Experimental measurements of the diffusion parameters of light hydrocarbons in water-saturated sedimentary rocks: II. Results and geochemical significance

Journal Article · Fri Jan 01 00:00:00 EST 1988 · Organic Geochemistry; (UK)

DOI:https://doi.org/10.1016/0146-6380(88)90247-1· OSTI ID:6992194

Krooss, B M; Leythaeuser, D ^[1]

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1. Institute of petroleum and Organic Geochemistry, Juelich (Germany, F.R.)

Diffusion parameters (diffusion coefficient, diffusion permeability, solubility coefficient) for methane, ethane, propane, n-butane, methylpropane and 2,2-dimethylpropane were measured on 21 samples of water-saturated sedimentary rocks at different temperatures (30, 50, and 70 C). The rock samples include sandstones, siltstones, and claystones with porosities ranging from 0.4 to 16.5% and permeabilities from <0.005 to 33.4 millidarcy. Experimental diffusion coefficients ranged from c. 6 {times} 10{sup {minus}10} to 9 {times} 10{sup {minus}13} m{sup 2}/s, solubility coefficients covered a range from c. 5 {times} 10{sup {minus}1} to 5 {times} 10{sup {minus}4}, and diffusion permeabilities lay between c. 4 {times} 10{sup {minus}12} and 1 {times} 10{sup {minus}14} m{sup 2}/s. Diffusion coefficients decrease with increasing molecular weight of the hydrocarbon compound, the decrease depending on the petrophysical properties and the mineralogy of the rocks and being most drastic in shales. None of the petrophysical parameters examined in this study (porosity, permeability, formation resistivity factor) gave a good correlation with the nonsteady-state diffusion coefficient, D. An excellent correlation was found between the formation resistivity factor, F, and the steady-state diffusion permeability. P. A possibly useful-though less significant-relation bearing some resemblance with Archie's law appears to exist between the porosity and the diffusion permeability. The temperature dependence of the diffusion parameters was determined on two calcareous sandstones. Based on an activated diffusion model activation energies for the diffusion process ranging around 50 kJ/mol were calculated for all hydrocarbons examined.

• OSTI ID: 6992194
• Journal Information: Organic Geochemistry; (UK), Vol. 12:2; ISSN 0146-6380
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
ALKANES
DIFFUSION
BUTANE
CLAYS
PERMEABILITY
ETHANE
METHANE
PROPANE
SANDSTONES
SILTSTONES
ACTIVATION ENERGY
CORRELATIONS
ENVIRONMENTAL TRANSPORT
MINERALOGY
MOLECULAR WEIGHT
NATURAL GAS
PETROLEUM
POROSITY
SEDIMENTARY ROCKS
SHALES
TEMPERATURE DEPENDENCE
ENERGY
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GASES
HYDROCARBONS
MASS TRANSFER
ORGANIC COMPOUNDS
ROCKS
020200* - Petroleum- Reserves
Geology
&amp; Exploration
030200 - Natural Gas- Reserves
Geology
&amp; Exploration