OBM and SBM Use and Discharge

• Offshore Chemical Regulations 2002
• Offshore Chemicals (Amendment) Regulations 2011 (pdf file)

Permit required to use and discharge chemicals, including drilling muds.

Amendments to the Offshore Chemicals Regulations 2002, made under Schedule 2 of the Offshore Petroleum Activities (Oil Pollution Prevention and Control) Regulations 2005 (OPPC) increase the powers of DECC inspectors to investigate non-compliances and risk of significant pollution from chemical discharges, including the issue of prohibition or enforcement notices.

• Offshore Petroleum Activities (Oil Pollution Prevention and Control) Regulations 2005
• Offshore Petroleum Activities (Oil Pollution Prevention and Control) (Amendment) Regulations 2011

These Regulations do not require a permit for discharge of OBM/OPF and SBMs as these are permitted under the Offshore Chemical Regulations 2002. However any contamination of cuttings by hydrocarbons from the reservoir will require a permit if being discharged overboard or re-injected (see Consents).

• Food and Environment Protection Act 1985 (FEPA)

A licence is required under FEPA for any waste disposal in the sea or under the seabed. However, the Deposits in the Sea (Exemptions) Order 1985 exempts from FEPA licensing the deposit on site or under the seabed of any chemicals and drill cuttings.

However, export of cuttings to another field for re-injection will require a licence under FEPA (see Re-injection).

• Convention on the Protection of the Marine Environment of the North East Atlantic 1992 (OSPAR Convention)
• OSPAR Decision 2000/3 on the Use of Organic-phase Drilling Fluids (OPF) and the Discharge of OPF-Contaminated Cuttings

The OSPAR Convention (in particular Annex III) is the main driver for reductions in oily discharges to the North Sea. The UK as a contracting party to the Convention is therefore obliged to implement any Decisions and Recommendations made by the Commissions. Certain decisions made under the earlier Paris Convention also still stand.

OSPAR Decision 2000/3 that came into effect on 16 January 2001 effectively eliminates the discharge of organic phase fluids (OPF) (oil based (OBM) or synthetic based (SBM) drilling fluids) or cuttings contaminated with these fluids. Use of OPF is still allowed provided total containment is operated. The use of diesel-oil-based drilling fluids is prohibited. The discharge of whole OPF to the sea is prohibited. The mixing of OPF with cuttings for the purpose of disposal is not acceptable. The discharge of cuttings contaminated with oil based fluids (OBF) (includes OBM and SBM) greater than 1% by weight on dry cuttings is prohibited. The use of OPF in the upper part of the well is prohibited. Exemptions may be granted by the national competent authority for geological or safety reasons.

The discharge into the sea of cuttings contaminated with synthetic fluids will only be authorised in exceptional circumstances. Authorisations to be based on the application of BAT/BEP. Best Available Techniques described within the Decision include recycling, recovery and reuse of muds.

• OSPAR Recommendation 2006/5 on a Management Regime for Offshore Cuttings Piles.

This recommendation sets out measures to reduce pollution from oil or other chemicals from cuttings piles.

The first stage of the Recommendation is to be carried out within two years of the Recommendation coming into effect with the second stage completed in a pre-determined timeframe laid out in Stage 1.

Also see Drilling Chemicals for legislation on chemical use and discharge associated with drilling muds.

• DECC Guidance on the OPPC Regulations (March 2011) .
• DECC Guidance Notes on the Offshore Chemicals Regulations (March 2011)

Note: revisions to these new guidance notes are not yet incorporated in this website, and will be included at the next quarterly review.

Chemical Permit

Permit required for use and discharge of chemicals under the Offshore Chemical Regulations 2002. See Drilling Chemicals.

OPPC Permit

Discharge 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).

Chemical Permit

Application for use (and discharge) of chemicals must be made using a PON15B 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 Non-Compliance).

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 Section C of the PON15. Equivalent discharge should also be shown in the appropriate chemical tables (Section G). Note that contamination of cuttings is not allowed to exceed 1% by dry weight.

OPPC Permit

If discharge or re-injection of cuttings contaminated with reservoir hydrocarbons is likely a permit will be required under the OPPC Regulations. Applications for a permit under the OPPC Regulations must be made by application form, which is available for download from DECC website.

Guidance Notes on the OPPC Regulations and Permit Application are available for download from DECC website.

FEPA Licence

see Re-injection.

Chemical Permit

PON15s must be submitted electronically to DECC via the UK Oil Portal. Operators will need to be registered with DECC for access to the Portal. To set up a UK Oil Portal Account, contact:

Elaine McLaughlin (PON 15B,C, E, F Administrator)
ElaineMcLaughlin@decc.gsi.gov.uk - 01224 254102

OPPC Permit

OPPC permit applications to DECC Offshore Inspectorate team by email.

FEPA Licence

see Re-injection.

Chemical Permit and OPPC Permit - 28 days before spud date.

FEPA Licence - see Re-injection (ca. 4-10 weeks)

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 PON15B must be applied for. Chemicals must be selected based on their environmental risk.

Also, 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 Cleanup)

OSPAR Recommendation 2006/5 on a management regime for cuttings piles 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 timeframe determined during the screening process. Also see Snippets.

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 Guidance Notes:

Good Practice for the Carriage of Oil Contaminated Cargoes for Transportation by Offshore Supply Vessel (PDF)

Marine Guidance Note (MGN 283(M)) 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 Recomendation 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 discahrge of the candidate for substitution; and
• 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 file) 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 eliinated, 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 repelaced, 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.

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 Reporting).

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).

Chemical Use and Discharge

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

As well as being used by DECC 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 (PON15D). This reporting requirement is now extended to term permits. A reporting template can be downloaded from the DECC website. 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

Chemical Use and Discharge

Reports need to be made electronically on the EEMS website after each well. 

DECC 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 DECC Environmental Management Team by email.

OPF/Base Oil Discharges

Condition 5 Return Forms to be submitted to DECC EDU-LED by email to emt@decc.gsi.gov.uk

Chemical Use and Discharge - EEMS reports to be submitted 28 days after permit expiry date.

Annual Progress Reports - Annual progress reports are required to be submitted on or before the 28 February of each calendar year.

OPF/Base Oil Discharges - submitted to DECC within 28 days of discharge.

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 non-compliance Notification Form 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 DECC (done through revised PON15B). DECC 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 DECC (in consultation with FRS/CEFAS) (application must still demonstrate that a consideration of environmental impact has been made) followed by a written application via the PON15B for record keeping. To avoid such situations, permit application should consider contingency chemicals.

The DECC Environmental Inspectorate Enforcement Policy sets out the general principles that Inspectors shall follow in relation to enforcement including prosecution.

DECC, 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, DECC may take action itself and recover reasonable costs back from the operator.

If DECC 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, DECC may serve a prohibition notice. This will specify the pollution risk, the steps required to remove it and the time period, and may withdraw a permit wholly or in part until the prohibition notice is withdrawn.

Permit holders applying for an emergency variation should telephone the DECC out of hours contact. These details will be passed to the DECC 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, DECC now require that all emergency chemical variation requests are made in writing following the initial contact telephone call. The DECC 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 PON15 permit within 2 working days of the emergency contact.

Applications need to be made to DECC 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 DECC and FRS (CEFAS in England and Wales).

Update - change to PON15 made after the application but before approval has been given.

Variation - change to PON15 made after approval has been given.

Application for a variation or update should be made by clearly amending the previously submitted PON15B.

All PON15B 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 PON15B will be required. Otherwise, a variation of the existing PON15B 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 DECC 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.

Changes in spud dates - DECC don't want to be prescriptive and are happy to see a drilling window based on risk. Normally DECC will limit the expected drilling window plus one month either side of that window - anything beyond this will need to be justified. Where DECC asks for spud date i.e. Section D of the PON 15 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 section D but environmental sensitivities and possible impacts should cover the period February to June.

If drilling occurs within this window, the only notification to DECC 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 PON15, the sensitivities addressed in the application must be examined to assess whether there is any significant adverse change. The conclusion should be advised to DECC's Environmental Manager who handled the original PON15 by e-mail, in addition to advising WONS. It should be noted that extra time must be allowed as DECC may need to go back to JNCC in cases where drilling will occur outside the original window.

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 DECC and FRS or CEFAS (as appropriate) first.

Reporting of use and discharge must be undertaken on a component basis of the whole mud.

Where a mud is recycled, DECC 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.