Gas Measurement Issues

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Gas Measurement Issues
BLM
Introduction and Issues
GMT created by RPC, but there is a
history Williams Common Static Wafer
V-Cone Purpose and Accomplishments Current and
Pending Issues
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Gas Measurement Issues
BLM
Current Team Members
Steve Klimetz, PE, Milwaukee FO John
Shufflebarger, IE Coordinator, Wyoming SO Gary
Roth, PET, Buffalo FO Rich Estabrook, PE,
California SO (Ukiah) Others
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Gas Measurement Issues
BLM
The beginning1999
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Common Static/Common Temperature
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Standard AGA Orifice Measurement
DP
Tf
SP
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DP1
Q1(DP1, SPc, FTc)
SPc
DP2
Q2(DP2, SPc, FTc)
FTc
DP3
Q3(DP3, SPc, FTc)
Butterfly Valves
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Gas Measurement Team
BLM

• Variance request denied
• State Director Review
• 3 years later

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?
Documentation
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Gas Measurement Team
BLM
The team

• PETs
• PEs
• Gas measurement expertise
• Regulatory expertise

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Gas Measurement Team
BLM
Criteria for approval

• Overall measurement uncertainty lt 3
• No significant bias
• Objective inspection procedures
• Document uncertainty and lack of bias

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Gas Measurement Team
BLM
Analysis approach

• Require 3rd party testing to establish and
  document uncertainty and bias
• Cooperation and communication a key

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Gas Measurement Team
BLM
Result

• Variance was approved
• COAs included operating limits established by
  lab testing

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Gas Measurement Team
BLM
Result

• Establish standard criteria and method for
  reviewing variances
• Use this standard Bureau-wide for consistency

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Gas Measurement Team
BLM
GMT Analysis of the Wafer V-Cone

• Variance requests for Wafer V-Cones in several
  Field Offices
• Use criteria developed for Williams Common
  Static to review Wafer V-Cones
• API standard for testing (5.7) had major
  loopholes
• GMT helped get API 5.7 changed (22.2) to close
  loopholes

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Gas Measurement Team
BLM
GMT Analysis of the Wafer V-Cone

• Additional testing required
• IM 2007-022 developed to offer guidance on
  approval

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GMT Purpose Accomplishments

• Why was the GMT Created?
• Recently
• Recommendation of the Royalty Policy Committee
• Recommendation adopted by the WO
• To assess new gas measurement technology

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GMT Purpose Accomplishments

• Historically To address issues like
• Offices were struggling with new measurement
  methods
• Approval of EFCs Wafer V-cones varied by Office
• Case by case approvals created large workloads.
• Approvals did not consider impacts to IE.
• Need for guidance on new issues like Btu or F.C.

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GMT Purpose Accomplishments

• What is the Purpose of the GMT?
• Official Purpose (RPC) Assess new technology
• Flow Conditioners
• Btu Standards
• Alternate Primary Elements (4 hole orifice, etc.)

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GMT Purpose Accomplishments

• What is the Purpose of the GMT?
• Other Purposes
• To be a resource to FO, SO, WO
• Help interpret and use meas. data, specs,
  protocols, etc
• To help develop/clarify policy and regulatory
  issues
• Consult/assist w/ insp., audit, enfor., actions

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GMT Purpose Accomplishments

• What is the Purpose of the GMT?
• Other Purposes
• Act as BLM liaison with industry organizations
  manufacturers.
• Help establish BLM gas measurement standards
• Assist w/ civil and criminal cases upon request

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GMT Purpose Accomplishments

• What has the GMT Accomplished?
• Developed WO IM 2006-233 Issuing NTL for EFCs
• Assisted issuance of State NTLs for EFCs
• Developed WO IM 2007-022 Wafer cone approval
• Participating on various API Committees

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GMT Purpose Accomplishments

• What has the GMT Accomplished?
• Developed criteria for analyzing new measurement
  device
• Conducted training sessions throughout BLM
  Offices
• Developed Uncertainty Calculator
• Laid ground work for revision to OO5

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Gas Measurement Team
BLM
Current/pending issues

• BTU sampling, analysis, reporting
• Allocation/Commingling/Beneficial Use
• Need for Low flow policy
• Volume statement verification
• New measurement devices

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Gas Measurement Team
BLM
Current/pending issues, cont

• Flow Conditioners
• EFC NTL status
• API update

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Gas Measurement Team
BLM
BTU/Gas Gravity
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20
15
Royatly Error,
10
5
Gravity
0
0
5
10
15
20
Gas Sampling/Analysis Error,
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Gas Measurement Team
BLM
BTU/Gas Gravity Sampling

• 1 sample per year for BTU required by OO5
• No sampling standards
• No analysis standards
• No requirement of where sample is taken
• Potential for bias is significant

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Gas Measurement Team
BLM
BTU reporting

• 3 methods of reporting
• Dry
• Wet (saturated)
• Real

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BTU Dry basis
Sales Volume 100 Mcf x 1000 MBTU/Mcf 100
MMBTU
100 Mcf natural gas 1000 MBTU/Mcf
Total Volume 100 Mcf
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BTU Wet basis
Sales Volume 98.26 Mcf x 1000 MBTU/Mcf
98.261 MMBTU
1.74 Mcf water vapor
98.26 Mcf natural gas 1000 MBTU/Mcf
Total Volume 100 Mcf
at 14.73 psi 60ºF
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BTU Real basis
Sales Volume 99.5 Mcf x 1000 MBTU/Mcf 99.5
MMBTU
0.5 Mcf water vapor based on analysis
99.5 Mcf natural gas 1000 MBTU/Mcf
Total Volume 100 Mcf
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Gas Measurement Team
BLM
BTU reporting

• 3 methods of reporting
• Wet (saturated)
• Dry
• Real
• BLM policy is wet, which results in up to a
  -1.74 in royalty

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Gas Measurement Team
BLM
Allocation Commingling
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• Lease measurement
• POM for each lease/CA/PA
• POM OGOR royalty point
• BLM stops at POM

WYW XXX
STATE
CA FEE
CA FED
STATE
FEE
Fuel
WYW XXX
MASTER METERS
GAS HANDLING COMPRESSION
GAS HANDLING COMPRESSION
Fuel
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• Allocation measurement
• BLM must inspect every meter
• Ensure beneficial use is proper and allocated
  correctly
• Account for complex allocation schemes
• Back-allocation of liquids
• Jurisdictional issues

WYW XXX
STATE
CA FEE
CA FED
STATE
FEE
Fuel
WYW XXX
MASTER METERS
GAS HANDLING COMPRESSION
GAS HANDLING COMPRESSION
Fuel
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Gas Measurement Team
BLM
Approval of Allocation Commingling

• Must ensure its in the publics interest and not
  just for operators convenience
• Production Accounting/verifiability
• Must identify all POMs involved!
• Ensure BLM authority and access
• Ensure Beneficial Use is allocated
  appropriately

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Gas Measurement Team
BLM
Low Flow Policy

• Many wells flowing at very low rates
• CBM
• Casing head gas
• Depleted producers

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Gas Measurement Team
BLM
Low Flow Policy, cont
What measurement standards should apply? What
should the threshold be? Leniency since risk of
significant mis-measurement is low Include in OO5
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Gas Measurement Team
BLM
Volume Statement Verification

• Goal Recalculate volumes for accuracy
• Rely on verifiable data and calculations
• Raw data DP, SP, Tf, flow time, IV
• Independent calculation of IMV
• V IMV x IV
• Red flag threshold gt 0.3

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Gas Measurement Team
BLM
Volume Statement Verification

• Must require IV in audit request
• Must issue written order if operator unable to
  provide IV
• Beware of 3rd party data services

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Issues New Meters
BLM

• Wafer V-Cone
• Rosemount 4-hole orifice
• Precision V-Cone
• Verabar (Accelabar)
• E-tube
• Ultrasonic

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Approved with conditions
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Rosemount 1595 Conditioning Orifice Plate The
Rosemount 1595 Conditioning Orifice Plate
simplifies installation by eliminating the need
for long straight-run required for accurate flow
measurement.
Withdrawn by manufacturer
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Precision V-Cone
Testing nearly complete
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Inquiries from manufacturer
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e-tube
Inquiries by manufacturer
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Ultrasonic
Case by case approval
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BLM
Issues Flow Conditioners

• Flow Conditioner Types
• Tube bundles/straightening vanes
• Isolating flow conditioners (flow
  conditioners)

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• Requirements for Upstream Piping
• Onshore Order 5 Requires compliance with AGA 3
  (1985)

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BLM
Issues Flow Conditioners
Isolating Flow Conditioners
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CPA 50E (flange) CPA TBR (tube bundle
replacement) (set screw) (CPA Canada Pipeline
Accessories)
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Daniel Profiler
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Savant pFC
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Set screw
Straightening Vanes Tube bundle
Orifice
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Set screw
Orifice
Flow Conditioner
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Orifice
Flow Conditioner
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BLM
Issues Flow Conditioners

• General Information
• Flow conditioners are not approved by AGA 3
  (1985) ?
• Require variance from Onshore Order 5
• They behave differently than straightening vanes
  ?
• AGA 3 installation diagrams do not apply
• Also not approved by AGA 3 (2000) (testing
  protocol only)
• BLM reviewing test data and will develop IM
  similar to wafer V-Cone IM (6 months)
• Interim guidance (1 month)

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BLM
Issues Flow Conditioners

• Enforcement Action
• If there is no variance on file
• Write INC using Onshore Order 5, III.C.3 as a
  reference
• Corrective action submit variance request

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BLM
Issues Flow Conditioners

• Approval
• Interim recommendation
• give provisional approval using manufacturer
  specs as a condition
• warn operators that this may change pending
  final review and guidance
• operator must identify make and model of flow
  conditioner on-site

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Issues NTL Status
BLM
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Issues API Update
BLM

• API 21.1 Electronic Gas Measurement
• Status Under revision
• Better define Integral Value
• New calibration requirements
• Better defined reporting requirements
• API 14.3.1 Concentric Square-edged Orifice
  Meters
• Status Revision balloted and approved new Y
  factor

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Issues API Update
BLM

• API 22.2 Testing Protocol for Differential
  Meters
• Status Under revision
• Better define testing requirements
• API 22.4 Testing Protocol for Transmitters
• Status Under development
• API 22.5 Testing Protocol for Flow Computers
• Status Under development

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Issues API Update
BLM

• API 20.1 20.6 Allocation Measurement
• Status Under revision