Hydraulic conductivity of shaly sands
- PPPG/Federal Univ. of Bahia, Salvador Bahia (Brazil)
The effects of clays on the hydraulic conductivity of a sandstone are analyzed by considering a simple clay coating structure for the sand grains. In the model, silicate insulating nuclei are uniformly surrounded by charged clay particles. The total charge on the clays is compensated by a counterion density Q{sub v}. Assuming a capillary flow regime inside this granular model a Kozeny-Carman type equation has been derived, expressing its intrinsic permeability k in terms of a porosity-tortuosity factor {phi}{sup (m{minus}0.5)} and of the parameter Q{sub v}. The power-law derived expression shows that k decreases with the amount of clay, not only because a high Q{sub v} implies a narrowing of the pore channels, but also because it modifies the hydraulic tortuosity of the medium. This new equation has been statistically tested with extensive petrophysical laboratory data for different types of shaly sandstones.
- OSTI ID:
- 89724
- Report Number(s):
- CONF-941015-; TRN: IM9536%%154
- Resource Relation:
- Conference: 64. annual meeting of the Society of Exploration Geophysicists and international exposition, Los Angeles, CA (United States), 23-27 Oct 1994; Other Information: PBD: 1994; Related Information: Is Part Of SEG international exposition and sixty-fourth annual meeting -- 1994 Technical program: Expanded abstracts with authors` biographies; PB: 1736 p.
- Country of Publication:
- United States
- Language:
- English
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