Hydrocarbon MigrationHydrocarbon Migration

Istvan CsatoUniversity of South CarolinaDepartment of Geological Sciences

Petroleum Geology Class 745Spring 2002

)( owo

o

o

wo

gE

gradpgE

Hydrostatic condition:

Buoyancy

0w

ww

gradpgE

Capillary Pressure

)11

(2pt

crr

p Capillary pressure

)11

(2)(pt

oworr

gz Condition of migration

o

c

o

wo

gradpgradpgE

Migration

Critical height of oil stringer:

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)11

(2

ow

ptcg

rrz

oo lrrgradPc pt

)11

(2

sin

czl

l

)( owo

og

E

o

cow

oo

gradPgE

sin)(

Migration

Darcy’s law:

)( owo

oo gk

q

oq specific discharge [m/s]

ok permeability of the matrix [m2]

o viscosity of oil [kg/m/s]

oo nSk r 2

2

8 r mean radius of the rock pores [m]

tortuosityn porosity

oS oil saturation

Migration

Migration

Vertical flow:

qo=11.3 cm/year

Updip flow at 2o slope:

qo=0.4 cm/year

Hydrodynamic Conditions

Hydrodynamic Traps

Compaction

Overpressure

Origin of Fluid Flow

1. Restricted-compaction

2. Meteoric Water Recharge

)()( www vt

)( ePk

q

)()( 2e

ww P

k

t

wvq

BSPe

)1( rw zgzgS

gzB w][ f

Mass conservation equation:

Fluid flow equation (Darcy’s Law):

Fluid Flow Compaction

Fluid Flow - Compaction

Effective Stress - Porosity

Hydraulic fracturing

Primary and Secondary Migration as a functionof rock permeability

Primary Migration Secondary Migration

Migration and Accumulation

Migration from Shale to Sandstone

Migration from Shale to Sandstone

Migration through Fractures

Example

Origin of Fluid Flow

1. Restricted-compaction

2. Meteoric Water Recharge

Hydrodynamic Traps

Tilt of Oil-Water Contact