WBM Use and Discharge

For information on the impact of Brexit on oil and gas environmental legislation, please refer to the pdf document downloadable from the Home Page.

Key Legislation:

For more detail on the Legislation relevant to this page, please use the following links:

Guidance Notes:



Consent Needed: Chemical Permit A permit to use and discharge chemicals is required under the Offshore Chemical Regulations 2002 (see Drilling Chemicals).Oil Discharge PermitDischarge or reinjection of cuttings contaminated with reservoir hydrocarbons (e.g. drilling through the pay-zone) require a permit under the OPPC Regulations (see OPPC Summary Table).FEPA LicenceIf exporting to another field for reinjection a FEPA Licence is required (see Reinjection).
How to Apply (Also see Drilling Chemicals for Further Details): Chemical Permit Application for use (and discharge) of chemicals must be made using a Drilling Operations Application (see Drilling Chemicals).OPPC PermitIf discharge or reinjection of cuttings contaminated with reservoir hydrocarbons is likely, a permit will be required under the OPPC Regulations. Applications. Application for a permit under the OPPC Regulations must be made via the UK Oil Portal as a Subsidiary Application Template (SAT) under the appropriate Master Application Template (MAT) in the new PETS system.Guidance Notes on the new PETS system are available here (PDF document).FEPA LicenceSee Reinjection.
Who to Apply to: Chemical Permit PETS applications must be submitted electronically to BIS via the UK Oil Portal (see Drilling Chemicals).Oil Discharge PermitOil Discharge permit applications to BEIS (offshore.inspectorate@decc.gsi.gov.uk) are to be made via the UK Oil Portal (see Drilling Chemicals).FEPA LicenceSee Reinjection.
When to Apply: Chemical Permit and Oil Discharge Permit28 days before spud date.FEPA LicenceSee Reinjection (ca. 4-10 weeks).
Chemicals: See Drilling Chemicals.
Payzone Contamination: Requirements are in place for monitoring and reporting of oil contamination when drilling through pay-zone.
Chemical Permit: All chemical use/discharge must be monitored and recorded. See Drilling Chemicals.Components of mud systems must be listed individually with their appropriate use and discharge (see the Reporting Requirements tab).
Discharge of Reservoir Hydrocarbon Contaminated Cuttings: When drilling with WBM through the oil bearing reservoir, samples of cuttings must be taken for analyses from a minimum of 5 sample data points across the oil bearing reservoir so as to allow a representative and average oil content on cuttings figure to be calculated (see OPPC Sampling Summary Table – Well Operations). Each sample must be analysed to determine the crude oil content using the Retort method. The following data should also be recorded:

  • Start and end depth of reservoir section
  • Diameter of well section
  • Total quantity of cuttings and associated fluids reinjected (tonnes)
  • Total quantity of cuttings and associated fluids discharged (tonnes)
Cuttings Piles: OSPAR Recommendation 2006/5 on a management regime for cuttings piles (Word document) calls for a cuttings pile management regime involving the initial screening of all cuttings piles completed within 2 years of the recommendation coming into effect. Screening should be followed by a BAT or BEP assessment which should, where applicable, be carried out in the time frame determined during the screening process. Also see the Snippets tab.
Reinjection of Reservoir Hydrocarbon Contaminated Cuttings: Where cuttings contaminated with reservoir hydrocarbon are being reinjected, there are no monitoring or sampling requirements (see OPPC Sampling Summary Table – Well Operations).
Chemicals: See Drilling Chemicals.
Reporting Mud Components: Reporting of use and discharge must be undertaken on a component basis of the whole mud.Where a mud is recycled, BEIS has agreed that for reporting purposes, the assumption can be made that the recycled mud being used for a base is a mixture of the predominant base oil and barites and can be reported as such. Where additional additives are added to the recycled mud, these will need to be reported separately.
Reservoir Hydrocarbons: For overboard discharge of reservoir hydrocarbon contaminated cuttings, the following must be reported to BEIS:

  • Depth, length and diameter of well section through oil bearing reservoir.
  • The date and time on which oil on cuttings samples were taken.
  • The analyses results of oil on cuttings concentration of all samples taken.
  • The total quantity of cuttings discharged from the oil bearing reservoir (tonnes).
  • The total quantity of oil discharged on cuttings from the oil bearing reservoir (tonnes).
  • The average percentage figure of oil on oil bearing reservoir cuttings discharged.

Reports must be submitted to BEIS via the Inspectorate Data mailbox (inspectorate.data@decc.gsi.gov.uk) within one calendar month of the end of the well operation. A report must be submitted even where there is a zero contamination with reservoir hydrocarbons.

There are no reporting requirements if cuttings contaminated with reservoir hydrocarbon are reinjected.

Chemical Permits: See Drilling ChemicalsAny chemical spill (i.e. accidental event) must be reported by PON1 (see Chemical Spills).
Oil Discharge Permit: Non-compliance would include discharge or reinjection of reservoir contaminated hydrocarbons without a valid permit being in place. Any non-compliance must be reported using the Oil Discharge non-compliance notification form, which can be downloaded from here (Word document) along with appropriate Guidance Notes (PDF document).
Offshore Inspection: The Offshore Oil and Gas Environment Unit Enforcement Policy sets out the general principles that Inspectors shall follow in relation to enforcement including prosecution.
OPPC Permit: If a Term Permit has been issued under the new OPPC Regulations (i.e. for an activity-specific time limited discharge operation), this will only be valid for that operation and will expire after this time. A new application will be required for new planned discharge operations.
Chemicals: See Drilling Chemicals.
None at present.