Permeabilities of sands

For waterproofing, sodium silicate concentrations below 30% are adequate concentrations between 35 and 70% are used for strength improvement. Grouts having 35 vol % or higher silicate resist deterioration on freeze—thaw or wet—dry cycles. Water permeability of sands can be reduced from 10 to 10 cm/s. Unconfined compressive strengths of stabilized sand can vary from 103 to 4130 kPa (15—600 psi) the normal range is between 690 and 1380 kPa. 

A study of the permeability of sand. Univ. Iowa Studies in Eng. Bulletin 7, New Series No. 316. 

Donat J (1929) Wisserkraft und Wisserwirtschaft, 25 (Enghsh trans An Article on the Permeability of Sand. Bureau of Reclamation, Denver, 1933)... 

Deltaic (distributary channel) Isolated or stacked channels usually with fine grained sands. May or may not be in communication Good producers permeabilities of 500-5000mD. Insufficient communication between channels may require infill wells in late stage of development... 

Assuming a Kozeiiy constant of 5, what would be the permeability of the reactor packed with the sand ... 

During well completion it is sometimes desirable or necessary to treat or stimulate the producing zone to improve permeability of the rock and to increase the flow of oil or gas into the casing. This may be accomplished by use of acid or by injection of fluid and sand under high pressure to fracture the rock. Such a trcatniciit usually improves the ability of the rock to allow fluid to flow through it into the well bore. At this point the drilling and completion phases have ended. 

Deposits of sand, dirt or permeable corrosion products on the metal surface (a type of crevice corrosion that is referred to as deposit attack). 

Cover design The ET cover was installed in 1999 and consists of a 3-ft silty sand/clayey sand layer, which overlies a 2-ft foundation layer. The cover soil was placed in 18-in. lifts and compacted to 95% with a permeability of <3 x 10 5 cm/s. Native vegetation was planted, including artemesia, salvia, lupines, sugar bush, poppy, and grasses. 

FML placed on a bed of sand, geotextiles, or other highly permeable materials would allow liquid to move through the defect in the FML, spread over the whole area of the clay liner, and percolate down as if the FML was not there. With clay liner soils that contain some rock, it is sometimes proposed that a woven geotextile be placed on top of the soil liner under the FML to prevent the puncture of rocks through the FML. A woven geotextile between the FML and the clay, however, creates a highly transmissive zone between the FML and the clay. The surface of the soil liner instead should be compacted and the stones removed so that the FML can be placed directly on top of the clay. 

Flow Tests. One foot long sand packs using Wilmington oil field unconsolidated sand were prepared for each of the flow tests. Porosity and permeability of all the sand packs were within 30-35% and 100-300 md, respectively. All core packs were evacuated to about 1 mm of mercury (Hg) before saturating them under gravity to assure complete water saturation. Table III gives the core and fluid properties for the flow tests. The properties of the cores were chosen so that they are close to the field conditions reported by Krebs(15). 

Properties and extraction processes Tight-formation gas is natural gas trapped in low-porosity (7 to 12%), low-permeability reservoirs with an average in-situ permeability of less than 0.1 millidarcy (mD), regardless of the type of the reservoir rock tight gas usually comprises gas from tight sands (i.e., from sandstone or limestone reservoirs) and shale gas. Sometimes tight gas also comprises natural gas from coal and deep gas from reservoirs below 4500 m. Shale gas is produced from reservoirs predominantly composed of shale rather than from more conventional sandstone or limestone reservoirs a particularity of shale gas is that gas shales are often... 

Test borings revealed that the fill material consists predominantly of thinly laminated silt with a relatively high clay content. Occasional discontinuous layers of fine sand were encountered at random locations, both horizontally and vertically. The water table gradient under nonpumping conditions was toward the canal with an approximate gradient of 0.011 ft/ft. Slug tests indicated an effective permeability of 1 x 10-5 cm/s. 

Plume No. 3 (areas 4 and 5) is located in low permeable, partially fractured clay from 0 - 10m bgs (k = 4 x 10" m/s), over a layer of sand and gravel (k = 5 x 10" m/s) down to 18m bgs, and underlain by clay. The groundwater table is at 1 Om bgs in the sand and gravel. In areas where this layer is absent, only perched groundwater occurs, at depths of between 2 and 12m bgs. Contamination was found throughout the whole profile, in concentrations between 15mg/l to free phase, with most of the free phase found in the upper clay layer. 

Nonadsorptive retention of contaminants can also be beneficial. For example, oil droplets in the subsurface are effective in developing a reactive layer or decreasing the permeability of a sandy porous medium. Coulibaly and Borden (2004) describe laboratory and field studies where edible oils were successfully injected into the subsurface, as part of an in-situ permeable reactive barrier. The oil used in the experiment was injected in the subsurface either as a nonaqueous phase liquid (NAPL) or as an oil-in-water emulsion. The oil-in-water emulsion can be distributed through sands without excessive pressure buildup, contrary to NAPL injection, which requires introduction to the subsurface by high pressure. 

All targets in these tests were secured to a post located in 4 ft of water. Targets were suspended from the post by a rope so that the targets were approximately 1 ft from the seafloor. For initial tests, a target was constructed using a commercially available TNT simulant. The simulant consists of TNT coated onto particles of sand, but the quantity of TNT in the simulant is insufficient to sustain a detonation. This target was placed inside a water-permeable fabric bag and was affixed to the pole as previously described. 

Water absorption is good and illustrative experiment, just like a comparison of the water permeabilities of clay and sand. 

---