Petroleum Unit Systems

	Abbr	SI	Oil Metric	Oil Field	Additional
Time	t	s	d = 86400 s	d = 86400 s	hr = 3600 s
Length	L	m	m = 3.281 ft	' = ft = 0.3048 m	km = 10³ m
Pipe Diameter	d, ø	m	m = 39.37 in	" = in = 0.0254 m	mm = 0.001 m= 0.0393701 in
Temperature	T	°C	°C	F = 9/5 T [°C] + 32	K = 273 °C
Pressure (absolute)	P	Pa	kPa = 10³ Pa = 0.145038 psi MPa = 1,000 Pa = 10³ Pa = 145.038 psi GPa = 1,000 Pa = 10⁶ Pa = 145,038 psi	psi = 6894.76 Pa = 6.89476 kPa	bar = 10⁵ Pa = 100 kPa = 14.5038 psi atm = 101,325 Pa = 101.325 kPa = 14.6959 psi
Pressure (gauge)	P_gauge	Pa	kPag = P[kPa] - 101,325 kPa	psig = P[psi] - 14.6959 psi
Rate (oil)	q, Q	m³/s	m³/d = 1.16 · 10^-5 m³/s	bpd = 0.184 · 10^-5 m³/s = 0.159 m³/d
Rate (gas)	q_g, Q_g	m³/s	m3/d = ???	scf = ft³ = ???
GOR	Y_g	m³/m³	m³/m³ = ???	scf/bbl = ???
Density (solids)	ρ	kg/m³	g/cm³ = 10³ kg/m³	g/cc = g/cm³ = 10³ kg/m³
Density (oil)	ρ_o	kg/m³	g/cm³ = 10³ kg/m³	°API = (141.5/ γ_o) - 131.5
Specific Gravity	γ	–	1 = 10³ kg/m³	1 = g/cm³	γ = ρ / ρ_w
Compressibility	c	Pa^-1	kPa^-1 = 10^-3 Pa^-1	psi^-1 = 0.145 · 10^-3 Pa^-1 = 0.145 kPa^-1
Permeability	k	m²	md = 9.869233×10⁻⁷ m²	md = 9.869233×10⁻⁷ m²	D = 9.869233×10⁻¹³ m²
Viscosity	μ	cp	cp = 10^-3 Pa · s	cp = 10^-3 Pa · s
Productivity	J	m³/(Pa·s)	m³/(d·kPa) = ???	bpd/psi = ???	m³/(d·atm) = ???
Transmissibility	σ	m³/(Pa·s)	(md·m)/cp = ???	(md·ft)/cp = ???	m³/(d·atm) =???
Pressure diffusivity	χ	m²/s	(md·kPa)/cp = ???	(md·psi)/cp = ???	(md·atm)/cp = ???
Wellbore storage	WBS, C_S	m3/Pa	m3/kPa = ???
Thermal conductivity	λ	W/(m·K)	W/(m·C) = ???	BTU/(hr⋅ft⋅°F) = ???
Specific heat capacity	c_p	J/K	kJ/C = ???	kJ/F = ???

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Petroleum Unit Systems