دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

a rheological model used to describe flow in some fluids. Bingham fluids have a linear shear stress, shear-rate behavior after an initial shear-stress boundary has been crossed. Plastic viscosity or PV is the slope of the line. Yield Point is the threshol

the shear stress measured at low shear rate after the mud has set for a period of time.

the consistency index, is the shear stress or viscosity of the fluid at one sec-1 shear rate. An increasing K raises the effective annular viscosity, increases hole cleaning capacity.

a plotted relationship that predicts shear stress levels at various envelopes of effective normal stress.

a fluid with a viscosity that does not produce a linear shear stress-shear stress graph.

n: an absolute flow property indicating the flow resistance of certain types of fluids. It is a measure of shearing stress.

n: a measure of internal resistance of fluid attributable to the amount,type and size of solids present in a given fluid. It is expressed as the number of dynes per sq cm of tangential shearing force in excess of the bingham yield value that will induce a un

an absolute flow property indicating the flow resistance of certain types of fluids. A measurement of shear stress.

n: a fluid moving as a unit in which all shear stress occurs at the pipe wall and hole wall. The stream thus assumes the shape of several telescopic layers of fluid with lowest velocities near the pipe and hole walls and the fastest in the middle.

n: the movement of a meterial as a unit without shearing within the mass. Plug flow is the first type of flow exhibited by a plastic fluid after overcoming the initial force required to produce flow.

fluid moves as a unit.

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: the breakdown of molecules of a substance such as a polymer when subjected to shear stress. See shear.

shear stress over angle of deformation.