Well Test - Extended

• Petroleum Licensing (Exploration and Production) (Seaward and Landward Areas) Regulations 2004
• Petroleum Licensing (Production) (Seaward Areas) Regulations 2008

The powers of the Secretary of State in relation to the development of and production from oil and gas fields were first set out in model clauses scheduled to the Petroleum and Submarine Pipelines Act 1975 (now superseded by the Petroleum Act 1998). Similar clauses are incorporated into every production licence. The Petroleum Licensing (Exploration and Production) (Seaward and Landward Areas) Regulations 2004 includes the full text of the four major sets of Model Clauses still in use. These Model Clauses regulate consents for extended well test production. Licences issued post 6 April 2008 will have Model Clauses as set out in the schedule to the 2008 Regulations.

• Offshore Petroleum Production and Pipelines (Assessment of Environmental Effects) Regulations 1999
• Offshore Production and Pipelines (Assessment of Environmental Effects) (Amendment) Regulations 2007

A formal EIA may be required if the oil and gas flared during the duration of the test is considered to be "significant" (see Performance Standards). The 2007 Amendment Regulations implement the requirements of the Public Participation Directive.

Any well test with a total flow duration of >96 hours or which produces a total of more than 2,000 tonnes of oil is classed by DECC as an Extended Well Test. This requires Consent for Test Production.

Consent for Test Production must be obtained in accordance with the requirement of the Model Clauses of the relevant Petroleum Production Licence (as consolidated by the Petroleum Act 1998).

There may be a requirement for an Environmental Impact Assessment (EIA) under the Offshore Petroleum Production and Pipelines (Assessment of Environmental Effects) Regulations 1999 (see Performance Standards).

Any chemical use proposed will require a Chemical Permit under the Offshore Chemicals Regulations 2002 (see Drilling Chemicals or Production Chemicals).

Operators will need to assess the risks to the environment, which might arise from their particular chemicals use and discharge. For some chemicals e.g. those on the OSPAR PLONOR list, assessment will be straightforward. Others will require a formal process of risk assessment, such as can be done using CHARM software. In this process, the predicted environmental concentration (PEC), determined from a knowledge of individual substance or product chemistry and the conditions of use, is compared with the Predicted No-effect Concentration (PNEC) determined from toxicity tests conducted to agreed protocols. This allows more informed assessments of risk to local sensitivities to be made in particular use and/or discharge scenarios. The use of the CHARM model is compulsory for calculating the Hazard Quotient (HQ) but other risk assessment models may be used to calculate the Risk Quotient (RQ) provided comparability with CHARM can be demonstrated.

Note: A permit/exemption is no longer required for potential oil fall-out from flaring under the OPPC Regulations. However, any oil fall-out must still be reported as an oil spill via the PON1 (see Oil Spill Reporting).

Application for Consent for Test Production by letter to DECC.

Application for a Consent for Test Production can also be made through the PON15 application process for some operations (see Drilling Chemicals and Workover and Production Chemicals as appropriate).

Letter should set out the timetable and objectives of the test and quantities of oil and gas to produced, saved or flared.

DECC Oil and Gas Office Contacts for Extended Well Test Consents are as follows:

Northern and Central North Sea

Southern North Sea and Onshore

Southern North Sea and Onshore

Ivor Newman
Tel: 020 7215 5163

Email: ivor.newman@decc.gsi.gov.uk

If applying by PON15 these 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 the DECC OED Environmental Management Team at ukop@decc.gsi.gov.uk

Any problems with PON15 submission contact the DECC OED EMT by email at emt@decc.gsi.gov.uk

The primary objective of an Extended Well Test is to obtain essential field information and DECC recognises that this may necessitate the flaring of substantial quantities of gas and possibly oil. The test should be designed so that oil and gas flaring is kept to the minimum that is technically and economically justified.

• Give careful consideration to the need for well test flaring.
• Use efficient burners if flaring required.
• Monitor discharge at all times.
• Operation to cease if any visible oil seen on sea surface.

There are no strict criteria governing the maximum volume to be produced or the duration of an Extended Well Test and the duration may be extended if there is a technical justification. However, it should be noted that Extended Well Tests are not an alternative to production under an approved Field Development Programme.

• Continuously monitor the production rates, water cut, downhole pressures and GOR histories.
• Cessatuib if operations if oil seen on the sea surface.

There are two types of reporting required for flaring. The first is statutory reporting to DECC (which for the purposes of this procedure details the requirements of the Consent for Test Production i.e. reporting flare volumes and associated details). The second is EEMS reporting of environmental emissions due to flaring.

Extended Well Test Consent: Reporting to DECC every Monday during the period of the consent, the Operator shall fax the following information relating to the previous week:

• Short technical summary of performance of gas handling plant, highlighting any features which have affected or could affect the operation of the plant.
• Daily rates in respect to oil production, gas production, gas export, gas used for fuel and gas flared.
• Cumulative average production for production and flare.
• Weekly calculations of gas compression plant efficiency.

Some consents may include the provision that specific monthly flare reporting is not needed and that flare volumes are reported in the routine field reporting into DECC Petroleum Production Reporting system. In this case, specific flare reporting would be by exception only if flaring is out of consent.

Upon completion of the test, the operator must inform the Department of the results of the test and of their intentions for the future production status of the well.

EEMS Reporting: complete relevant parts of applicable atmospheric emissions inventory EEMS pro forma, that can be found at the EEMS website.

Extended Well Test Consent: DECC's Petroleum Production Reporting according to terms of consent.

EEMS Reporting: Completed forms should be submitted electronically to the EEMS website where they can also be viewed, amended and updated.

Extended Well Test Consent: Schedule of reporting will be established through consent. It varies widely according to stage of field production and between fields and operators.

EEMS Reporting: annually before 1st March if on production installation or 28 days following completion of well test on MODUs.

A permit is no longer required for potential flare drop-out. However, if flare drop out does occur, a PON1 report must be submitted.

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