Hard Close-In

Hard Close-In

Definition(s)

Hard Close-In

To Close-in a well by closing a BOP with the choke and/or choke line valve closed. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Hydrogen Sulfide Service

Hydrogen Sulfide Service

Definition(s)

Hydrogen Sulfide Service

Refers to equipment designed to resist corrosion and hydrogen embrittlement caused by exposure to hydrogen sulfide. 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 Standards  
Gunk Squeeze

Gunk Squeeze

Definition(s)

Gunk Squeeze

Procedure whereby a gunk slurry is pumped into a subsurface zone. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Gunk Slurry

Gunk Slurry

Definition(s)

Gunk Slurry

A slang term to denote a mixture of diesel oil and bentonite. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards
Gunk Plug

Gunk Plug

Definition(s)

Gunk Plug

A volume of gunk slurry placed in the well bore. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Gas Cut Drilling Fluid

Gas Cut Drilling Fluid

Definition(s)

Gas Cut Drilling Fluid

Drilling Fluid that has become entrained with gas from previously drilled gas bearing formation which in turn lowers the drilling fluid density and hydrostatic head of the drilling fluid column. 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 Standards  
Gas Buster

Gas Buster

Definition(s)

Gas Buster

A slang term to denote a mud: gas separator. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Gas Buster

Slang for mud / gas separator. Source: IADC UBO / MPD Glossary, December 2011. Global Standards  
Fracture Gradient

Fracture Gradient

Definition(s)

Fracture Gradient (Frac Gradient)

The pressure gradient (psi/ft) at which the formation accepts whole fluid from the well bore. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Flow Line Sensor

Flow Line Sensor

Definition(s)

Flow Line Sensor

A device to monitor rate of fluid flow from the annulus. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Formation Pressure

Formation Pressure

Definition(s)

Formation Pressure (Pore Pressure)

Pressure exerted by fluids within the pores of the formation (see Pore Pressure). Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Formation Pressure

The pressure at the bottom of a well when shut-in at the wellhead. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Formation Integrity Test (FIT)

Formation Integrity Test (FIT)

Definition(s)

Formation Integrity Test

Application of pressure by superimposing a surface pressure on a fluid column in order to determine ability of a subsurface zone to withstand a certain pressure. Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global Standards

Formation Integrity Test

See Formation Competency Test. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards
Formation Integrity

Formation Integrity

Definition(s)

Formation Integrity

See Formation Competency. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Formation Fracture Gradient

Formation Fracture Gradient

Definition(s)

Formation Fracture Gradient

The hydrostatic value expressed in psi/ft. that is required to initiate a fracture in a subsurface formation (geologic strata). 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 Standards  
Formation Competency Test

Formation Competency Test

Definition(s)

Formation Competency Test (Formation Integrity Test)

Application of pressure by superimposing a surface pressure on a fluid column in order to determine ability of a subsurface zone to withstand a certain hydrostatic pressure. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards
Formation Competency

Formation Competency

Definition(s)

Formation Competency (Formation Integrity)

The ability of the formation to withstand applied pressure. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Formation Breakdown

Formation Breakdown

Definition(s)

Formation Breakdown

An event occurring when borehole pressure is of magnitude that the exposed formation accepts whole fluid from the borehole. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Fluid Density

Fluid Density

Definition(s)

Fluid Density

The unit weight of fluid; e.g., pounds per gallon (lb/gal). Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Final Circulating Pressure

Final Circulating Pressure

Definition(s)

Final Circulating Pressure

Drill string pressure required to circulate at the selected kill-rate adjusted for increase in kill drilling fluid density over the original drilling fluid density; used from the time kill drilling fluid reaches the bottom of the drill string until kill operations are completed or a change in either kill drilling fluid density or kill-rate is effected. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Dynamic Well Kill Procedure

Dynamic Well Kill Procedure

Definition(s)

Dynamic Well Kill Procedure

A planned operation to control a flowing well by injecting fluid of a sufficient density and at a sufficient rate into the well bore to effect a kill without completely closing in the well with the surface containment equipment. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Dynamic Well Kill Procedure

A planned operation to control a flowing well by injecting fluid of a sufficient density and at a sufficient rate into the wellbore to effect a kill without completely closing in the well with the surface containment equipment. Refer to Appendix A—Shallow Gas Well Control. Source: API RP 64, Recommended Practice for Diverter Systems Equipment and Operations, Second Edition, November 2001 (March 1, 2007). Global Standards  
Drilling Break

Drilling Break

Definition(s)

Drilling Break

A change in the rate of penetration that may or may not be a result of penetrating a pressured reservoir. 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 Standards  
Diverter System

Diverter System

Definition(s)

Diverter System

The assemblage of an annular sealing device, flow control means, vent system components, and control system which facilitates closure of the upward flow path of the well fluid and opening of the vent to the atmosphere. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Diverter System

The assemblage of an annular sealing device, flow control means, vent system components, and control system which facilitates closure of the upward flow path of the well fluid and opening of the vent to the atmosphere. Source: API RP 64, Recommended Practice for Diverter Systems Equipment and Operations, Second Edition, November 2001 (March 1, 2007). Global Standards  

Diverter System

"Diverter system" means an assembly of nipples, valves, and piping attached to a well's structural or conductor casing for venting a gas kick away from the drill rig. Source: Alaska Oil and Gas Conservation Commission, Definitions, Alaska Admin. Code tit. 20, § 25.990, December 7, 2012. Regulations

 
Displacement

Displacement

Definition(s)

Displacement

The volume of steel in the tubulars and devices inserted and/or withdrawn from the well bore. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Displacement (compressor)

Volume displaced by each stroke of a piston in a reciprocating compressor cylinder. Source: IADC UBO / MPD Glossary, December 2011. Global Standards  

Displacement (pipe)

Physical volume of a pipe section, usually in cubic feet. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Degasser

Degasser

Definition(s)

Degasser

A vessel, which utilizes pressure reduction and/or inertia to separate entrained gases from the liquid phases. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Degasser

A system which separates the gas phase from multiphase fluids. Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global Standards  

Degasser

Equipment that removes undesirable gases from a liquid, especially gases entrained in drilling or completion fluids. Relies on pressure reduction or inertia to accomplish separation of liquid and gas phases. Source: IADC UBO / MPD Glossary, December 2011. Global Standards  
Cut Drilling Fluid

Cut Drilling Fluid

Definition(s)

Cut Drilling Fluid

Well control fluid, which has been reduced in density or unit weight because of entrainment of less dense formation fluids or air. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Closing Unit

Closing Unit

Definition(s)

Closing Unit

The assembly of pumps, valves, lines, accumulators, and other items necessary to open and close the BOP equipment. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Closing Unit

The assemblage of pumps, valves, lines, accumulators, and other items necessary to open and close the BOP equipment and diverter system. Source: API RP 64, Recommended Practice for Diverter Systems Equipment and Operations, Second Edition, November 2001 (March 1, 2007). Global Standards  
Circulating Head

Circulating Head

Definition(s)

Circulating Head

A device attached to the top of drill pipe or tubing to allow pumping into the well. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Choke Pressure

Choke Pressure

Definition(s)

Choke Pressure

See Backpressure. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  
Choke Line

Choke Line

Definition(s)

Choke Line

The high-pressure piping between BOP outlets or wellhead outlets and the choke manifold. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Choke Line

A high-pressure line connected below a BOP to transmit well fluid flow to the choke manifold during well control operations. Source: API SPEC 16D, Specification for Control Systems for Drilling Well Control Equipment and Control Systems for Diverter Equipment, Upstream Segment, Second Edition, July 2004. Global Standards  

Choke Line

“Choke line” means an extension of pipe from the blowout preventer which is used to direct well fluid from the annulus to the choke manifold. [Mich. Admin. Code R 408 (2013)]. Source: Oil and Gas Drilling and Servicing Operations, Michigan Administrative Code R 408, February 8, 2013. Regulations      
Choke Manifold

Choke Manifold

Definition(s)

Choke Manifold

Used to control flowing pressure from underbalance well. May be used on connections or trips to either keep production from displacing the drilling fluid (HP gas wells), or to artificially charge the annulus to avoid loading to reservoir pressure equilibrium (prolific oil wells). Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Choke Manifold (Control Manifold)

The system of valves, chokes, and piping to control flows from the annulus and regulate pressures in the drill string/annulus flow system. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Choke Manifold (Control Manifold)

"Choke manifold" means an assembly of valves, chokes, gauges, and lines used to control the rate of flow from the well when the blowout preventers are closed. Source: Corporation Commission, Oil and Gas Conservation, Oklahoma Administrative Code 165:10, February 2013. Regulations  
Casing Seat Test

Casing Seat Test

Definition(s)

Casing Seat Test

A procedure whereby the formation immediately below the casing shoe is subjected to a pressure equal to the pressure expected to be exerted later by a higher drilling fluid density or by the sum of a higher drilling fluid density and backpressure created by a kick. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards