BAKER HUGHES - Drilling Fluids Reference Manual

GLOSSARY OF TERMS
Solution - A mixture of two or more components that form a homogeneous single phase. Example
solutions are solids dissolved in liquid, liquid in liquid, gas in liquid.
Solvent - Liquid used to dissolve a substance (the solute).
Sour Gas - A general term for those gases that are acidic either alone or when associated with water.
Two sour gases associated with oil and gas drilling and production are hydrogen sulfide (H 2 S) and
carbon dioxide (CO 2 ). Sulfur oxides and nitrogen oxides, generated by oxidation of certain sulfur or
nitrogen bearing materials, are also in this category but not found in the anaerobic conditions of the
subsurface.
Souring - A term commonly used to mean fermentation.
Specific Gravity - See Gravity, Specific.
Specific Heat - The number of calories required to raise 1 gram of substance 1 degree Centigrade.
The specific heat of a drilling fluid gives an indication of the fluid's ability to keep the bit cool for a
given circulation rate.
Spudding In - The starting of drilling operations for a new hole.
Spud Mud - The fluid used when drilling starts at the surface, often a thick bentonite-lime slurry.
Spurt Loss - See Surge Loss.
Squeeze - A procedure whereby slurries of cement, fluid, gunk plug, etc. are forced into the
formation by pumping into the hole while maintaining a back pressure, usually by closing the rams.
Stability Meter - An instrument to measure the breakdown voltage of invert emulsions.
Stacking a Rig - Storing a drilling rig upon completion of a job when the rig is to be withdrawn from
operation for a period of time.
Starch - A group of carbohydrates occurring in many plant cells. Starch is specially processed (pre
gelatinized) for use in fluids to reduce filtration rate and occasionally to increase the viscosity.
Without proper protection, starch is subject to bacterial degradation resulting in the fermentation and
the alteration of fluid properties.
Static - Opposite of dynamic. See Quiescence.
BAKER HUGHES DRILLING FLUIDS
REFERENCE MANUAL
REVISION 2006 15-44