WBM Use and Discharge

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

A Permit is required under the Offshore Chemical Regulations 2002 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.

The amendment regulations came into force on 30 March 2011 and clarify the status of accidental releases and the reporting procedure for PON1s.

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

These Regulations introduced a permitting system for oil discharges to replace the requirement for an exemption under POPA. Any contamination of cuttings by hydrocarbons from the reservoir will require a permit if being discharged overboard or reinjected (see Consents).

• Food and Environment Protection Act 1985 (FEPA)
• Deposits in the Sea (Exemptions) Order 1985

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 reinjection will require a licence under FEPA (see Reinjection).

• 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.

Chemical Permit

A permit to use and discharge chemicals is required under the Offshore Chemical Regulations 2002 (see Drilling Chemicals)

OPPC Permit

Discharge 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 Licence

If exporting to another field for reinjection a FEPA Licence is required (see Reinjection).

Chemical Permit

Application for use (and discharge) of chemicals must be made using a PON15B (see Drilling Chemicals)

OPPC Permit

If discharge or reinjection 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 Reinjection.

Chemical Permit

PON15s must be submitted electronically to DECC via the UK Oil Portal (see Drilling Chemicals).

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)

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 Reporting).

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); and
• Total quantity of cuttings and associated fluids discharged (tonnes).

see Drilling Chemicals

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.

For overboard discharge of reservoir hydrocarbon contaminated cuttings, the following must be reported to DECC:

• 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 DECC via the Inspectorate Data mailbox 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.

see Drilling Chemicals

Any chemical spill (i.e. accidental event) must be reported by PON1 (see Chemical Spills).

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 OPPC non-compliance notification form, which can be downloaded from DECC website along with appropriate Guidance Notes.