OBM and SBM 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:

Supporting Legislation:
Guidance Notes:
Consent Needed: Chemical PermitPermit required for use and discharge of chemicals under the Offshore Chemical Regulations 2002. See Drilling Chemicals.Oil Discharge PermitDischarge or re-injection 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 Licence

If exporting to another field for re-injection a FEPA Licence is required (see Re-injection).

How to Apply for It (Also see Drilling Chemicals for further details): Chemical PermitApplications for use (and discharge) of chemicals must be made using a drilling operation application even where there will be no overboard discharge. Applications for permits should cover not just chemicals expected to be used but also those that may need to be used on a contingency basis (see the Non Compliance tab). If using offshore cuttings treatment technology (e.g. Rotomill), estimates of the total quantity of OBM/OPF being discharged on cuttings and in discharge water streams needs to be included in the Chemical SAT of the drilling operation application. Equivalent discharge should also be shown in the appropriate chemical tables. Note that contamination of cuttings is not allowed to exceed 1% by dry weight.Oil Discharge PermitIf discharge or re-injection of cuttings contaminated with reservoir hydrocarbons is likely, an oil discharge permit will be required under the OPPC Regulations. This permit can be applied for as a Subsidiary Application Template (SAT) on the UK Oil Portal.Guidance Notes on the OPPC Regulations and Permit Application are available for download from the BEIS website (PDF document).

FEPA Licence

See Reinjection.

Who to Apply to: Chemical PermitDrilling operation applications must be submitted electronically to BEIS via the UK Oil Portal (UKOP). Operators will need to be registered with BEIS for access to the Portal. To obtain access to the UKOP contact UKOP@decc.gsi.gov.ukOil Discharge PermitOil Discharge Permit applications are made on a Subsidiary Application Template (SAT) in the UKOP Portal Environmental Tracking (PETS) system. The SAT application is initiated from the relevant Master Application Template (MAT).FEPA Licence

See Reinjection.

When to Apply: Chemical Permit and Oil Discharge Permit – 28 days before spud date.FEPA Licence – see Reinjection (around 4 to 10 weeks).
Discharge of OPF/OBM or Base Oil at Well Start-Up: Any discharges of OBM/OPF or base oil that may occur at well start-up should be included in the drilling operation application (or well intervention operation application) , including estimates of volumes and tonnage of expected discharge. Actual discharge should be reported via a Condition 5 Return Form (see the Reporting Requirements tab).
OBM Components: The components of OBM mud systems must be listed individually on the drilling operation application.
Limits Placed on Use and Discharge of OBM and Cuttings:

Only the permitted mud systems are to be used.

OBM and SBM chemicals are “Z” rated chemicals under the OCNS scheme and therefore overboard discharge is prohibited. However, discharge of treated cuttings with <1% of OPF/OBM contamination by dry weight is allowed.

OBM/SBM use also requires a Chemical Permit (even though no overboard discharge) and there will be limits placed on use and discharge of chemicals. If variation in chemicals (drilling mud) used or permitted volume of usage is exceeded, a variation under the drilling operation permit must be applied for. Chemicals must be selected based on their environmental risk.

See Drilling Chemicals for further details.

Consider the implications of well cleanup and the need to minimise the possibility of OBM/SBM contaminated fluid being discharged (see Well Clean-up)

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.

Backloading of Oily Slops: Operations giving rise to ‘oil contaminated fluids’ include well clean-up, cementing, mud pit cleaning and operations where well bore fluids become contaminated with oil based mud, crude oil or condensate. In addition, fluids from rig floor drains and other tank cleaning operations could also be included. Backloading of slops must meet the requirements of MCA and HSE GuidanceNotes:Marine Guidance Note (MGN 283(M)) (PDF document) Dangerous Goods – Guidance on the Back Loading of Contaminated Bulk Liquids from Offshore Installations to Offshore Supply/Support Vessels.HSE Safety Notice Bulletin Number OSD 3-2010
UK National Plan for the phase-out of substances identified as candidates for substitution – in line with OSPAR Recommendation 2006/3:(The full text of the current UK National Plan for phase out can be found on the CEFAS website) OSPAR Recommendation 2006/3 requires that as soon as is practicable and not later than 1 January 2017, Contracting Parties to OSPAR should have phased out the discharge of offshore chemicals that are, or which contain substances, identified as candidates for substitution except for those chemicals where despite considerable efforts, it can be demonstrated that this is not feasible due to technical or safety reasons. Demonstration of those reasons should include a description of those efforts.Having considered the requirements of OSPAR Recommendation 2006/3, the UK has decided to base its National Plan for the prioritisation of phase-out on the following criteria:

  • Perceived difficulty of phase out
  • Securing the replacement of candidates for substitution in preference to eliminating operational discharges to the marine environment
  • Prioritisation based on the persistence, bioaccumlation and toxicological properties of the chemical

The UK National Plan also incorporates justification of continued use and/or discharge as an additional element: for those substances where replacement and/or eliminating discharges to the marine environment is not currently feasible, offshore operators or their chemical suppliers will annually be required to:

  • Confirm the efforts made to phase out the use and/or discharge of the candidates for substitution
  • Confirm the nature and timing of planned research and development studies or trials to supplement those efforts conform whether any measures have been taken to reduce the use and/or discharge of the candidate for substitution
  • Confirm the technical and/or safety issues that make it necessary to continue use and/or discharge of the candidate for substitution

UK National Plan level criteria and interim target dates are (See the full text of the UK National Plan (PDF document) on the CEFAS website for definitions of persistence, bioaccumulating and toxicity):

  • Level 1 (highest priority)
    • Organic substances that are highly persistent, bioaccumulating and toxic
    • Chemicals to be replaced; or discharges to the marine environment to be eliminated or continued use and/or discharge to be formally justified by end December 2010.
  • Level 2
    • Moderately persistent, bioaccumulating and toxic, or
    • Highly persistent and bioaccumulating, or
    • Highly persistent and toxic chemicals
    • To be replaced, or discharges to the marine environment eliminated, or continued use and/or discharge to be formally justified by end December 2012.
  • Level 3
    • Moderately persistent and bioaccumulating, or
    • Moderately persistent and toxic, or
    • Bioaccumulating and toxic chemicals
    • To be replaced, or discharges to the marine environment eliminated and/or discharge formally justified by end December 2014.
  • Level 4 (lowest priority)
    • Highly persistent organic substances, or
    • Inorganic substances with toxicity <1mg/l
    • Chemicals to be replaced, or discharges to the marine environment eliminated, or continued use and/or discharge to be formally justified by end December 2016.
Chemicals: All chemical use/discharge must be monitored and recorded. Components of oil based mud systems must be listed individually with their appropriate use and discharge (see the Reporting Requirements tab).
Re-injection of OBM/SBM Cuttings: Where OBM/SBM cuttings contaminated with reservoir hydrocarbon are being reinjected, there are no monitoring or sampling requirements.
Offshore Treatment: Where offshore treatment technology is being used (e.g. Rotomill), additional sampling requirements are made:

  • Powder samples must be taken every 2 hours and samples divided with one portion retained for further analysis if required.
  • Samples taken during each 12 hour period should be combined and an oil analysis performed.
  • A sample of recovered water must be taken before discharge and analysed for oil content.

Oil analysis of both powder and water streams must be performed using DECC approved methods (TTCE solvent extraction method as amended) (see Drilling Chemicals for further details).

What to Report:

Chemical Use and Discharge

Reports should be made on all drilling and well chemicals as required by BEIS using the EEMS drilling fluids spreadsheet available from the EEMS website.

As well as being used by BEIS to check actual use and discharge of chemicals against the term permit, they will also be used towards compilation of the OSPAR returns, which Contracting Parties are obliged to make.

For certain problematic substances, such as those identified for substitution, the Department may require more frequent reporting. A condition in the permit will make this clear if necessary.

Analysis reports of any offshore treatment effluent streams (powder and water) must also be submitted at the end of well.

Annual Progress Reports on Substitution Chemicals

Previously progress reports on substitution chemicals have only been requested for production chemicals (production operation permits). This reporting requirement is now extended to term permits. A reporting template can be downloaded here (Excel document). Reporting includes summary of chemicals replaced, summary of chemicals still to be replaced and justification for continued use and/or discharge.

OPF/Base Oil Discharges

Discharges of OPF and base oils (e.g. at well start-up) must be reported via the Condition 5 Return Form (Word document). This form must be submitted via the EEMS website.

Who to Report to: Chemical Use and DischargeReports need to be made electronically on the EEMS website after each well. BEIS will use EEMS reports to cross check against permit conditions to ensure compliance.

Annual Progress Reports on Substitution Chemicals

Reports need to be submitted to BEIS Environmental Management Team by email.

OPF/Base Oil Discharges

Condition 5 Return Forms to be submitted to DECC via EEMS on the UK Oil Portal.

When to Report: Chemical Use and DischargeEEMS reports to be submitted 28 days after permit expiry date.Annual Progress ReportsAnnual progress reports are required to be submitted on or before 28 February of each calendar year.OPF/Base Oil Discharges

To be submitted to BEIS within 28 days of discharge.

What to do if in Breach of Consent/ Authorisation: Overboard discharge of OBM/SBM as “Z” ranked chemicals is prohibited, therefore any discharge would be in breach of the Chemical Permit. DECC Permit Condition noncompliance Notification Form (Word document) is to be used for reporting any identified non-compliances against Chemical Permit Conditions issued under the provisions of the Offshore Chemical Regulations 2002. Change in chemical type or increase in volume of use or discharge not provided for in the permit, requires application for a variation to BEIS (done through drilling operation permit variation). BEIS recognises that in rare circumstances, unforeseen use of chemicals may be required at very short notice. Provision is made for oral approval for use from BEIS (in consultation with MS/CEFAS) (application must still demonstrate that a consideration of environmental impact has been made) followed by a written application via the drilling operation permit for record keeping. To avoid such situations, permit application should consider contingency chemicals.
Spills: Any accidental spills of OBM/SBM mud, other drilling chemicals or contaminated cuttings must be reported by PON1 (see Chemical Spills).
Offshore Inspection: The DECC Environmental Inspectorate Enforcement Policy sets out the general principles that Inspectors shall follow in relation to enforcement, including prosecution. BEIS, if of the opinion that the OCR 2002 Regulations have been contravened, may issue an enforcement notice. This will specify the matters that constitute or are likely to constitute a contravention, steps required to rectify the matter and the time period within which these steps must be undertaken. If an enforcement notice is not addressed, BEIS may take action itself and recover reasonable costs back from the operator. If BEIS is of the opinion that the operation of an offshore installation involves an imminent risk of serious pollution as a consequence of any discharge of chemical, BEIS may serve a prohibition notice. This will specify the pollution risk, the steps required to remove it and the time period, and BEIS may withdraw a permit wholly or in part until the prohibition notice is withdrawn.
Permit Duration: Permits for drilling chemicals will normally be issued for a specified period and are “Term Permits”.
Renewal: Not applicable as permits are issued for a specified period. BEIS must be notified of any drilling schedule changes.
Emergency Variation: Permit holders applying for an emergency variation should telephone the EIS out of hours contact. These details will be passed to the BEIS on-call Environmental Inspector who will contact the permit holder to further discuss the emergency variation request. Following a review of the chemical permitting procedures, BEIS now requires that all emergency chemical variation requests are made in writing following the initial contact telephone call. The BEIS on-call Environmental Inspector will email a data request by email, with completed questions returned by email. Following a review of the request a written response granting or approving the variation will be sent by return of email.The applicant must subsequently formally vary the permit within 2 working days of the emergency contact.
Update, Variation or New Permit: Applications need to be made to BEIS for a variation in the terms and conditions of a permit if there is any increase in the use and discharge of chemicals or changes in the chemicals used. All applications need to be considered by BEIS and FRS (CEFAS in England and Wales).Update – change to permit made after the application but before approval has been given.Variation – change to permit made after approval has been given.Application for a variation or update should be made by clearly amending the previously submitted drilling operation permit. All drilling operation application submissions must be linked to the relevant WONS well file for the drilling consent application (PON4). Where a drilling programme is amended, the need to submit either a permit variation or new permit will depend on whether the change to work programme would be classed as a re-drill (i.e. if a new WONS well file would be generated). If a new WONS well file is needed, a new drilling operation application will be required. Otherwise, a variation of the existing drilling operation permit can be submitted.If submitting a variation, all sections should be completed describing any changes in drilling and chemical usage relating to the new works. If any changes are required, for example to take account of a process modification or to add additional activities/discharge streams, permit holders must apply for an oil discharge permit variation. This must be prepared by amending the original application with any changes clearly highlighted. Variations will be dealt with by BEIS as quickly as possible, but 28 days should be allowed for the assessment of any significant changes.Note – a variation or update cannot be submitted once a Term Permit has expired, and a new application must be submitted.
Drilling Outside Expected Spud Date: Changes in spud datesBEIS do not want to be prescriptive and are happy to see a drilling window based on risk. Normally BEIS will limit the expected drilling window plus one month either side of that window – anything beyond this will need to be justified. Where BEIS asks for a spud date, i.e. in the MAT of the drilling operation application, this should be given and the narrative section used to explain where and why there is built in flexibility. For example if the expected spud date is the 15th March and a total drilling period of 60 days then the 15th of March should still be quoted in the MAT but environmental sensitivities and possible impacts should cover the period from February to June.If drilling occurs within this window, the only notification to BEIS will be the new spud date that should be advised through WONS. If drilling is due to start before, or continue after, the window notified in the permit, the sensitivities addressed in the application must be examined to assess whether there is any significant adverse change. The conclusion should be advised to BEIS’s Environmental Manager who handled the original permit by e-mail, in addition to advising WONS. It should be noted that extra time must be allowed as BEIS may need to go back to JNCC in cases where drilling will occur outside the original window.
Field Trials for New Chemicals: It is likely that field trials involving the use and discharge of new chemicals can be encompassed through a request for a variation to an existing permit since a field trial will have been planned in advance. If there is any doubt about how this should be handled, then the operator and the chemical company are strongly advised to discuss the proposed field trial with BEIS and FRS or CEFAS (as appropriate) first.
BEIS (then DECC) Environmental Alert (001/2014) – PON1 Reporting: Issued by BEIS (then DECC) on 31 March 2014, this environmental alert (PDF file) highlights failures by a number of operators to comply with PON1 reporting requirements. Operators are reminded that in accordance with current reporting requirements, PON1s must be reported within 6 hours to:

  • Aberdeen Maritime Rescue Coordination Centre (MRCC) in addition to immediate telephone notification to the nearest MRCC Coastguard Station.
  • Department of Business, Environment and Industrial Strategy (BEIS); additional telephone notification is required to the Department for specific scenarios as detailed within the PON1 reporting guidance.
  • Joint Nature Conservation Committee (JNCC) and any relevant Statutory Nature Conservation Body (SNCB) in accordance with installation oil pollution emergency plan arrangements.
Deep Water Horizon In addition, as part of ongoing reviews of oil spill contingency arrangements in light of the Macondo well incident, drilling operation applications for exploration, appraisal or development wells must:

  • Confirm that the operation is covered by an approved OPEP or OPEP application
  • Include a section dealing with accidental events, summarising the worst-case scenarios assessed and modelled in the OPEP and the measures in place to prevent and control the release
  • Include or reference any relevant environmental impact assessment studies.
  • Additional changes may be required in the future, when BEIS has reviewed outstanding reports relating to the Macondo incident.
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.