دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: one of the alkaline earth elements with a valence of 2 and an atomic weight of about 40. Calcium compounds are a common cause of water hardness. Calcium is also a component of lime, gypsum, and limestone.

n: dissolved calcium ions in sufficient concentration to impart undesirable properties, such as flocculation, reduction in yield of bentonite, and increased fluid loss, in a drilling fluid. See also anhydrite, calcium carbonate, calcium sulphate, gypsum, lime.

n: The process that calcium ion enters into the drilling fluid when drilling in the calcareous formation or cement plug.

n: a chemical compound of calcium, sulphur, and oxygen, CaSﾰ4. Although sometimes considered a contaminant of drilling fluids, it may at times be added to them to produce certain proper- ties. Like calcium carbonate it forms scales in waterhandling facilities, which may be hard to remove. See anhydrite, gypsum.

n: a freshwater drilling mud using calcium oxide (lime) or calcium sulphate (gypsum) to retard the hydrating qualities of shale and clay formations, thus facilitating drilling. Calcium-treated muds resist salt and anhydrite contamination but may require further treatment to prevent gelation (solidification) under the high temperatures of deep wells.

n: 1. a disklike plate of anhydrite, gypsum, limestone, or sulphur overlying most salt domes in the Gulf Coast region. 2. impermeable rock overlying an oil or gas reservoir that tends to prevent migration of oil or gas out of the reservoir.

n: a nonfermenting cellulose product used in drilling fluids to combat contamination from anhydrite (gypsum) and to lower the water loss of the mud.

n: A production manufactured by acetic acid chloride after plant fibre is alkalized. Usually used as filtrate reducer and adhesion promoter.

n: a substance formed by melting ground limestone, clay or shale, and iron ore in a kiln. Cement kIinker is ground into a powdery mixture and combined with small amounts of gypsum or other materials to form cement.

n pi: a slurry of portland cement and water and sometimes one or more additives that affect either the density of the mixture or its setting time. The portland cement used may be high early strength, common (standard),or slow setting. Additives include accelerators (such as calcium chloride),retarders (such as gypsum),weighting materials (such as barium sulphate),lightweight additives (such as bentonite),or a variety of lost circulation materials (such as mica flakes).

n: The bonding material for cementing.

n: a sedimentary rock formed by precipitation of dissolved solids from water evaporating in enclosed basins. Examples are gypsum and salt.

a formation formed by the evaporation of water from shallow seas. Very low permeability.