BAKER HUGHES - Drilling Fluids Reference Manual

GLOSSARY OF TERMS
Limestone - See Calcium Carbonate.
Live Oil - Crude oil that contains gas and has not been stabilized or weathered. This oil can cause gas
cutting when added to fluid and is a potential fire hazard.
Logging - See Fluid Logging and Electric Logging.
Loss of Circulation - See Circulation, Loss of.
Loss of Head or Friction Loss - See Pressure Drop Loss.
Lost Circulation Additives - Materials added to a drilling fluid to control or prevent lost circulation.
These non-soluble materials are added in varying amounts and are classified as fiber, flake, or
granular.
Lost Returns - See Circulation, Loss of.
Low-Colloid Oil Mud - An oil mud designed and maintained with a minimum of colloid-sized
solids, typically by omitting fatty-acid soaps and lime, and minimizing organophilic clays and
fluid-loss additives. Low-colloid oil mud, also called a relaxed filtrate oil mud, increases drilling
rate. A disadvantage is that filter cake formed on sands is not tight, can quickly become very thick,
and can cause pipe to stick by differential pressure.
Low-Gravity Solids - A type of drilling-fluid solid having a lower density than the barite (4.20
g/cm 3 ) or hematite (5.505 g/cm 3 ) that is used to weight up a drilling mud, including drill solids plus
the added bentonite clay. Low gravity solids are normally assumed to have a gravity of 2.6 g/cm 3
Low-Solids Fluids - A designation given to any type of fluid where high performing additives, e.g.,
CMC, have been partially or wholly substituted for commercial or natural clays, for comparable
viscosity and densities (weighted with barite), a low-solids fluid will have a lower volume-percent of
low gravity solids content.
Low-Yield Clays - Commercial clays chiefly of the calcium montmorillonite type having a yield of
approximately 15 to 30 bbl/ton.
Lypophile - A substance usually colloidal and easily wetted by oil.
Lypophilic - Having an affinity for the suspending medium, such as bentonite in water.
BAKER HUGHES DRILLING FLUIDS
REFERENCE MANUAL
REVISION 2006 15-29