Weighting agents

The viscosifier clays are considered nontoxic but they may contain elevated concentrations of metals tightly bound to the clay matrix [33]. 

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Production and Consumption. About 80% of the world s barite production is used as a weighting agent for the muds ckculated in rotary drilling of oil and gas wells (see PETROLEUM, DRILLING FLUIDS AND OTHER OIL RECOVERY CHEMICALS). Table 2 shows the U.S. production—consumption balance. The 1988 demand for barite increased nearly 40% over that recorded in 1987. However, by the end of 1988, oil prices had declined and renewed economic uncertainties depressed exploration and development activity. Barite demand fell accordingly and imports of lower cost foreign product exceeded domestic production. 

Oil-base muds are composed of oil as the continuous phase, water as the dispersed phase, emulsifiers, wetting agents, and gellants. There are other chemicals used for oil-base mud treatment such as degellants, filtrate reducers, weighting agents, etc. 

The cement usually is mixed dry with the additives. Depending on the application of the cement, a wide variety of additives can be incorporated. These include accelerators, retarders, dispersants, extenders, weighting agents, gels, foamers, and fluid loss additives. 

Additives and mixtures to reduce or prevent lost circulation Density-increasing or weighting agents Free water control and solid suspending agents Spacers and chemical washes or preflushes Specialty cement blends... 

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. 

What has long been sought and badly needed is a soluble weighting agent less corrosive than, and equally non-damaging as, the popular calcium and zinc halides. Preliminary laboratory and field data indicate TKPP may be the solution. 

Ba 2.8 0.5 7.6 200 26 36 100 271 Filler, extender, or weighting agent in paints, plastics, and rubber. Others aggregate in high-density concrete used for radiation shielding, contrast medium in medical X-rays, and ingredient in faceplate glass of cathode ray tubes used in televisions and computer monitors. 

The major components of all drilling mud systems are similar. All of today s mud systems contain emulsifiers, wetting agents, thinners, weighting agents, gelling agents, brine, and small amounts of other substances and chemicals suspended in... 

Aromatic composition Resin (weighting agent) Spray dried Acacia gum Water... 

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