The API Number Standard: an Identifier for Petroleum Industry Wells in the USA

The API Number

“The PPDM Standard: Association is a not An Identifier for for profit society Petroleum Industry Wells in the USA that collaborates with industry to develop Professional Data Management standards for the Petroleum Industry.”

The API Number Standard: An identifier for Petroleum Industry Wells in the USA

Version: 2013 This Standard replaces: American Petroleum Institute Bulletin D12A, revised 1979 Abstract: This Standard defines an identifier for wells and wellbores in the petroleum industry of the USA. This Standard is compatible with previous versions of the D12A Number, with emphasis on the identification of every wellbore. Prepared by: PPDM Association Date published: May 31, 2013 Date of next review: May 31, 2018 Document type: Standard Keywords: standards, petroleum, well, wellbore, identifier, USA, API Number, API Well Number, D12A

DISCLAIMER

The Professional Petroleum Data Management (PPDM) Association makes no representation, warranty, or guarantee in connection with the contents of this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting from use or application hereunder or violation of federal, state, or local regulation with which the contents may conflict.

EXECUTIVE SUMMARY

This document defines and supports a standard for the identification of petroleum wells in the USA. This Standard is the official successor to Bulletin D12A of the American Petroleum Institute (API). In 2010, the API transferred custody of this Standard to the Professional Petroleum Data Management (PPDM) Association.

The revised API Number is at least a 12-digit number assigned to every wellbore and is the successor to previous versions. It is a foundation for the management and exchange of all information from or about all petroleum wells in the USA. Comprehensive data management is essential for the regulation, operation, and evaluation of wells, and for mitigating safety and environmental risks. This Standard provides for the unique identification of every wellbore.

The API Number specification provides continuity with the D12A Number while addressing numerous challenges that have evolved in the past three decades: well designs and data flows have become more complex, safety and environmental risks have increased where unidentified wellbores are present, and data exchange is difficult where identifiers are assigned inconsistently.

Anadarko Petroleum Corporation Rick Prucha Houston, TX

Baker Hughes Jonathan Watcharine Houston, TX

Baker Hughes Lynette Wooley Houston, TX

BP Jeremy Eade Houston, TX

Chesapeake Energy Chevy Thomason Oklahoma City, OK

Chesapeake Energy David Baker Oklahoma City, OK

Chevron Ayodele Oni Houston, TX

Chevron Stephen Barbee Houston, TX

Bureau of Safety and Environmental Enforcement (BSEE) Katherine Ross New Orleans, LA

Department of Environmental Conservation - New York Donald Drazan Albany, NY

Drillinginfo Josef Joubert Austin, TX

Drillinginfo Mark Robinson Austin, TX

Devon Energy Corp. Lance Byrd Houston, TX

IHS Bruce Smith Denver, CO

Llano Systems & Data Management Mac McLaughlin Houston, TX

Marathon Oil Corporation Shari Bourgeois Houston, TX

Oklahoma Corporation Commission (OCC) Bob Griffith Oklahoma City, OK

PPDM Association Jeffrey Bonus Calgary, AB

PPDM Association Dave Fisher Calgary, AB

TGS James Stolle Houston, TX

REGULATOR REVIEW

Standard has been shared with 16 states and 8 provided feedback. The feedback was positive towards the new standard. For a full list of states involved in the review please contact the PPDM Association www.ppdm.org.

The PPDM Association Copyright 2013, PPDM Association, All Rights Reserved. www.ppdm.org Page 3 of 27 DEFINITIONS ...... 5 INTRODUCTION ...... 6 Identifying Wells and Wellbores ...... 6 The Importance of a Standard Identifier ...... 6 Purpose ...... 6 Design Considerations ...... 7 History ...... 7 The D12A Number in Current Use ...... 8 PRINCIPLES ...... 8 THE API NUMBER: STRUCTURE AND USE ...... 9 Structure ...... 9 Rules for API Number Construction ...... 11 Extension Construction ...... 12 RECOMMENDED PROCEDURES ...... 13 Assignment of the API Number ...... 13 Historical Wells ...... 13 Omissions ...... 14 Error Corrections ...... 14 Identified Well Types ...... 14 Roles and Authorities ...... 15 CODES FOR STATES AND COUNTIES ...... 16 State and Pseudo-State Codes ...... 16 County and Pseudo-County Codes ...... 18 ILLUSTRATIONS OF API NUMBER ASSIGNMENT ...... 19 APPENDIX ...... 26 Comparison of Major Changes – Bulletin D12A 1979 vs. API Number Standard 2013 ...... 26 References ...... 27

The following definitions support the terminology used in this Standard. Where capitalized in this document, the term has the meaning as defined here.

Standard The term “Standard” in this document means the specifications for the API Number.

D12A Number The term used within this Standard to refer to the “API Well Number” identifier introduced in 1966 by the American Petroleum Institute and defined in Bulletin D12A.

API Number The API Number is the identifier for wells and wellbores defined by this Standard. “API” is not an acronym; it has no implied meaning. The name does not refer to the American Petroleum Institute, but simply acknowledges the long-standing adoption by the petroleum industry of “API” or “API Number” in reference to the identifier.

Well A Well is a proposed or actual drilled hole in the ground designed to exchange (or facilitate the exchange of) fluids between a subsurface reservoir and the surface (or another reservoir), or to enable the detection and measurement of rock properties.

Well Origin A Well Origin is the location on the surface of the earth or sea bed where the drill bit is planned to or does penetrate the earth to establish or rework a Well.

Total Depth The Total Depth is the final terminating point of a Wellbore at the end of drilling operations.

Wellbore A Wellbore is a path of drilled footage from the Well Origin to Total Depth.

Implementation An Implementation is a documented process for applying this Standard to assign identifiers within the scope or jurisdiction of a specific business or regulatory entity.

Authority An Authority is the entity with ownership of the Implementation and responsibility for its maintenance.

Primary Assigning Authority The Primary Assigning Authority is the governmental or jurisdictional agency (e.g., regulator) that assigns API Numbers.

Identifying Wells and Wellbores Wells are integral to the petroleum industry. Information about every well is an important asset for governments, owners, and service providers. The USA has several million petroleum-related wells, each with abundant and complex information in a variety of forms, both physical and digital. Management of this information is a vital activity to support the full range of activities related to wells (regulations, operations, evaluations, financial and contractual transactions, public safety, protection of correlative rights, etc.).

The most common and effective tool for information management is a unique well identifier. The purpose of a unique well identifier is to enable unequivocal recognition of a single instance of a well. The term “well” has various meanings throughout the industry, but this Standard follows the Definitions section above.

As wells have become more complex, especially when multiple Wellbores share the same surface location, the challenges of information management have increased. A full range of problems and risks (operational, financial, environmental, etc.) may arise from inadequate access to information about every Wellbore. Thus, the need for identifiers has expanded to encompass all Wellbores.

The Importance of a Standard Identifier Well information is widely used and shared throughout the industry. If all players follow the same standard, identifiers are much more useful and errors are reduced. In 1966 the American Petroleum Institute (API) introduced a well identifier to fulfil this role. The API Well Number specifications were published as American Petroleum Institute Bulletin D12A (hereinafter called “Bulletin D12A”) and were widely adopted.

This new Standard creates a Wellbore identification number to supersede the predecessor API Well Number, hereinafter called the D12A Number. This responds to the evolving needs of the industry and the complexity of modern well configurations. Continuity with the D12A Number, as much as possible, is important for maintaining the integrity of well information. This Standard introduces several changes, the most significant of which are:

 The API Number is at least 12 digits, with an optional extension.  All Wellbores must be identified, including bypasses and deepenings.  Each API Number is created by a specific Implementation of this Standard. The Implementation accommodates local requirements (regulations, operational practices, etc.), but must adhere to this Standard’s specifications.  Any Implementation of this Standard may employ an Extension. This document defines the proper structure for the initial 12 digits and offers guidance for the extension.

Purpose The purpose of the API Number is to uniquely and permanently identify every Well and Wellbore pertinent to the petroleum industry of the USA. Though defined for the petroleum industry, this Standard may be applied to other classes of wells (e.g., water, sulfur, coal) as deemed appropriate by the regulatory agency, state, or other entity. If applied to other such classes, the uniqueness of each API Number must be maintained across the class boundaries.

The PPDM Association Copyright 2013, PPDM Association, All Rights Reserved. www.ppdm.org Page 6 of 27 Design Considerations This Standard was designed to meet the petroleum industry’s needs for accurate identification. These business needs are based on findings of the Well Identification Project of the PPDM Association. The project included extensive stakeholder interviews with regulators, operators, service providers, and data vendors. The main business needs identified from these interviews were:

 An identifier for every Wellbore  Accommodation to newer well designs and data systems  Reasonable continuity with the D12A Number  Simplicity of migration from the old to the new number  Consistent, conformable adoption of this Standard by the industry, including regulatory agencies

This Standard was not designed to address:

 Wells outside the USA  Wells outside the petroleum industry  Wellbore events; these can be identified using an Extension or with a different identification method

History The most common historical method for well identification was a combination of operator name, lease name, and lease well number. This structure is inadequate for the management of vast amounts of data on millions of wells and is not amenable to computer processing. Moreover, each of these data elements is subject to change during the life of a well.

In 1966, the American Petroleum Institute published a numbering scheme applicable to all wells in the United States. The specifications are in Bulletin D12A; the latest published version appeared in 1979. This numbering scheme assigns each well a 10-digit unique identifier. Some wellbores are also identified with a 12-digit version of the number.

Use of the D12A Number was recommended as a standard practice for the identification of wells. Although widely adopted, it is not consistently applied. Moreover, the D12A Number has not kept pace with changes in well design, drilling technology, regulatory requirements, and the exchange of well information among systems and organizations.

After several incomplete efforts to revise the Bulletin D12A specifications, the American Petroleum Institute eventually decided that the well numbering standard was no longer within its mission or capacity. A formal agreement on the transfer of custody from the American Petroleum Institute to PPDM Association was concluded in 2010. Details of the history and content of the agreement are in the charter of PPDM’s Well Identification Project.

The PPDM Association is now the custodian of the API D12A Bulletin, subject to the terms of the agreement with the American Petroleum Institute. This bulletin is available at www.wellidentification.org or www.ppdm.org, or from the PPDM Association office in Calgary, Canada.

This Standard was created by a work group composed of representatives of the USA upstream petroleum industry and managed by the PPDM Association.

The PPDM Association Copyright 2013, PPDM Association, All Rights Reserved. www.ppdm.org Page 7 of 27 The D12A Number in Current Use The D12A Number is widely used in the USA by regulators, operators, vendors, etc. However, there are significant variations in its use, and these variations do not conform to Bulletin D12A. Examples of inconsistent application of the Bulletin D12A specifications are:

 The number is 10, 12, or 14 digits long.  Many Wellbores are not identified.  For a well that deviates into an adjacent county or state, a few state regulators assign a county code based on the producing zone location instead of the well’s surface location.  Different meanings are assigned to digits 11 – 14.

The D12A Number was designed to identify a well, defined as a “hole in the ground.” It provides for the identification of some (not all) additional wellbores associated with a single surface location. However, Bulletin D12A does not require the identification of all wellbores. Moreover, many state regulators assign the D12A Number as 10 digits only and therefore do not provide an identifier for any Wellbores other than the first one. Some applications of the D12A Number go beyond Bulletin D12A by adding an extension (digits 13 – 14) for certain activities (“events” or “supplemental operations”) in the well.

Many non-regulatory entities have developed proprietary well identification number schemes to overcome the limitations and inconsistencies of the regulatory D12A Number. However, these solutions are generally costly and inadequate for exchanging well information with other parties and for regulatory compliance.

PRINCIPLES

The design of this Standard and the recommendations for creating the revised API Number are guided by several principles in hierarchal order:

1. Every Well and Wellbore is identified by an API Number. 2. The API Number is a unique number. 3. The API Number is a permanent number. 4. The API Number from the Primary Assigning Authority supersedes any other identifier in public circulation. 5. Every API Number is related to a Well Origin. 6. The API Number conforms to this Standard.

Structure The API Number is composed of four semantic parts. An optional extension may be attached:

 State code  County code  Well code  Wellbore code

 Extension for supplementary information (optional)

API Number Unique County Non- Unique Well (Well Origin) Standard Unique Wellbore Positions: 1-2 3-5 6-10 11-12 13+ Code Extension State County Well Wellbore Name: (Optional) Example: 31 101 22963 03 0+ Note: Only digits are allowed in positions 1 – 12.

Figure 1. Structure of the API Number

It would be prudent for any new implementation of this Standard to anticipate a possible future need for alphabetic characters to accommodate the increasing complexity of wells and wellbores. Alphanumeric and special characters may be used in the Extension.

The state code represents a state or pseudo-state (e.g., Offshore Federal Waters) in the United States. Leading and trailing zeros (0’s) are significant and must be preserved. This Standard currently does not identify US territories, though they may be assigned a state or pseudo-state code in the future.

See the “State and Pseudo-State Codes” section for the list of state codes.

County Code (three digits - positions 3 – 5)

The county code represents an onshore county, parish (Louisiana), USGS quadrangle (Alaska), or a pseudo-county for offshore state and federal waters. When combined with the state code (digits 1 – 2), every county / pseudo-county in the USA is uniquely identified. Leading and trailing zeros are significant and must be preserved.

See the “County and Pseudo-County Codes” section for information regarding county codes.

Well Code (five digits – positions 6 – 10)

A well code is assigned to each Well, as determined by a unique Well Origin (surface location). Every well code must be unique within a county. When combined with the state and county codes (digits 1 – 5), every Well in the USA is uniquely identified. All Wellbores sharing the same Well Origin must have the same digits 1 – 10 because they belong to the same Well. All numbers from 00000 to 99999 are available unless they have been assigned. Numbers assigned under the previous guideline (Bulletin D12A) should be retained. Leading and trailing zeros are significant and must be preserved. This Standard applies no temporal order or significance to the sequence of the well code.

Wellbore Code (two digits – positions 11 – 12)

The wellbore code is assigned to each Wellbore. Every wellbore code must be unique within a Well. When combined with the state, county, and well codes (digits 1 – 10), every Wellbore in the USA is uniquely identified. All numbers from 00 to 99 are available unless they have been assigned. Numbers assigned under the previous guideline (Bulletin D12A) should be retained. Leading and trailing zeros are significant and must be preserved. This Standard applies no temporal order or significance to the sequence of the wellbore code.

Extension (any positions beyond position 12)

This Standard reserves and defines only digits 1 – 12. All positions beyond the 12th digit are an extension. Their use in an Implementation is not prohibited by this Standard. However, any extensions to the API Number must not be used to identify Wellbores. See the “Extension Construction” section.

The PPDM Association Copyright 2013, PPDM Association, All Rights Reserved. www.ppdm.org Page 10 of 27 Rules for API Number Construction The principles of this Standard require every API Number to be unique and permanent. Therefore, the API Number is a unique combination of state, county, well, and wellbore codes.

State Code

The state codes are required by this Standard and are part of this Standard. Any API Number containing an arbitrary or unapproved state code is a potential violation of the rule of uniqueness for numbers in the USA. If a new state code is required, it will be created by the PPDM Association.

Codes for existing states and pseudo-states in onshore and offshore areas of the United States are listed in the “State and Pseudo-State Codes” section.

County Code

County codes are required by this Standard, but the county codes are not assigned by the Standard. The Primary Assigning Authority is responsible for the consistent use of county codes. However, the use of an arbitrary or unapproved county code is a violation of the Principle of uniqueness for the API Number within a state or pseudo-state.

The codes are available from the appropriate state or other regulatory body. County codes are listed by the PPDM Association at www.wellidentification.org/usa in support of this Standard. Codes for counties and pseudo-counties were listed in Bulletin D12A as published in 1979, except for codes created since then by Arizona, California, Colorado, and New Mexico.

If a new county code is required, it will be created by the Primary Assigning Authority in that state or federal area. Consultation with the PPDM Association is advised.

Well Code

Each Well Origin (penetration of the earth surface) must have a well code that is unique within a county. Digits 1 – 10 of the API Number identify a unique Well Origin, as shown in Figure 1.

The well code is required by this Standard. The actual code assigned is the responsibility of the Authority that implements this Standard and creates the API Numbers.

This Standard does not reserve numbers or number ranges for the well code. This does not prohibit the use of numbers with special meaning at the Implementation level, provided the uniqueness of the API Number is maintained. Reserved numbers were specified in Bulletin D12A for the retroactive identification of historical wells and for non-regulatory use. By removing this reservation, this Standard allows for maximum use of the number range 00000 – 99999; however, any numbers already assigned, including those D12A Numbers, should not be reissued.

If the range of available well codes is exhausted within a county, a second county code should be created. For example, this was done about 1992 for Kern County, CA (county codes 029, 030). See the County Code section above.

Each Wellbore must have a wellbore code that is unique within a Well. Digits 1 – 12 of the API Number identify a unique Wellbore, as shown in Figure 1.

A wellbore code is assigned to each of the following as permitted or created:

 The first borehole from a Well Origin (see Figure 2)  A borehole from the side of an existing Wellbore (see figures 4 and 5)  A borehole from the bottom/end of an existing Wellbore, commonly referred to as a deepening or lengthening (see figures 9 and 10). The definition of deepening and/or lengthening is determined by the Authority implementing this Standard.

A wellbore code is required by this Standard. The actual code assigned is the responsibility of the Primary Assigning Authority that creates the API Number.

Extension Construction This Standard reserves and defines positions 1 – 12. Positions beyond the 12th are not defined by this Standard or by any published version of Bulletin D12A. Some current implementations of the D12A Number use positions 13 – 14 with a variety of meanings for local purposes. In order to achieve a high level of continuity with the D12A Number, this Standard does not attempt a single prescription for positions 13+. However, the following guidance is offered to encourage consistency.

Use positions 13 – 14 only to describe events that create physical configuration changes within the Wellbore:

 Completions  Plugbacks  Conversions of well type if this involves recompletion (not just a change in well status)  Drilling modifications within the zone (if not deemed a new Wellbore by the Authority, see Wellbore Code)

Never use positions 13 – 14 to identify:

 Wellbores, including laterals  Deepenings

Avoid using positions 13 – 14 to describe administrative events such as:

 Regulatory filings  Subsequent permits (except for a significant physical change; see above)  Sundry notices

Positions beyond the 12th must not be used to identify a Wellbore, including deepenings. A primary goal of the new Standard is to identify every Wellbore in a way that facilitates the exchange of information. This is a significant change from implementations of the D12A Number that use digits 13 – 14 (or even digits 11 – 14) to identify Wellbores.

Assignment of the API Number The goal of unambiguous recognition and exchange of well information is best achieved when every Wellbore has a single unique and permanent API Number assigned by the Primary Assigning Authority (in general, the regulatory agency). The API Numbers are then published or otherwise disseminated to the public and the industry.

An identifier may also be assigned for internal or commercial purposes by an operating company, a data vendor, or a service provider. To preserve uniqueness and avoid confusion, this identifier should be clearly differentiated from the regulator’s API Number, perhaps by using a distinct label for the identifier (e.g., API Number_INTERNAL).

The assignment procedure is part of the required specifications for each Implementation of this Standard. The procedure must have a consistent method for recognizing each new Well and Wellbore, conforming to the requirements of this Standard. This includes the following drilling situations.

 If a well is junked while drilling, and the rig is skidded to spud a new hole nearby, a new API Number (with a unique well code) must be assigned because a new Well Origin has been created. See Figure 6.  If an abandoned Well is re-entered and a new Wellbore is drilled, the new API Number retains digits 1 – 10 of the original Well because the Well Origin is the same.  If a Wellbore is re-entered and deepened (lengthened), this Standard allows each Authority to define the criteria for determining if this operation creates a new Wellbore or if it is deemed to be merely a change in the value of Total Depth. This determination should be based on the definitions of deepening and/or lengthening in the specifications for the Implementation. See Figures 9 and 10.

The timing of the assignment of the API Number is at the discretion of the Authority, but the industry’s expectation is that the API Number be assigned and published as soon as possible. This is usually assigned when the application is received or the drilling permit is issued. When additional Wellbores are drilled within a Well, the regulator may assign an API Number in advance (e.g., if an additional or amended permit is required) or when the drilling information is received and processed. An API Number, once assigned, should not be reassigned to a different Well or Wellbore. See Figure 14.

Each Authority should maintain a repository (master list) of all assigned API Numbers in its jurisdiction, including historical (legacy) numbers and ones that are omitted, cancelled, or deleted. This list should be made public. For any changes, the list should include the old and new numbers and the change status.

Historical Wells Most wells in the USA already have an identifier, based on Bulletin D12A, called the D12A Number. These legacy numbers should be incorporated into the master list of API Numbers without revision unless uniqueness is not assured. Although a legacy number may be non-compliant, it is generally better to keep it; this “grandfather” provision respects principles 3 and 4. If the legacy number is only 10 digits, a wellbore code must be added: see the “Omissions” section below.

The PPDM Association Copyright 2013, PPDM Association, All Rights Reserved. www.ppdm.org Page 13 of 27 Omissions If a hole is drilled from the side or bottom of an existing Wellbore, but is not assigned an API Number, this Standard’s requirement to identify every Wellbore is violated. Similarly, a pilot hole (drilled to prepare for a sidetrack) must be identified. The Authority determines whether to allow the omission to persist (contrary to this Standard) or to assign an API Number. See figures 9 and 10.

The retroactive assignment of the API Number to historical wellbores is an important benefit to the industry, but may take many years to accomplish. This Standard does not prescribe specific wellbore codes for this task and does not require the sequence of wellbore codes to signify the actual sequence of drilling. A wellbore code already assigned should not be reassigned in any situation. See Figure 14.

Error Corrections According to Principle 3, the API Number is a permanent identifier that must never change. However, in some cases it may be necessary to cancel or replace the number. The Authority (e.g., a regulator) decides if an error warrants correction. The specifications in the Authority’s Implementation of this Standard should include procedures for amending errors and reporting the changes. Notification of all errors and corrections should be made public.

If an error or other non-compliance does not affect uniqueness, the Authority may deem that changing the API Number is more problematic than retaining the error. This is especially true if the number has been in the record for a significant period of time. For example, an incorrect county code may persist without impairing the uniqueness of the API Number.

Duplicate Numbering

According to Principle 2, any duplication of numbers must be corrected to preserve the integrity of the entire API Number system. The Authority should either cancel both numbers and issue a new API Number or retain the original number and cancel all others. If an assigned API Number is withdrawn for correction or any other reason, it must not be reused. Duplication arises in any of the following situations.

 Identical API Numbers o different Well Origins with the same digits 1 – 10 o different Wellbores with the same API Number (digits1 – 12)

 Multiple API Numbers o one Well Origin with more than one unique set of digits 1 – 10 o one Wellbore with more than one API Number (digits 1 – 12)

Identified Well Types This Standard is designed to identify all Wellbores pertinent to the petroleum industry of the USA. These include wells for service, disposal, core test, and stratigraphic test, and wells intended to supply water for petroleum production operations.

The API Number may also be assigned to other wells (e.g., coal, sulfur), provided that this use does not violate the uniqueness and integrity of the API Number for the petroleum industry.

The PPDM Association Copyright 2013, PPDM Association, All Rights Reserved. www.ppdm.org Page 14 of 27 Roles and Authorities Regulators issue permits to drill a well. The API Number may be created by the regulator or other Primary Assigning Authority as an identifier for the Well and Wellbores. Adoption of this Standard is at the discretion of the regulator or government.

Operators are subject to regulatory requirements, including the identification of their wells. Operators therefore use the regulator’s identifiers, although they may also use different identifiers for internal purposes.

Data Vendors collect well information from regulators and other sources and sell the information to their customers. Data vendors may create their own identifiers and/or use the regulatory identifiers. Their clients often require the well identifiers from every jurisdiction to be normalized to a common format.

Service Providers are subject to the requirements of their customers and the regulators, including the identification of wells. Service providers therefore use the regulatory identifiers, although they may also use different identifiers for internal purposes and for delivery of information to their customers.

The PPDM Association is the owner of the API Number Standard and its name identity (brand). Ownership includes the right and responsibility to maintain this Standard and to revise it when necessary. The PPDM Association makes this Standard’s specification freely available to the industry and the public for the purpose of identifying wells and wellbores in the USA. The PPDM Association does not create or distribute well numbers. The PPDM Association may comment on another entity’s compliance with this Standard, but has no authority to enforce this Standard.

State and Pseudo-State Codes The API Number uses the state and pseudo-state codes listed below. They are part of this Standard and are the same codes as published in American Petroleum Institute Bulletin D12A, 1979.

These state codes were originally developed as early as 1952 by IBM and are not the same as codes from other standards organizations, such as American National Standards Institute (ANSI), Federal Information Processing Standard (FIPS), InterNational Committee for Information Technology Standards (INCITS), International Organization for Standardization (ISO), and US Census Bureau.

State Codes for the United States Refer to Map No. 1 on the following page State Code State Code Alabama 01 Nevada 27 Arizona 02 New Hampshire 28 Arkansas 03 New Jersey 29 California 04 New Mexico 30 Colorado 05 New York 31 Connecticut 06 North Carolina 32 Delaware 07 North Dakota 33 District of Columbia 08 Ohio 34 Florida 09 Oklahoma 35 Georgia 10 Oregon 36 Idaho 11 Pennsylvania 37 Illinois 12 Rhode Island 38 Indiana 13 South Carolina 39 Iowa 14 South Dakota 40 Kansas 15 Tennessee 41 Kentucky 16 Texas 42 Louisiana 17 Utah 43 Maine 18 Vermont 44 Maryland 19 Virginia 45 Massachusetts 20 Washington 46 Michigan 21 West Virginia 47 Minnesota 22 Wisconsin 48 Mississippi 23 Wyoming 49 Missouri 24 Alaska 50 Montana 25 Hawaii 51 Nebraska 26

Pseudo-State Codes for United States Offshore Federal Waters Pseudo-State Code Alaska Offshore 55 Pacific Coast Offshore 56 Northern Gulf of Mexico 60 Atlantic Coast Offshore 61

Note: Not all offshore waters are designated by pseudo-state codes. Please consult the relevant Authority (state or federal) for precise definitions.

The PPDM Association Copyright 2013, PPDM Association, All Rights Reserved. www.ppdm.org Page 17 of 27 County and Pseudo-County Codes County, parish (Louisiana), USGS quadrangle (Alaska) and pseudo-county (offshore state and federal waters) codes are provided by the appropriate state or federal agency. In support of this Standard, the codes are also available at www.wellidentification.org/usa or from the PPDM Association.

These codes are the same as in American Petroleum Institute Bulletin D12A, 1979, with additions for new counties. The county codes are not necessarily the same as codes from other standards organizations such as American National Standards Institute (ANSI), Federal Information Processing Standard (FIPS), InterNational Committee for Information Technology Standards (INCITS), International Organization for Standardization (ISO), US Census Bureau, etc.

The figures that follow are presented for the purpose of illustrating the use of the API Numbering procedures. The figures were selected to show the proper method of number assignment for different conditions under which wells are drilled. Consistent use is important for clarity, especially where well information is exchanged between parties.

Figure 2. A simple vertical Well, one Wellbore

Figure 3. A simple directional or deviated Well, one Wellbore

Figure 4. Multiple Wellbores – Each Wellbore is assigned a different wellbore code, but they all have the same first 10 digits because they all begin at the same Well Origin.

Figure 5. Bypass – A second wellbore is drilled to bypass a problem and continues to the original target. The first wellbore retains the API Number already assigned because a number, once assigned to a Wellbore, must never be changed or moved; even if the bypass re-enters the original, both Wellbores should be identified.

Figure 6. Skidded Well – The initial Wellbore was junked before reaching the target. The rig was skidded and a new Well spudded. The new Well is assigned a new well code because a new Well Origin has been created.

Figure 7. Pad Wells – Wells from an onshore multi-well pad. Each is a separate penetration of the earth’s surface. Therefore, each has a different well code (digits 6 – 10.) There are three Wells, each with one Wellbore. The drilling order is not implied in the number.

Figure 8. Platform Wells – Wells from an offshore platform. Each is a separate penetration of the earth’s seabed. Therefore, each has a different well code (digits 6 – 10.) There are three Wells, each with one Wellbore. The drilling order is not implied in the number.

Figure 9. Deepening – Deepening an existing Wellbore creates a new Wellbore, thus requiring a new API Number, subject to the definition of deepening set by the Authority. Note that the first 10 digits remain the same.

Figure 10. Extending a Horizontal (lengthening) – Lengthening an existing Wellbore creates a new Wellbore, thus requiring a new API Number, subject to the definition of deepening/lengthening set by the Authority. Note that the first 10 digits remain the same. If the vertical hole is a pilot hole (“strat hole”) in preparation for kicking off a horizontal leg, it is nevertheless a Wellbore with its own API Number.

Figure 11. Wellbore Crosses County Line – Surface location in one county, Wellbore bottom and/or completion in adjacent county. The API Number has the county code for the surface location.

Figure 12. Wellbore Crosses State Line – Surface location in one state, Wellbore bottom hole, and/or completion in adjacent state. The API Number has the state and county codes for the surface location.

Figure 13. Wellbore from onshore to offshore – Surface location onshore, Wellbore bottom hole, and/or completion offshore. The API Number has the state and county codes for the surface location.

Figure 14. Permitted three Wellbores, one Drilled – The one drilled was originally permitted as wellbore code 01 by the assigning Authority and no change to numbering is required. Undrilled Wellbores retain the API Number as assigned.

Comparison of Major Changes – Bulletin D12A 1979 vs. API Number Standard 2013 Bulletin D12A (1979) API Number Standard (2013) Reason for Change

Official Name: API Well Number Official Name: API Number It is now a Well and Wellbore (referred to as “D12A Number” in identifier. The API name provides this Standard continuity and familiarity.

Identify only wellbores to new target Identify all wellbores Valuable information is associated with every wellbore, including bypass and pilot hole.

Deepening not identified Identify a deepening Deepening is a new Wellbore. Definition of deepening is made by regulator.

Well defined as “hole in the Well and Wellbore are defined Strengthen the definition to reduce ground;” wellbore not defined confusion. The definitions control the assignment of the API Number.

Surface location determines state + Well Origin location Well Origin is a more precise county code definition of surface location, but no change in design.

Digits 11 – 12 optionally blank for At least 12 digits Remove the option to identify only a initial hole “well” or a well + initial wellbore.

Unique well code Well code Name change only.

Directional sidetrack code Wellbore code Name change only.

Reserved well code range for No reserved range Maximize the numbers available. historical wells

Exempt well code range for non- No exempt number range A non-regulator should use its own regulators implementation (with different name), not a special set of well code numbers in the API Number.

Reserved sidetrack code range (e.g., No reserved range Maximize the numbers available. 70 – 89)

All county codes are listed County codes not listed Refer to other sources for actual county codes: regulators, PPDM Association website.

Identify only some types of wells Capable of identifying all wells The API Number is intended for the pertinent to the petroleum industry entire petroleum industry, including relevant non-petroleum wells (e.g.,

Bottom or producing zone in a API Number always relates to the Replace Bulletin D12A’s suggestion different county or state – Well Origin with a firm requirement for recommend keeping surface D12A consistent assignment of the API Number Number based on surface location (Well Origin).

Ledger books by county, listing all Master list (digital) Request regulators to maintain a D12A Numbers assigned public list of D12A Number (legacy) and API Numbers, including deletions and changes.

Supplemental well operations Deepening is a new wellbore code. Parts of the industry adopted the (rework, deepening, etc.) are not Other operations may be identified draft proposals of the 1990s to create identified with D12A Number by extension (13+) a variety of 14-digit D12A Numbers. The API Number may have an extension to provide continuity with 14-digit designs.

References

 American Petroleum Institute Bulletin D12A Bulletin 1979

 PPDM Association Global Well Identification Framework 2013

 PPDM Association API State Comparison 2010

 PPDM Association What is a Well? 2012

 American Petroleum Institute Bulletin D12A draft revision 1992

 American Petroleum Institute Bulletin D12A draft revision 2000