Page 320 - Shale Shakers Drilling Fluid Systems

302 SHALE SHAKERS AND DRILLING FLUID SYSTEMS

Guar gum slurries developed in clear fresh or brine water possess pseudo-
plastic flow properties.

Gum Any hydrophilic plant polysaccharides or their derivatives that, when dis-
persed in water, swell to produce a viscous dispersion or solution. Un-
like resins, they are soluble in water and insoluble in alcohol.

Gumbo Small, sticky drilled solids that hydrate as they move up an annulus form-
ing large agglomerations of cuttings. Usually, gumbo is characteristically
observed with water-based drilling fluids when drilling shales containing
large quantities of smectite clay.

Gumbo Buster See.- Gumbo Remover.

Gumbo Remover A device that removes gumbo from a drilling fluid; usually mounted in
the flowline between the well and shakers.

Gunk Plug A volume of bentonite in oil that are pumped in a well to combat lost
circulation. When the bentonite encounters water, it expands and creates
a gunk plug with a high viscosity and gel structure. The plug may or may
not be squeezed. See.- Diesel Oil Plug.

Gunning the Pits Mechanical agitation of the drilling fluid in a pit by means of a mud gun.
See.- Mud Gun.

Gyp See: Gypsum.

Gypsum Gypsum, CaS0 4»2H 2O, is calcium sulfate and is frequently encountered
while drilling. It may occur as thin stringers or in massive formations.
See: Anhydrite, Calcium Sulfate.

Hardness (Water) The hardness of water is due principally to the calcium and magnesium
ions. The total hardness is measured in terms of parts per million of cal-
cium carbonate or calcium and sometimes equivalents per million of
calcium. See: API Bulletin RP 13B.

Head The height a column of fluid would stand in an open-ended pipe if it was
attached to the point of interest. The head at the bottom of a 1,000 foot
well would be 1,000 feet, but the pressure would depend on the density
of the drilling fluid in the well.

Heaving The partial or complete collapse of the walls of a hole resulting from
internal pressures due primarily to swelling from hydration or formation
pressures or internal stresses. See: Sloughing.

Heavy Solids See: High-Gravity Solids (HGS).

Hertz A unit of frequency: Cycles per second.

Heterogeneous A substance that consists of more than one phase and is not uniform,
such as colloids, emulsions, and the like. It has different properties in
different parts.

High-Gravity Solids (HGS) Solids purchased and added to a drilling fluid specifically and solely to
increase drilling fluid density. Barite (4.2 specific gravity) and hematite
(5.05 specific gravity) are the most common. See: Low-Gravity Solids (LGS).