Oilfield terminology: Hydrocarbon, Chloride, Viscosity, Drilling rig, Blowout, Drilling fluid, Centrifugal pump, Drill string, Mud logging, List of components of oil drilling rigs, Lost circulation, Petrology, Tripping, Corrected d-exponent, Marsh funnel

Source: Wikipedia. Pages: 54. Chapters: Hydrocarbon, Chloride, Viscosity, Drilling rig, Blowout, Drilling fluid, Centrifugal pump, Drill string, Mud logging, List of components of oil drilling rigs, Lost circulation, Petrology, Tripping, Corrected d-exponent, Marsh funnel, Annular velocity, Wellhead, Shale shakers, Squeeze job, Annulus, Rotary table, Solids control, Mud tank, Desander, Drill bit, Flow line, Kelly drive, Stand, Deviation survey, Mud pump, Mud cleaner, Conductor tensioner, Drill pipe, Producible fraction, Flow show, Top drive, Possum belly, Conductor pipe, Drill line, K factor crude oil refining, Elevators, Sucker rod, Mud Gun, Casing head, Swivel, Traveling block, Relief well, Estimated pore pressure, Crown block, Directional well, Kelly hose, Mud weight, Wellbore, Rate of penetration, Pipe rack, Drill floor, Bell nipple, Formation fluid, Weight on bit. Excerpt: Viscosity is a measure of the resistance of a fluid which is being deformed by either shear stress or tensile stress. In everyday terms (and for fluids only), viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity. Put simply, the less viscous the fluid is, the greater its ease of movement (fluidity). Viscosity describes a fluid's internal resistance to flow and may be thought of as a measure of fluid friction. For example, high-viscosity felsic magma will create a tall, steep stratovolcano, because it cannot flow far before it cools, while low-viscosity mafic lava will create a wide, shallow-sloped shield volcano. All real fluids (except superfluids) have some resistance to stress and therefore are viscous, but a fluid which has no resistance to shear stress is known as an ideal fluid or inviscid fluid. The study of flowing matter is known as rheology, which includes viscosity and related concepts. The word "viscosity" is derived from the Latin "", which means white mistletoe. A viscous glue called birdlime was made from mistletoe berries and used for lime-twigs to catch birds. Laminar shear of fluid between two plates. Friction between the fluid and the moving boundaries causes the fluid to shear. The force required for this action is a measure of the fluid's viscosity. This type of flow is known as a Couette flow. Laminar shear, the non-constant gradient, is a result of the geometry the fluid is flowing through (e.g. a pipe).In general, in any flow, layers move at different velocities and the fluid's viscosity arises from the shear stress between the layers that ultimately opposes any applied force. The relationship between the shear stress and the velocity gradient can be obtained by considering two plates closely spaced at a distance y, and separated by a homogeneous substance. Assuming that the plates are very large, with a large area A, such that edge effects may be i