دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: See annular pressure loss.

n: The pressure deficiency through the flowing direction due to friction resistance when drilling fluid flows in the annular.

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.

fF = (db/2V2) (P/L). Where  = density (ppg),V = avg. fluid velocity (ft/sec),P is pressure loss over length L (ft).

n: a restriction installed in a line of flowing fluid that produces relatively high differential pressures with relatively low permanent pressure losses as the fluid flows through the device. By measuring the differential, the volume of fluid flowing through the tube can be inferred.

n: a reduction in the pressure of a fluid caused by its motion against an enclosed surface (such as a pipe). As the fluid moves through the pipe, friction between the fluid and the pipe wall and within the fluid itself creates a pressure loss. The faster the fluid moves, the greater are the losses.

n: I. a reduction in the amount of force a fluid exerts against a surface, such as the walls of a pipe. It usually occurs be- cause the fluid is moving against the sur- face and is caused by the friction between the fluid and the surface. 2. the amount of pressure indicated by a drill pipe pressure gauge when drilling fluid is being circulated by the mud pump. Pressure losses occur as the fluid is circulated.

n: the differential pressure in the flowing liquid stream (which will vary with flow rate) between the inlet and outlet of a meter, flow straightener, valve, strainer, length of pipe, and so on.

n: a specially designed nozzle that is installed in a line through which fluids are flowing. It is used to measure the volume of fluids. It works on the same principle as an orifice plate in that the nozzle causes a pressure drop from which volume of flow can be inferred. It is used where the velocity of flow is particularly high because the pressure loss through the nozzle is lower than through an orifice. See orifice plate.