Choke

Choke

Definition(s)

Choke

A device with either a fixed or variable aperture used to control the rate of flow of liquids and/or gas. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Choke

Equipment used to restrict and control the flow of fluids. Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global Standards Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global Standards  

Choke

Equipment used to restrict and control the flow of fluids and gas. Source: API SPEC 17D, Design and Operation of Subsea Production Systems—Subsea Wellhead and Tree Equipment, Upstream Segment, Second Edition May 2011 (Errata September 2011). Global Standards  

Choke

A device with a fixed (positive) or variable (adjustable) orifice installed in a line to restrict the flow and control the rate of production from the well. Source: IADC UBO / MPD Glossary, December 2011. Global Standards  
Casing Shear Ram

Casing Shear Ram

Definition(s)

Casing Shear Ram (CSR)

A closing component in a ram blowout preventer that is capable of shearing or cutting certain tubulars. NOTE: Casing shear rams are not required to seal. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards  
Buffer Tank

Buffer Tank

Definition(s)

Buffer Tank

A targeted, horizontal, cylindrical tank that changes the direction of fluid flow downstream of the choke and serves to direct flow to the flare line or gas buster. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards  
BSR

BSR

Definition(s)

BSR

Bending-strength ratio. Source: API RP 7G-2, Recommended Practice for Inspection and Classification of Used Drill Stem Elements, First Edition, August 2009. Global Standards  

BSR

Blind shear ram. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards Source: Oil & Gas UK, Guidelines on subsea BOP systems, Issue 1, July 2012, Global Standards  

BSR

Bending strength ratio. Source: API SPEC 7-1, Specification for Rotary Drill Stem Elements, First Edition, March 2006 (Addendum April 2011). Global Standards
Blowout Preventer Stack

Blowout Preventer Stack

Definition(s)

Blowout Preventer Stack

Complete assembly of well control equipment, including preventers, spools, valves, and nipples connected to the top of the wellhead or wellhead assemblies, consisting of the lower marine riser package (LMRP) and lower stack.

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

Blowout Preventer Stack

Complete assembly of well control equipment, including preventers, spools, valves, and nipples, connected to the top of the wellhead or wellhead assemblies. Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global Standards

Blowout Preventer Stack

The assembly of well control equipment including preventers, spools, valves and nipples connected to the top of the wellhead. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Blowout Preventer (BOP) Stack

The assembly of well control equipment including preventers, spools, valves, and nipples connected to the top of the casing-head that allows the well to be sealed to confine well fluids to the wellbore. Source: API RP 64, Recommended Practice for Diverter Systems Equipment and Operations, Second Edition, November 2001 (March 1, 2007). Global Standards  

Blowout Preventer Stack

The complete assembly of well control equipment, including preventers, spools, valves, and nipples connected to the top of the wellhead or wellhead assemblies. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards  

Blowout Preventer Stack

"Blowout preventer stack" means the assembly of well control equipment including preventers, spools, valves, and nipples connected to the top of the casinghead carrier. Source: Corporation Commission, Oil and Gas Conservation, Oklahoma Administrative Code 165:10, February 2013. Regulations
Blowout Preventer Control System (Closing Unit)

Blowout Preventer Control System (Closing Unit)

Definition(s)

Blowout Preventer Operating and Control System (Closing Unit)

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

Blowout Preventer Control System (Closing Unit)

The assembly of pumps, valves, lines, accumulators, and other items necessary to open and close the blowout preventer equipment. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards

 
Blind Shear Ram

Blind Shear Ram

Definition(s)

Blind Shear Ram

Closing and sealing component in a ram BOP that first shears the tubular in the wellbore and then seals the bore or acts as a blind ram if there is no tubular in the wellbore.

Source: API STANDARD 16AR, Standard for Repair and Remanufacture of Drill-through Equipment, First Edition, April 2017. Global Standards

Blind Shear Ram (BSR)

A closing and sealing component in a ram blowout preventer that first shears certain tubulars in the wellbore and then seals off the bore or acts as a blind ram if there is no tubular in the wellbore. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards  

Blind Shear Ram (BSR)

A closing and sealing component in a ram blowout preventer that first shears certain tubulars in the wellbore and then seals the bore, or acts as a blind ram if there is no tubular in the wellbore. NOTE Other common names for this ram include shearing, blind shear, or blind/shear rams. Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards  

Blind/Shear Rams

Blind rams with a built-in cutting edge that will shear tubulars that may be in the hole, thus allowing the blind rams to seal the hole. Used primarily in subsea systems. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Blind-Shear Ram

Closing and sealing component in a ram blowout preventer that first shears the tubular in the wellbore and then seals off the bore or acts as a blind ram if there is no tubular in the wellbore. Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global Standards Source: API SPEC 16A, Specification for Drill-through Equipment, Third Edition, June 2004 (Errata/Supplement November 2004). Global Standards
Blind Ram

Blind Ram

Definition(s)

Blind Ram

Closing and sealing component in a ram BOP that seals the open wellbore.

Source: API STANDARD 16AR, Standard for Repair and Remanufacture of Drill-through Equipment, First Edition, April 2017. Global Standards

Blind Ram

A closing and sealing component in a ram blowout preventer that seals the open wellbore. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards  

Blind Rams (blank, master)

Rams whose ends are not intended to seal against any drill pipe or casing. They seal against each other to effectively close the hole. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Blind Ram

Closing and sealing component in a ram blowout preventer that seals the open wellbore. Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global Standards Source: API SPEC 16A, Specification for Drill-through Equipment, Third Edition, June 2004 (Errata/Supplement November 2004). Global Standards
Bell Nipple

Bell Nipple

Definition(s)

Bell Nipple

A piece of pipe, with inside diameter equal to or greater than the BOP bore, connected to the top of the BOP or marine riser with a side outlet to direct the drilling fluid returns to the shale shaker or pit. Usually has a second side outlet for the fill-up line connection. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Bell Nipple

A piece of pipe, with inside diameter equal to or greater than the BOP bore, connected to the top of the BOP or marine riser with a side outlet to direct the drilling fluid returns to the shale shaker or pit. Usually has a second side outlet for the fill-up line connection. Source: API RP 64, Recommended Practice for Diverter Systems Equipment and Operations, Second Edition, November 2001 (March 1, 2007). Global Standards  

Bell Nipple (Mud Riser, Flow Nipple)

A piece of pipe, with inside diameter equal to or greater than the blowout preventer bore, connected to the top of the blowout preventer or marine riser with a side outlet to direct the drilling fluid returns to the shale shaker pit. NOTE: This pipe usually has a second side outlet for the fill-up line connection. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards
Articulated Line

Articulated Line

Definition(s)

Articulated Line

An articulated line is a choke or kill line assembled as a unit, with rigid pipe, swivel joints, and end connections, designed to accommodate specified relative movement between end terminations. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global Standards  
Annular Blowout Preventer

Annular Blowout Preventer

Definition(s)

Annular Blowout Preventer

Blowout preventer that uses an annular-shaped elastomeric sealing element to seal the space between the tubular and the wellbore or an open hole. Source: API STANDARD 16AR, Standard for Repair and Remanufacture of Drill-through Equipment, First Edition, April 2017. Global Standards Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global Standards

Annular Blowout Preventer

A blowout preventer that uses a shaped elastomeric sealing element to seal the space between the tubular and the wellbore or an open hole. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards  

Annular Blowout Preventer

Blowout preventer that uses a shaped elastomeric sealing element to seal the space between the tubular and the wellbore or to seal an open hole. Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards  

Annular Blowout Preventer

Blowout preventer that uses a shaped elastomeric sealing element to seal the space between the tubular and the wellbore or an open hole. Source: API SPEC 16A, Specification for Drill-through Equipment, Third Edition, June 2004 (Errata/Supplement November 2004). Global Standards
Adapter Spool

Adapter Spool

Definition(s)

Adapter Spool

A spool used to connect drill-through equipment with different end connections, nominal size designation and/or pressure ratings to each other. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards  

Adapter Spool

Connects blowout preventers of different sizes or pressure ratings to the casing head. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Accumulator

Accumulator

Definition(s)

Accumulator (Riser Tensioner)

A pressure vessel charged with gas (nitrogen generally) over liquid that is pressurized on the gas side from the tensioner high-pressure gas supply bottles and supplies high pressure hydraulic fluid to energize the riser tensioner cylinder. 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  

Accumulator (BOP)

A pressure vessel charged with gas (nitrogen) over liquid and used to store hydraulic fluid under pressure for operation of blowout preventers. 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  

Accumulator

A pressure vessel charged with nitrogen or other inert gas and used to store hydraulic fluid under pressure for operation of BOPs. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Accumulator

A pressure vessel charged with inert gas and used to store hydraulic fluid under pressure. Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global Standards  

Accumulator

A pressure vessel charged with non-reactive or inert gas used to store hydraulic fluid under pressure for operation of blowout preventers. 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  

Accumulator (Riser Tensoiner)

Pressure vessel charged with gas (generally nitrogen) over liquid that is pressurized on the gas side from the tensioner high-pressure gas supply bottles and supplies high-pressure hydraulic fluid to energize the riser tensioner cylinder. 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  
Annulus

Annulus

Definition(s)

Annulus

Space between the inner diameter of pipe A and the outer diameter of pipe B when pipe B is positioned inside pipe A.

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

Annulus

The space between the outer wall of one string of pipe (casing or tubing) suspended in a wellbore and the inner wall of the next larger casing or the borehole wall; i.e., the space between concentric pipe strings. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  

Annulus

Space surrounding the pipe in the wellbore. NOTE The outer wall of the annular space may be either surface or casing. Source: API RP 10B-2, Recommended Practice for Testing Well Cements, First Edition, July 2005 (Reaffirmed: July 2010). Global Standards  

Annulus

Any space between concentric tubulars or between the tubular and the wellbore (formation). Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards  

Annulus

The space between two pipes, when one pipe is laterally positioned inside the other. 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  

Annulus

Space between two concentric plastic sheaths of an unbonded flexible pipe cross-section. Source: API RP 17B, Recommended Practice for Flexible Pipe, Fourth Edition, July 2008. Global Standards  

Annulus

The space between the drill string and the inside diameter of the hole being drilled, the last string of casing set in the well, or the marine riser. 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  

Annulus

Space between the internal pressure sheath and outer sheath. NOTE Permeated gas and liquid is generally free to move and mix in the annulus. Source: API SPEC 17J, Specification for Unbonded Flexible Pipe, Third Edition, July 2008. Global Standards  

Annulus

The space between the borehole and tubulars or between tubulars, where fluid can flow. The annulus designation between the production tubing and production casing is the “A” annulus. Outer annuli between other strings are designated B, C, D, etc. as the pipe sizes increase in diameter. Source: API STD 65 – Part 2, Isolating Potential Flow Zones During Well Construction, Upstream Segment, Second Edition, December 2010. Global Standards  

Annulus

“Annulus” means the space between a wellbore and tubulars or between tubulars where fluid can flow. Source: Division of Mineral Resources Management - Oil and Gas, Ohio Administrative Code, Chapter 1501:9, January 2012. Regulations  

Annulus

Space between two pipes when one pipe is inside the other. 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
Fresh Water Aquifer

Fresh Water Aquifer

Definition(s)

Fresh Water Aquifer

A fresh water aquifer is a subsurface formation which generally contains water with less than 3,000 mg/l TDS and which supplies any public water supply system or currently supplies drinking water for human/livestock consumption or which contains sufficient water to supply a public water system. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  
Inactive Well Monitoring Program Design

Inactive Well Monitoring Program Design

Definition(s)

Inactive Well Monitoring Program Design

The procedures discussed in this document are intended for operators use in designing their own inactive well programs. The primary concern in managing inactive wells is identifying changing wellbore conditions in a timely manner so action can be taken before fluid migration occurs. For example, if monitoring indicates the completion interval changes from a non-pressured formation to a pressured formation, the operator should reevaluate the well's fluid migration potential and take action, as appropriate. The purpose of the program is to monitor pressures and to take appropriate action when unusual changes occur. The guidelines and examples presented are not intended to cover ail wellbore conditions or pressured formation scenarios. It is assumed that operators will use these concepts to design specific programs to meet any special circumstances that may arise. NOTE: When developing inactive well program, operators should consult applicable Federal, state, and local regulations, as well as consider lease and landowner obligations, to ensure their program meets all requirements. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  
Well Monitoring Programs

Well Monitoring Programs

Definition(s)

Well Monitoring Programs

The API inactive well program describes monitoring that could be used by an operator for wells in the four fluid migration potential categories. The well monitoring program requirements and monitoring frequencies increase as the fluid migration potential increases. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards
Fluid Migration Potential

Fluid Migration Potential

Definition(s)

Fluid Migration Potential

The API inactive well program evaluates the potential for wellbore fluids to migrate through an inactive wellbore. Four fluid migration potential categories are defined in Table 3-1 as minimum, low, moderate, and significant. The appropriate fluid migration potential category for an inactive well is determined by the presence, or absence, of pressured formations and by the number of levels of protection. Concerns in evaluating the fluid migration potential are pressured formations existing as the completion interval or pressured formations existing behind uncemented casing in the same uncemented annulus as a fresh water aquifer that is not completely covered by surface casing. Pressured formations behind cemented casing are isolated and have minimum potential for fluid migration. TABLE 3-1 CATEGORIES OF FLUID MIGRATION POTENTIAL INTO FRESH WATER AQUIFERS Fluid Migration Potential Category Minimum There are no pressured formations, or the only pressured formations are isolated from the fresh water aquifers by cemented production casing, liner, or intermediate casing. Low The well has two or more levels of protection, there is no sustained pressure on the surface casing annulus, and The completion interval is a pressured formation, and all other pressured formations are isolated from the fresh water aquifers by cementing production casing, liner, or intermediate casing, or The completion interval may or may not be a pressured formation, but there are two or more levels of protection between the shallowest uncemented pressured formation and the lowermost fresh water aquifers. Moderate The well has one level of protection, there is no sustained pressure on the surface casing annulus, and The completion interval is a pressured formation, and all other pressured formations are isolated from the fresh water aquifers by cemented production casing, liner, or intermediate casing, or The completion interval may or may not be a pressured formation, but there is one level of protection between the shallowest uncemented pressured formation and the lowermost fresh water aquifer. Significant The well has zero levels of protection, and the completion interval is a pressured formation, or There is sustained pressure on the surface casing annulus, or The Christmas-tree or stuffing-box assembly design and mechanical integrity is not sufficient to provide long-term containment of the wellbore fluids, or A pressured formation and a fresh water aquifer exist in the same uncemented annulus. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards

Well Construction

Well Construction

Definition(s)

Well Construction

The construction features of inactive wells which provide the mechanical barriers to fluid migration include: i) surface casing installed below all fresh water aquifers with cement circulated to the surface; 2) any intermediate casing installed and cemented, 3) production casing installed and cemented into the lowermost confining zone; and 4) any tubing and packer set in the well above the completion interval. The Christmas-tree or stuffingbox assembly isolates the wellbore fluids from the surface and provides readily accessible gauges on all tubing, casing, and annuli outlets for ease of monitoring pressures. The mechanical integrity of these well construction components is the key factor in their ability to provide a barrier to fluid migration. There are inactive wells which provide adequate protection against fluid migration into a fresh water aquifer or to the surface, but they may not have all of the construction details discussed above. By tailoring the monitoring program to a well's construction, operators can increase monitoring frequency for inactive wells that have fewer barriers to fluid migration. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  

Well Construction

A set of operations to be directed by the lease operator employing the drilling contractor and third-party services equipment and personnel. Source: API  Bulletin 97, Well Construction Interface Document Guidelines, First Edition, December 2013. Global Standards
Inactive Well Program Goal

Inactive Well Program Goal

Definition(s)

Inactive Well Program Goal

The goal of the API inactive well program is to focus operator efforts on those inactive wells that pose a threat to fresh water aquifers or the surface. The API program involves a risk-based approach to developing effective monitoring programs for inactive wells so that fluid migration into fresh water aquifers, surface soils, or surface waters is prevented. TO meet this goal and to provide the greatest flexibility in monitoring program design, it is suggested that operators take appropriate action to add levels of protection whenever practical or appropriate. For example, temporarily abandoning a producing well completed with a packer in a pressured formation adds a level of protection, since the completion interval is isolated. In such a case, the risk of wellbore fluid migration from the completion interval is reduced, which may justify less frequent monitoring. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  
Inactive Well Program Concepts

Inactive Well Program Concepts

Definition(s)

Inactive Well Program Concepts

The API inactive well program is a risk-based approach for determining if an inactive well poses a threat to fresh water aquifers, surface soils, or surface waters. The methodology described in the following sections identifies wellbore conditions that prevent fluid migration from pressured formations. Fluid migration potentials for inactive wells are defined based upon the presence of pressured formations and upon the well construction and its mechanical integrity. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  
Level of Protection

Level of Protection

Definition(s)

Level of Protection

A level of protection is a barrier to fluid migration into fresh water aquifers that has mechanical integrity, and its integrity can be monitored with some degree of confidence. Well construction components, such as surface casing, production casing, tubing and packer, and wellbore plugs, are such barriers. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  

Level of Protection

A level of protection is a barrier to fluid migration into fresh water aquifers that has mechanical integrity, and its integrity can be monitored with some degree of confidence. The well construction components, such as surface casing, production casing, tubing and packer, and wellbore plugs, are such barriers. Levels of protection are sometimes referred to as layers of protection. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  
Pressured Formation

Pressured Formation

Definition(s)

Pressured Formation

A pressured formation is any producing, injection, disposal, permeable hydrocarbon bearing, or permeable salt water bearing formation penetrated by the well which has sufficient pressure to initiate and sustain significant fluid migration into a fresh water aquifer or to the surface. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  
Temporarily Abandoned Well

Temporarily Abandoned Well

Definition(s)

Temporarily Abandoned Well

An inactive well should be classified as TA when the completion interval is isolated. The completion interval may be isolated using the bridge plug method, the cement squeeze method, or the balanced cement plug method. As an alternative to the bridge plug method, isolation of the completion interval may also be achieved by installing a plug in an existing packer which does not have tubing. Temporary abandonment should be used when an operator is holding a wellbore in anticipation of future utilization, such as in an enhanced oil recovery project. TA status should begin the day afìer the completion interval has been isolated from the wellbore. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  

Temporarily Abandoned (TA)

Inactive wells in which the completion interval has been isolated from the interior of the casing. The completion interval may be isolated using the bridge plug method, the cement squeeze method or the balanced cernent plug method. If a packer is installed in the well, isolation of the completion interval may also be achieved by installing a plug in the packer which has no tubing. Temporary abandonment is generally used when a well is a candidate for future utilization, such as in a possible enhanced oil recovery project. TA status should begin the day after the completion interval has been isolated from the wellbore. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  

Temporarily Abandoned Well

TEMPORARILY ABANDONED WELL shall mean a well which is incapable of production or injection without the addition of one or more pieces of wellhead or other equipment, including valves, tubing, rods, pumps, heater-treaters, separators, dehydrators, compressors, piping or tanks. Source: Oil and Gas Conservation Commission, Practice and Procedure, Code of Colorado Regulations, 2 CCR 404-1, February 2013. Regulations
Shut-in Well

Shut-in Well

Definition(s)

Shut-In Well

Well with one or more valve(s) closed on the flow path. Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global Standards

Shut-In Well

An inactive well should be classified as shut-in when the completion interval is open to the tubing or to the casing. A shut-in well may have tubing and packer, which isolates the interior of the casing above the packer from the completion interval. A well may also be shut-in without a packer which exposes the interior of the casing to any fluids from the completion interval. Shut-in wells may have been removed from active service in anticipation of workover, temporary abandonment, or plugging and abandonment operations. Generally, the wellbore condition is such that its utility may be restored by opening valves or by energizing equipment involved in operating the well. Shut-in status should begin three months after production, injection, disposal, or workover operations cease. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  

Shut-In

Inactive wells in which the completion interval is open to the tubing and to the casing, or is open to the tubing only. The well may be shut-in without packer and with or without tubing, in which case the interior of the casing is not isolated from the completion interval. Or, the shut-in well may have tubing and packer, which isolates the interior of the casing above the packer from the completion interval. Shut-in wells have been removed from active service in anticipation of a workover, temporary abandonment, or plugging and abandonment operations. Generally, the wellbore condition is such that its utility may be restored by opening valves or by energizing equipment involved in operating the well. Shut-in status should begin 90 days after production, injection, disposal or workover operations cease. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  

Shut-In Well

SHUT-IN WELL shall mean a well which is capable of production or injection by opening valves, activating existing equipment or supplying a power source. Source: Oil and Gas Conservation Commission, Practice and Procedure, Code of Colorado Regulations, 2 CCR 404-1, February 2013. Regulations
Inactive

Inactive

Definition(s)

Inactive

The term inactive, when used with regard to well status, is broadly defined by regulatory agencies and covers a wide spectrum of wellbore conditions. Furthermore, Federal and state regulatory programs rarely make a distinction between inactive wells which have the completion interval isolated from the wellbore and those which have open completion intervals. Well status terms such as shut-in, standing, temporarily abandoned (TA), inactive, suspended, etc. have generally been used interchangeably by regulatory agencies. Industry and regulatory agencies should standardize the terminology used to describe inactive wells. API recommends that inactive wells be classified as either shut-in or TA as defined below. Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards  

Inactive

“Inactive well” means a well that is not being used for beneficial purposes such as production, injection or monitoring and that is not being drilled, completed, repaired or worked over. Source: Oil and Gas, New Mexico Administrative Code Title 19, Chapter 15, January 2013. Regulations
VIV

VIV

Definition(s)

VIV

In-line and transverse oscillation of the riser string as the result of the periodic shedding of vortices from sea currents. Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global Standards  

VIV

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

VIV

Vortex-induced vibration. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global Standards Source: API RP 17B, Recommended Practice for Flexible Pipe, Fourth Edition, July 2008. Global Standards Source: API SPEC 17E, Specification for Subsea Umbilicals, Upstream Segment, Fourth Edition, October 2010. Global Standards Source: ISO 19901-7:2013, Petroleum and natural gas industries – Specific requirements for offshore structures – Part 7: Stationkeeping systems for floating offshore structures and mobile offshore units. Global Standards  

VIV

In-line and transverse oscillation of a riser in a current induced by the periodic shedding of vortices. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards
UV

UV

Definition(s)

UV

Ultraviolet. Source: API RP 14G, Recommended Practice for Fire Prevention and Control on Fixed Open-type Offshore Production Platforms: Upstream Segment, Fourth Edition, April 2007. Global Standards Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global Standards Source: API RP 17B, Recommended Practice for Flexible Pipe, Fourth Edition, July 2008. Global Standards Source: API SPEC 17J, Specification for Unbonded Flexible Pipe, Third Edition, July 2008. Global Standards Source: API RP 98, Personal Protective Equipment Selection for Oil Spill Responders, First Edition, August 2013. Global Standards  

UV

Ultra-violet. Source: API SPEC 17E, Specification for Subsea Umbilicals, Upstream Segment, Fourth Edition, October 2010. Global Standards Source: Rules for Classification and Construction, IV Industrial Services, 6 Offshore Technology, 9 Guideline for Personnel Transfers by Means of Lifting Appliances, Edition 2011, Germanischer Lloyd SE, Global Standards
UKOOA

UKOOA

Definition(s)

UKOOA

United Kingdom Offshore Operators Association. Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global Standards Source: Prevention of Fire and Explosion, and Emergency Response on Offshore Installations, Offshore Installations (Prevention of Fire and Explosion, and Emergency Response) Regulations 1995, Approved Code of Practice and guidance (UK HSE L65), Second Edition, 1997. Regulatory Guidance Source: A Guide to the Offshore Installations and Pipelines Works (Management and Administration) Regulations 1995, Guidance on Regulations (UK HSE L70), Second Edition, 2002. Regulatory Guidance Source: Rules for Classification and Construction, IV Industrial Services, 6 Offshore Technology, 9 Guideline for Personnel Transfers by Means of Lifting Appliances, Edition 2011, Germanischer Lloyd SE, Global Standards
SWL

SWL

Definition(s)

SWL

A load-carrying member with thrust bearings that allows the load to rotate. Source: API RP 2D, Operation and Maintenance of Offshore Cranes, Seventh Edition, December 2014. Global Standards

SWL

Safe working load. Source: API RP 2D, Operation and Maintenance of Offshore Cranes, Seventh Edition, December 2014. Global Standards Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global Standards Source: API SPEC 17D, Design and Operation of Subsea Production Systems—Subsea Wellhead and Tree Equipment, Upstream Segment, Second Edition May 2011 (Errata September 2011). Global Standards Source: Rules for Classification and Construction, IV Industrial Services, 6 Offshore Technology, 9 Guideline for Personnel Transfers by Means of Lifting Appliances, Edition 2011, Germanischer Lloyd SE, Global Standards Source: Rules for Classification – Offshore units, DNVGL-OU-0101, Offshore drilling and support units, DNV GL, July 2015. Global Standards  

SWL

Still water level. Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global Standards