Oil & Gas Terms in Category Y

Yield value

The yield value (commonly called “yield point”) is the resistance to initial flow, or represents the stress required to start fluid movement.

This resistance is due to 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 lb/100 square feet, is determined by the direct-indicating viscometer by subtracting the plastic viscosity from the 300-rpm reading.

Yield

A term used to define the quality of a clay by describing the number of barrels of a given centipoise slurry that can be made from a ton of clay.

Based on the yield, clays are classified as bentonite, high yield, low yield, etc., types of clays.

Not related to yield value below.

See api rp 13b for procedures.

Yield point

In drilling-fluid terminology, yield point means yield value (which see).

Of the two terms, yield point is more common.