Barite-water

Fenter P, McBride MT, Srajer G, Sturchio NC, Bosbach D (2001a) Structure of HEDP adsorbed at the barite-water interface. (Abstract) 222nd American Chemical Society Annual Meeting, Chicago, IL, Aug. 26-30, 2001... 

Dense medium-solvent mixture Density range (/kg.m h Solvent (additive) Barite-water 3200-4000... 

Barite, predominately BaSO, meets the overall requirements for weighting material better than other materials and is used for increasing the density of drilling fluids throughout the world. Commercial barite has a lower specific gravity than pure barium sulfate owing to the presence of associated minerals, such as silica. Barite is virtually insoluble in water and does not react with other mud constituents. Most operators prefer barite that meets API specifications (Table 2) (23). The barite content in mud depends on the desired density but can be as high as 2000 kg/km (700 lb/bbl). 

Although numerous mud additives aid in obtaining the desired drilling fluid properties, water-based muds have three basic components water, reactive soHds, and inert soHds. The water forming the continuous phase may be fresh water, seawater, or salt water. The reactive soHds are composed of commercial clays, incorporated hydratable clays and shales from drilled formations, and polymeric materials, which may be suspended or dissolved in the water phase. SoHds, such as barite and hematite, are chemically inactive in most mud systems. Oil and synthetic muds contain, in addition, an organic Hquid as the continuous phase plus water as the discontinuous phase. 

The fused product contains about 60—85% barium sulfide, unreacted barium sulfate, and impurities present in barite and ash. The soluble barium sulfide is extracted from the mixture with water and separated from the insoluble impurities by filtration. 

Precipitated or synthetic barium carbonate is the most commercially important of all the barium chemicals except for barite. Barium carbonate is an unusually dense material, that is almost kisoluble ki water and only slightly soluble ki carbonated water. It does dissolve ki dilute hydrochloric, nitric, and acetic acids and is also soluble ki ammonium nitrate and ammonium chloride solutions. 

Barium is reported in the kiln spill in three different forms water-soluble, eg, BaS, BaO acid-soluble, eg, BaCO, aluminate, siUcate, ferrate and insoluble, eg, unreduced barite. 

Example. It is desired to increase the specific weight of 700 bbl of 12.0-lb/gal mud to 14.0-lb/gal mud. To keep the new mixture from becoming too viscous, 1 gal of water is to be added with each 100-lb sack of barite. A final mud volume of 700 bbl is required. Determine the volume of initial mud that should be discarded and the weight of barite to be added [7]. 

The total volume of water to be added with the barite, (gal), often called dilution water, is... 

The dilution-discard method is the traditional (sometimes the only) way to control the constant increase of colloidal size cuttings in weighted water-base muds. It is effective but also expensive, due to the high cost of barites used to replace the total weighting material in the discard. The daily mud dilutions amount to an average of 5 to 10% of the total mud system. 

Barite. This mineral additive requires much more water to be added to the cement slurry than does hematite. This large amount of added water required will decrease the compressive strength of the cement. This additive can be used to increase the specific weight of a cement slurry to as high as 19 Ib/gal. 

The above-mentioned consideration indicates that important factors controlling the precipitations of barite and silica are surface area/water mass ratio (A/M), temperature, precipitation rate constant (k) and flow rate (u), and the coupled fluid flow-precipitation models are applicable to understanding the distributions of minerals in submarine hydrothermal ore deposits. 

Christy, A.G. and Putnis, A. (1993) The kinetics of barite dissolution and precipitation in water and sodium chloride barines at 44-850°C. Geochim. Cosmochim. Acta, 57, 2161-2168. 

Dominant sulfides and sulfate minerals in the Osorezan area are pyrite, marcasite, orpiment, realgar, stibnite, krennerite, coloradoite, jordanite, wurtzite, sphalerite, cinnabar, and barite (Aoki, 1992b). H2S concentration of the Osorezan hot spring is very high, compared with the other Japanese geothermal waters (Table 2.4). 

Weighting agents (Table 10-10) are added to increase the density of the cement. They are typically used to combat high bottom-hole pressures. Common additives are powdered iron, ferromat, powdered magnetite, and barite. Hematite ean be used to increase the density of a mixture up to 2200 kg/m (19 Ib/gal). Hematite requires the addition of some water. 

Ilmenite has a specific gravity of 4700 kg/m. It requires no addition of water when added to the slurry. Ilmenite has a minimal effect on the thickening time and compressive strength. Barite requires more water then hematite when added to the cement. This results in a decrease of the compressive strength of the set cement. 

Manheim FX, Pauli, CK (1981) Patterns of ground water salinity changes in a deep continental-oceanic transect off the southeastern Atlantic coast of the U.S.A. J Hydrol 54 95-105 Martin P, Akber RA (1999) Radium isotopes as indicators of adsorption-desorption interactions and barite formation in groundwater. J Environ Radioact 46 271-286 McCarthy J, Shevenell L (1998) Obtaining representative ground water samples in a fractured and karstic formation. Ground Water 36 251-260... 

Osthols E (1995) Thorium sorption on amorphous silica. Geochim Cosmochim Acta 59(7) 1235-1249 Palmer MR, Edmond JM (1993) Uranium in river water. Geochim Cosmochim Acta 57 4947-4955 Paytan A, Moore WS, Kastner M (1996) Sedimentation rate as determined by Tla activity in marine barite. Geochim Cosmochim Acta 60(22) 4313-4320... 

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