Related Oil & Gas Terms

• Direct-reading viscometer

  Commonly called a “v-g meter.” the instrument is a rotational-type device powered by means of an electric motor or handcrank, and is used to determine the apparent viscosity, plastic viscosity, yield point, and gel strengths (all of which see) of drilling fluids. the usual speeds are 600 and 300 revolutions per minute. see api rp13b...

• 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...

• Apparent viscosity

  1. the viscosity of a fluid measured at a given shear rate at a fixed temperature. in order for a viscosity measurement to be meaningful, the shear rate must be stated or defined. 2. the viscosity of a fluid measured at the shear rate specified by api. in the bingham plastic rheology model, apparent viscosity...

• Dilatant fluid

  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 share. the yield point, as determined by conventional calculations from the direct-indicating viscometer readings, is negative; however, the true...

• Stormer viscometer

  A rotational shear viscometer used for measuring the viscosity and gel strength of drilling fluids. this instrument has been largely superseded by the direct-indicating viscometer....