OR/16/052 Appendix 1

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Kessler, H, Terrington, R, Wood, B, Ford, J, Myers, T, Thorpe, S, and Burke, H. 2016. Specification of in- and output data formats and deliverables for commissioned 3D geological models. British Geological Survey Internal Report, OR/16/052.

The use of borehole data in 3D geological modelling or in geological assessments that involve the interpretation of borehole record information.

Key message: Project leaders should review the information below to ensure they are using the correct borehole data (open access/confidential) before commencing any 3D geological modelling projects.

  1. There is an increasing emphasis and need for the data underpinning 3D geological models to be openly available. Such openness is required for model users to appreciate the data density used to build the model, to evaluate the uncertainty of geological interpretations and ultimately have confidence in our scientific output. For these reasons, careful consideration of the confidentiality of the borehole data is essential, which is the topic of this notice.
  2. The confidentiality status or rating of a borehole record is indicated by the confidentiality codes 1 to 6. These are defined in table below and the usage restrictions are clearly stated. Please note that breaches could open BGS to legal proceedings.
Table 1    Confidentiality codes for borehole data
Code Description Example reasons for confidentiality restriction Use restrictions Database objects
1 No conditions apply (non-confidential) Open data No restrictions QL_BOREHOLE_OPEN_ACCESS
2 Protect — management (conditions apply) Applies where data can be non-confidential but there are restrictions or conditions on its release. These restrictions include not being permitted to supply the data Use if other data is unavailable QL_BOREHOLE_SEMICLOSED_ACCESS
3 Position of bore and name of owner may be given Contractors wish to retain control of information/do not want the public to use their data without permission Use if other data is unavailable QL_BOREHOLE_OPEN_ACCESS
4 Existence of bore within an area and owners name may be given

** Not shown on the GeoIndex

Sensitive locations, e.g. power stations or mineral exploration sites Do not use QL_BOREHOLE_CLOSED_ACCESS
5 BGS will consult owners before any information is given

** Not shown on the GeoIndex

Information is not allowed into the public domain e.g. Provision of information may facilitate a breach of security Do not use QL_BOREHOLE_CLOSED_ACCESS
6 Records contain flag to highlight that confidentiality is unknown, not entered or not applicable In this case we are unsure about the rights of these records Do not use QL_BOREHOLE_UNKNOWN_ACCESS
  1. Opportunities may exist for some of the confidential borehole data to be revisited and made openly available after discussions with the original data donator/owner. If during the course of your modelling work you feel there are significant numbers of confidential boreholes that would critically aid your modelling please highlight these to Records Management (Rod Bowie) who will establish if these records can be re-graded and therefore appear in the code 1 objects for open use.
  2. A statistical analysis of borehole data and model surfaces (Dearden et al. 2013) demonstrates that it is not possible to reverse-engineer data contained in a confidential borehole records by interrogating a 3D geological model (e.g. by creating a ‘virtual’ borehole log output on the same site as a confidential borehole shown in the online GeoIndex).
  3. To convey to the user or customer that borehole record data does not contribute to the geological model surfaces directly, text should accompany all models stating that borehole records have been ‘considered’ in the production of the model, rather than ‘used’. The term ‘considered’ implies that the model user cannot reproduce the borehole record.
  4. Currently confidentiality is defined at the borehole level so a confidential borehole may have one or more borehole logs (within Borehole Geology) associated with that borehole, these will also be considered confidential. No confidential borehole geology logs should be released externally.

Recommendations
Recommendations for system developers:

Use database objects as identified in Table 1 (which will be automatically kept up to date) when building queries to access borehole logs for modelling. Using these objects will ensure that results carry a definitive corporate confidentiality status. Recommendations for geologists:

  • Use non-confidential boreholes (code 1) in preference to partially confidential boreholes (code 3) if possible.
  • For boreholes coded 2, 4, 5 and 6, if confidentiality restrictions cannot be lowered (or established), do not use them.
  • If you use bespoke access systems to obtain borehole data, please be aware of the confidentiality codes you should use in your queries to extract data for your modelling work.

Recommendations for data/model delivery:

  • When delivering 3D geological models state that borehole records have been considered in the production of the model, rather than used.
  • Delivering data from Borehole Geology database.

Records in Borehole Geology linked to a Borehole with a confidentiality code of 1 can be released. All others (codes 2–6) must not be released.

  • Delivering geological models via the web (Groundhog).

When preparing 3D models for release via the web (Groundhog), the geographic locations of boreholes with confidentiality codes 1 and 3 can be released. The locations, or details of boreholes with confidentiality codes 2, 4, 5 and 6, should not be released.

  • Delivering geological models as surfaces.

A geological model surface can be delivered with the geographic locations of code 1, 2 and 3 boreholes that were considered in the construction of that surface. It is likely that not all boreholes considered in the modelling will penetrate the surface in question; only those boreholes that penetrate the surface should be shown. The locations, or details of boreholes with confidentiality codes 4 and 5, should not be released.

  • Delivering geological models in 3D viewers.

When preparing 3D geological models in a viewer, non-confidential records (code 1) can be incorporated as geology-attributed borehole sticks. Confidential borehole (code 3) records must be ‘empty’ and not show the geological interface depths. They must penetrate the entire model so that the basal depth is not released. Accompanying text should explain this situation. The locations, or details of boreholes with confidentiality codes 2, 4, 5 and 6, should not be released.

DEARDEN R, BOWIE R, KESSLER H, Terrington R, Shelley C, and Thorpe S. 2013. 3D data products: delivery of information relating to confidential borehole records. British Geological Survey, Internal Report, CR/13/127. 41pp