Methodology
The method is written down and versioned before a well is assessed.The numbers in it are yours.
BarrierLedger implements a written method profile. It does not carry an opinion about what your thresholds should be — it carries the ones your integrity policy sets, applied consistently and recorded.
How a profile is governed
The method profile
A profile is a document the platform follows.
One profile covers one well type. It defines the rules end to end, so an assessment can be explained without reading the code that produced it.
MAWOP/MAP determination
Which value governs each monitored annulus, where it came from, and the rule that decides between several applicable limits.
Assessment algorithm
How a period reading is classified against the governing limit, which trend rules apply, and what each outcome sets.
Well status logic
The two-barrier model, the status vocabulary, every transition rule, and how incidents, tests and overrides affect status.
SCP handling
The policy for wells that cannot be bled to zero, handled as a first-class exception path with its own acceptance criteria.
Exception policies
Missing or stale readings, overdue tests, out-of-range data, a missing governing limit, an annulus with no method — each with its status effect, flag and whether it blocks the review.
Test scheduling
Frequencies per test type and annulus, the grace period, the escalation path, and what evidence closes a test.
Risk ranking
The likelihood and consequence matrix, what feeds each score, and how risk ranks a dashboard. The matrix is supplied, not assumed.
Manual overrides
Who may request and who may approve, what may never be overridden, the mandatory reason, the expiry, and the rule that an override never rewrites the computed result.
Tolerances
The numeric tolerances and the level each applies at — annulus, well or asset, reading or monthly — and the rule that a tolerance may never silently widen a band or suppress an exception.
Worked examples
Every rule and every exception gets a worked example whose expected output is computed independently before the engine is written against it.
Profile versioning
A change to a profile creates a new version. Completed assessments keep the version they used.
The barrier model
Two-barrier envelopes, versioned per well.
Each well carries versioned barrier envelopes and barrier elements, and a schematic drawn from the register itself. Status is expressed per annulus and per well from the same vocabulary.
What the envelope model carries
- The barrier elements that make up each envelope, from the barrier-element templates for that archetype.
- The annulus-to-envelope mapping, so an annulus outcome moves the right envelope and not just a colour.
- A schematic rendered per well from strings, deviation survey, cement tops, packers and junction metadata.
- A versioned envelope history, so a change to the model is visible rather than retrospective.
Status vocabulary
One annulus, start to finish
Six steps, and none of them skip the record.
This is the path a single annulus takes through an assessment. Every step contributes something a reviewer can point at.
- 01
The governing limit
The annulus’s MAWOP/MAP value is read as master data, with its source, its date and the reference behind it. Where several limits apply, the assessment compares against the governing limit and records which one governed and where each came from.
- 02
Band classification
The reading is classified against the bands in the profile for that well type, expressed as a percentage of the governing limit. The band boundaries are profile data, not constants in the engine.
- 03
Trend rules
A sustained rise across the profile’s configured window produces its own outcome, separate from a single high reading, and raises a bleed-off / SCP diagnostic action. The trigger and the acceptance criteria are profile data supplied by you.
- 04
One outcome, with its effect
Exactly one outcome is recorded per assessed annulus per assessment, together with the flag raised, the effect on status, the action required and whether it blocks the review.
- 05
Roll-up to the well
Annulus outcomes roll up to the well through the profile’s own precedence rules, and the well’s barrier envelopes are evaluated against the same profile version.
- 06
Provenance
The run keeps its inputs hash, source-file hashes, the method-profile version, the engine build, the schema version, and any override and approval record attached to it.
Determinism is part of the method, not a performance claim: the same inputs and the same profile version produce the same outcome, and a re-run supersedes the previous assessment instead of overwriting it.
Where the numbers come from
Nothing here is our opinion.
Integrity assessment is not a place for a vendor’s default. Four things are deliberately yours.
We do not invent a threshold
No band boundary, trend rate, staleness limit, grace period or tolerance ships as a default. Each is supplied in the profile, cited to its source, and versioned.
We do not compute your MAWOP for you
In the current profile the value is imported or entered as master data with its source and date. Deriving it from component ratings and casing design limits is a separate piece of work and is not presented as done.
We do not let one profile serve two well types — or two regimes
A profile covers one archetype. Injectors and disposal wells get their own profiles, and a profile is never stretched to cover a well type it was not written for.
We do not write your submissions
Outputs are in-house integrity reports. The platform does not file with a regulator, certify compliance or approve a well.
The reference set is yours, not ours
Worked examples before engine code
Versioning
An assessment made last year still explains itself this year.
Method profiles change. The record of what was applied should not change with them.
A version, not an edit
Changing a profile creates a new version. The old version stays readable, so an assessment made last year can still be explained this year.
Assessments keep their version
A completed assessment records the profile version it used and is not silently re-interpreted when the profile moves on. Comparing two versions is an explicit act, not a side effect.
Signature gates use
A profile version must be signed before it can be used to assess anything. The engine implements the profile; it does not improvise around a gap in it.
Reconciliation, in the same discipline
Methodology FAQ
Questions about the method.
“Our wells are unusual.”
Before a well is assessed, the method for its type will be written down, versioned and signed — that is the commitment, and a profile that is not signed cannot assess anything. If your wells need different rules, that is a method conversation, not a code change.
“What about regulators?”
We do not produce regulatory submissions and we do not file anything on your behalf. The platform produces in-house integrity reports — the record you prepare your submissions from. You remain responsible for regulatory submissions and official well records.
Which well types can be assessed?
Method profiles are per well type, and one profile never serves another type. A well whose type has no signed profile is reported unassessable — it is never assessed under another type’s profile to make a plan or a dashboard look complete.
Where does the MAWOP or MAP value come from?
Each monitored annulus carries its own MAWOP/MAP value as master data with its source, date and reference, imported with your register or entered directly. The platform compares readings against that value; it does not derive the value from component ratings.
What happens when a well cannot be bled to zero?
The method proposes that a well that cannot be bled to zero is treated as a first-class exception path rather than a footnote: the assessment records the exception, the flag and whether it blocks the review. The definition of SCP and the acceptance criteria come from your integrity policy and are recorded in the profile — we do not adopt a regulator’s or a standard’s definition by default.
Bring us the policy behind your limits.
Send the register and the document your MAWOP/MAP values come from. We will tell you which rules we can apply as written, which need a profile of their own, and what is missing.