Oil rate
4,800
bopd · baseline
B annulus
31–34
barg · MAASP 70
B rebuild
21.2
barg at 48 h
A annulus
109
barg · gas-lift path
SCSSV leak
0.44
L/min · limit 0.50
Potential uplift
+400–600
bopd · not yet available
Current engineering disposition
REVIEW REQUIREDDo not approve the proposed +10% choke optimisation at this time.
Continued production at the current approved baseline can be considered conditionally, subject to IR-P17-2026-04, six-hourly B-annulus readings and escalation triggers. Evidence demonstrates sustained B-annulus behaviour and worsening rebuild, but not a proved leak location.
| What changed? | B pressure progressed from historical 0–3 barg to repeatable rebuild; 2026 rebuild reached 21.2 barg at 48 h. SCSSV leak increased from 0.31 to 0.44 L/min while still passing. |
| Trustworthy? | Replacement transmitter, controlled bleed/rebuild and long-term history support genuine sustained behaviour. |
| Questionable? | One isolated 68 barg spike and the 4 barg PTX/local-gauge disagreement. |
| Missing? | Overdue B-annulus fingerprint sample and definitive diagnostic isolation. |
| MAASP meaning? | Below 70 barg is not proof of acceptable integrity. |
Operating envelope
| Parameter | Current | Approved basis |
|---|---|---|
| A annulus | 109 barg | 95–115 normal MAASP 165 |
| B annulus | 31–34 barg | ≥15 review ≥40 escalate MAASP 70 |
| C annulus | 0.4 barg | 0–1 normal MAASP 30 |
| Gas lift | 4.2 MMscf/d | Restriction target ≤4.3 |
| Choke | 42% | No increase without WI approval |
Active restriction
IR-P17-2026-04 · issued 03 Sep · review/expiry 30 Sep 2026. No production increase without Well Integrity Engineer approval.
IR-P17-2026-04 · issued 03 Sep · review/expiry 30 Sep 2026. No production increase without Well Integrity Engineer approval.
What would change the decision?
- Immediate escalation: B ≥40 barg, rebuild >25 barg/24 h, confirmed active leak path, second barrier degradation, or C rise >3 barg.
- Supportive evidence: validated gauges, completed fingerprint, diagnostic pressure-response evidence and stable SCSSV trend.
- Increase gate: written WI approval, bounded mechanism, staged test envelope and enhanced surveillance.
Reasoning chain
CONTEXT → VALIDATE → DETECT → COMPARE → INTERPRET → HYPOTHESISE → ASSESS BARRIERS → ASSESS RISK → DECIDE → ACT → VERIFY → LEARN
Current state: evidence is sufficient to restrict the proposed increase, but insufficient to localise the source.
Trend explorer
Long-term history and decision-critical event points. Suspect data are explicitly excluded from strong conclusions.
Limit interpretation
| Signal | Observation | Interpretation |
|---|---|---|
| A annulus | 95–115 barg flowing | Expected gas-lift pressure. |
| B annulus | 31–34 barg | Above review level; sustained rebuild abnormal. |
| C annulus | ~0.4 barg | Stable; not proof of B integrity. |
Data quality gates
- 68 barg isolated spike: suspect.
- PTX 27.1 versus local gauge 31.0 barg: validate both.
- THT flatline: exclude from thermal conclusions.
- Six hours missing B data: do not interpolate.
- Fingerprint overdue: source attribution unresolved.
Barrier envelope
Simplified benchmark model, not a certified barrier diagram.
PRIMARY
Tubing · packer · tree · SCSSV · hanger sealsNo direct tubing failure evidence; packer uncertain; SCSSV functional but degrading.
SECONDARY
9 5/8 in casing · seals · annulus valvesNo leak localisation; casing and wellhead-seal hypotheses remain open.
OUTER
13 3/8 in casing · C annulusC stable; evidence against broader outer communication.
Barrier status register
| Element | Status | Reason |
|---|---|---|
| Production tubing | No demonstrated failure | No direct failure evidence. |
| Production packer | Uncertain | No conclusive direct test. |
| SCSSV | Functional / degrading | 0.44 versus 0.50 L/min; rising trend. |
| Tree valves | Pass | Latest tests pass. |
| 9 5/8 casing | Hypothesis open | No direct localisation. |
| A/B seals | Hypothesis open | No definitive isolation. |
| C containment | Stable | No correlated rise. |
Conditional failure hypotheses
Do not force one root causeRankings are decision aids, not probabilities.
Scenario laboratory
Select a scenario to see its effect on evidence, uncertainty and disposition.
Surveillance plan
| Activity | Status | Use |
|---|---|---|
| A/B/C review | Daily · current | Trend and operating correlation. |
| Manual B gauge | Weekly · disagreement | Investigate >2 barg difference. |
| Bleed/rebuild | Monthly while open | Record 1/4/8/12/24/36/48 h. |
| Fingerprint | Overdue | Compare with lift and produced gas. |
| SCSSV test | Current | Acceptance plus trend. |
Required next actions
- Maintain baseline; no increase without WI approval.
- Validate PTX and local gauge.
- Complete fingerprint sample.
- Run controlled pressure-response diagnostics.
- Trend SCSSV leak rate.
- Record B every 6 h flowing and every 4 h after bleed-down.
Evidence register and traceability
| Class | Source | Evidence | Engineering use |
|---|
Configuration control
| Document | Status | Value | Treatment |
|---|---|---|---|
| WI-ENV-P17-REV4 | CURRENT | B MAASP 70 barg | Governing basis. |
| WI-ENV-P17-REV2 | SUPERSEDED | B MAASP 85 barg | Traceability only. |
| IR-P17-2026-04 | ACTIVE | No increase without WI approval; GL ≤4.3 | Current restriction. |
| WSP-P17-2026 | CURRENT | Fingerprint while unresolved | Activity overdue. |