12.6.3 Channel

Topic Version	1	Published	11/11/2016	Topic Change History
For Standard	WITSML v2.0
Type:	Class		Stereotype:	«XSDcomplexType»

A channel object. It corresponds roughly to the LogCurveInfo structure in WITSML1411, and directly corresponds to the ChannelMetadataRecord structure in ETP. In historian terminology, a channel corresponds directly to a tag.

Channels are the fundamental unit of organization for WITSML logs.

Table 12.6.3-1 Attributes
Name	Type	Notes
DataType	EtpDataType	The underlying ETP data type of the value.
GrowingStatus	ChannelStatus	The status of a channel with respect to creating new measurements. Statuses include: Active: A channel is actively producing data points. Inactive: A channel is offline or not currently producing, but may begin producing again in the future. Closed: A channel will never produce points again. The rules for when a channel is to be closed will vary some for different kinds of channels. For example, time-based surface channels may remain open for the entire life of the drilling operation, whereas depth-based wireline channels are closed at the end of the wireline job
Mnemonic	String64	The mnemonic name for this channel. Mnemonics are not unique within a store.
Source	String64	Source of the data in the channel. Enter the contractor name who conducted the log.
Uom	UnitOfMeasureExt	The underlying unit of measure of the value.

Table 12.6.3-2 Associations
Association	Notes
From: Channel.PointMetadata 0..*To: PointMetadata Association
From: Channel. To: AbstractObject Generalization
From: Channel. 0..1To: Wellbore Association
From: Channel. To: ChannelStatus Dependency
From: Channel.DerivedFrom 0..*To: Channel Association	For derived channels, a list of the source channels which went into the derivation. For example, if you create a composite GR channel from several separate measured channels, this would point to those channels. Note, that these references are for provenance only. The derived data must be store independently on the server for a derived channel.
From: Channel.LogChannelMetadata 1To: LogChannelMetadata Association
From: Channel.Parent 0..1To: AbstractObject Association	The containing data object for the channel set. For example, for a Log, this could be either the wellbore for the log or a LoggingRun
From: Channel.Index 1..*To: ChannelIndex Association
From: Channel.AxisDefinition 0..*To: LogChannelAxis Association	Indicates that the curve is an array curve (i.e., multi-valued samples), and provides meta data by which an axis of the array can be understood.
From: Channel. To: EtpDataType Dependency
From: Chromatograph.Channel 0..1To: Channel Association
From: ChannelSet.Channel 1..*To: Channel Association
From: GasPeak.Channel 1To: Channel Association
From: Channel.DerivedFrom 0..*To: Channel Association	For derived channels, a list of the source channels which went into the derivation. For example, if you create a composite GR channel from several separate measured channels, this would point to those channels. Note, that these references are for provenance only. The derived data must be store independently on the server for a derived channel.
From: GasInMud.Channel 1To: Channel Association