Screen Cloth

Screen Cloth

Definition(s)

Screen Cloth

Type of screening surface woven in square, rectangular or slotted openings. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards
Sand Trap

Sand Trap

Definition(s)

Sand Trap

First compartment and the only unstirred or unagitated compartment in a surface system, and intended as a settling compartment. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards
Retort

Retort

Definition(s)

Retort

Instrument used to distill oil, water and other volatile material in a drilling fluid. NOTE The amount of volatile fluid is used to determine oil, water and total solids contents as volume fraction percent, expressed as a percent (see ISO 10414-1 or ISO 10414-2). Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards
Removal Section

Removal Section

Definition(s)

Removal Section

First section in the surface drilling-fluid system, consisting of a series of compartments to remove gas and undesirable solids. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards
Possum Belly

Possum Belly

Definition(s)

Possum Belly

Compartment, or back tank, on a shale shaker into which the flow line discharges, and from which drilling fluid is either fed to the screens or is bypassed, if necessary. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Plugging

Plugging

Definition(s)

Plugging

Wedging or jamming of openings in a screening surface by near-size particles, preventing passage of undersize particles and leading to the blinding of the screen (see blinding). Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Plastic Viscosity

Plastic Viscosity

Definition(s)

Plastic Viscosity

Measure of the high-shear-rate viscosity which depends upon the number, shape and size of solids and the viscosity of the liquid phase. NOTE Plastic viscosity is calculated by subtracting the 300 r/min concentric cylinder viscometer reading from the 600 r/min concentric cylinder viscometer reading (see ISO 10414-1 and ISO 10414-2). Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards
Particle Size Distribution

Particle Size Distribution

Definition(s)

Particle Size Distribution

Mass, or net volume, classification of solid particles into each of the various size ranges as a percentage of the total solids of all sizes in a fluid sample. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Particle

Particle

Definition(s)

Particle

Discrete unit of solid material that consists of a single grain or of any number of grains stuck together. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Overflow

Overflow

Definition(s)

Overflow (or Centrate)

Discharge stream from a centrifugal separation that contains a higher percentage of liquids than does the feed. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Oil-Based Drilling Fluid

Oil-Based Drilling Fluid

Definition(s)

Oil-Based Drilling Fluid

Drilling fluid in which the continuous phase is not miscible with water, and water or brine is the dispersed phase. NOTE Oil-based drilling fluids are usually referred to as non-aqueous drilling fluids, or NAF. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Near-Size Particle

Near-Size Particle

Definition(s)

Near-Size Particle

Particle whose size is close to the size of the openings in the screen through which its passage is under evaluation. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Mud Gun

Mud Gun

Definition(s)

Mud Gun

Submerged nozzle used to stir drilling fluid with a high-velocity stream. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Mud Compartment

Mud Compartment

Definition(s)

Mud Compartment

Subdivision of the removal, addition or check/suction sections of a surface system. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Mud Cleaner

Mud Cleaner

Definition(s)

Mud Cleaner

Combination of hydrocyclones and screens in series with the underflow of the hydrocyclones. NOTE The hydrocyclone overflow returns to the drilling fluid, while the underflow of the hydrocyclones is processed through a vibrating screen. The screen is usually of size API 150 or finer. The screen solids discharge is discarded while the liquid and solids passing through the screen are returned to the drilling fluid. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Marsh Funnel Viscosity

Marsh Funnel Viscosity

Definition(s)

Marsh Funnel Viscosity (or Funnel Viscosity)

Viscosity measured with the instrument used to monitor drilling fluid. NOTE A Marsh funnel is a tapered container with a fixed orifice at the bottom so that, when filled with 1 500 cm3 of fresh water, 946 cm3 (one quart) will drain in 26 s. It is used for comparison values only and not to diagnose drilling fluid problems. See ISO 10414-1 (API RP 13B-1) and ISO 10414-2 (API RP 13B-2). Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Impeller

Impeller

Definition(s)

Impeller

Spinning disc in a centrifugal pump with protruding vanes used to accelerate the fluid in the pump casing. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  

Impeller

Rotating part of a centrifugal compressor/pump that imparts kinetic energy to a fluid. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Hydrocyclone

Hydrocyclone

Definition(s)

Hydrocyclone (or Cone or Cyclone)

Liquid-solids separation device utilizing centrifugal force for settling. NOTE Fluid enters tangentially and spins inside the hydrocyclone. The heavier solids settle to the walls of the hydrocyclone and move downward until they are discharged at the hydrocyclone apex. The spinning fluid travels partway down the hydrocyclone and back up to exit out the top of the hydrocyclone through a vortex finder. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Hopper

Hopper

Definition(s)

Hopper (Mud Hopper)

Large funnel- or coned-shaped device into which dry components are poured to uniformly mix the components with liquids or slurries that are flowing through the lower part of the cone. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Hook Strip

Hook Strip

Definition(s)

Hook Strip

Hooks on the edge of a screen section of a shale shaker which accept the tension member for screen mounting. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
High Specific Gravity Solids

High Specific Gravity Solids

Definition(s)

High Specific Gravity Solids

Solids added to a drilling fluid specifically to increase drilling-fluid density. NOTE Barite (specific gravity = 4,2) and haematite (specific gravity = 5,05) are the most common. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Head

Head

Definition(s)

Head

Height that a fluid column would reach in an open-ended pipe if the pipe were attached to the point of interest. NOTE The head at the bottom of a 300 m (1 000 ft) well is 300 m (1 000 ft), but the pressure at that point depends upon the density of the drilling fluid in the well. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  

Head

Potential energy exerted by a column of liquid that has the ability to do work; expressed as the vertical height of the column. Source: IADC UBO / MPD Glossary, December 2011. Global Standards  
Gumbo

Gumbo

Definition(s)

Gumbo

Cuttings that agglomerate and form a sticky mass as they are circulated up the wellbore. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Flow Rate

Flow Rate

Definition(s)

Flow Rate

Volume of liquid or slurry which moves through a pipe in one unit of time. NOTE It is expressed as cubic metres per minute, gallons per minute, barrels per minute, etc. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Flow Capacity

Flow Capacity

Definition(s)

Flow Capacity

Rate at which equipment, such as a shaker, can process drilling fluid and solids. NOTE It is a function of many variables, including shaker configuration, design and motion, drilling fluid rheology, solids loading, and blinding by near-size particles. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Equalizer

Equalizer

Definition(s)

Equalizer

Opening for flow between compartments in a surface fluid-holding system which allows all compartments to maintain the same fluid level. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Effluent

Effluent

Definition(s)

Effluent

Discharge of liquid, generally a stream, after some attempt at separation or purification has been made. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Educator

Educator

Definition(s)

Educator (Pressure Jet)

Device using a high velocity jet to create a low pressure region (Bernoulli Principle) which draws liquid or dry material to be blended with the drilling fluid. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Eductor

Eductor

Definition(s)

Eductor (Fluid Stream)

Device utilizing a fluid stream discharging under high pressure from a jet through an annular space to create a low pressure region. NOTE When properly arranged, it can evacuate degassed drilling fluid from a vacuum-type degasser or pull solids through a hopper. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  
Drilling Fluid

Drilling Fluid

Definition(s)

Drilling Fluid

Water or oil-based fluid that is circulated down the drill pipe into the well and back up the annulus to the rig for purposes including containment of formation pressure, the removal of cuttings, bit lubrication and cooling, treating the wall of the well, and acting as a media for the pulsed transmission of well and drilling data to surface.

Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global Standards

Drilling Fluid

Any liquid or slurry pumped down the drill string and up the annulus of a hole during the drilling operation. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards  

Drilling Fluid

A water or oil-based fluid circulated down the drillpipe into the well and back up to the rig for purposes including containment of formation pressure, the removal of cuttings, bit lubrication and cooling, treating the wall of the well and providing a source for well data. Source: API RP 16Q, Recommended Practice for Design, Selection, Operation and Maintenance of Marine Drilling Riser Systems, First Edition, November 1993 (Reaffirmed August 2001). Global Standards Source: ISO 13624-1:2009, Petroleum and natural gas industries – Drilling and production equipment – Part 1:Design and operation of marine drilling riser equipment. Global Standards  

Drilling Fluid

"Drilling fluid" means any fluid used for the purpose of drilling a well. Source: Alaska Oil and Gas Conservation Commission, Definitions, Alaska Admin. Code tit. 20, § 25.990, December 7, 2012. Regulations  

Drilling Fluid

Drilling fluid: fluid for the construction of the borehole, to which materials or preparation of whatever content have been added. Source: Mining Regulation of the Netherlands, WJZ 02063603, Netherlands,16 December 2002. Regulations