exported
equivalent
christmas tree
IRI:
http://www.inf.ufrgs.br/ontologies/copi#Christmastree
Generated on 2026-04-09
Natural Language Definition
EN
A christmas tree is an assembly that bears a well fluid control function, is connected to a wellhead, and contains master valves for controlling formation fluids from oil and gas wells.
PT-BR
Uma árvore de natal é um conjunto que possui uma função de controle de fluidos de poço, está conectada a uma cabeça de poço, e contém válvulas mestras para controlar fluidos de formação de poços de petróleo e gás.
Formal Axioms
Semi-formal (Aristotelian)
Every christmas tree is an assembly that has the function to control well fluids and is connected to a wellhead and has master valves as component parts.
First-Order Logic Theory
Loading…
▸ Stored override
∀x (ChristmasTree(x) ↔ (Assembly(x) ∧ ∃f(WellFluidControlFunction(f) ∧ bearerOf(x,f)) ∧ ∃w(Wellhead(w) ∧ hasComponentPartAtAllTimes(x,w)) ∧ ∃v(MasterValve(v) ∧ hasComponentPartAtAllTimes(x,v))))
OWL 2 / Turtle
@prefix copi: <https://www.inf.ufrgs.br/ontologies/copi/> .
@prefix : <https://www.inf.ufrgs.br/ontologies/copi/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix bfo: <http://purl.obolibrary.org/obo/> .
@prefix iof-core: <https://spec.industrialontologies.org/ontology/construct/> .
@prefix iof-av: <https://spec.industrialontologies.org/ontology/annotation/> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix qudt: <http://qudt.org/schema/qudt/> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix apv: <http://inf.ufrgs.br/ontologies/apv#> .
### COPI — Core Ontology for Petroleum Installations
### Class module: ChristmasTree
<https://www.inf.ufrgs.br/ontologies/copi>
rdf:type owl:Ontology ;
dcterms:title "Core Ontology for Petroleum Installations (COPI)"@en ;
dcterms:title "Ontologia Core para Instalações de Petróleo (COPI)"@pt-br ;
dcterms:description "BFO/IOF-Core conformant ontology of equipment classes for petroleum production plants, developed using the five-step RDL enrichment method."@en ;
skos:scopeNote "Material artifacts (bfo:material_entity) that (i) are part of a petroleum production plant, and (ii) bear at least one function whose realization involves the transport (e.g. production and injection), processing (separation and other processes), control, monitoring, measurement, containment or offloading of material or energy."@en ;
skos:scopeNote "Artefatos materiais (bfo:material_entity) que (i) fazem parte de uma planta de produção de petróleo, e (ii) possuem ao menos uma função cuja realização envolve o transporte (p. ex. produção e injeção), processamento (separação e outros processos), controle, monitoramento, medição, contenção ou escoamento de material ou energia."@pt-br ;
skos:scopeNote "COPI provides high-level equipment categories defined by function to demonstrate the defined-class mechanism. Equipment subtypes are annotated with references to CFIHOS and PCA RDL terms. COPI is not a reference data library; organizations should use CFIHOS, PCA RDL, or ISO 14224 for comprehensive equipment classification."@en ;
skos:scopeNote "COPI fornece categorias de alto nível de equipamentos definidas por função para demonstrar o mecanismo de classe definida. Os subtipos de equipamentos são anotados com referências aos termos do CFIHOS e do PCA RDL. COPI não é uma biblioteca de dados de referência; organizações devem utilizar o CFIHOS, o PCA RDL ou a ISO 14224 para classificação abrangente de equipamentos."@pt-br ;
owl:versionInfo "1.1.0" ;
owl:imports <https://spec.industrialontologies.org/ontology/core/Core/> ;
owl:imports <http://purl.obolibrary.org/obo/bfo/2020/bfo.owl> ;
dcterms:creator "Nicolau Oyhenard dos Santos"@en ;
dcterms:contributor "Cauã Antunes" ;
dcterms:contributor "Haroldo Rojas" ;
dcterms:contributor "Rafael Petry" ;
dcterms:contributor "Régis Romeu" ;
dcterms:contributor "Mara Abel" ;
dcterms:isPartOf <https://inf.ufrgs.br/projetos/OntoKG> ;
dcterms:publisher "Universidade Federal do Rio Grande do Sul (UFRGS)"@en ;
dcterms:license <https://creativecommons.org/licenses/by/4.0/> ;
dcterms:created "2026-04-08"^^xsd:date ;
dcterms:modified "2026-10-08"^^xsd:date ;
apv:GlobalMinLanguageCoverage "en pt-br" ;
apv:ClassURIFormationRule "https://www[.]inf[.]ufrgs[.]br/ontologies/copi/(COPI_[0-9]{7}|[A-Z][A-Za-z0-9]*)" ;
apv:ClassMinAnnotationCoverage "rdfs:label https://spec.industrialontologies.org/ontology/annotation/naturalLanguageDefinition" .
iof-av:naturalLanguageDefinition rdf:type owl:AnnotationProperty ;
apv:MinAnnotationLength 20 .
### Identity-giving function
:COPI_0000693 rdf:type owl:Class ; # WellFluidControlFunction
rdfs:subClassOf iof-core:DesignedFunction ;
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty bfo:BFO_0000054 ; # realizedIn
owl:allValuesFrom :COPI_0000694 # WellFluidControlProcess
] ;
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty bfo:BFO_0000054 ; # realizedIn
owl:someValuesFrom :COPI_0000694 # WellFluidControlProcess
] ;
rdfs:label "well fluid control function"@en ;
rdfs:label "função de controle de fluido de poço"@pt-br .
### Process type
:COPI_0000694 rdf:type owl:Class ; # WellFluidControlProcess
rdfs:subClassOf :COPI_0000010 ; # FlowControl
rdfs:label "well fluid control process"@en ;
rdfs:label "processo de controle de fluido de poço"@pt-br .
:COPI_0000010 rdf:type owl:Class . # FlowControl
:COPI_0000694 # WellFluidControlProcess
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasInput ;
owl:someValuesFrom :COPI_0000390 # FormationFluid
] ;
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasSpecifiedOutput ;
owl:someValuesFrom :COPI_0000390 # FormationFluid
] .
### Equipment universal: ChristmasTree
:COPI_0000228 rdf:type owl:Class ; # ChristmasTree
owl:equivalentClass [
rdf:type owl:Class ;
owl:intersectionOf (
iof-core:Assembly
[
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasFunction ; # Object branch (MaterialArtifact/Assembly/Object/FiatObjectPart)
owl:someValuesFrom :COPI_0000693 # WellFluidControlFunction
]
[
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasComponentPartAtAllTimes ;
owl:someValuesFrom :COPI_0000728 # MasterValve
]
[
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasComponentPartAtAllTimes ;
owl:someValuesFrom :COPI_0000734 # WingValve
]
)
] ;
rdfs:label "christmas tree"@en ;
rdfs:label "árvore de natal"@pt-br ;
iof-av:naturalLanguageDefinition "A christmas tree is an assembly that bears a well fluid control function, is connected to a wellhead, and contains master valves for controlling formation fluids from oil and gas wells."@en ;
skos:definition "A christmas tree is an assembly that bears a well fluid control function, is connected to a wellhead, and contains master valves for controlling formation fluids from oil and gas wells."@en ;
iof-av:naturalLanguageDefinition "Uma árvore de natal é um conjunto que possui uma função de controle de fluidos de poço, está conectada a uma cabeça de poço, e contém válvulas mestras para controlar fluidos de formação de poços de petróleo e gás."@pt-br ;
iof-av:semiFormalNaturalLanguageAxiom "Every christmas tree is an assembly that has the function to control well fluids and is connected to a wellhead and has master valves as component parts."@en ;
iof-av:firstOrderLogicAxiom "∀x (ChristmasTree(x) ↔ (Assembly(x) ∧ ∃f(WellFluidControlFunction(f) ∧ bearerOf(x,f)) ∧ ∃w(Wellhead(w) ∧ hasComponentPartAtAllTimes(x,w)) ∧ ∃v(MasterValve(v) ∧ hasComponentPartAtAllTimes(x,v))))"@en ;
skos:definition "[ISO 15926-4] A <CHRISTMAS TREE> is a <PIPING SYSTEM> that is an assembly of pipes and piping parts, with valves and associated control equipment that is connected to the top of a wellhead and is intended for control of fluid from a well."@en ;
skos:definition "[CFIHOS] A physical object that is an assembly of pipes and piping parts, with valves and associated control equipment that is connected to the top of a wellhead and is intended for control of fluid from a well."@en ;
skos:definition "[SLB Glossary] The set of valves, spools, and fittings connected to the top of a well to direct and control the flow of formation fluids from the well."@en ;
skos:definition "[OnePetro] The control sections that sits above the basic wellhead. It may contain hangers, master valves, annular valves, wing valves, and gauges or pressure, flow rate or monitoring measurement equipment."@en ;
skos:definition "[POSC Caesar] An 'artefact' that is an assembly of pipes and piping parts, with valves and associated control equipment that is connected to the top of a wellhead and is intended for control of fluid from a well."@en .
:COPI_0000728 rdf:type owl:Class ; # MasterValve
rdfs:subClassOf :COPI_0000077 ; # Valve
rdfs:label "válvula mestra"@pt-br ;
rdfs:label "master valve"@en .
:COPI_0000734 rdf:type owl:Class ; # WingValve
rdfs:subClassOf :COPI_0000077 ; # Valve
rdfs:label "válvula lateral"@pt-br ;
rdfs:label "wing valve"@en .
# Disjointness: ChristmasTree and Separator
[] rdf:type owl:AllDisjointClasses ;
owl:members ( :COPI_0000228 :COPI_0000084 ) . # ChristmasTree, Separator
# Disjointness: ChristmasTree and HeatExchanger
[] rdf:type owl:AllDisjointClasses ;
owl:members ( :COPI_0000228 :COPI_0000092 ) . # ChristmasTree, HeatExchanger
# Disjointness: ChristmasTree and Compressor
[] rdf:type owl:AllDisjointClasses ;
owl:members ( :COPI_0000228 :COPI_0000073 ) . # ChristmasTree, Compressor
Axiomatization Decision Log
1
Identity-Giving Function
Function class
WellFluidControlFunction
⊑ DesignedFunction
Realized in
WellFluidControlProcess
⊑ FlowControl
The consistent theme across all definitions is the function to control, direct, and regulate the flow of formation fluids from oil/gas wells. This is a specialized control function distinct from general flow control, as it specifically manages well production fluids at the wellhead interface.
2
Genus Determination
Assembly
bfo:Object (BFO_0000030)
Causally unified material artefact composed of physically connected,
separable MaterialComponent parts. Satisfies
Assembly ⊑ MaterialArtifact ⊑ bfo:Object.
Christmas tree is explicitly described as an 'assembly of pipes and piping parts, with valves and associated control equipment'. While 'PIPING SYSTEM' appears in parent_candidates, this is too specialized - christmas trees are not primarily piping systems but rather integrated assemblies that include valves, control equipment, sensors, and structural components in addition to piping. The assembly nature is emphasized across all sources, indicating physically connected, removable subcomponents unified into a single maintainable unit.
3
Necessary Parts
| Part class | Parent | Relation |
|---|---|---|
| MasterValve | Valve | hasComponentPartAtAllTimes |
| WingValve | Valve | hasComponentPartAtAllTimes |
These parts represent the essential components that make a christmas tree functional - primary control valves, structural body, and control equipment. Piping components are inherited from Assembly level.
4
Process Participation Signature ⟨I, O, T⟩
Inputs (I)
FormationFluid
— from well bore, multi-phase hydrocarbon stream
Outputs (O)
FormationFluid
— controlled flow rate and pressure to production system
Transformation (T)
flow control and pressure regulation of well fluids
Christmas trees receive uncontrolled formation fluids from the well and output controlled fluids to the production system. The transformation involves pressure and flow rate control rather than compositional change.
5
Axiom Mode Decision
Necessary + Sufficient
— modelled as a defined class
(≡, EquivalentClass). Automatic classification is
appropriate for this concept.
Disjointness Axioms
Separator
HeatExchanger
Compressor
C2: Compressor. C4: Separator, HeatExchanger. Christmas trees have a specialized well fluid control signature incompatible with separation processes, heat transfer, or compression. They are control devices, not processing equipment.
Cross-Standard Observations
All sources consistently describe christmas trees as assemblies for well fluid control connected to wellheads. ISO 15926 provides the most comprehensive definition including piping system context, while SLB focuses on the valve and fitting aspects. OnePetro emphasizes the control sections and measurement equipment. The terminology and core function are remarkably consistent across petroleum industry standards.
