دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

a kick control method that circulates the well immediately and mud weight is brought up gradually. (Concurrent method).

n: a method for killing well pressure in which circulation is commenced immediately and mud weight is brought up in steps, or increments, usually a point at a time. Also called circulate- andweight method.

n: See circulate-and-weight method.

a well pressure control operation in which circulation is started immediately and mud density is brought up in steps until the well has been completely circulated to the kill weight fluid.

a fluid column margin of some type. Usually well control mud weight, gas column, etc.

n: the mass or weight of a substance per unit volume. For instance, the density of a drilling mud may be 10 pounds per gallon, 74.8 pounds/cubic foot, or 1,198.2 kilograms/cubic metre. Specific gravity, relative density, and API gravity are other units of density.

n: Mass per unit volume expressed in pounds per gallon (ppg),grams per cubic (g/cc),or pounds per cubic ft (lb/cu.ft). Drilling-fluid density is commonly referred to as mud weight.


the mass per volume of a substance. Density of fresh water is 8.33 pounds per gallon or 1 gram/cc.

n: a condition in which the drill stem becomes stuck against the wall of the wellbore because part of the drill stem (usually the drill collars) has become embedded in the filter cake. Necessary conditions for differential-pressure sticking, or wall sticking, are a permeable formation and a pressure differential across a nearly impermeable filter cake and drill stem. Also called wall sticking. See differential pressure, filter cake.

n: One of the mechanisms causing stuck pipe by having excessive mud weight.

a common method of pipe sticking where the overbalance pressure in the wellbore pushes the tubing against the side of the wellbore in a permeable formation.

equivalent mud weight.

equivalent mud weight.

n: (ECD) the increase in bottomhole pressure expressed as an increase in pressure that occurs only when mud is being circulated. Because of friction in the annulus as the mud is pumped, bottomhole pressure is slightly, but significantly, higher than when the mud is not being pumped. ECD is calculated by dividing the annular pressure loss by 0.052, dividing that by true vertical depth, and adding the result to the mud weight Also called circulating density, mudweight equivalent

n: The effective drilling-fluid weight at any point in the annulus of the well bore during fluid circulation.ECD includes drilling-fluid density, cuttings in the annulus, and annular pressure loss.

the effective fluid density that the formation sees when the friction pressure on the fluids returning to surface is added to the fluid density.

The equivalent mud weight felt by the formation when circulating with a certain mud weight and holding a backpressure. A 10 lb/gal mud in a 10,000 ft well with 1000 psi backpressure would generate an equivalent mud weight of about 11.9 lb/gal.

n: (PbS) lead sulphide. Technical grades (specific gravity about 7) are used for increasing the density of drilling fluids to points impractical or impossible with barite. gall n: damage to steel surfaces caused by friction and improper lubrication.

n: leadsulphate. Technical grades (specific gravity gbout 7) are used for increase density of drilling fluids to points impractical or impossible with barite.

lead sulfide, PbS. A mud weighting additive for high mud weights.