EIA

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EIAs Weekly Underground Natural Gas Storage
Program

• Federal Energy Regulatory Commission
• Technical Conference
• September 28, 2004
• Elizabeth Campbell
• Energy Information Administration (EIA)
• Elizabeth.Campbell_at_eia.doe.gov

www.eia.doe.gov
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Overview of Presentation

• Survey respondents and sample
• Survey content
• Collection methods
• Estimation
• Release of estimates

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EIA Underground Natural Gas Storage
SurveysWeekly and Monthly
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Terms for Natural Gas in Storage
Working Gas The volume of gas in the reservoir
that is in addition to the base gas. It may or
may not be completely withdrawn during any
particular withdrawal season. Conditions
permitting, volumes may be withdrawn and
reinjected more than once during any
season. Base Gas The volume of gas needed as a
permanent inventory to maintain adequate
reservoir pressures and deliverability rates
throughout the withdrawal season.

• Source EIA-912 Weekly Underground Natural Gas
  Storage Report Instructions.

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Weekly Storage Report Regions

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Weekly Underground Natural Gas Storage Report
Form EIA-912
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Overview of Operations

• Working gas volumes as of 900 a.m. on Friday
  due by COB Monday
• Respondents report company volumes at a regional
  level estimates allowed
• EIA edits data quality comparisons provided to
  monthly surveys
• EIA provides secure work areas for processing

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Revision Policy for Respondents

• Revised data should be submitted whenever the
  measure of working gas for the prior week in any
  region has been revised by 500 million cubic feet
  or more.
• Respondents are requested to submit a revised
  form when that happens

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Revision Policy for the EIA Weekly Natural Gas
Storage Report (WNGSR)

• Revisions shall be disseminated in the WNGSR
  according to the established schedule and shall
  occur when the effect of reported changes is at
  least seven billion cubic feet at either a
  regional or national level.
• If a revision is made, changes to all regions
  shall be recorded.
• Changes shall only lead to a published revision
  when it exceeds the seven billion cubic feet
  threshold.
• Revisions shall not be disseminated on an
  unscheduled basis.
• EIA will include revisions in the estimates as
  part of the next release of the Weekly Natural
  Gas Storage Report on its web site.

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Estimation Formula

• where
• Y Estimate of working gas for a region
• A Estimation factor in the given region
• wwg Weekly working gas in storage for sample
  operators in region for the collection week
• n Number of operators in the estimation
  companies group
• m Number of operators in the base group hence
  the total number of operators in the sample group
  equals n m
• K Volumes of working gas that exhibited little
  or no variation at a company level, for companies
  in the nonsampled group

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Weekly Natural Gas Storage Report
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Weekly Natural Gas Storage Report
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www.eia.doe.gov
www.eia.doe.gov