Services related to boreholes
BoreholeView service specifications
The BoreholeView specification document, accessible at https://forge.brgm.fr/svnrepository/epos/trunk/Documents/EPOS_Borehole_V.1.0.1.docx, contains comprehensive information about all aspects of the service: scope, definitions, models, (data) content, vocabularies, standards, encoding. However, the rather complex document is most likely not easily read and understandable on the first attempt. Therefore, the most important points and some general issues are summarised here.
Borehole data will be handled at the central node of the TCS Geological Information and modelling. The first service, which is presently being launched, is the BoreholeView. Once available through the EPOS ICS, it will allow the user to search for and filter boreholes by a specific set of descriptive data and geography elements. These descriptive elements will be harvested from the data suppliers to a catalogue at TCS Geological Information and Modelling level, the European Borehole Index.
More information about the technical approach at the TCS level is available through the ‘Borehole Data/service organisation rationale’ was defined in late autumn 2016. https://owncloud.epos-ip.org/remote.php/webdav/WP15%20Boreholes/Files/21061122_Potsdam_Borehole_IT_slides_final.pptx.
BoreholeView is designed for quick access to basic information about boreholes. It also allows for easy and quick inclusion of new data sources and providers. Thus, extended features like integrated access to advanced datasets like downhole data are not included. However, these can be referenced form the BoreholeView content by links (URL). EPOS BoreholeView is based on the GeoSciML4 Lite (i.e. simple feature) application schema.
The content of the BoreholeView service, i.e. of the European Borehole Index, is described in Section 7.4.3 of the specification document and summarised here for your convenience. Some attribute values are regulated by vocabularies, which is indicated by (vocab) in the list below.
- identifier - Unique identifier
- name - Human readable display name of the borehole
- description - Human readable description of the borehole
- purpose (vocab) - Purpose of the borehole.
- status (vocab) - Status of the borehole.
- drillingMethod (vocab) - Dominant method that was used for drilling.
- operator - The organisation or agency responsible for commissioning of the borehole.
- driller - The organisation responsible for drilling the borehole.
- drillStartDate - The date of the end of drilling formatted according to ISO 8601 (e.g. 2012-03-28).
- drillEndDate - The date of the end of drilling formatted according to ISO 8601 (e.g. 2012-03-28).
- startPoint (vocab) - The position relative to the ground surface where the borehole commenced.
- inclinationType (vocab) - The type of inclination of the borehole.
- boreholeMaterialCustodian - The organisation that is the custodian of the material recovered from the borehole.
- boreholeLength_m - The length of a borehole, in metres, as determined by the data provider.
- elevation_m - The elevation data, in metres, for the borehole (i.e., wellbore) start point.
- elevation_srs - The spatial reference system of the elevation value
- positionalAccuracy - An estimate of the accuracy of the location of the borehole collar location.
- source - Details and citations to source materials for the borehole and, if available, URLs to reference material and publications describing the borehole.
- parentBorehole_uri - A URI referring to one or more representations of a parent borehole (e.g., a parent well of a sidetrack wellbore).
- metadata_uri - A URI referring to a metadata record describing the provenance of data.
- location (shape) - Geometry defining the extent of the borehole start point.
- cored - Indicates whether a core sample was retrieved from the borehole when drilling.
- accessToPhysicalDrillCore - Indicates whether access to physical drill core is possible.
- boreholeUse (vocab) - Present use of the borehole.
The following attributes can provide links to more complex data flows:
- detailedDescription - Indicates whether a more detailed description of that borehole exists.
- geophysicalLogs - Indicates whether geophysical logs of that borehole exist.
- geologicalDescription - Indicates whether geological description of that borehole exists.
- groundWaterLevel - Indicates whether groundwater level measurements from this borehole exist.
- groundWaterChemistry - Indicates whether water analyses from this borehole exist.
- rockGeochemistry - Indicates whether the chemistry of the penetrated rock was analysed and if result are available.
- poreGasChemistry - Indicates whether the pore fluid of the penetrated rock was analysed and if result are available.
- geoTechnicalInfo - Indicates whether geotechnical information from the borehole exists.
For the effective utilisation of BoreholeView, it is necessary to structure the content of the attributes with the exception of those that require free text description. This happens either through the data type in the technical implementation (e.g. date) or by vocabularies with approved attribute values. The vocabularies used in BoreholeView are listed below with links to their content. See also Section 7.4.4 in the specification document. Where possible, existing standardised vocabularies were used and, if necessary, extended (thus, the latter are at least temporarily hosted by the TCS).
1. Borehole purpose and Borehole use: the vocabulary Inspire BoreholePurposeValue.
http://inspire.ec.europa.eu/codelist/BoreholePurposeValue A request for the addition of a dedicated entry for ‘multiDisciplinary Scientific Research’ is going on. Thus the following URI should be used for this need (even if it does not resolve yet). http://inspire.ec.europa.eu/codelist/BoreholePurposeValue/multiDisciplinaryScientificResearch
2. Borehole status: vocabulary based on BoreholeML (under development!).
3. Drilling method: the vocabulary is based on the IUGS-CGI vocabulary boreholedrillingmethod (2016) with additional entries defined by WP15.
4. Borehole startpoint: the vocabulary is based on the documentation of GeosciML so far.
Based on the information flow collected within WP15, additional entries may be added by WP15. https://epos.brgm-rec.fr/datalift/skos/vocabs/StartPoint
5 Borehole inclination: the vocabulary is based on the documentation of GeosciML with additional entries defined by WP15.
OGC WFS services compliant to this specification (application schema) are progressively being set up by WP15 and allow borehole data providers to expose their borehole information according to the BoreholeView specification. Example:
An example file has been set up to demonstrate the use of the BoreholeView specification. It is available here: https://forge.brgm.fr/svnrepository/epos/trunk/instances/BoreholeView.xml Implementation of BoreholeView for data providers and data owners:
Data providers and data owners have two options to make their data available through the European Borehole Index. If the borehole information is already stored in a database, WP15 will help to set up a BoreholeView service that can be harvested, including translation of attributes and attribute values to BoreholeView specifications. If data hosting is required, the node for scientific drilling data can help. If the request for data hosting is significant, specific tools might be set up at the TCS Geological Information and Modelling central node. Concluding remarks
We hope that the above summary is clear for you. If you have any questions, please do not hesitate to contact us, preferably via this HG mailing list, that everybody can follow and take benefit of the discussion, questions and answers. Please give us your initial feedback in advance of the Prague meeting, i.e. by the 22nd February at the latest. Please do not forget to include relevant information about your interests in drilling data and, if applicable, data sets.
Henning Lorenz & Sylvain Grellet