1.0        PURPOSE

The requirement is to have a unique well identifier, recognised by DECC and understood by all CDA members, and also to allow for wells to be identified differently by individual companies.

2.0        SPECIFIC REQUIREMENTS

2.1 To be able to identify wells uniquely prior to spud by target reference and/or slot number
2.2 To maintain aliases
2.3 To recognise components of the DECC well number
2.4 To be able to sort wells efficiently

3.0        DECC WELL NAMES

3.1 A company wishing to drill a new well must apply to DECC for consent. This is now done online for all offshore wells through the DECC WONS system. The first application contains the company well name alias and provisional details of the proposed well. When the well is spudded the operating company submits details of the spud date and actual location of the well.

3.2 DECC then creates an official well name and advises the operating company.

3.3 On completion the operating company updates WONS with the completion date and other well attributes associated with the completed well.

3.4 The only official well number is the DECC well registration number. This is generated in accordance with the guidelines in the DECC notice PON12 and is supplied by the DECC once notification of spud has been received. DECC will decide whether any sidetrack, applied for or notified, is allocated a new number or suffix on the basis of information supplied by the operating company.  Any disputes or problems on these will be handled by DECC. Companies may additionally carry their own well identifier, but when reporting or providing data to the DECC, the main well identifier must be the one generated by DECC. Company chosen aliases may be used in addition to the DECC number for convenient cross-reference, but never on their own. If companies have wells not recognised by DECC then these can only be labelled with a DECC-like number in the official field if it is clearly differentiated as an identifier and not an officially recognised DECC well number. Such numbers will first be created in DEAL and may then be used by CDA for storage of data from wells not officially recognised by DECC.

4.0        DEAL WELL HEADERS AND WELL ATTRIBUTES: PARENT WELL AND WELL BORE

4.1 DEAL (http://www.ukdeal.co.uk/) became the prime site for well header information in Q2 2003.

4.2 To comply with the POSC Well Header model (on which WONS is based) well data passed from WONS will be held on the DEAL database as Parent Well and Well Bore each with their associated attributes.

4.3 The chief attribute of the Parent Well is the seabed location. Since any change in seabed location generates a new DECC well there will be no two Parent Wells with the same seabed location. It follows that re-spudding of a well results in a new Parent Well whereas a sidetrack will result in a new Well Bore.

4.4 A Parent Well may have one or many Well Bores. Most of the well header attributes, including spud and completion date, are associated with the Well Bore. Where a company has used the mechanical sidetrack suffix or the re-entry suffix this will be a Well Bore name. A company might also wish to define other Well Bores not recognised by DECC but discriminated by the attributes associated with the Well Bore.

Example:

Parent Well	211 / 11a- 1	Well Bore	211 / 11a- 1
		Well Bore	211 / 11a- 1Z
		Well Bore	211 / 11a- 1ZR01

4.5 Where a company wishes to use their own well bore name which nevertheless corresponds to a DEAL well bore then this name will be populated in the Well Bore alias field.

Example:

Parent Well	211 / 11a- 1
Well Bore	211 / 11a- 1Z	Owner	DEAL	Alias	211 / 11a- 1ST1	Owner	FDS

There may be many aliases for the same well bore. Each alias will also have an owner of the well bore alias name.

4.6 When an exploration or appraisal well becomes a production well a new Well Bore will be created for the production well. DECC will be recognised as the owner of both the exploration/appraisal and production Well Bore names. The latest status of the exploration/production well will become ‘Production’. The synonym names will also be shown as aliases to cross-reference the two wells.

Example:

Parent Well	16/07a- 27
Well Bore	16/07a- 27	Owner	DECC	Alias	16/07a-C1	Owner	DECC
Well Bore	16/07a-C1	Owner	DECC	Alias	16/07a- 27	Owner	DECC

       
5.0        EXISTING DECC WELL NAMING STANDARD (PON 12)

5.1 DECC recognise each new seabed location as a new well.

5.2 The DECC well number comprises seven components (a) – (g) which uniquely define a well.

5.3 Country Quad / Block Part Block - Platform Well Suffix

(a) (b) / (c) (d) - (e) (f) (g)
e.g. 211 / 30b- A21Z first sidetrack of well 21 on platform A in Part-block 211/30b

5.4 The current DECC standard allows for a single character well name suffix to describe the well status.

211 / 11a- 1 first well drilled in retained part block 211/11a of quad 211 block 11
211 / 11a- 1A re-spudded well (a new parent well)
211 / 11a- 1Z sidetracked well

5.5 Defined suffix letters:

A, B, C, etc.– DECC Pon12 re-spud wells 
Z, Y, X, etc. – DECC Pon12 sidetrack wells 

6.0        DEAL AMENDMENTS TO DECC WELL NAMING CONVENTION

6.1 SIDETRACKS NOT RECOGNISED BY DECC

For sidetracks not recognised by DECC, but recognised by the Operator or Data Release Agent as separate Well Bores for which there may be data, it is recommended that suffixes J, K, L .... are used.  Where applied the well name would be a Well Bore associated with the official DECC parent well.

6.2 RE-ENTRY WELLS

Re-entry wells are considered by the PON 12 definition of a well to be the same surface location and therefore to be the same well number as the original. This causes difficulties for companies who wish to distinguish re-entries as separate events and thus be able to associate the well attributes and products with a distinct name.

Re-entry wells recognised by DEAL are distinguished by the addition of the suffix Rxx where xx is a number. Values less than 10 will be written as 0x to retain the full three characters. Where applied the well name would be a Well Bore associated with the official DECC parent well.

Examples: 
211 / 11a- 1 First well in retained part block 211 / 11a in quad 211 block 11
211 / 11a- 1A Respudded well
211 / 11a- 1AR01 First re-entry to respudded well
211 / 11a- 1AR02 Second re-entry to respudded well
211 / 11a- 2 Second well in retained part-block 211 / 11a
211 / 11a- 2Z First sidetrack
211 / 11a- 2ZR01 First re-entry to first sidetrack

6.3 PILOT WELLS

For pilot wells not recognised by DECC, e.g. those drilled as a part of a site survey, it is recommended that these are stored as unspudded wells with a target reference of EB (Exploratory Borehole). If two Exploratory Boreholes are drilled in the same block the second would have target reference EB2. It follows from this that EB is only an acceptable target reference for Exploratory Boreholes. If the Exploratory Borehole is later used for a purpose that makes it a well recognised by DECC it will be numbered in the normal way.

6.4 DECC PON12 can be accessed from the DECC web site.

6.5 The latest set of DECC approved well numbers can now be accessed from DEAL.

 
APPENDIX A: ADDITIONAL WELL BORES

1.0 PROCEDURES FOR ADDING WELL BORES TO DEAL

1.1 The set of Parent Well and Well Bore names currently on DEAL is derived from the CDA and DECC merged databases. Further Parent Wells and Well Bores have been added to enable data owners and Data Release Agents to match their Well Bore names to a DEAL Well Bore. The Parent Well and Well Bore names all comply with the CDA well naming standard CS2.

1.2 The Parent Well list should always agree with the DECC well names, since there must be a new DECC well name for every new seabed location. However the Well Bores recognised by Operators and the Data Release Agents may differ from those recognised by DECC. Any re-entry well will fall into this category but there are also sidetracks which are not recognised by DECC.

1.3 To be able to accurately match the Well Bore attributes to the true Well Bore additional Well Bores have to be created in DEAL. The source of information on these additional well bores will come from:

a. CDA DataStore, where data has been received for Well Bores which are not recognised by DECC and therefore cannot be loaded unless a new well bore is created.
b. Scout Group database for E&A wells
c. Data Release Agent (DRA) Well Bore listings
d. Data Owners

1.4 Before creating any new Well Bore for new well data  DEAL will confirm with DECC whether there is a reason why the Well Bore does not have official recognition. For legacy data the additional Well Bores will be adopted from the DRA lists to enable accurate data matching.

1.5 If a Well Bore is created in DEAL but the well is subsequently adopted as official by DECC then the DECC Well Bore name will become the official Well Bore name and the BGS created name will become an alias.   

1.6 Where DECC have recognised a re-spud Well Bore but have not created the original Well Bore this will be created with a standard name and with DEAL as the data owner. For example, if QQ/BB- 1A is an official DECC Well Bore then QQ/BB- 1 can be created without reference to DECC for confirmation. In this case a new DEAL Parent Well would be created as well as the Well Bore, since the re-spud has a different location than the original well. DEAL would be the owner of the Parent Well name.

1.7 When advice is received by DEAL that an additional Well Bore is required, the name of the Well Bore will be kept as an alias and a new Well Bore name will be created according to CS2 standards. Where the Well Bore is a sidetrack which is not recognised by DECC then care will be taken to create a name that will not subsequently cause confusion with an official DECC name. For example, if a well QQ/BB- 1 has recognised sidetracks 1Z and 1Y then the next official DECC sidetrack will be 1X. If there is a sidetrack that is not recognised by DECC but which the Operator wishes to describe as a distinct Well Bore, DEAL will create a new Well Bore with name QQ/BB- 1J, 1K etc. using the alphabet letters from J forwards to avoid potential clashes with DECC names.

1.8 In all cases the owner of the Well Bore name will be retained as an attribute (Well_Naming_System in the database). Thus, all Parent Well names and official DECC Well Bore names will have DECC as owner. Well Bores required to load data to the DataStore or to match DRA or Scout Group Well Bores will have DEAL as the  Well Bore name owner,  since the name will be created by DEAL according to the standards set out in CS-2, with the Data Owner, DRA or Scout Group name as an alias.. 

1.9 The Data Owners will be contacted to confirm the attributes of the Well Bores.