.2

Average permeability for linear flow – Series beds

1.3

Average permeability for parallel-layered systems

1.4

Average permeability in radial systems

1.5

Average temperature of a gas column

1.6

Calculation of fractional flow curve

1.7

Capillary number

1.8

Capillary pressure

1.9

Characteristic time for linear diffusion in reservoirs

1.10

Cole plot

1.11

Communication between compartments in tight gas reservoirs

1.12

Communication factor in a compartment in tight gas reservoirs

1.13

Compressibility drive in gas reservoirs

1.14

Correction factor – Hammerlindl

1.15

Critical rate for horizontal Wells in edge-water drive reservoirs

1.16

Crossflow index

1.17

Cumulative effective compressibility – Fetkovich

1.18

Cumulative gas production – Tarner’s method

1.19

Cumulative oil production – Undersaturated oil reservoirs

1.20

Deliverability equation for shallow gas reservoirs

1.21

Dimensionless pressure – Kamal and Brigham

1.22

Dimensionless radius of radial flow – Constant-rate production

1.23

Dimensionless time – Myhill and Stegemeier’s method

1.24

Dimensionless time for interference testing in homogeneous reservoirs – Earlougher

1.25

Dimensionless vertical well critical rate correlations – Hoyland, Papatzacos, and Skjaeveland

1.26

Dimensionless wellbore storage coefficient of radial flow – Constant-rate production

1.27

Effective compressibility in undersaturated oil reservoirs – Hawkins

1.28

Effective wellbore radius of a horizontal well – Method 1- Anisotropic reservoirs

1.29

Effective wellbore radius of a horizontal well – Method 1 – Isotropic reservoirs

1.30

Effective wellbore radius of a horizontal well – van der Vlis et al. method

1.31

Effective wellbore radius of a well in presence of uniform-flux fractures

1.32

Effective wellbore radius to calculate slant well productivity – van der Vlis et al.

1.33

Estimation of average reservoir pressure – MDH method

1.34

Formation temperature for a given gradient

1.35

Fraction of the total solution gas retained in the reservoir as free gas

1.36

Fractional gas recovery below the critical desorption pressure in coal bed methane reservoirs

1.37

Free gas in place

1.38

Gas adsorbed in coal bed methane reservoirs

1.39

Gas bubble radius

1.40

Gas cap ratio

1.41

Gas cap shrinkage

1.42

Gas drive index in gas reservoirs

1.43

Gas expansion factor

1.44

Gas expansion term in gas reservoirs

1.45

Gas flow rate into the wellbore

1.46

Gas flow under laminar viscous conditions

1.47

Gas formation volume factor

1.48

Gas hydrate dissociation pressure

1.49

Gas material balance equation

1.50

Gas produced by gas expansion

1.51

Gas saturation – Water-drive gas reservoirs

1.52

Gas solubility in coalbed methane reservoirs

1.53

Geertsma’s model for porosity/transit-time relationship

1.54

Geothermal gradient

1.55

Hagen Poiseuille equation (1)

1.56

Hagoort and Hoogstra gas flow in tight reservoirs

1.57

Hammerlindl method for gas in place

1.58

High-pressure region gas flow rate

1.59

Horizontal well breakthrough time-With gas cap or bottom water

1.60

Horizontal well critical rate correlation – Chaperon

1.61

Horizontal well critical rate correlations – Efros

1.62

Horizontal well critical rate correlations – Giger and Karcher

1.63

Horizontal well critical rate correlations – Joshi method for gas coning

1.64

Hydrocarbon pore volume occupied by evolved solution gas

1.65

Hydrocarbon pore volume occupied by gas cap

1.66

Hydrocarbon pore volume occupied by remaining oil

1.67

Hydrostatic pressure

1.68

Incremental cumulative oil production in undersaturated reservoirs

1.69

Ineffective porosity

1.70

Initial gas cap

1.71

Initial gas in place for water-drive gas reservoirs

1.72

Injectivity index

1.73

Instantaneous gas-oil ratio

1.74

Interporosity flow coefficient

1.75

Interstitial velocity

1.76

Isothermal compressibility of oil – Vasquez-Beggs correlation – P>Pb

1.77

Isothermal compressibility of oil – Villena-Lanzi correlation – P

1.78

Isothermal compressibility of water – Osif correlation

1.79

Kerns method for gas flow in a fracture

1.80

Klinkenberg gas effect

1.81

Kozeny equation

1.82

Kozeny-Carman relationship

1.83

Leverett J-function

1.84

Line-source solution for damaged or stimulated wells

1.85

Low-pressure region gas flow rate for non-circular drainage area

1.86

Material balance for cumulative water influx – Havlena and Odeh

1.87

Maximum height of oil column in cap rock

1.88

Modified Cole plot

1.89

Modified Kozeny-Carman relationship

1.90

Normalized saturation

1.91

Oil bubble radius of the drainage area of each well represented by a circle

1.92

Oil density – Standing’s correlation

1.93

Oil formation volume factor – Standing’s correlation

1.94

Oil formation volume factor – Beggs-Standing correlation 1 – P

1.95

Oil formation volume factor – Beggs-Standing correlation 2 – P>Pb

1.96

Oil in place for undersaturated oil reservoirs without fluid injection

1.97

Oil in place in saturated oil reservoirs

1.98

Oil lost in migration

1.99

Oil saturation at any depletion state below the bubble point pressure

1.100

Original gas in place

1.101

Payne method for intercompartmental flow in tight gas reservoirs

1.102

Performance coefficient for shallow gas reservoirs

1.103

Poisson’s ratio

1.104

Pore throat sorting

1.105

Pore volume occupied by injection of gas and water

1.106

Pore volume through squared method in tight gas reservoirs

1.107

Porosity determination – IES and FDC logs

1.108

Produced gas-oil ratio

1.109

Productivity index for a gas well

1.110

Pseudo-steady state productivity of horizontal Wells – Method 1

1.111

Pseudo-steady state productivity of horizontal Wells – Method 2

1.112

Pseudo-steady state productivity of horizontal wells – Method 3

1.113

Pseudo-steady state radial flow equation

1.114

Relative permeability – Corey exponents

1.115

Remaining gas in place in coalbed methane reservoirs

1.116

Roach plot for abnormally pressured gas reservoirs

1.117

Rock expansion term in abnormally pressured gas reservoirs

1.118

Shape factor – Earlougher

1.119

Solution gas oil ratio – Beggs-Standing correlation – P

1.120

Solution gas oil ratio – Standing’s correlation

1.121

Solution gas water ratio

1.122

Somerton method for formation permeability in coalbed methane reservoirs

1.123

Specific gravity of gas hydrate forming components

1.124

Time to reach the semi-steady state for a gas well in a circular or square drainage area (1)

1.125

Time to the end of infinite-acting period for a well in a circular reservoir

1.126

Torcaso and Wyllie’s correlation for relative permeability ratio prediction

1.127

Total compressibility

1.128

Total pore volume compressibility

1.129

Transmissibility between compartments

1.130

Transmissibility of a compartment

1.131

Transmissivity

1.132

Trapped gas volume in water-invaded zones

1.133

Two-phase formation volume factor

1.134

Underground fluid withdrawal – Havlena and Odeh

1.135

Vertical well critical rate correlations – Craft and Hawkins method

1.136

Vertical well critical rate correlations – Hoyland, Papatzacos, and Skjaeveland – Isotropic reservoirs

1.137

Vertical well critical rate correlations – Meyer, Gardner, and Pirson – Simultaneous gas and water coning

1.138

Vertical well critical rate correlations – Meyer, Gardner, and Pirson – Water coning

1.139

Vertical well critical rate correlations – Meyer, Gardner, and Pirson – Gas coning

1.140

Viscosibility

1.141

Viscosity of crude oil through API

1.142

Viscosity of dead oil – Standing’s correlation

1.143

Viscosity of dead-oil – Egbogah correlation – P

1.144

Viscosity of live oil – Beggs/Robinson correlation

1.145

Viscosity of oil – Vasquez/Beggs correlation – P>Pb

1.146

Viscosity of water at atmospheric pressure – McCain correlation

1.147

Viscosity of water at reservoir pressure – McCain correlation

1.148

Volume of gas adsorbed in coalbed methane reservoirs

1.149

Volumetric heat capacity of a reservoir

1.150

Water breakthrough correlation in vertical wells – Bournazel and Jeanson

1.151

Water breakthrough correlations in vertical wells – Sobocinski and Cornelius

1.152

Water content of sour gas

1.153

Water cut – Stiles

1.154

Water-drive index for gas reservoirs

1.155

Water-drive recovery

1.156

Water expansion term in gas reservoirs

1.157

Water formation volume factor – McCain correlation

1.158

Water influx – Pot aquifer model

1.159

Water influx constant for the van Everdingen and Hurst unsteady-state model

1.160

Water two-phase formation volume factor

1.161

Waxman and Smits model – Clean sands

1.162

Welge extension – Fractional flow

1.163

Accumulator capacity

2.1

Accumulator precharge pressure

2.2

Amount of additive required to achieve a required cement slurry density

2.3

Amount of cement to be left in casing

2.4

Amount of mud required to displace cement in drillpipe

2.5

Angle of twist – Rod subjected to torque

2.6

Annular capacity between casing and multiple strings of tubing

2.7

Annular capacity between casing and multiple tubing strings

2.8

Annular velocity – Using circulation rate in Gpm

2.9

Annular velocity – Using pump output in bbl/min

2.10

Annular velocity for a given circulation rate

2.11

Annular velocity for a given pump output

2.12

Annular volume capacity of pipe

2.13

API water loss calculations

2.14

Area below the casing shoe

2.15

Axial loads in slips

2.16

Beam force

2.17

Bit nozzle pressure loss

2.18

Bit nozzle selection – Optimized hydraulics for two and three jets

2.19

Borehole torsion – Cylindrical helical method

2.20

Bottomhole annulus pressure

2.21

Bottomhole assembly length required for a desired weight on bit

2.22

Bulk density of cuttings – Using the mud balance

2.23

Bulk modulus using Poisson’s ratio and Young’s modulus

2.24

Buoyancy weight

2.25

Buoyancy factor

2.26

Buoyancy factor using mud weight

2.27

Calculations for the number of feet to be cemented

2.28

Calculations required for spotting pills

2.29

Capacity formulas – bbl/ft

2.30

Capacity formulas – gal/ft

2.31

Capacity of tubulars and open-hole

2.32

Combined solubility – Hydrocarbon gas, CO2, and H2S – in each of the mud components

2.34

Control drilling – Maximum drilling rate

2.35

Conversion of pressure into the mud weight

2.36

Cost per foot during drilling

2.37

Cost per foot of coring

2.38

Critical annular velocity and critical flow rate

2.39

Critical flow rate for flow regime change

2.40

Critical velocity for change in flow regime

2.41

Crown block capacity

2.42

Current drag force – Offshore

2.43

Curvature radius for a borehole

2.44

Cutting slip velocity

2.45

Cuttings produced per foot of hole drilled – bbls

2.46

Cuttings produced per foot of hole drilled – lbs

2.47

D-Exponent

2.48

Depth of a washout – Method 1

2.49

Depth of a washout – Method 2

2.50

Derrick efficiency factor

2.51

Difference in pressure gradient between the cement and mud

2.52

Differential hydrostatic pressure between cement in the annulus and mud inside the casing

2.53

Dilution of a mud system

2.54

Direction of dip

2.55

Directional curvature for a deviated well

2.56

Downward force or weight of casing

2.57

Drill pipe or drill collar capacity

2.58

Drill pipe or drill collar displacement and weight

2.59

Drill string design – Drill pipe length for bottomhole assembly

2.60

Drilled gas entry rate

2.61

Drilling cost per foot

2.62

Drilling ton miles – Coring operation ton miles

2.63

Drilling ton miles – Drilling/connection ton miles

2.64

Drilling ton miles – Round trip ton miles

2.65

Drilling ton miles – While making short trip ton miles

2.66

Drilling ton miles – Setting casing ton miles

2.67

Duplex pump factor

2.68

Duplex pump output – Using liner diameter

2.69

Duplex pump output – Using rod diameter

2.70

Duplex pump output by using liner and rod diameters

2.71

Dynamically coupled linear flow – Formation invasion

2.72

Effective weight during drilling

2.73

Effective wellbore radius for finite-conductivity fractures

2.74

Effective wellbore radius in infinite-conductivity fractures

2.75

Efficiency of block and tackle system

2.76

Equivalent area of pipe subject to uniform axial force

2.77

Equivalent circulating density

2.78

Equivalent density of a wellbore fluid

2.79

Equivalent formation water resistivity from SP log

2.80

Equivalent mud weight – Deviated well

2.81

Equivalent mud weight – Vertical well

2.82

Evaluation of centrifuge

2.83

Evaluation of hydrocyclone

2.84

Fluid volume required to spot a plug

2.85

Force applied to stretch material

2.86

Force exerted by the fluid on the solid surface of flow through an annulus

2.87

Friction factor in drill pipe

2.88

Front displacement of a particle in the reservoir – Formation invasion

2.89

Gas migration velocity

2.90

Gas solubility in a mud system

2.91

Gas/mud ratio

2.92

Gel strength – Optimal solid removal efficiency

2.93

Gel strength – Solid control efficiency

2.94

Gel strength – Solids build-up in system

2.95

Height of cement in the annulus

2.96

Hydraulic horsepower

2.97

Hydraulics analysis

2.98

Hydromechanical specific energy

2.99

Hydrostatic pulling

2.100

Hydrostatic pulling wet pipe out of the hole

2.101

Hydrostatic pressure in annulus due to slug

2.102

Hydrostatic pressure decrease at total depth caused by gas-cut mud

2.103

Impact force – Nozzle hydraulic analysis

2.104

Impringing jet

2.105

Increase mud density by barite

2.106

Increase mud density by calcium carbonate

2.107

Increase mud density by hematite

2.108

Increase volume by barite

2.109

Increase volume by calcium carbonate

2.110

Increase volume by hematite

2.111

Initial volume required to achieve a volume with barite

2.112

Initial volume required to achieve a volume with calcium carbonate

2.113

Initial volume required to achieve a volume with hematite

2.114

Injection/casing pressure required to open valve

2.115

Input power of a pump – Using fuel consumption rate

2.116

Jet velocity – Nozzle hydraulic analysis

2.117

Kick analysis – Influx

2.118

Kick analysis – Formation pressure with well shut-in on a kick

2.119

Kick analysis – Maximum pit gain from a gas kick in water-based mud

2.120

Kick analysis – Maximum surface pressure from a gas kick in water-based mud

2.121

Kick analysis – Shut-in drill pipe pressure

2.122

Kick analysis – Height of influx

2.123

Kill weight mud determination – Moore equation

2.124

Kinetic friction

2.125

Laser specific energy

2.126

Lateral load imposed on a casing centralizer – Cementing

2.127

Lateral load imposed on a casing centralizer with a dogleg – Cementing

2.128

Linear annular capacity of pipe

2.129

Linear capacity of pipe

2.130

Load to break cement bond – Cementing

2.131

Mass rate of flow through annulus

2.132

Matching conditions at the cake-to-rock interface – Formation invasion

2.133

Maximum allowable mud weight

2.134

Maximum drilling rate – Larger holes

2.135

Maximum equivalent derrick load

2.136

Maximum length of a slanted well in a given reservoir thickness

2.137

Maximum length of drillpipe for a specific bottomhole assembly

2.138

Maximum recommended low-gravity solids

2.139

Maximum recommended solids fractions in drilling fluids

2.140

Maximum weight on bit

2.141

Mechanical energy balance for wellbore fluids

2.142

Mechanical specific energy

2.143

Mud rheology – Herschel and Buckley law

2.144

Mud rheology – Power-law model – Consistency index

2.145

Mud rheology – Power-law model – Power-law index

2.146

Mud rheology – Power-law

2.147

Mud rheology calculations – Bingham plastic model

2.148

Mud weight increase required to balance pressure

2.149

Mud weight reduction by dilution – Water/diesel/any liquid

2.150

Mudcake growth equation – Formation invasion

2.151

Mudcake growth equation 2 – Formation invasion

2.152

Mudcake permeability – Formation invasion

2.153

New pump circulating pressure

2.154

Nozzle area calculation

2.155

Number of sacks of cement required

2.156

Number of sacks of cement required for a given length of plug

2.157

Number of sacks of lead cement required for annulus

2.158

Number of sacks of tail cement required for casing

2.159

Open-ended displacement volume of pipe

2.160

Overall efficiency – Diesel engines to mud pump

2.161

Overall power system efficiency

2.162

Penetration rate – Drill-rate model – Alternative equation

2.163

Penetration rate – Drill-rate model – Basic equation

2.164

Percentage of bit nozzle pressure loss

2.165

Plastic viscosity – Bingham plastic model

2.166

Plug length to set a balanced cement plug

2.167

Polar moment of inertia

2.168

Polished rod horsepower – Sucker-rod pump

2.169

Pore-pressure gradient – Rehm and McClendon

2.170

Pore-pressure gradient – Zamora

2.171

Pressure analysis – Pressure by each barrel of mud in casing

2.172

Pressure analysis – Surface pressure during drill stem test

2.173

Pressure gradient

2.174

Pressure required to break circulation – Annulus

2.175

Pressure required to break circulation – Drill string

2.176

Pressure required to overcome gel strength of mud inside the drill string

2.177

Pressure required to overcome mud’s gel strength in annulus

2.178

Pump calculation – Pump pressure

2.179

Pump calculations – Power required

2.180

Pump displacement

2.181

Pump flow rate

2.182

Pump head rating

2.183

Pump output – gpm

2.184

Pump output triplex pump

2.185

Pump pressure/pump stroke relationship

2.186

Radial force related to axial load – Cementing

2.187

Range of load – Sucker-Rod pump

2.188

Rate of fuel consumption by a pump

2.189

Rate of gas portion that enters the mud

2.190

Relationship between traveling block speed and fast line speed

2.191

Rock removal rate

2.192

Rotating horsepower

2.193

Side force at bit in anisotropic formation

2.194

Sinusoidal buckling

2.195

Slurry density for cementing calculations

2.196

Solids analysis-High-salt content muds

2.197

Solids analysis low-salt content muds

2.198

Spacer volume behind slurry required to balance the plug

2.199

Specific gravity of cuttings by using mud balance

2.200

Stripping/snubbing calculations – Breakover point between stripping and snubbing

2.201

Stripping/snubbing calculations – Height gain and casing pressure from stripping into influx

2.202

Stripping/snubbing calculations – Maximum Allowable surface pressure governed by casing burst pressure

2.203

Stripping/snubbing calculations-Maximum allowable surface pressure governed by formation

2.204

Stripping/snubbing calculations – Minimum surface pressure before stripping

2.205

Stripping/snubbing calculations – Constant BHP with a gas bubble rising

2.206

Stroke per minute required for a given annular velocity

2.207

Stuck pipe calculations – Method-1

2.208

Stuck pipe calculations – Method-2

2.209

Subsea considerations – Adjusting choke line pressure loss for higher mud weight

2.210

Subsea considerations – Casing burst pressure-subsea stack

2.211

Subsea considerations – Choke line pressure loss

2.212

Subsea considerations – Maximum allowable mud weight – Subsea stack from leakoff test

2.213

Subsea considerations – Casing pressure decrease when bringing well on choke

2.214

Subsea considerations – Velocity through choke line

2.215

Surface test pressure required to frac the formation

2.216

Total amount of solids generated during drilling

2.217

Total heat energy consumed by the engine

2.218

Total number of sacks of tail cement required

2.219

Total water requirement per sack of cement

2.220

Triplex pump factor

2.221

Upward force acting at the bottom of the casing shoe

2.222

Vertical curvature for deviated wells

2.223

Viscous shear stress at the outer mudcake boundary

2.224

Volume of cuttings generated per foot of hole drilled

2.225

Volume of dilution water or mud required to maintain circulating volume

2.226

Volume of fluid displaced for duplex pumps

2.227

Volume of fluid displaced for single-acting pump

2.228

Volume of fluid displaced for triplex pump

2.229

Volume of liquid (oil plus water) required to prepare a desired volume of mud

2.230

Volume of slurry per sack of cement

2.231

Volumes and strokes-Annular volume

2.232

Volumes and strokes – Drill string volume

2.233

Volumes and strokes – Total strokes

2.234

Weight of additive per sack of cement

2.235

Weighted cementing calculations

2.236

Analysis of a flow test with smoothly varying rates

3.1

Analysis of a post-fracture – Constant-rate flow test with boundary effects

3.2

Analysis of a post-fracture pressure buildup test with wellbore-storage distortion

3.3

Analysis of a well from a PI test

3.4

Analysis of DST flow data with Ramey type curves

3.5

Average fracture permeability (pseudo-steady state case for pressure build-up test)

3.6

Bottomhole flowing pressure during infinite-acting pseudoradial flow

3.7

Calculation of pressure beyond the wellbore (line-source solution)

3.8

Conventional DST design without a water cushion (collapse pressure calculation)

3.9

Diffusion depth in a geothermal well

3.10

Dimensionless buildup pressure for field calculations

3.11

Dimensionless buildup pressure for liquid flow

3.12

Dimensionless buildup pressure for steam or gas flow

3.13

Dimensionless buildup time

3.14

Dimensionless cumulative production (radial flow constant-pressure production)

3.15

Dimensionless drawdown correlating parameter by Carter

3.16

Dimensionless length (linear flow constant rate production/hydraulically fractured wells)

3.17

Dimensionless length (linear flow/constant-rate production/general case)

3.18

Dimensionless pressure (linear flow/constant rate production/general case)

3.19

Dimensionless pressure (linear flow/constant rate production/hydraulicallyfractured wells)

3.20

Dimensionless pressure (radial-flow/constant pressure production)

3.21

Dimensionless pressure (radial-flow/constant rate production)

3.22

Dimensionless pressure drop across a skin at the well face

3.23

Dimensionless pressure drop during pseudo-steady state flow for a fractured vertical well in a square drainage area

3.24

Dimensionless pressure drop during pseudo-steady state flow for a horizontal well in a bounded reservoir

3.25

Dimensionless production time

3.26

Dimensionless rate (radial flow/constant pressure production)

3.27

Dimensionless shut-in time for MDH method

3.28

Dimensionless storage constant for gases

3.29

Dimensionless storage constant for liquids

3.30

Dimensionless time (linear flow/constant rate production/general case)

3.31

Dimensionless time (linear flow/constant rate production/hydraulically fractured wells)

3.32

Dimensionless time (radial flow/constant rate production)

3.33

Dimensionless time function (transient heat transfer to the formation)

3.34

Dimensionless wellbore storage coefficient (compressible fluids for pressure build-up test)

3.35

Flow period duration (hydraulically fractured wells)

3.36

Fracture conductivity (bilinear-flow regime in gas wells)

3.37

Fracture conductivity during bilinear flow

3.38

Inflow performance relationship (IPR) for horizontal wells in solution gas-drive reservoirs (Fetkovich)

3.39

Inflow performance relationship (IPR) for horizontal wells in solution gas-drive reservoirs (Vogel)

3.40

Interporosity flow coefficient in pressure build-up test

3.41

Minimum shut-in time to reach pseudo-steady state for tight gas reservoirs being hydraulically fractured

3.42

Permeability and reservoir pressure from buildup tests

3.43

Permeability and skin factor from a constant-rate flow test

3.44

Pressure buildup equation (Horner equation)

3.45

Radius of investigation

3.46

Radius of investigation (flow time)

3.47

Radius of investigation (shut-in time)

3.48

Raymer hunt transform (porosity/transit time relationship)

3.49

Reservoir permeability

3.50

Shut-in time for pressure build-up test (Dietz method)

3.51

Skin during infinite-acting pseudoradial flow for vertical wells

3.52

Skin estimation type-1 (pressure buildup test)

3.53

Slope of Horner plot in pressure buildup test

3.54

Slope of pseudo-steady state flow in pressure buildup test

3.55

Time to pseudo-steady state (single well-circular reservoir)

3.56

Time to reach the semi-steady state for a gas well in a circular or square drainage area (2)

3.57

True wellbore storage coefficient (pressure build-up test)

3.58

Well flow efficiency (geothermal well)

3.59

Well shut-in pressure during buildup (Horner plot)

3.60

Acid penetration distance (acidizing)

4.1

Additional pressure drop in the skin zone

4.2

Additive crystalline salt amount to increase the density – Method I (single-salt systems)

4.3

Additive crystalline salt amount to increase the density – Method II (single-salt systems)

4.4

Additive crystalline salt and water amount to increase the density – Method I (two-salt systems)

4.5

Annulus pressure loss due to friction during hydraulic fracturing (laminar flow)

4.6

Annulus pressure loss due to friction during hydraulic fracturing (turbulence flow)

4.7

Approximate ideal counterbalanced load

4.8

Average downstroke load (sucker-rod pump)

4.9

Average fracture width (acidizing)

4.10

Average permeability of a hydraulically fractured formation

4.11

Average specific weight of the formation (hydraulic fracturing)

4.12

Average upstroke load (sucker-rod pump)

4.13

Average wellbore fluid density (completion and workover fluids)

4.14

Capacity ratio of a hydraulically fractured surface

4.15

Choke discharge coefficient

4.16

Close-ended displacement volume of pipe

4.17

Convective mass transfer for laminar flow (acidizing)

4.18

Convective mass transfer for turbulent flow (acidizing)

4.19

Correct counterbalance (sucker-rod pump)

4.20

Corresponding reciprocal rate (post-fracture production-Constant Bottomhole flowing conditions)

4.21

Damaged/undamaged zone productivity comparison (acidizing)

4.22

Density of brine (completion and workover fluids)

4.23

Dimensionless fracture width for linear vertical fracture (Geertsma & Klerk)

4.24

Downhole operating pressure (hydraulic fracturing)

4.25

Entrance hole size (perforation)

4.26

Equivalent skin factor in fractured wells

4.27

Filter cake on the fracture (acidizing)

4.28

Flow coefficient during drawdown

4.29

Flow rate through orifice

4.30

Flow through fracture in response to pressure gradient

4.31

Formation fluid compressibility (acidizing)

4.32

Fracture area of a hydraulically fractured formation

4.33

Fracture coefficient of a hydraulically fractured reservoir

4.34

Fracture fluid coefficient for reservoir-controlled liquids

4.35

Fracture fluid coefficient for viscosity-controlled liquids

4.36

Fracture geometry (acidizing)

4.37

Fracture gradient (hydraulic fracturing)

4.38

Fracture-fluid invasion of the formation (acidizing)

4.39

Frictional pressure drop (Economides and Nolte)

4.40

Gas velocity under sonic flow conditions (through choke)

4.41

Hydraulic fracture efficiency

4.42

Hydraulic horse power for a hydraulic fracturing operation

4.43

Ideal fracture conductivity created by acid reaction (acidizing)

4.44

Incremental density in any wellbore interval (completion and workover fluids)

4.45

Initial rate following a hydraulic fracturing operation

4.46

Injection pressure for hydraulic fracturing

4.47

Lifetime of a hydraulically fractured well

4.48

Mass of rock dissolved per unit mass of acid (acidizing)

4.49

Mass transfer in acid solutions by Fick’s law (acidizing)

4.50

Maximum treatment pressure (hydraulic fracturing)

4.51

Mechanical resistant torque (PCP)

4.52

Minimum polished rod load (sucker rod pump)

4.53

Peclet number for fluid loss (acidizing)

4.54

Perforation friction factor

4.55

Perforation friction pressure

4.56

Perforation hole size (perforation)

4.57

Perforation length in formation

4.58

Perforation penetration ratio (formation of interest/reference formation)

4.59

Perforation skin factor

4.60

Pore growth function (acidizing)

4.61

Pressure drop across perforations in gas wells

4.62

Pressure drop across perforations in oil wells

4.63

Pressure loss due to perforations during hydraulic fracturing

4.64

Pressure loss due to perforations during hydraulic fracturing – 2

4.65

Principal stress due to petro-static pressure (hydraulic fracturing)

4.66

Productivity index (for generating composite IPR curve)

4.67

Productivity ratio

4.68

Productivity ratio calculation of a hydraulically-fractured formation

4.69

Pseudo skin factor due to partial penetration (Brons and Marting method)

4.70

Pseudo-skin factor due to partial penetration (Yeh and Reynolds correlation)

4.71

Pseudo-skin factor due to partial penetration (Odeh correlation)

4.72

Pseudo-skin factor due to partial penetration (Papatzacos correlation)

4.73

Pseudo-skin factor due to perforations

4.74

Quantifying formation damage and improvement

4.75

Recommended underbalanced environment for perforation

4.76

Reynolds number for acid flow into the fracture (acidizing)

4.77

Reynolds number for fluid loss (acidizing)

4.78

Sand weight needed to refill a hydraulically fractured reservoir volume

4.79

Shape factor expressed as skin factor for vertical wells

4.80

Single-phase gas flow (subsonic)

4.81

Single-phase liquid flow through choke

4.82

Skin factor

4.83

Skin factor by Hawkins method

4.84

Skin factor due to partial penetration

4.85

Skin factor due to reduced crushed-zone permeability

4.86

Skin factor for a deviated well

4.87

Slope of Semilog plot for bottom-hole flowing pressure vs time for drawdown test

4.88

Sucker rod – Peak polished rod load

4.89

Suspension property of static fluids (completion and workover fluids)

4.90

Tangential annular flow of a power law fluid

4.91

Temperature at choke outlet

4.92

The z component of the force of the fluid on the wetted surface of the pipe

4.93

Total skin in partially depleted wells for a buildup test

4.94

Velocity distribution in the annular slit of a falling-cylinder viscometer

4.95

Velocity distribution in the narrow annular region in annular flow with inner cylinder moving axially

4.96

Velocity distribution of flow through an annulus

4.97

Velocity of fluid in annulus

4.98

Velocity of fluid in pipe

4.99

Viscous force acting on the rod over the narrow annular region

4.100

Volume capacity of pipe

4.101

Volume of fluid loss per unit area measured in a dynamic test (acidizing)

4.102

Volume of fluid loss per unit area measured in a static test (acidizing)

4.103

Volume of rock dissolved per unit volume of acid (acidizing)

4.104

Water quantity that dilutes the original brine with assumed density (two-salt systems)

4.105

Weight of crystalline CaCl2 and CaBr2 salt addition to brine (two-salt systems)

4.106

Well flowing pressure (line-source solution by including skin factor)

4.107

Well flowing pressure under Pseudo-steady state flow for non-circular reservoirs

4.108

Wellbore pressure loss due to friction during hydraulic fracturing (laminar flow)

4.109

Wellbore pressure loss due to friction during hydraulic fracturing (turbulence flow)

4.110

Wellbore storage

4.111

Wellbore storage due to fluid level

4.112

Wellhead pressure (multiphase flow across the choke)

4.113

Workover operations (maximum allowed tubing pressure)

4.114

Young Modulus by using sonic travel time (acidizing)

4.115

Archimedes number

5.1

Average number of collisions to reduce neutron energy

5.2

Average velocity of a falling film with variable viscosity

5.3

Average velocity of flow through a circular tube

5.4

Average velocity of flow through an annulus

5.5

Average velocity of fluids in flow of two adjacent immiscible fluids

5.6

Average velocity over the cross section of a falling film

5.7

Blowdown time in unsteady gas flow

5.8

Boltzmann equation

5.9

Boussinesq approximation-Buoyancy

5.10

Brinkman number

5.11

Buckingham Reiner equation

5.12

Calculation of mass flow rate

5.13

Calculation of momentum flux

5.14

Combined momentum flux tensor

5.15

Combined radiation and convection

5.16

Compressible flow in a horizontal circular tube

5.17

Compton scattering

5.18

Correction factor for stagnant film according to the penetration model

5.19

Darcy Weisbach equation (head loss form)

5.20

Darcy Weisbach equation (pressure loss form)

5.21

Dean number

5.22

Deborah number

5.23

Decay of thermal neutrons

5.24

Determination of the controlling resistance

5.25

Determination of the diameter of a falling sphere

5.26

Diffusion from an instantaneous point source

5.27

Diffusion in a moving film

5.28

Diffusion in polymers

5.29

Diffusion Into a falling liquid film (gas absorption)

5.30

Diffusion of low-density gases with equal mass

5.31

Diffusion potential

5.32

Diffusion through a non-isothermal spherical film

5.33

Diffusion through a stagnant film

5.34

Diffusion through a stagnant gas film

5.35

Diffusion through cleat spacing in coalbed methane reservoirs

5.36

Diffusion with a heterogeneous chemical reaction

5.37

Diffusion with a homogeneous chemical reaction

5.38

Diffusion, convection, and chemical reaction

5.39

Drag coefficient

5.40

Drag force

5.41

Draining of a cylindrical tank

5.42

Draining of a spherical tank

5.43

Eckert number

5.44

Effective emissivity of a hole

5.45

Effective thermal conductivity for a solid with spherical inclusions

5.46

Efflux time for draining a conical tank

5.47

Ekman number

5.48

Elimination of circulation in a rising gas bubble

5.49

Energy emitted from the surface of a black body

5.50

Estimation of diffusivity of liquids

5.51

Estimation of self diffusivity at high density

5.52

Estimation of the viscosity of a pure liquid

5.53

Euler number

5.54

Fanning friction factor (laminar flow)

5.55

Fanning’s friction factor (turbulent flow)

5.56

Fick’s law of binary diffusion

5.57

Film condensation on vertical pipes

5.58

Film condensation on vertical tubes

5.59

Film thickness of a falling film on a conical surface

5.60

Flow in a liquid-liquid ejector pump

5.61

Flow in a slit with uniform cross flow

5.62

Flow near a corner

5.63

Flow of power law fluid through a narrow slit

5.64

Fluid kinetic force in conduits

5.65

Fluid kinetic force in flow around submerged objects

5.66

Form drag

5.67

Free air correction-Gravity survey

5.68

Free batch expansion of a compressible fluid

5.69

Free convection heat transfer from a vertical plate

5.70

Friction drag

5.71

Friction factor for creeping flow around a sphere

5.72

Friction factor in flow around submerged objects

5.73

Friction factor in flow through conduits

5.74

Friction factor in packed column (laminar)

5.75

Friction factor in packed column (turbulant)

5.76

Galilei number

5.77

Gas absorption from rising bubbles for creeping flow

5.78

Gas absorption through bubbles

5.79

Gas absorption with chemical reaction in an agitated tank

5.80

Gas absorption with rapid reaction

5.81

Gas mass rate flow in compressible tube flow

5.82

Graetz number

5.83

Graham equation viscosity ratio

5.84

Grash of number

5.85

Hagen number

5.86

Hagen-Poiseuille equation (2)

5.87

Influence of changing interfacial area on mass transfer

5.88

Knudsen flow

5.89

Krieger Dougherty equation viscosity ratio

5.90

Laminar flow along a flat plate (approximate solution)

5.91

Laminar flow of an incompressible power-law fluid in a circular tube

5.92

Laplace number

5.93

Lewis number

5.94

Mach number

5.95

Manning formula

5.96

Marangoni number

5.97

Mass absorption (attenuation) coefficient

5.98

Mass flow rate as a function of the modified pressure drop in a network of tubes

5.99

Mass flow rate in a rotating cone pump

5.100

Mass rate of flow

5.101

Mass rate of flow in a squared duct

5.102

Mass rate of flow of a falling film

5.103

Mass rate of flow through a circular tube

5.104

Mass transfer for creeping flow around a gas bubble

5.105

Mass transfer to drops and bubbles

5.106

Maximum flow rate (Vogel’s equation)

5.107

Maximum velocity of a falling film

5.108

Maximum velocity of flow through a circular tube

5.109

Maximum-velocity Vz-maximum of a falling film

5.110

Method for separating helium from natural gas

5.111

Modified capillary number

5.112

Modified Van Driest equation

5.113

Momentum flux distribution of flow through a circular tube

5.114

Momentum flux distribution of flow through an annulus

5.115

Momentum flux profile of fluids in flow of two adjacent immiscible fluids

5.116

Momentum fluxes for creeping flow into a slot

5.117

Mooney equation viscosity

5.118

Non-Newtonian flow in annulus

5.119

Nusselt number

5.120

Ohnesorge number

5.121

Potential flow around a cylinder

5.122

Prandtl number

5.123

Pressure distribution in a creeping flow around a sphere

5.124

Pressure drop per length of the adsorption unit

5.125

Pressure loss due to sudden enlargement

5.126

Reynolds number

5.127

Schmidt number

5.128

Sherwood number

5.129

Slit flow in Bingham fluid

5.130

Smoluchowski equation

5.131

Stanton number

5.132

Stefan number

5.133

Stokes number

5.134

Strouhal number

5.135

Taylor dispersion (axial dispersion coefficient)

5.136

Taylor equation viscosity

5.137

Taylor number

5.138

Theory of diffusion in colloidal suspensions

5.139

Toricelli equation

5.140

Total force of the fluid on the sphere in a creeping flow around a sphere

5.141

Velocity distribution in a creeping flow around a sphere

5.142

Velocity distribution of a falling film with variable viscosity

5.143

Velocity distribution of flow through a circular tube

5.144

Velocity profile of fluids in flow of two adjacent immiscible fluids

5.145

Viscosity by a falling-cylinder viscometer

5.146

Winsauer equation

5.147

Acoustic transit time

6.1

Amplitude transmission coefficient in seismic reflection and refraction

6.2

Apparent intensity reflected by recorder (gamma ray)

6.3

Apparent resistivity

6.4

Apparent sorption compressibility

6.5

Atlas wireline neutron lifetime log

6.6

Barenblatt-Chorin universal velocity distribution

6.7

Coefficient of reflection

6.8

Compaction correction factor for sonic logs in shale lithology

6.9

Composite capture cross section of the formation (Schlumberger thermal decay time tool)

6.10

Correlation of mud cake resistivity to mud resistivity

6.11

Correlation of mud filtrate resistivity to mud resistivity

6.12

Diffuse-layer thickness

6.13

Effect of clay on conductivity

6.14

Effective photoelectric absorption cross section index

6.15

Electric resistance to a radial current from a wellbore

6.16

Electrochemical potential (SP log)

6.17

Electrokinetic potential (developed across a mud cake)

6.18

Electron density index (GR absorbtion logging)

6.19

Epithermal neutron diffusion coefficient

6.20

Epithermal neutron distribution (epithermal neutron flux)

6.21

Fertl and Hammack equation

6.22

Formation conductivity in dual water model

6.23

Formation factor – Archie’s equation

6.24

Formation factor (Archie’s equation with resistivity logs)

6.25

Formation resistivity and permeability (Carothers) relation for limestones

6.26

Formation resistivity and permeability (Carothers) relation for sandstones

6.27

Formation resistivity and porosity relations for carbonate rocks

6.28

Formation resistivity and porosity relations from well log data based on Porter and Carothers data

6.29

Fraction of total porosity occupied by clays

6.30

Fresh water-filled porosity (fresh-water-bearing limestones)

6.31

Fxo / Fs approach

6.32

Gamma ray log shale index

6.33

General form of the Archie equation-Water saturation from resistivity logs

6.34

Generalized relationship between formation resistivity factor and porosity (Chevron formula)

6.35

Geometric coefficient for the electrode

6.36

Geometric coefficient for the lateral device

6.37

Geometric coefficient for the normal sonde

6.38

Half thickness value

6.39

Hingle nonlinear-resistivity/linear-porosity crossplot

6.40

Humble equation (formation resistivity factor vs porosity)

6.41

Integrated radial geometric factor

6.42

Lennard Jones potential

6.43

Linear absorption (attenuation) coefficient

6.44

Maximum potential for self-potential (SP) log

6.45

Mean free path (photon absorption)

6.46

Membrane potential

6.47

Neutron lethargy (logarithmic energy decrement)

6.48

Neutron porosity of shale zone

6.49

Oil saturation determination (IE and CDN logs)

6.50

Pair production (gamma ray interactions)

6.51

Phillips equation (sandstones)

6.52

Photoelectric absorption cross sectional area

6.53

Pickett crossplot

6.54

Poisson’s ratio (seismic arrival time method)

6.55

Porosity by using density log data

6.56

Porosity corrected for gas effect

6.57

Porosity-neutron flux relationship

6.58

Rate of radioactive decay

6.59

Relation between concentration of K, Th, or U and recorded total gamma ray signal

6.60

Relationship between rock resistivity and water saturation

6.61

Relationship between SSP and Rw (NaCl predominant)

6.62

Relationship between SSP and Rw (non-ideal shale membrane)

6.63

Relationship between SSP and Rw for water containing salts (non-NaCl predominant)

6.64

Resistivity of a partially saturated shaly sand with hydrocarbons (Vsh models)

6.65

Resistivity of a water-saturated shaly sand (Vsh models)

6.66

Rock conductivity (relatively clean water bearing rocks)

6.67

Shale index from gamma ray spectrometry

6.68

Simandoux (total shale) equation

6.69

Sonic porosity (Raymer Hunt Gardner method)

6.70

Spacing between transmitter and receiver

6.71

Static self potential

6.72

Time between the initiation of the pulse and the first arrival acoustic energy at the receiver

6.73

Time-average relation in compacted formations (porosity/transit time relationships)

6.74

Time-average relation in uncompacted formations (porosity/transit time relationships)

6.75

Tortuosity (resistivity logs)

6.76

Total rock conductivity

6.77

True porosity from sonic log (corrected for compaction)

6.78

True resistivity – Archie

6.79

Volumetric photoelectric absorption cross section

6.80

Water salinity index ratio

6.81

Water saturation determination (IE and CDN logs)

6.82

Water saturation from neutron tools

6.83

Water saturation – Resistivity logs

6.84

Wavelength equation

6.85

Wellbore electric voltage generation

6.86

Acceptable reliability level

7.1

Additional production estimation with new wells

7.2

Annual gross revenue after royalties and wellhead taxes

7.3

Annuity from future value

7.4

Annuity from present value

7.5

Average annual rate of return method

7.6

Average book rate of return method

7.7

Calculation of unknown interest rate

7.8

Compound interest

7.9

Cost depletion

7.10

Cumulative interest on operational expenses during the lifetime of a well

7.11

Effective interest rate for periodic compounding

7.12

Exploration efficiency

7.13

Future value of an annuity

7.14

Future value of present sum

7.15

Generalized expected value calculation

7.16

Growth rate of return for continuous compounding

7.17

Hoskold method for annual rate of return prediction-1

7.18

Hoskold method for annual rate of return prediction-2

7.19

Initial capital needed to survive in a minimum chance scenario

7.20

Meterage model

7.21

Minimum number of jobs to survive in a minimum chance scenario

7.22

Minimum profit ratio per a risky job

7.23

Net cash flow

7.24

Net present value

7.25

Operating cash income

7.26

Payback Period

7.27

Present value of an annuity

7.28

Present value of a deferred annuity

7.29

Present value of future sum

7.30

Present value of profit/investment ratio for an oil well

7.31

Present value of uniform gradient series

7.32

Present worth expectation for a risky job

7.33

Probability of an oilfield discovery

7.34

Profitability index

7.35

Rate of growth per unit of exploration length

7.36

Simple interest

7.37

Total expected additional production discovery

7.38

Total expected additional production discovery in constant production per unit area

7.39

Total new production area estimation expected to be discovered

7.40

Amount of heat required to increase the temperature

8.1

Benedict-Webb-Rubin PVT equation

8.2

Critical pressure Cavett relation

8.3

Critical temperature Cavett method

8.4

Effective thermal conductivity of composite solids

8.5

Einstein equation effective viscosity

8.6

Equilibrium vaporization ratio

8.7

Equilibrium vaporization ratio of heptane

8.8

Evaporation loss from an oxygen tank

8.9

Expansion factor for diffuse layer

8.10

Flat-plate boundary layer model

8.11

Freezing of a spherical drop

8.12

General thermal conductivity

8.13

Heat conduction in a cooling fan

8.14

Heat flux distribution in a wall

8.15

Heat loss by free convection from a horizontal pipe

8.16

Heat released during in-situ combustion given by Burger & Sahuquet

8.17

Heat transfer coefficient for condensation – Pure vapors on solid surface

8.18

Heat transfer in packed bed

8.19

Heat transfer rate in laminar forced convection along heated flat plate

8.20

Jacoby aromaticity factor

8.21

Joule Thompson expansion

8.22

Latent heat of hydrocarbon mixture

8.23

Mixing fluids of different densities

8.24

Mole fraction of a component in liquid phase

8.25

Mole fraction of a component in vapor phase

8.26

Necessary inhibitor concentration required in liquid phase to reduce hydrate point

8.27

Peng Robinson characterization factor

8.28

Peng Robinson PVT equation

8.29

Pseudo-reduced conditions

8.30

Radiant heat transfer between disks

8.31

Radiated energy flux

8.32

Radiation across an annular gap

8.33

Radiation shields

8.34

Rayleigh number

8.35

Redlich-Kwong PVT equation

8.36

Reservoir gas density

8.37

Stefan-Boltzmann law

8.38

Surface temperature of a heating coil

8.39

Temperature due to free convection

8.40

Temperature increase due to forced convection

8.41

Temperature profile after viscous heat transfer

8.42

Temperature profile with a nuclear heat source

8.43

Thermal conductivity for pure metals

8.44

Thermal conductivity of polyatomic gases

8.45

Thermal conductivity of liquids

8.46

Thermal conductivity of solids with gas pockets

8.47

Thermal diffusivity

8.48

Thermal energy of a fissionable substance

8.49

Thermoelastic effect on stress

8.50

Unsteady evaporation of a liquid

8.51

Van Der Waals PVT equation

8.52

Wien displacement law

8.53

Absolute viscosity for Saybolt viscosimeter measurements

9.1

Absolute viscosity for Ubbelohde viscosimeter measurements

9.2

Adhesion tension

9.3

Amott-Harvey wettability index

9.4

Apparent facial tension (De Nouy ring method)

9.5

Average compressibility of oil

9.6

Average gas solubility

9.7

Characterization factor for oil distillation

9.8

Clasius-Clapeyron equation for water vapor

9.9

Clay concentration of drilling mud (methylene blue test)

9.10

Contact angle

9.11

Correction factor for facial tension (De Nouy ring method)

9.12

Drilling mud density (solid content analysis of drilling muds)

9.13

Effective porosity

9.14

Error percentage of porosity measurements

9.15

Facial tension (De Nouy ring method)

9.16

Filtration rate for API fluid loss measurement

9.17

Filtration volume without spurt loss

9.18

Filtration volume with spurt loss

9.19

Gas permeability measurement (lab measurement using Klinkenberg effect)

9.20

Kinematic viscosity for Saybolt viscosimeter measurements

9.21

Liquid permeability (permeameter lab measurement)

9.22

Permeability determination using porosity data (Kozeny-Carman equation)

9.23

Pycnometer volume correction

9.24

Relative centrifugal force

9.25

Relative permeability

9.26

Reservoir wettability characterization (rise in core method)

9.27

Resistance

9.28

Resistivity

9.29

Resistivity index-Archie’s law

9.30

Solid content ratio of drilling mud

9.31

Specific gravity of air (upper phase) (De Nouy ring method)

9.32

Standard discharge time for Saybolt viscosimeter measurements

9.33

Total porosity

9.34

USBM wettability index

9.35

Yield of clays as drilling fluids

9.36

Areal extent of heated zone

10.1

Average reservoir temperature in a cyclical steam injection process

10.2

Bottomhole pressure in a static geothermal well

10.3

Chromatographic lag in polymer flooding

10.4

Cumulative heat injected for steam drive – Myhill and Stegemeier

10.5

Depth of carbon dioxide alteration front (Battlet-Gouedard, 2006)

10.6

Depth of carbon dioxide alteration front (Kutchko, 2008)

10.7

Dimensionless heat injection rate (Gringarten and Sauty)

10.8

Dimensionless injection rate of air for in-situ combustion

10.9

Dimensionless ratio of effective volumetric heat capacity of injected steam to that of the steam zone

10.10

Dimensionless time for semi-steady state flow in coal bed methane reservoirs

10.11

Dimensionless time in wet combustion by Kuo

10.12

Dykstra-Parsons coefficient

10.13

Effective (apparent) transmissivity

10.14

Effective oil transmissivity for thermal stimulation

10.15

Equivalent atomic H/C ratio of fuel for in-situ combustion

10.16

Equivalent volume of steam injected – Myhill and Stegemeier

10.17

Equivalent water saturation in burned zone in-situ combustion by Nelson

10.18

Estimates of cumulative oil displacement

10.19

Estimates of oil displacement rate

10.20

Estimating fraction of heat injected in latent form (steam-drive)

10.21

Estimating heat injection rate (steam-drive)

10.22

Estimating performance prediction of steam-drive reservoirs (cumulative oil produced)

10.23

Estimating recovery steam drive (volume of steam in reservoir)

10.24

Estimating steady-state five-spot injection rate (steam-drive)

10.25

Estimating volume of steam injection (steam-drive)

10.26

Fraction of heat injected in latent form – Myhill and Stegemeier

10.27

Fraction of injected heat remaining in reservoir

10.28

Fractional flow of water in hot floods dependent on temperature and saturation in hot water flood

10.29

Growth of steam-heated area – Marx-Langenheim

10.30

Heat loss over an incremental length of a well (two-phase flow)

10.31

Heat ratio of contents in a geothermal reservoir

10.32

Heat released during in-situ combustion – Burger & Sahuguet

10.33

Heat remaining in reservoir – Marx and Langenheim

10.34

Horizontal well breakthrough time in a bottom-water-drive reservoir

10.35

Ignition delay time in in-situ combustion

10.36

Injected air required to burn through unit bulk of reservoir for in-situ combustion by Nelson and McNiel

10.37

Mass of fuel burned per unit bulk reservoir volume combustion – Nelson and McNiel

10.38

Minimum air flux required for advance of fire front – Nelson and McNiel

10.39

Oil breakthrough newly swept zone

10.40

Oil recovery as a function of the fraction of oil displaced from heated zone

10.41

Oil solubilization factor

10.42

Oil volume at breakthrough by Craig, Geffen, and Morse

10.43

Oil-steam ratio – Marx and Langenheim

10.44

Proppant settlement in fracture

10.45

Rate of advancement of combustion front (in-situ combustion)

10.46

Rate of growth of heated zone in hot water heated reservoir

10.47

Rate of oxygen-reacted per unit mass of fuel

10.48

Relationship with real and dimensionless time in hot water floods

10.49

Reservoir flow for gas flow in a formation

10.50

Reservoir flow through the wellbore of a geothermal well

10.51

Saturation of layer under hot water flood

10.52

Slug size in polymer floods

10.53

Temperature increase with time during in-situ combustion process

10.54

Temperature of a producing geothermal well

10.55

Temperature of a single-phase liquid or gas injected geothermal well

10.56

Total heat loss of a geothermal well

10.57

Total oil production from in-situ combustion – Nelson and McNeil

10.58

Total oil production from wet in-situ combustion – Nelson and McNeil

10.59

Total water production from in-situ combustion – Nelson and McNeil

10.60

Volume of burned part of reservoir (in-situ combustion)

10.61

Volume of reservoir burnt by wet combustion

10.62

Volumetric heat capacity

10.63

Wet combustion design (in-situ combustion)

10.64

Axial stress around vertical wellbore

11.1

Axis of a deviated borehole from an arbitrary origin

11.2

Bulk modulus (using Lame)

11.3

Bulk modulus (using Poisson’s ratio and Lame’s constant)

11.4

Bulk modulus (using Poisson’s ratio and shear modulus)

11.5

Change in pore volume due to initial water and rock expansion

11.6

Cohesive strength of rocks

11.7

Compressibility of a coalbed methane formation

11.8

Effect of pore pressure on stress

11.9

Effective stress on individual grains

11.10

Failure criteria (Mohr-Coulomb)

11.11

Formation compressibility by using hydrofrac data

11.12

Fracture conductivity

11.13

Fracture gradient (Eaton)

11.14

Fracture gradient (Holbrook)

11.15

Fracture gradient (Matthews and Kelly)

11.16

Fracture gradient (Zoback and Healy)

11.17

Fracture pressure (Hubert and Willis)

11.18

Fracture volume (GDK method)

11.19

Fracture volume (Perkins and Kern method)

11.20

Fracture width (GDK method)

11.21

Fracture width (Perkins and Kern method)

11.22

Hoek and Brown criteria for principal stress failure

11.23

Horizontal effective stress (assuming no lateral strain as per Lorenz and Teufel)

11.24

Horizontal maximum stress (Bredehoeft)

11.25

Induced fracture dip

11.26

Initial effective horizontal stress

11.27

Isothermal compressibility of limestones (Newman correlation)

11.28

Least principal stress as function of depth in Gulf of Mexico (Hubbert and Willis)

11.29

Least principal stress as function of depth in Gulf of Mexico (Matthew and Kelly)

11.30

Linearized Mohr failure line

11.31

Linearized Mohr coulomb criteria

11.32

M Modulus (using shear modulus and bulk modulus)

11.33

M Modulus (using Young’s modulus and Poisson’s ratio)

11.34

Maximum anisotropic failure stress

11.35

Maximum compression at vertical wellbore

11.36

Maximum normal stress in tangential direction at wellbore wall (hoop stress)

11.37

Maximum plane tangential stress acting on deviated wellbore (1)

11.38

Maximum principal stress failure (Hoek and Brown)

11.39

Maximum principal stress in normal faulting

11.40

Maximum principal stress in reverse faulting

11.41

Maximum principal stress in strike-slip faulting

11.42

Maximum principal stress calculation using breakout width

11.43

Minimum compression at vertical wellbore

11.44

Minimum normal stress in tangential direction at wellbore wall (hoop stress)

11.45

Maximum plane tangential stress acting on deviated wellbore (2)

11.46

Modified lade criterion

11.47

Normal stress in radial direction near wellbore

11.48

Normal stress in rock at failure

11.49

Normal stress in tangential direction at wellbore wall (hoop stress)

11.50

Normal stress in tangential direction near wellbore (hoop stress)

11.51

Pore pressure increase due to fluid activity (Mody and Hale)

11.52

Pore pressure increase due to given fluid activity contrast (Mody and Hale)

11.53

Pore pressure of shale (Flemings)

11.54

Pore pressure of shale (Traugott)

11.55

Porosity irreversible plastic deformation occurs

11.56

Pressure required to induce a tensile fracture (breakdown pressure)

11.57

Pressure to grow fractures (Abe, Mura, et al.)

11.58

Radial stress around vertical wellbore

11.59

Ratio of pore pressure change to original due to depletion

11.60

Rotation of maximum principal stress near wellbore

11.61

Rotation of maximum principal stress near wellbore (Zoback \ Day-Lewis)

11.62

Shale compaction

11.63

Shear modulus

11.64

Shear modulus from Young’s modulus

11.65

Shear stress near vertical well

11.66

Slowness of the formation

11.67

Storativity of fractures

11.68

Stress at edge of wellbore breakout

11.69

Stress component near normal faulting in reservoir

11.70

Stress components in original coordinate system in depletion drive

11.71

Stress intensity at tip of mode I fracture

11.72

Stress path (induced normal faulting)

11.73

Stress path of reservoir with changes in production

11.74

Stress perturbation (Segall and Fitzgerald)

11.75

Subsidence due to uniform pore pressure reduction in free surfaces

11.76

Unconfined compressive strength of rock

11.77

Velocity of bulk compressional waves

11.78

Velocity of compression waves

11.79

Velocity of shear waves

11.80

Yield strength (Bingham plastic model)

11.83

Allowable gas velocity through gas separator

12.1

Allowable velocity in downcomer for tray type tower

12.2

Bed diameter of adsorption unit

12.3

Bed length of adsorption unit

12.4

Block efficiency factor

12.5

Bottom distillation column rate

12.6

Breakthrough time in an adsorption unit

12.7

Breathing loss of natural gas

12.8

Capacity coefficient of valves in gas processing

12.9

Column diameter of packed towers

12.10

Cooling of an ideal gas

12.11

Correction factor for foamless separation

12.12

Correlation factor for Benedict-Webb-Rubin equation

12.13

Critical pressure values for pressure in Van Der Waals equation

12.14

Downcomer velocity in tray type tower

12.15

Electrical heating of a pipe

12.16

Energy requirement of single-stage ideal compressor

12.17

Error in thermocouple temperature measurement

12.18

Eykman molecular refraction

12.19

Fenske’s method for minimum theoretical plates

12.20

Gas capacity of separator

12.21

Gas mass velocity in an adsorption unit

12.22

Gas mass velocity in separator

12.23

Gas originally adsorbed

12.24

Gas pressure testing time for unsteady gas flow

12.25

Gravitational attraction of a layer (Bouguer correction)

12.26

Heating of a liquid in an agitated tank

12.27

Height of downcomer filling

12.28

Inhibitor injection rate required

12.29

Instrumentation noise control

12.30

Internal diameter of gas separator

12.31

Isostacy-Airy hypothesis

12.32

Lift coefficient

12.33

Mass of steel Shell in adsorption unit

12.34

Mass transfer zone length of adsorption unit

12.35

Modified Clapeyron criteria

12.36

Packed column actual height

12.37

Pan-Maddox equation for density

12.38

Pan-Maddox equation for molecular weight

12.39

Photoelectric effect

12.40

Power requirement for pumping a compressible flow fluid through a long pipe

12.41

Pressure criteria for separator by ASME (external radius)

12.42

Pressure criteria for separator by ASME (internal radius)

12.43

Pressure storage

12.44

Proportional band in pressure controller

12.45

Raoult’s law in glycol dehydration unit

12.46

Refrigerator shaft speed

12.47

Relative humidity

12.48

Required oil length in separator

12.49

Required separator liquid section

12.50

Required water length in separator

12.51

Residence time of water in separator

12.52

Residence time oil in separator

12.53

Retention time in a liquid-liquid vessel

12.54

Safety relief valves sizing in vapor services

12.55

Steady-state temperature controller

12.56

Still column diameter in glycol dehydration unit

12.57

Stripping factor

12.58

Surface tension from density

12.59

Tarnishing of metal surfaces

12.60

TEG weight percent in glycol dehydration unit

12.61

Temperature after refrigeration

12.62

Temperature dependent source rate for flow reactor

12.63

Temperature distribution in a hot-wire anemometer

12.64

Terminal velocity in a separator

12.65

Thickness criteria of spherical shells in separator (ASME)

12.66

Top distillation column rate

12.67

Vapor mass velocity of tray type tower

12.68

Wall thickness criteria for separator by ASME (external radius)

12.69

Wall thickness criteria for separator by ASME (internal radius)

12.70

Water loading in adsorption unit

12.71

Weight of rich TEG in glycol dehydration unit

12.72

Wobbe index

12.73

Work done by expansion tube refrigerator

12.74