Oil and Gas Reserves System Surveys

U.S. DEPARTMENT OF ENERGY
Energy Information Administration
Office of Oil and Gas
Washington, DC 20585

Form Approved
OMB Number: 1905-0057
Expiration Date: xx/xx/20xx

ANNUAL SURVEY OF DOMESTIC OIL AND GAS RESERVES
FORM EIA-23S
Summary Level Survey Instructions

SURVEY YEAR 2009
Table of Contents
Page

General Instructions ..........................................................................................

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A. Purpose ..................................................................................................................
B. Who Must Submit Form EIA-23S...........................................................................
C. When and Where to Submit...................................................................................
D. Record Keeping Requirements..............................................................................
E. Sanctions ...............................................................................................................
F. Disclosure of Information .......................................................................................
G. Reporting Standards ..............................................................................................
1. Proved Reserves .............................................................................................
2. Survey Year Production ...................................................................................
3. Total Operated Basis .......................................................................................
4. States and Geographic Subdivisions...............................................................
5. Reporting Units ................................................................................................
6. EIA Secure File Transfer Information………………………..............................

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Specific Instructions ..........................................................................................

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H. Cover Page - Operator Identification .....................................................................
I. Summary Report ....................................................................................................
J. Definitions ..............................................................................................................

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For Information, Assistance, or Additional Forms
Contact the EIA-23 Coordinator 800-879-1470
8:00 a.m. – 4:30 p. m. Central Time

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GENERAL INSTRUCTIONS
A. PURPOSE

C. WHEN AND WHERE TO SUBMIT

The Energy Information Administration (EIA) of the
Department of Energy (DOE) seeks, with Form EIA-23S, to
gather and summarize credible and timely data regarding
proved reserves and production of crude oil, natural gas,
lease condensate, and other related matters. The
Government will use the resulting information to develop
national and regional estimates of proved reserves of
domestic crude oil, natural gas, and natural gas liquids and
to facilitate national energy policy decisions.

The completed 2009 survey forms must be submitted on or
before April 16, 2010. Filing electronically, using Secure File
Transfer or Fax, is encouraged.
Secure File Transfer: See page 4 for information
Fax completed forms to: 202 586-1076
Mail completed paper forms to:
Oil and Gas Surveys
U. S. Department of Energy, EIA
Ben Franklin Station
PO Box 279
Washington DC 20044-0279

B. WHO MUST SUBMIT FORM EIA-23S
Each operator (Section J Definitions, page 6) of domestic oil
and/or gas wells as of December 31, 2009 that has been
selected must file either a Form EIA-23S or a Form EIA23L.

When entering responses on hard copies, type or print in
black ink using all capital letters. EIA-23L forms and
instructions are available on the EIA website..

Filing requirements are based on operator category or size,
which is determined by the total or gross (8/8ths) annual
operated production rate. Production refers to the total
calendar year production from all domestic oil and/or gas
wells operated on December 31, 2009, including wells
abandoned during the year.

For information concerning requests for extension of time to
file or for exception from filing Form EIA-23S, contact the
EIA-23 Coordinator 800-879-1470 from 8:00 a.m. to 4:30
p.m. Central Time.

Each operating affiliate of a parent company must file its own
Form EIA-23. The parent company must file only if it is an
operator itself. If no parent company exercises ultimate
control over your company, please indicate that on the Cover
Page.

D. RECORD KEEPING REQUIREMENTS
All records necessary to reconstruct the data on this form
must be retained and available for a period of three (3) years
from the filing due date.

If you have received the EIA-23S Summary Level Report
form, but your total gross operated production exceeds
400 thousand barrels (400 MBbls) of crude oil or 2 billion
cubic feet (2,000 MMCF or 2 BCF) of natural gas, or you
operate wells in the federal offshore or coalbed methane
gas wells, contact the EIA-23 Coordinator 800-879-1470
to obtain the EIA-23L Field Level Report form and
instructions.

E. SANCTIONS
The timely submission of Form EIA-23S by those required to
report is mandatory under Section 13 (b) of the Energy
Information Administration Act of 1974 (FEAA) (Public Law
93-275), as amended. Failure to respond may result in a civil
penalty of not more than $2,750 a day for each violation, or a
fine of not more than $5,000 a day for each willful violation.
The government may bring a civil action to prohibit reporting
violations that may result in a temporary restraining order or
a preliminary or permanent injunction without bond. In such
civil action, the court may also issue mandatory injunctions
commanding any person to comply with these reporting
requirements.

Note that as defined, day-to-day physical operation of a well
or wells does not alone qualify a person as the operator.
Physical operation may occasionally be divorced from
operatorship, such as in the instance of manipulation of
swing wells by a gas pipeline company representative or the
manipulation and maintenance of wells located on an
offshore platform by the platform manager. While the
operator's own personnel usually perform such duties, the
key factor is that the operator is the person who makes
management decisions regarding the well(s) in question on
behalf of the owner(s).

F. DISCLOSURE OF INFORMATION
The annual production of crude oil, lease condensate, and
natural gas reported on Form EIA-23 are considered public
information. These data elements may be released in
company-identifiable form and will not be protected from
disclosure in identifiable form when releasing statistical
aggregate information. All other information reported on
Form EIA-23 will be protected and not disclosed to the public
to the extent that it satisfies the criteria for exemption under
the Freedom of Information Act (FOIA), 5 U.S.C. §552, the
DOE regulations, 10 C.F.R. §1004.11, implementing the
FOIA, and the Trade Secrets Act, 18 U.S.C. §1905.

If you are not certain whether you are the operator, contact
the EIA-23 Coordinator 800-879-1470 for assistance in
making this determination. If you are not the operator of oil
and/or gas wells on December 31, 2009 (perhaps a former
operator or solely a working or royalty interest owner), you
should complete and sign the Cover Page only and return it
to EIA along with a letter stating when operations ceased and
what became of the wells you previously operated.

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The Federal Energy Administration Act requires the EIA to
provide company-specific data to other Federal agencies
when requested for official use. The information reported on
this form may also be made available, upon request, to
another component of the Department of Energy (DOE); to
any Committee of Congress, the Government Accountability
Office, or other Federal agencies authorized by law to
receive such information. A court of competent jurisdiction
may obtain this information in response to an order. The
information may be used for any nonstatistical purposes such
as administrative, regulatory, law enforcement, or
adjudicatory purposes.

Examples:
Of the total 8/8ths interest, respondent's share is 50 percent
and the associated royalty share is 6.25 percent.
Respondent operates property. Respondent reports 100
percent of proved reserves and production.
Of the total 8/8ths interest, respondent's share is zero but it
operates the property (i.e., a contract operator). Respondent
reports 100 percent of proved reserves and production.

3. States and Geographic Subdivisions

Disclosure limitation procedures are applied to the protected
statistical data published from EIA-23 survey information to
ensure that the risk of disclosure of identifiable information is
very small.

To determination in which state or geographic subdivision to
report proved reserves and production data is based on the
location of the field(s) containing the oil and/or gas. If a field
overlaps two or more states or subdivisions, the proved
reserves data must be subdivided into the appropriate
geographic components.

Confidential information collected on Form EIA-23 will be
provided to United States Department of Interior offices (the
Mineral Management Service and the United States
Geological Survey) for statistical purposes only, in
conducting their resource estimation activities.

For a State in which you operated but not listed on the form,
specify the two-letter postal code in the line labeled "Other
States". Enter the production and reserves in Columns A
through I.

G. REPORTING STANDARDS

Offshore proved reserves data are required separately for
the State and Federal domains. If an offshore field lies on or
between disputed boundaries, include all data in the State
offshore area.

1. Proved Reserves
EIA recognizes that the judgment of geologists and
petroleum engineers is required in the reserve estimation
process, and that as a result, proved reserves are estimates
rather than precise quantitative measurements.

4. Reporting Units
Volumes must be reported in whole numbers and not contain
decimals. All volumes are to be reported in the appropriate
reporting units as shown below:

Proved reserves of oil and gas as of December 31, 2009 are
the estimated quantities of oil and/or gas, which geological
and engineering data demonstrate with reasonable certainty
to be recoverable in future years from known reservoirs
under existing economic and operating conditions. (See
Proved Reserves, Crude Oil; Proved Reserves, Natural
Gas; and Proved Reserves, Lease Condensate, Section I
Definitions, page 9.)

a. Crude Oil: All crude oil volumes are to be reported in
thousands of barrels (MBbls) (42 U.S. gallons per barrel
at atmospheric pressure corrected to 60° Fahrenheit) and
excluding basic sediment and water.
b. Natural Gas: All natural gas volumes are to be reported
in millions of cubic feet (MMCF) at 14.73 psia and 60°
Fahrenheit, wet after lease separation.

2. Survey Year Production
Production data are required from all operators. If the actual
production data are not available at the time Form EIA-23S is
prepared, estimate production.

It is recognized that the operator in many instances has no
knowledge of the ultimate reduction of the gas stream
produced from his properties, which may result from further
downstream processing. The operator is requested to report
volumes of natural gas, which remain after processing
through lease and field separation facilities. Lease use and
flared and vented gas are also considered production
and should be included in the volumes reported.
EIA obtains data from gas processing plants separately. Gas
volumes reported on Form EIA-23S must not be corrected
for liquids removed by these plants. If you do not know if a
field facility through which your gas is processed is currently
reporting data to EIA or not, contact the EIA-23 Coordinator
to obtain information on those plants which report.

If any properties were acquired during the survey year,
production data from the acquired properties should be
reported from the date of purchase. If any properties were
sold during the survey year, production data should be
reported until the date of sale.

Total Operated Basis
All data on Schedule A (reserves and related data by field)
are to be reported on an 8/8ths or Total Operated Basis.
When reporting on this basis, production and reserves data
for any properties on which operations were acquired during
the survey year should be reported from the date of transfer
or purchase. If any properties were sold or transferred to a
new operator during the survey year, production and
reserves data should be reported until the date of sale or
transfer.

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c. Lease Condensate: All lease condensate volumes are to
be reported in thousands of barrels (MBbls) (42 U.S.
gallons per barrel, at atmospheric pressure corrected to 60°
Fahrenheit).

5. EIA Secure File Transfer Information
EIA is ensuring the security of your transactions by using the
latest Internet security technology. The technology being
used to protect your data is encryption which is the
scrambling of data into a code that is unreadable to anyone
who does not have the key that deciphers it. The secure
hypertext transfer protocol (https) is a communications
protocol designed to transfer this encrypted information
between computers over the World Wide Web. All
information is protected by 128-bit encryption to maintain the
privacy and confidentiality of your data. The only thing you
need to take advantage of strong encryption technology is a
secure browser, one that supports 128-bit encryption.

d. Rounding: Round liquid volumes 500 barrels and above
up to ‘1’ MBbls, and less than 500 barrels down to ‘0’
MBbls. Round gas volumes 500 MCF and above up to ‘1’
MMCF, and less than 500 MCF down to ‘0’ MMCF.
e. Negative and Positive Volumes: All data are to be
entered as whole number integers without plus (+) or minus
(-) symbols.

To use the EIA https secure file transfer system:
1. Click to open the SFT webpage
or type in the URL in your browser:
https://signon.eia.doe.gov/upload/noticeoog.jsp
The EIA SFT Notice to Users page appears.
2. Read and then click the Accept button.
The Secure File Transfer System page appears.
At the bottom of this page, in blue text, click on
Instructions for Secure File Transfer.
If you have any trouble transferring your files, please call the
EIA User Services Center 202-586-8959 or email them at
[email protected].

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SPECIFIC INSTRUCTIONS
and approve the accuracy of this submission and the date of
the signing. This report should be reviewed and approved by
a responsible officer or the office responsible for regulatory
filings. If filed electronically, there is no requirement to submit
a signed cover page.

H. COVER PAGE - Operator Identification
You are required to enter those items that are incorrect
or missing from the preprinted form.

Part I. Identification

I. SUMMARY REPORT

EIA Operator ID Code: If this item is missing, contact the
EIA-23 coordinator.

SECTION 1.0: Operator Detailed Data Report
Item 1.1: EIA Operator ID Code – This is the same as the
Cover Page EIA Operator ID Code.

Operator Name, Address, City, State, Zip Code. Enter the
legal name and address of the operator. If a foreign address,
enter city, local equivalent of State name (e.g., province), and
country.

Item 1.2: Operator Name - This is the same operator name
on the Cover Page. Enter the first 35 characters of the
operator name. If the name exceeds 35 characters, do not
abbreviate, but simply truncate the extra characters from the
right.

Item 1: Contact Information. Name, telephone number, fax
number, and e-mail address of the person most
knowledgeable about the reported data. This person should
be familiar with the data provided, and will be the person to
whom inquiries will be directed, if necessary.

Item 1.3: Original - Enter an ‘X' in the box if this is the first
submission of this schedule for the survey year. Otherwise
leave blank.

Item 2: Was your company an oil and gas field operator
...? Check the appropriate box and follow the instructions for
completing the rest of the form.

Item 1.4: Amended - Enter an ‘X' if this schedule amends a
previously submitted schedule. Otherwise, leave blank.

SECTION 2.0: Production and Reserves Data

Item 3: Company Status, Name, and/or Address Change
or Correction. If there was a change to the company name
or address, or if the company was sold, merged with another
company or the company went out of business, check the
appropriate box and complete Item 4.

Provide data in Columns A through I for each State or
geographic subdivision in which you were an operator of oil
and/or gas wells as of December 31, 2009. Proved reserves
and production for 2009 are to be reported on a Total
Operated Basis. (See Section G, Reporting Standards)

Item 4: Note Change Company Name, Address, and/or
Contact Information. If any box in Item 3 was checked,
enter the new or correct company name, address, or contact
person here.

You are not required to complete entries with zeros for states
or subdivisions in which you do not operate wells. Leave
these entries blank.
REPORTING INSTRUCTIONS

Part II. Parent Company Identification
Item 5: Is there a parent company …? Check the
appropriate box. If Box 2 is checked, provide parent company
information in Items 6 through 10.

2009 Reserves Data
December 31, 2009 Proved Reserves Data - Enter
estimates of total proved reserves for operated properties if
estimates are available. The estimates should be based on
your most recent evaluations, adjusted for production through
December 31, 2009, and for any other relevant factors. If
reserves were depleted during 2009, enter zero. The
resulting estimates for reserves should be consistent with the
definitions of proved reserves. (See Section J, Definitions,
page 6)

Item 6: Parent Company Name. Enter the legal name and
address of the parent company, if any that exercises ultimate
control over the respondent.
Example: You are Company A, which takes direction
from Company B, which in turn takes direction from
Company C. Report Company C as the parent company,
rather than Company B.
Items 7-10: Address, City, State, and Zip Code. Enter the
address, City, State, and Zip Code of the parent company.

Column A: Crude Oil Reserves
Column D: Natural Gas Reserves
Column G: Lease Condensate Reserves

Part III. Approval
Items 11 thru 14: Approval - Enter the name and title of the
individual designated by the respondent company to review

Note: If no proved reserves estimates are available,
enter "NA" in Column(s) A, D, and/or G.

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• small amounts of hydrocarbons that exist in gaseous
phase in natural underground reservoirs but are liquid at
atmospheric pressure after being recovered from oil well
(casinghead) gas in lease separators and are
subsequently commingled with the crude stream without
being separately measured
• small amounts of non-hydrocarbons produced with the oil,
such as sulfur and various metals.
When a State regulatory agency specifies a definition of
crude oil which differs from that above, the State definition is
to be followed.

2009 Production Data
December 31, 2009 Production Data are required from all
operators. If the actual survey year production data are not
available at the time the Form EIA-23S is prepared, estimate
production. Lease use and flared and vented gas are also
considered production and should be included in the
volumes reported.
Production from Properties With Reserves Estimated:
Enter the 2009 production for those operated properties with
proved reserves data that were reported in Columns A, D, or
G in the corresponding Columns B, E, or H.

Field Separation Facility: A surface installation designed to
recover lease condensate from a produced natural gas
stream usually originating from more than one lease, and
managed by the operator of one or more of these leases.
(See Lease Condensate)

Column B: Crude Oil Production
Column E: Natural Gas Production
Column H: Lease Condensate Production

Gross Working Interest Ownership Basis: Gross working
interest ownership is the respondent's working interest in a
given property plus the proportionate share of any royalty
interest, including overriding royalty interest, associated with
the working interest. (See Working Interest and Royalty
Interest {Including Overriding Royalty})

Production from Properties for Which Reserves Were
NOT Estimated: Enter the 2009 production for those
operated properties for which proved reserves estimates are
NOT available in existing company records and were
therefore NOT reported in Columns A, D or G.

Lease Condensate: A mixture consisting primarily of
pentanes and heavier hydrocarbons which is recovered as a
liquid from natural gas in lease or field separation facilities.
This category excludes natural gas plant liquids, such as
butane and propane, which are recovered at downstream
natural gas processing plants or facilities. The output of
natural gas processing plants is reported on Form EIA-64A,
Annual Report of the Origin of Natural Gas Liquids
Production and Form EIA-816, Monthly Natural Gas Liquids
Report.

Column C: Crude Oil Production
Column F: Natural Gas Production
Column I: Lease Condensate Production
U.S. TOTALS: Sum the entries in each column and enter the
totals on the last line of page 2, U.S. Totals.

J. DEFINITIONS
These definitions have been formulated with reference to the
particular purposes of Form EIA-23S. They are not
necessarily synonymous with the same or similar terms used
in DOE regulations, and are not to be construed as definitions
applicable for any purposes other than the collection and
reporting of data on Form EIA-23S.

Lease Separator: A facility installed at the surface for the
purpose of separating gases from:
• produced crude oil and water at the temperature and
pressure conditions of the separator, and/or
• that portion of the produced natural gas stream, which
liquefies at the temperature and pressure conditions of the
separator.

Affiliated (Associated) Company: An entity that is directly
or indirectly owned, operated, or controlled by another entity.
(See Person and Control)

Natural Gas: A gaseous mixture of hydrocarbon compounds,
the primary one being methane. The parameters for
measurement are cubic feet at 60 degrees Fahrenheit and
14.73 pounds per square inch absolute (psia). The Energy
Information Administration measures wet natural gas and its
sources of production, associated/dissolved natural gas
and non-associated natural gas, and dry natural gas,
which are produced from wet natural gas. This EIA survey
does not include landfill gas (biomass gas), synthetic natural
gas, coke oven gas, or manufactured gas.

Control: The term control (including the terms controlling,
controlled by, and under common control with) means the
possession, direct or indirect, of the power to direct or cause
the direction of the management and policies of a person,
whether through the ownership of voting shares, by contract
or otherwise. (See Person)
Crude Oil (excluding Lease Condensate): A mixture of
hydrocarbons that exists primarily in the liquid phase in
natural underground reservoirs and remains liquid at
atmospheric pressure after passing through surface
separating facilities. Such hydrocarbons as lease condensate
and natural gasoline recovered as liquids from natural gas
wells in lease or field separation facilities and later mixed into
the crude stream are excluded. Depending upon the
characteristics of the crude stream, it may also include:

Wet natural gas: A mixture of hydrocarbon compounds
and small quantities of various non-hydrocarbons existing
in the gaseous phase or in solution with crude oil in porous
rock formations at reservoir conditions. The principal
hydrocarbons normally contained in the mixture are
methane, ethane, propane, butane, and pentane.

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Production, Lease Condensate: The volume of lease
condensate produced during the survey year. Lease
condensate volumes include only those volumes recovered
from lease or field separation facilities. (See Lease
Condensate)

Typical non-hydrocarbon gases that may be present in
reservoir natural gas are water vapor, carbon dioxide,
hydrogen sulfide, nitrogen and trace amounts of helium.
Under reservoir conditions, natural gas and its associated
liquefiable portions occur either in a single gaseous phase
in the reservoir or in solution with crude oil and are not
distinguishable at the time as separate substances. Note:
The Securities and Exchange Commission and The
Financial Accounting Standards Board refer to this product
as natural gas.

Production, Natural Gas: The volume of natural gas
withdrawn from reservoirs during the survey year less:
• the volume returned to such reservoirs in cycling,
repressuring of oil reservoirs and conservation operations
• the shrinkage resulting from the removal of lease
condensate
• non-hydrocarbon gases where they occur in sufficient
quantity to render the gas unmarketable.

Dry natural gas: Natural gas that remains after:
• the liquefiable hydrocarbon portion has been
removed from the gas stream (i.e., gas after lease,
field and/or plant separation)
• any volumes of non-hydrocarbon gases have been
removed where they occur in sufficient quantity to
reduce the gas quality below minimum pipeline
specifications (rendering it unmarketable).

Lease use and flared and vented gas are considered
production and should be included in the volumes reported.
Volumes of gas withdrawn from gas storage reservoirs and
native gas, which has been transferred to the storage
category, are not considered production.

Natural Gas Processing Plant: Facilities designed to
recover natural gas liquids from a stream of natural gas that
may or may not have passed through lease separators and/or
field separation facilities. These facilities also control the
quality of the natural gas stream to be marketed. Cycling
plants are classified as natural gas processing plants.

Proved Reserves, Crude Oil: Proved reserves of crude oil
as of December 31 of the survey year are the estimated
volumes of all liquids defined as crude oil, which geological
and engineering data demonstrate with reasonable certainty
to be recoverable in future years from known reservoirs under
existing economic and operating conditions.

Operator: The person responsible for the management and
day-to-day operation of one or more crude oil and/or natural
gas wells as of December 31, 2009. The operator is generally
a working interest owner or a company under contract to the
working interest owner(s). Wells included are those, which
have proved reserves of crude oil, natural gas, and/or lease
condensate in the reservoirs associated with them, whether
or not they are producing. Wells abandoned during 2009 are
also to be considered operated as of December 31, 2009.
(See Person, Proved Reserves of Crude Oil, Proved
Reserves of Natural Gas, Proved Reserves of Lease
Condensate, Survey Year, and Reservoir)

Reservoirs are considered proved if economic producibility is
supported by actual production or conclusive formation test
(drill stem or wire line), or if economic producibility is
supported by core analyses and/or electric or other log
interpretations. The area of an oil reservoir considered
proved includes:
• that portion delineated by drilling and defined by gas-oil
and/or oil-water contacts, if any
• the immediately adjoining portions not yet drilled, but
which can be reasonably judged as economically
productive on the basis of available geological and
engineering data.

Ownership: (See Gross Working Interest Ownership
Basis)

In the absence of information on fluid contacts, the lowest
known structural occurrence of hydrocarbons is considered to
be the lower proved limit of the reservoir.

Parent Company: A firm that directly or indirectly controls
another entity. (See Affiliated {Associated} Company and
Control)

Volumes of crude oil placed in underground storage are not
considered proved reserves.

Person: An individual, a corporation, a partnership, an
association, a joint-stock company, a business trust or an
unincorporated organization.

Reserves of crude oil which can be produced economically
through application of improved recovery techniques (such as
fluid injection) are included in the proved classification when
successful testing by a pilot project, or the operation of an
installed program in the reservoir, provides support for the
engineering analysis on which the project or program was
based.

Pool: In general, a reservoir. In certain situations a pool may
consist of more than one reservoir. (See Field Area)
Production, Crude Oil: The volumes of crude oil that was
extracted from oil reservoirs during the survey year. These
volumes are determined through measurement of the
volumes delivered from lease storage tanks or at the point of
custody transfer, with adjustment for:

Estimates of proved crude oil reserves do not include the
following:
• oil that may become available from known reservoirs in
the future
• natural gas liquids (including lease condensate)
• oil, the recovery of which is subject to reasonable doubt
because of uncertainty as to geology, reservoir
characteristics, or economic factors
• oil that may occur in undrilled prospects

• net differences between opening and closing lease
inventories
• basic sediment and water
• Crude oil used on the lease is considered production.

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• oil that may be recovered from oil shales, coal, Gilsonite
and other such sources.
•
It is not necessary that production, gathering or transportation
facilities are installed or operative for a reservoir to be
considered proved.

It is not necessary that production, gathering or transportation
facilities are installed or operative for a reservoir to be
considered proved. It is to be assumed that compression will
be initiated if and when economically justified.

Proved Reserves, Lease Condensate: Proved reserves of
lease condensate as of December 31 of the survey year are
the estimated volumes expected to be recovered in future
years in conjunction with the production of proved reserves of
natural gas based on the recovery efficiency of lease and/or
field separation facilities currently installed. (See Lease
Condensate and Proved Reserves of Natural Gas)

Reservoir: A porous and permeable underground formation
containing an individual and separate natural accumulation of
producible hydrocarbons (oil and/or gas) which is confined by
impermeable rock or water barriers and is characterized by a
single natural pressure system.

Reserves: (See Proved Reserves)

Royalty Interests (Including Overriding Royalty): Rights
that entitle their owner(s) to a share of the mineral production
from a property or to a share of the proceeds from a property.
They do not contain the rights and obligations of operating
the property and normally do not bear any of the costs of
exploration, development, and operation of the property.

Proved Reserves, Natural Gas: Proved reserves of natural
gas as of December 31 of the survey year are the estimated
volumes which analysis of geologic and engineering data
demonstrates with reasonable certainty to be recoverable in
future years from known reservoirs under existing economic
and operating conditions. Reservoirs are considered proved if
economic producibility is supported by actual production or
conclusive formation test (drill stem or wire line), or if
economic producibility is supported by core analyses and/or
electric or other log interpretations.

Subdivision: A prescribed portion of a given State or other
geographical region defined in this publication for statistical
reporting purposes.
Subsidiary Company: A company which is controlled
through the ownership of voting stock or a corporate joint
venture in which a corporation is owned by a small group of
businesses as a separate and specific business or project for
the mutual benefit of the members of the group. (See
Control)

The area of a gas reservoir considered proved includes:
• that portion delineated by drilling and defined by gas-oil
and/or gas-water contacts, if any
• the immediately adjoining portions not yet drilled, but
which can be reasonably judged as economically
productive on the basis of available geological and
engineering data.

Survey Year: The year to which data reported on this form
pertains.
Total Operated Basis: The total reserves or production
associated with the wells operated by an individual operator.
This is also commonly known as the gross operated or 8/8ths
basis.

In the absence of information on fluid contacts, the lowest
known structural occurrence of hydrocarbons is considered to
be the lower proved limit of the reservoir.

Working Interest: Rights that permits the owner(s) to
explore, develop, and operate a property. The working
interest owner(s) bear(s) the costs of exploration,
development, and operation of the property. In return for
these investments, the owner(s) is (are) entitled to a share of
the mineral production from the property or to a share of the
proceeds from the property.

Volumes of natural gas placed in underground storage are
not considered proved reserves.
For natural gas reserves, wet after lease separation, an
appropriate reduction in the reservoir gas volume must be
made to cover the removal of the liquefiable portions of the
gas in lease and/or field separation facilities and the
exclusion of nonhydrocarbon gases where they occur in
sufficient quantity to render the gas unmarketable.

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MAPS OF SELECTED STATE SUBDIVISIONS

Alaska Subdivisions and U.S. Geological Survey Quadrangles

Source: After U.S. Geological Survey

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Subdivisions of California

Source: Energy Information Administration, Office of Oil and Gas.

10

Subdivisions of Louisiana

Source: Energy Information Administration, Office of Oil and Gas

11

Subdivisions of New Mexico

Source: Energy Information Administration, Office of Oil and Gas

12

Subdivisions of Texas

Source: Energy Information Administration, Office of Oil and Gas

13

Western Planning Area, Gulf of Mexico Outer Continental Shelf Region

Source: After Minerals Management Service, U.S. Department of the Interior

14

Central Planning Area, Gulf of Mexico Outer Continental Shelf Region

Source: After Minerals Management Service, U.S. Department of the Interior

15

Eastern Planning Area, Gulf of Mexico Outer Continental Shelf Region

Source: After Minerals Management Service, U.S. Department of the Interior.

16