Borehole

What is a Borehole?

A Borehole is the generalized term for any narrow shaft drilled in the ground, either vertically, horizontally, inclined, or deviated.

Realizations

Data model	Concept name	Definition
OGC GeoSciML	Borehole	A Borehole is the generalized term for any narrow shaft drilled in the ground, either vertically, horizontally, or inclined.
IFC	IFCBorehole	A Borehole is the generalized term for any narrow shaft drilled in the ground, either vertically, horizontally, or inclined.
AGS	LOCA	AGS LOCA includes exploratory holes of any type, e.g. borehole, trial pits, CPT
DIGGS	Borehole	A sampling feature feature that is a deep, narrow excavation made by drilling and/or extraction of earth material. Boreholes are constructed typically for the purpose of investigating subsurface geologic or geotechnical conditions, exploring for water or oil, for installation of wells or other downhole monitoring installations.
DIGGS	Sounding	A sampling feature that is created by a measurement or construction activity through insertion of a probe or tool into the ground.

Properties

A proposed list of borehole properties

Name|Definition id|Identifier name|A human-readable display name for the borehole. description|A human-readable description for the borehole. metadata|A URI referring to a metadata record describing the provenance of data. remarks|Any general remarks about the borehole. boreholePurpose|The purpose for which the borehole was drilled. boreholeUse|The curent use of the borehole which could differ from the purpose for which the borehole was initially drilled. status|The current status of the borehole.( eg. planned, completed, destroyed) source|Details and citations to source materials for the borehole and, if available, providing URLs to reference material and publications describing the borehole. This could be a short text synopsis of key information that would also be in the metadata record referenced by metadata_uri. associatedFile|Identifies external files associated with this borehole. This allows for the feature to be further elaborated with information that cannot be represented by ASCII text, such as a photograph or other media, binary data, or a formatted report. whenDestroyed|The time period during which the hole was destroyed or forever abandoned. This date must occur after all related observations, measurements or activities had been performed in the borehole, and should reflect the time after which no observations or activities are possible in the hole. drillingMethod|The method(s) used to contruct the hole. drillingEquipment|The equipment used to construct the hole. operator|The organisation or agency responsible for commissioning of the borehole (as opposed to the agency which drilled the borehole). driller|The organisation responsible for drilling the borehole (as opposed to commissioning the borehole). drillStartDate|The datetime of the start of drilling formatted according to ISO8601 (e.g., 2012-03-17T00:00:00). drillEndDate|The date of the end of drilling formatted according to ISO8601 (e.g., 2012-03-28T00:00:00). BoreholeLengthPlanned|The planned length of a borehole e.g. in a site investigation program. BoreholeLengthDrilled|The total length of a borehole as drilled and logged. Length may have different sources (e.g., driller's measurement, logger's measurement, survey measurement). startPoint|The position relative to the ground surface that marks the origin for meauring distance along a borehole's trajectory. collarGeometry|2D or 3D point geometry that represents the location of the borehole at the ground surface in geographic space. srsName|The URI of a spatial reference system. If collarGeometry is a 2D point, this is the horizontal SRS. If collarGeometry is a 3D point, this must be a either a 3D SRS, a known compound SRS, or the EPSG code of the horizontal component of a compound SRS. elevation_srsName|The URI of a spatial reference system of the elevation of the collarGeometry. (e.g., mean sea level). Mandatory if collarGeometry and srsName is the EPSG code of the horizontal component of a compound SRS. elevation_srsName shall be a one dimensional vertical SRS (i.e., EPSG code in the range 5600-5799). positionalAccuracy|An estimate of the accuracy of the location of the collarGeometry. Ideally, this would be a quantitative estimate of accuracy (e.g., 20 metres). locality|Non-coordinate location information for a borehole. localCoordinates|A geometry object that holds the values of local coordinates for the borehole collar location. This object is used to carry information about the location of a feature in its original local reference system if not originally recorded in a well-known SRS. azimuth|For a straight but inclined borehole, the azimuth of the borehole's trajectory as a plane angle measurement, where 0 is true north, incrementing clockwise. inclination|For a straight but inclined borehole, the inclination of the borehole's trajectory as a plane angle measurement, where 0 is vertical and 90 is horizontal. trajectoryType|Describes the general character of the borehole's trajectory. (vertical, inclined, deviated) trajectoryGeometry|A geometry that represents and locates the borehole shape. It is represented as a lineString in 3D space and is of the same SRS as collarGeometry. A borehole can have multiple centerlines to represent sidetracks or to serve as a linear referencing element for observations within the borehole that may be located relative to different datums (eg. ground surface vs rig table). linearReferencing|Defines the linear spatial reference system for the borehole. This LSRS can then be used to define the location of observations within the borehole as a 1D position along the borehole's trajectory, rather than in geographic coordinates.
boreholeType|Type of borehole. (core drilling, destructive drilling, trial pit, sounding)

FAQ

What about Trial Pit?

Despite a lot of similarities with borehole, the Trial Pit is proposed as a different concept.

See https://github.com/opengeospatial/Geotech/wiki/TrialPit for its description.

What about Borehole core?

A borehole core is considered as a MaterialSample.

See https://github.com/opengeospatial/Geotech/wiki/MaterialSample for its description.

What about Borehole Logs and Observations?

All observations, measurements and test descriptions from a Borehole are considered as Observations.

See https://github.com/opengeospatial/Geotech/wiki/Observation for their description.

GitHub issue

https://github.com/opengeospatial/Geotech/issues/10