Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Vortex
Definition(s)
Vortex
Cylindrical or conical shaped core of air or vapour lying along the central axis of the rotating slurry inside a hydrocyclone. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsVolume of Solids Drilled
Definition(s)
Volume of Solids Drilled
Volume of solids drilled over a specified interval. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsViscosity
Definition(s)
Viscosity
Ratio of shear stress to shear rate. NOTE 1 In the SI system, viscosity is expressed in pascal seconds (Pa⋅s). NOTE 2 If the shear stress is expressed in the CGS system (dynes per square centimetre) and the shear rate is expressed in reciprocal seconds, the viscosity is expressed in poise, P. 1 P = 1 dyn·s/cm2 = 1 g⋅cm−1⋅s−1 = 10−1 Pa⋅s. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsViscosity
Measure of a fluid's tendency to resist flow. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsUnweighted Drilling Fluid
Definition(s)
Unweighted Drilling Fluid
Drilling fluid that does not contain commercial suspended solids added for the purpose of increasing the density of the drilling fluid. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsUnoccluded
Definition(s)
Unoccluded
Unobstructed area of a screen opening. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsUnderflow
Definition(s)
Underflow (Centrifugal Separator)
Discharge stream from a centrifugal separator that contains a higher percentage of solids than does the feed. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsUnderflow (Screen Separator)
Discharge stream from a screen separator that contains a lower percentage of solids than does the feed. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsTrip Tank
Definition(s)
Trip Tank
Gauged and calibrated vessel used to account for fill and displacement volumes as pipe is pulled from and run into the hole. NOTE Close observation allows early detection of formation fluid entering a wellbore and of drilling fluid loss to a formation. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsTotal Non-Blanked Area
Definition(s)
Total Non-Blanked Area
Net unblocked area that will permit the passage of fluid through a screen. NOTE 1 It is expressed in square metres (square feet). NOTE 2 Some screen designs can eliminate as much as 40 % of the gross screen panel area from fluid flow due to backing-plate and bonding-material blockage. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsTotal Dilution
Definition(s)
Total Dilution
Volume of drilling fluid that would be built to maintain a specified volume fraction of drilled solids over a specified interval of footage if there were no solids removal system. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsTensioning
Definition(s)
Tensioning
Stretching of a screening surface of a shale shaker to the proper tension while positioning it within the vibrating frame. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsSump
Definition(s)
Sump
Pan or lower compartment below the lowest shale-shaker screen. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsSump
Sump―a container constructed of steel, fiberglass, sealed concrete, or some other impermeable material utilized for temporary storage of E and P Waste, including, but not limited to, wash water and solids (sludge) generated by the removal/cleaning of residual amounts of E and P Waste from storage containers. Source: Natural Resources, Office of Conservation – General Operations, Louisiana Administrative Code, Title 43, Part XIX, March 2013. RegulationsSump
“Sump” means an impermeable vessel, or a collection device incorporated within a secondary containment system, with a capacity less than 500 gallons, which remains predominantly empty, serves as a drain or receptacle for de minimis releases on an intermittent basis and is not used to store, treat, dispose of or evaporate products or wastes. Source: Oil and Gas, New Mexico Administrative Code Title 19, Chapter 15, January 2013. RegulationsSump
A pit or excavation, for holding liquids. Source: Petroleum Safety Orders--Drilling and Production, Definitions, California Code of Regulations, 8 CCR § 6505, December 2012. RegulationsSuction Compartment
Definition(s)
Suction Compartment (General)
Any compartment from which a pump removes fluid. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsSuction Compartment (Specific)
Area of the check/suction section that supplies drilling fluid to the suction of the drilling fluid pumps. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsSlug Tank
Definition(s)
Slug Tank
Small compartment, normally adjacent to the suction compartment, used to mix special fluids to pump downhole. NOTE Slug tanks are most commonly used to prepare a small volume of weighted drilling fluid before a drillstem trip in and out of the borehole. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsSieve Analysis
Definition(s)
Sieve Analysis
Classification by mass of solid particles passing through or retained on a sequence of screens with decreasing aperture sizes. NOTE Sieve analysis can be carried out by wet or dry methods. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsSieve
Definition(s)
Sieve
Laboratory screen with wire-mesh or electronically-punched holes of known dimensions. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsShale Shaker
Definition(s)
Shale Shaker
Mechanical device that separates cuttings and large solids from a drilling fluid. NOTE The separation methods can include vibrating screens, rotating cylindrical screens, etc. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsShale Shaker
A vibrating screen that removes relatively large size cuttings from the drilling fluid returns. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards Source: API RP 64, Recommended Practice for Diverter Systems Equipment and Operations, Second Edition, November 2001 (March 1, 2007). Global StandardsScreening
Definition(s)
Screening
The maximum uplift force during spud can extraction.
Source: API RP 781 Security Plan Methodology for the Oil and Natural Gas Industries.1st Ed. September 2016. Global Standards