With proper attention to mud properties and coring practice, unconsolidated reservoir sands can be successfully cored with rubber sleeve coring tools. With proper handling and preparation, which includes freezing the cores at the well site, drilling lab samples with liquid nitrogen, maintaining the core in the frozen state until stress is applied, and cleaning with solvents in the pressure vessel, many useful petrophysical parameters may be measured on unconsolidated sand cores. Simulated reservoir stress is applied to a sample during measurements to offset the effects of stress relief during the drilling and surfacing of the core. When the maximum in-situ stress is exceeded in the laboratory, the pore compression curve shows a "knee", i.e., an increased rate of compaction. If these knees occur and small geologic features are seen to be preserved in core slabs, we consider these to be evidence that the coring and core handling techniques described preserve the in-situ particle arrangement of the sand. Methods for measurement of porosity, permeability, formation factor, resistivity index and oil-water capillary pressure are described and the resultant data are presented for samples from some unconsolidated Louisiana sands. These data are believed to represent in-situ stress conditions. To measure the air-liquid initial-residual nonwetting-phase saturation relation (Si-Sr) and the mercury-air capillary pressure-saturation relation (Hg Pc-SHg) the sample is artificially consolidated with diluted EPOSAND while at in-situ effective stress. The now-consolidated sample is removed from the pressure vessel, and these relations are measured by standard methods. Corrections are applied to these data to account for the presence of the EPON, and the Si-Sr and Hg Pc-SHg relations are calculated for the original unconsolidated sample.
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September 01 1980
The Measurement Of Petrqphyshcal Properties Of Unconsolidated Sand Cores
The Log Analyst 21 (05).
Paper Number: SPWLA-1980-vXXIn5a3
September 01 1980
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Swanson, B.F., and E.C. Thomas. "The Measurement Of Petrqphyshcal Properties Of Unconsolidated Sand Cores." The Log Analyst 21 (1980): No Pagination Specified.
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