دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: the viscosity of a drilling fluid as measured with a directindicating, or rotational, viscometer.

n: The viscosity a fluid appears to have on a given instrument at a stated rate of shear. It is a function of the plastic viscosity and the yield point. The apparent viscosity in centipoises, as determined by the direct-indicating viscometer, is equal to the

the viscosity at a given shear rate and a given temperature.

n: a dilatant. or inverted plastic, fluid is usually made up of a high concentration of well-dispersed solids that exhibits a nonlinear consistency curve passing through the origin. The apparent viscosity increases instantaneously with increasing rate of shear. The yield point, as determined by conventional calculations from the direct-indicating viscometer readings, is negative;however, the true yield point is zero.

n: This fluid is one of non-Newtonian flow patterns whose unique feature
is that once the fluid is subjected to force,it will start flowing without any gel strength.




a well dispersed, high solids content liquid that has very high apparent viscosity with any applied shear.

n: the process of characteristic impairment when all kinds of fluid treating chemical is subjected to mechenic rate of shear.

n: a fluid in which the viscosity remains constant for all rates of shear if constant conditions of temperature and pressure are maintained. Most drilling fluids behave as non-Newtonian fluids, as their viscosity is not constant but varies with the rate of shear.

n: the basic and wsimplest fluids from the standpoint of viscosity consideration in which the shear force is directly proportional to the shear rate. These fluids will immediately begine to move when a pressure or force in excess of zero is applied. examples

a fluid whose shear force and response is directly proportional to shear rate. Yield point is zero.

n: a kinds of non-Newtonian fluid, its character is that it flows when enforced by slim shear stress.



a complex non-Newtonian fluid without thixotrophy. Flow starts with pressure but apparent viscosity decreases instantaneously with increasing rate of shear.

n: rate (commonly given in rpm) at which an action resulting from applied forces causes or tends to cause two adjacent parts of a body to slide relative to each other in a direction parallel to their plane of contact.

n: this is the relative velocity of the fluid layers, divided by their normal separation distance. See also viscosity.

the rate of shearing of a fluid during a viscosity measurement. The rate of movement between plates.

n: A kind of small sized chamber blender,which have higher rate of shear,usually be used to blend cement slurry.

n: the resistance to initial flow, or the stress required to start fluid movement. This resistance is caused by electrical charges located on or near the surfaces of the particles. The values of the yield point and thixotropy, respectively, are measurements of the same fluid properties under dynamic and static states. The Bingham yield value, reported in pounds/100 square foot, is determined from a directindicating viscometer by subtracting the plastic viscosity from the 300-rpm reading. Also called yield point.

Also called movable shear stress. The viscosity dont change along with the shear stress when shear stress arrive a given value,now shear stress and rate of shearing present direct ratio relation, the value of crossing point of this direct ratio relation