Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
COE
Definition(s)
COE
Corps of Engineers. Source: Deepwater Well Control Guidelines. IADC GuidelinesCI
Definition(s)
CI
Coefficient of Inertia. Source: Deepwater Well Control Guidelines. IADC GuidelinesCLFP
Definition(s)
CLFP
Choke and kill line friction pressures. Source: Deepwater Well Control Guidelines. IADC GuidelinesBU
Definition(s)
BU
Business unit. Source: Deepwater Well Control Guidelines. IADC GuidelinesBTF
Definition(s)
BTF
Blowout task force. Source: Deepwater Well Control Guidelines. IADC GuidelinesBPM
Definition(s)
BPM
Barrels per minute. Source: Deepwater Well Control Guidelines. IADC GuidelinesBCP
Definition(s)
BCP
Blowout contingency plan. Source: Deepwater Well Control Guidelines. IADC GuidelinesAX/VX
Definition(s)
AX/VX
Ring gasket Source: Deepwater Well Control Guidelines. IADC GuidelinesAPV (Air Pressure Vessel)
Definition(s)
APV
Air Pressure Vessel. Source: Deepwater Well Control Guidelines. IADC GuidelinesAs Low As Reasonably Practical (ALARP)
Definition(s)
ALARP
As Low As Reasonably Practical. Source: Deepwater Well Control Guidelines. IADC GuidelinesAnchor Handling Vessel (AHV)
Definition(s)
AHV
Anchor Handling Vessel. Source: Deepwater Well Control Guidelines. IADC GuidelinesSSSV System Equipment
Definition(s)
SSSV System Equipment
components which include the surface-control system, control line, SSSV, safety valve lock, safety valve landing nipple, flow couplings and other downhole control components [SOURCE: ISO 10417] Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsSubsurface-controlled Subsurface Safety Valve SSCSV
Definition(s)
Subsurface-controlled Subsurface Safety Valve SSCSV
SSSV actuated by the characteristics of the well itself Note 1 to entry: Note 1 to entry: These devices are usually actuated by the differential pressure through the SSCSV (velocity type) or by tubing pressure at the SSCSV (high or low pressure type). [SOURCE: ISO 14723] Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsSurface-controlled Subsurface Safety Valve SCSSV
Definition(s)
Surface-controlled Subsurface Safety Valve SCSSV
SSSV controlled from the surface by hydraulic, electrical, mechanical or other means Note 1 to entry: The SCSSV is sometimes called DHSV (downhole safety valve). [SOURCE: ISO 14723] Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsSubsea Isolation Valve
Definition(s)
Subsea Isolation Valve
SSIV SIV valve which closes within a defined time limit derived from the risk assessment in order to reduce consequences of pipeline/riser leak or rupture Note 1 to entry: The SSIV can be an actuated valve (e.g. remotely controlled subsea valve) or a non-activated valve (subsea check valve). An activated valve is normally designed as fail safe (i.e. closes and remains closed on all failures external to the valve and actuator themselves). Note 2 to entry: Where the flexible risers are connected directly to the subsea wellhead, the master and wing valve may be considered to represent the SSIV function. [SOURCE: ISO 14723] Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsHIPPS Valve
Definition(s)
HIPPS Valve
valve used as a final element in a HIPPS system. Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsHigh Integrity Pressure Protection System
Definition(s)
High Integrity Pressure Protection System
HIPPS HIPS exclusively devoted to protection against overpressure Note 1 to entry: Alternative terminology: over pressure protection system (OPPS). Note 2 to entry: A HIPPS can be used as an alternative to, e.g.: • full pressure rating of downstream equipment, or • adequately sized mechanical pressure relief devices, or • design the disposal system for simultaneous reliefs. Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsHigh Integrity Protection System
Definition(s)
High Integrity Protection System
System composed of sensors, logic solvers, and final control elements for the purpose of taking the process to a safe state when predetermined conditions are met.- NOTE: Other terms commonly used for a SIS include emergency shutdown system (ESD, ESS), safety shutdown system (SSD), and safety interlock system (see E.3.3.1).
High Integrity Protection System
HIPS Non-conventional autonomous safety instrumented system with sufficiently high safety integrity (see 3.2.1) to protect equipment against exceeding the design parameters- Note: 1 to entry: Deviations from industry standards describing mechanical protection systems (e.g. ISO 23251[31] = API
Functioning Analysis
Definition(s)
Functioning Analysis
set of activities aiming to analyse how an item performs as required Note 1 to entry: This is the counterpart of the dysfunctioning analysis which aims to analyse how an item fails when the functioning analysis aims to analyse how an item works by, e.g. identifying, sorting out and characterizing the various functions related to the item. Note 2 to entry: The term “functional” analysis is often used as a synonym of “functioning” analysis. However, the term “functional analysis” which has several meanings is not used in this Technical Report to avoid confusion. Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsFormal Language
Definition(s)
Formal Language
set of words, semantics and logical rules with sound mathematical properties Note 1 to entry: Programming languages are an example of formal language with mathematical properties allowing them to be compiled into computer executable code. Note 2 to entry: Every reliability model has an underlying formal language behind the graphical elements (e.g. the Binary logic for Boolean models). Note 3 to entry: Specific formal languages have been developed to model the functioning and the dysfunctioning of industrial systems (e.g. AltaRica[11][12]). According to their powerfulness of modelling and their mathematical properties they can be compiled toward event trees, fault trees, Markov graphs, Petri nets, accident sequences, etc. Some of them can also be directly used for Monte Carlo simulation. Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsDysfunctioning Analysis
Definition(s)
Dysfunctioning Analysis
set of activities aiming to analyse the dysfunctions of an item Note 1 to entry: This is the counterpart of the functioning analysis which aims to analyse how an item works when the dysfunctioning analysis aims to analyse how an item fails by e.g. identifying, sorting out, characterizing and/or evaluating the probability of occurrence of the dysfunctions. Note 2 to entry: The term “dysfunctional” analysis is often used as a synonym of “dysfunctioning” analysis. Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsDysfunction
Definition(s)
Dysfunction
impaired or abnormal functioning of an item Note 1 to entry: This term is built from the Greek prefix “dys” (i.e.” with difficulty”) and the Latin term “functio” (i.e. an activity with a given aim). Primarily used in the medical field, this term is now often used within the technological field as a more generic term than “failure” or “fault”. Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsCritical State
Definition(s)
Critical State
in a states-transitions model, state belonging to a given class of states and which is distant from the failure class of states by only one transition Note 1 to entry: This is a mathematical concept in relationship with e.g. Markovian process or Petri nets models. EXAMPLE The states of a safety system can be sorted out into two classes: class OK when the safety action is available and KO when the safety action is inhibited. In this case a critical state with regards to the safety system failure belongs to the class OK and only one failure (i.e. on event) is needed to have a transition to the class KO. Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsSpurious Action
Definition(s)
Spurious Action
result of a spurious activation of a safety function Note 1 to entry: A spurious safety action is not necessary safe. An example of spurious action is a spurious trip. Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsSpurious Activation (of a safety function)
Definition(s)
Spurious Activation (of a safety function)
untimely demand of a safety function when this is not needed Note 1 to entry: The spurious activation of a safety function may be due to the occurrence of one or several safe failures. Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsStaggered Testing (of redundant items)
Definition(s)
Staggered Testing (of redundant items)
test of several items with the same test interval but not at the same time EXAMPLE Figure 9 shows staggered tests for two item A and B. Note 1 to entry: When the redundant components of a system are tested at the same time (i.e. when the tests are synchronous) their availabilities are good (just after a test) and bad (just before a test) at the same time. This correlation means that the unavailabilities of the components peak simultaneously. This has a detrimental effect on the system availability which can be cancelled by de-synchronizing the tests. A practical way to do that is staggering the tests (e.g. testing one component in the middle of the test interval of the other); the unavailability peaks are also staggered and this improves the average availability of the system.
Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global Standards