Data Driven. Solution Focused.
CAPP Guidelines
H2S Release Rate Assessment and Audit
Forms July 2012 Presentation
Presented by Andy Newsome
Wednesday October 3, 2012
www.XITechnologies.com
Welcome
• H2S understanding required for compliance and to avoid any
negative impact on public safety
• ERCB continually evolving regulations and audit requirements
means we as an industry need to have processes and tools that
will evolve as well
Today’s goals:
•
•
•
Due Diligence
Educate
Ease Anxiety
Disclaimer
This is not a full review of the CAPP guidelines. We recommend you take the time to review the
guidelines in its entirety.
Agenda
10:10 am – 10:15 am
History
10:15 am – 11:00 am
CAPP Guidelines
11:00 am – 11:30 am
Questions & Answers
11:30 am – 12:00 pm
Networking and Refreshments
History
1997
• ERCB and CAPP members meet
to discuss need for consistency
CAPP Guidelines exist to:
2000
• XI’s H2S Gold Search created
• Clarify Requirements
• Streamline Methodology
2002
• Directive 56, formerly Guide 56,
released by ERCB
2010
• Need for ERCB and CAPP
information realignment
• Best Practices
• Templates
CAPP Guidelines
Review
July 2012
H2S Release Rate Assessment and Audit Forms
1 Introduction
“Regulators in Western Canada mandate the preparation of
an H2S release rate before an application to drill a well can
be submitted.”
Too many times research is done after the fact
July 2012
H2S Release Rate Assessment and Audit Forms
Page 1-1
1 Introduction – Guideline Changes
“The industry is now required to determine the H2S release rate
potential for all wells, regardless of the H2S concentration.
Consequently, the maps no longer apply.”
• Maps no longer
apply
• Determine the H2S
release rate (RR)
potential for all
wells
July 2012
H2S Release Rate Assessment and Audit Forms
Page 1-1
1 Introduction – Guideline Changes
“elaboration of search area requirements,”
Regulators’ Perspective
Industry’s Perspective
Too hard to create rules to
encompass all scenarios
The more subjectivity, the
harder it is to comply
July 2012
H2S Release Rate Assessment and Audit Forms
Page 1-1
1 Introduction – Guideline Changes
“removal of the outdated EPZ calculations and
provision of guidance for using the ERCBH2S
program for calculating the EPZ based on the
maximum H2S release rate as determined from
the guidelines in this document”
• Directive 71 took over EPZ calculation rules
• CAPP Guidelines and H2S Search were impacted
July 2012
H2S Release Rate Assessment and Audit Forms
Page 1-1
1 Introduction – Other Guideline Changes
Please review the rest of the changes on your own:
• “Clarification of when net pay adjustments are necessary”
• “Streamlining of the calculation procedure”
• “Updates to horizontal well calculations to account for multiple
stimulations”
• “Addition of commingling guidelines”
• “Inclusion of newer best-practice procedures that were not
documented in the previous guidelines”
• “Addition of acid gas injection guidelines”
• “Addition of guidelines for producing wells (post-testing phase)”
• “Alignment with Alberta ERCB regulations and British Columbia
OGC regulations”
July 2012
H2S Release Rate Assessment and Audit Forms
Page 1-1
1 Introduction
“It is the user’s responsibility to determine the appropriate level of
analysis required for each specific application;…
The EPZ includes
residents or
areas with high
public usage
The well is
located within
5.0 km of an
urban density
development
(>50 dwellings)
The well is a
critical or special
sour well
Determine level of expertise and
types of resources required
July 2012
H2S Release Rate Assessment and Audit Forms
Page 1-1
2.1 Maximum H2S Release Rate Determination
“The H2S RR for each potential zone that may contain H2S gas is
determined by multiplying the maximum H2S content and AOF rate
as determined by the geological and engineering review of the
available data. The paired data points need not be from the same
well. The sum of the RRs from each zone becomes the
cumulative RR for the drilling, completion/servicing, and
suspended/producing RR, as applicable to the project.”
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-1
2.1 Maximum H2S Release Rate Determination
H2S Search:
• Identify every potential zone
• For each zone
• Search H2S and flow rate sample set
• Assign both a representative sample
• Calculate RR
• Provide cumulative rate for entire well
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-1
2.1 Maximum H2S Release Rate Determination
“The H2S RR is used as an input to calculate an EPZ. The EPZ is
calculated using the ERCBH2S…”
ERCB Directive 71:
“The licensee must use
ERCBH2S properly, prior to
filing the ERP, to calculate
the size of the EPZ for sour
gas with a hydrogen sulphide
(H2S) concentration of 0.1
moles per kilomole
(mol/kmol) (0.0001 mole
fraction or 100 ppm) or
greater.”
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-1
2.2 H2S Release Rate Assessment – H2S Release
Rate Process Flow
Requirement to Drill Well
Requirement to Drill Well
Need geological prognosis
• If you consider H2S prior to
approving well, Surface
Land / Geology can follow
the basics of these
guidelines too
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-2
2.2 H2S Release Rate Assessment – H2S Release
Rate Process Flow
Requirement to Drill Well
Summarize formations
that may be
productive. Identify
casing points/hole
sections
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-2
2.2 H2S Release Rate Assessment – H2S Release
Rate Process Flow
• Start with all
formations
• Identify all relevant
formations (sour or
not)
• Know well design
(casing) beforehand
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-2
2.2 H2S Release Rate Assessment – H2S Release
Rate Process Flow
Requirement to Drill Well
Collect and validate gas
analysis data. Collect flow
data for sour zones
• Representative data points
for every formation
• ‘Geologically analogous’
• Validation – not just
collection
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-2
2.2 H2S Release Rate Assessment – H2S Release
Rate Process Flow
Requirement to Drill Well
Complete engineering
adjustments for each
formation
(unstimulated conditions)
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-2
2.2 H2S Release Rate Assessment – H2S Release
Rate Process Flow
• Use formulas from
guidelines in
sections 5 and 6
• Apply well
specifications
against H2S Search
RRs to determine
adjustment
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-2
2.2 H2S Release Rate Assessment – H2S Release
Rate Process Flow
Requirement to Drill Well
Complete engineering
adjustment for completion
interval
(stimulated condition)
• RRs for all operations
• Address drilling and
completion operations
individually
• Ensure chosen sample is
best and most
representative flow rate
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-2
2.2 H2S Release Rate Assessment – H2S Release
Rate Process Flow
Requirement to Drill Well
Determine H2S RR for Each
Hole Section, Completion
Zone, and Producing Zone
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-2
2.2 H2S Release Rate Assessment – H2S Release
Rate Process Flow
Directive 56 – Schedule 4.3
Drilling
July 2012
All forms cumulative
Completions
Calculate target zones –
all forms cased
Production
Similar to Completions
H2S Release Rate Assessment and Audit Forms
Page 2-2
2.2 H2S Release Rate Assessment – H2S Release
Rate Process Flow
Requirement to Drill Well
Determine Well
Classification for Drilling,
Completion, and
Producing Operations
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-2
2.2 H2S Release Rate Assessment – H2S Release
Rate Process Flow
Directive 56 – Table 7.1
• Identifies Well
Classifications
• Based on:
• Maximum H2S
content
• Potential H2S RR
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-2
2.3.1 Release Rate Cases - Drilling Case
“If multiple casing strings are cemented in place during a drilling
operation, then separate RRs can be determined for each hole
section.”
• Casing points splits
potential release rate in two
• Intermediate hole
release rate
• Main hole (after uphole
zones isolated)
• Higher of the two (or more) is to be applied as drilling RR
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-3
2.3.1 Release Rate Cases - Drilling Case
“An assessment of shallow formations (above the top of the
Mannville) is generally not necessary if deeper zones will contribute
to the H2S release rate of the well…”
• Should expect shallow zones to be sweet
• Shallow sour zones are suspect
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-3
2.3.1 Release Rate Cases - Drilling Case
“…unless it is known that the shallower zones may significantly
impact the H2S release rate.”
• Only if deeper zones to be penetrated are sour
• If shallow zone is sour, likely an erroneous or
‘discountable’ sample
• Deal with the test or discount the form and document
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-3
2.3.1 Release Rate Cases - Drilling Case
“During drilling operations, the formations are considered to be
unstimulated. Therefore, flow adjustments to a skin value of zero
may be made to offset data from a stimulated zone…”
• Post stimulated flow rates are
flagged
• Use more representative
sample
• Apply formulas from Sec 5,
apply adjustment in H2S
Search
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-3
2.3.2 Release Rate Cases – Compl./Servicing Case
“Most often, the primary target represents the highest H2S release
rate potential. However, in some cases, a secondary zone may
represent the highest stimulated H2S release rate…”
• Reference formation with the higher H2S
• Exceptions to this are in the guidelines
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-3
2.3.2 Release Rate Cases – Compl./Servicing Case
“Vertical flow analysis may be conducted to further adjust from
sandface AOF to surface AOF. If completion operations are restricted
to “wellhead on” techniques…”
Ensure you:
• Research reference well
to understand test
conditions
• Reference other data
sources for clarification
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-3
2.3.3 Release Rate Cases - Producing Case
“..same issues identified for completion H2S RR calculations apply to
producing…also used to set the “level” designation of the well…”
• Level designation summary, found at:
http://ercb.ca/ids/pdf/id97-06.pdf
• Compare well design and flow rate to reference well
• Consider tubing configuration/potential flow restrictions
• Apply results to summary sheet
• Update level designation summary pre and post drilling
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-4
2.3.4 Release Rate Cases - Commingling
“For any of the drilling, completion/servicing and producing cases,
situations may arise where more than one sour formation is open to
flow into the wellbore…”
• Cannot just add two RRs must consider backflow pressures too
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-4
2.3.4 Release Rate Cases - Commingling
“If one or more of the offset analogue wells has only multi-zone AOF
data, and the proposed well will be completed in only one of those
zones , then the analogue AOF test may be adjusted…”
• Tests spanning
multiple formations:
• Potential formation
misassignment
• Potential flow from
multiple sources
July 2012
H2S Release Rate Assessment and Audit Forms
Page 2-5
3.1 Data Sampling - Search Area
“…concentrations tend to vary… within a single well from sample to sample...”
“…better understanding of the geological analogue allows the analyst to
restrict data to more representative samples…”
“…as the number of data points in a representative sample set increase, the
confidence of the data quality also increases.”
• 10 wells provided for each formation
• Proximal search often gives best geological representation
• Involve geology when unsure
July 2012
H2S Release Rate Assessment and Audit Forms
Page 3-6
3.1 Data Sampling - Search Area
“…3x3 twp study area…to define appropriate geological analogies
from which representative H2S and AOF samples can be obtained.”
• Doesn’t mean ALL samples
within 3x3 townships
• Consider all present pools
within 3x3 townships as
potentially analogous
• Board Order System.
http://ercb.ca/data-andpublications/orders/board-order-system
July 2012
H2S Release Rate Assessment and Audit Forms
Page 3-6
3.1 Data Sampling - Search Area
“…smaller review areas may be sufficient if data can be obtained.
Conversely, the best geological analogues may be more distant…”
“minimum five representative analogous samples for H2S and AOF…
However, search area may become so large that it extends beyond
any geological correlation…less than five samples is warranted.”
• Dependent on your area and available data
July 2012
All 10 wells found
within 5-10km
Consider expanding
search area
Farthest sample
found >30km
Should be sufficient
H2S Release Rate Assessment and Audit Forms
Page 3-6
3.1 Data Sampling - Search Area
“Data points are representative if they cannot be discounted for
technical reasons. If samples that have a higher H2S concentration
than the sample selected are discounted, then the applicant must
support the decision with geological or engineering reasoning.”
July 2012
H2S Release Rate Assessment and Audit Forms
Page 3-6
3.1 Data Sampling - Search Area
• Factors to consider when
authenticating both gas
analyses and flow rates:
• Formation assignment
• Distance
• Test date
• Sample type
• Most common feedback
from ERCB:
• “Document/explain your
work”
July 2012
Resources provided by XI:
Browse Feature
Assign a different sample
Re-assign test
Engineering/Geological
Discussion
• Footnotes
• Data alerts and flags
• InfoXchange
•
•
•
•
H2S Release Rate Assessment and Audit Forms
Page 3-6
3.1 Data Sampling - Search Area
Data Alerts, Flags, and Footnotes
July 2012
H2S Release Rate Assessment and Audit Forms
Page 3-6
3.1 Data Sampling - Search Area
Alerts
Issues
• Non Identified Sour
• Spans multiple
formations
• Suspicious interval
• InfoXchange record
July 2012
H2S Release Rate Assessment and Audit Forms
Page 3-6
3.1 Data Sampling - Search Area
“Analysts may find some samples show “trace” H2S concentrations
that are not quantified or show very low concentrations in areas
that are typically considered to be sweet.”
• Will help industry in reducing the number of wells
licensed as sour unnecessarily
July 2012
H2S Release Rate Assessment and Audit Forms
Page 3-6
3.1 Data Sampling - Search Area
• “All samples with H2S show values at less than 50 ppm conc”
• “Over 80% of the representative samples are sweet (0% H2S)”
• “The Operator believes the trace samples are erroneous.”
• If met it can allow analysts to discount trace H2S samples
July 2012
H2S Release Rate Assessment and Audit Forms
Page 3-6
3.1.1 Data Sampling - Drilling Inside Existing Pool
Penetrating an
existing pool
(Must be able to demonstrate)
July 2012
Only reference data samples from
pool itself
Highest H2S
concentration
Use unless it can be discounted or
you can demonstrate a trend to
prove otherwise
Data sampling
insufficient
Consider outside data points
H2S Release Rate Assessment and Audit Forms
Page 3-7
3.1.1 Data Sampling - Drilling Inside Existing Pool
10 Gas Analyses for Pekisko
Pekisko A
Max H2S content: 0.37%
Pool Max: 7.23%
(Pekisko A identified)
July 2012
H2S Release Rate Assessment and Audit Forms
Page 3-7
3.1.2 Data Sampling - Drilling Outside Existing Pool
Guidelines:
• Start within 5 km
• Minimum of 3 reference pools
• The pool max of a multi-well pool is the most representative, and
considered one test (geologically analogous pools only)
• You are not forced to find data simply to meet the requirement
H2S Search:
• Minimum 5 km, all samples considered, 10 highest chosen
• Beyond 5km, 10 wells found.
• Any pools identified, Pool Max provided
• Get more data if needed
July 2012
H2S Release Rate Assessment and Audit Forms
Page 3-7
3.1.2 Data Sampling - Drilling Outside Existing Pool
10 Gas Analyses for Banff
Max H2S content: 0.17%
July 2012
Banff Pools identified in search
(within 5 km)
H2S Release Rate Assessment and Audit Forms
Page 3-7
3.2 Data Sampling - H2S Sampling and Data Quality
• Use for revising your production RR post completion
• Identify which sample types are more reliable
July 2012
H2S Release Rate Assessment and Audit Forms
Page 3-8
4.1 Geologic Interpretation of Potentially Sour
Formations
Guidelines:
• Consider every potential
formation individually
H2S Search:
• Stay conservative, make
sure all are addressed
• Reliable geological
prognosis
• Footnotes provided for
formation related alerts
and to document results
July 2012
H2S Release Rate Assessment and Audit Forms
Page 4-9
4.2 Gas Cap Versus Oil Leg Flow Rates
Regulations
If the gas
analysis is
taken from a
solution gas
sample
July 2012
Can result in a
high release
rate for your
well
H2S Release Rate Assessment and Audit Forms
Calculate a
release rate for
the gas cap and
oil leg
individually
Page 4-9
4.3 Wellbore Design Considerations and Slant Wells
Regulations:
• Intermediate casing
can have significant
effect on H2S RR and
EPZ planning
• Slant wells <30∘ can
be considered vertical
H2S Search:
• Split Summary
July 2012
H2S Release Rate Assessment and Audit Forms
Page 4-9/10
5 Engineering Adjustments
6 EPZ Modeling
Engineering Adjustments
•
•
•
•
•
•
•
•
5.1 Calculate AOF
5.2 Adjustment for Reservoir Pressure
5.3 Adjustment to Zero Skin
5.4 Adjustment for Net Pay or Contacted Reservoir Length
5.5 Adjustment for Contacted Reservoir Length
5.6 Adjustment for Stimulation of Wells
5.7 Adjustment From Sandface AOF to Wellhead AOF
5.8 Acid Gas Injection Wells
EPZ Modeling
July 2012
H2S Release Rate Assessment and Audit Forms
Page 4-9/10
Data Driven. Solution Focused.
Questions
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