NS-17 — NorthSea Well Services Operations Workspace

Job overview — NS-17

NP-04 · Northern Pioneer · Caledonia Offshore Energy plc

About this workspace NorthSea Well Services uses a digital operations system for job management, equipment records, HSE documentation and reporting. Real systems include RigER, WellEz, Halliburton OpenWells and SAP FSM. Document structure follows real UKCS practice: Tier 1 — Caledonia's Well Operations Programme (operator-approved, Well Examiner signed per SI 1996/913 DCR); Tier 2 — NorthSea WS Job Pack / DOP (service company execution document); Offshore-only — Site Pack + ISSOW Permit to Work (platform-controlled, raised after arrival).

Client

Caledonia Offshore Energy plc

Asset

Northern Pioneer

Well

NP-04

Required WP

10,000 psi

MAWHP

10,000 psi

MASP

5,000 psi

Confirmed via TQ-001

Planned peak

7,200 psi

Operating margin

28%

Min required: 15%

Mob deadline

17 Aug 2026 — 06:00

Job status

Execution underway

Assigned personnel

Operations CoordinatorJames Reid

Field EngineerYou (candidate)

Outgoing FE — handoverPriya Mehta

Equipment & LogisticsSandra McKenzie

Client Ops Rep (offshore)Tom Calloway

Operating envelope — NP-04

MAWHP10,000 psi

MASP5,000 psi

Max pump pressure (equipment)7,500 psi

Planned peak operating pressure6,800–7,200 psi

Max strainer ΔP50 psi

Return rate range38–45 bpm

Max wellhead temperature85°C

Min operating margin required15%

Programme documents

Documents released for NS-17 pre-job planning

Real UKCS document structureOn a real North Sea job a Field Engineer receives two documents onshore and two platform-controlled documents after arrival offshore. This workspace reflects that structure exactly.

Tier 1 — Operator document (onshore)

📋 Well Operations Programme — NP-04 Rev BAvailable

Caledonia Offshore Energy plc · Examined per SI 1996/913 DCR · Well Examiner signedSections: Objectives · Well data · Barriers · Operations sequence · Fluids · Pressure testing · Amendments

Tier 2 — Service company document (onshore)

📋 NS-17 Job Pack / DOPAvailable

NorthSea Well Services Ltd · Subordinate to the Well Operations ProgrammeContains: treatment schedule · procedures · equipment list · NSWSL-NS17-PROC-001 Rev A · certificates · previous job notes (RST-01 strainer recommendation)

Offshore-only — platform-controlled (available after mobilisation)

📐 Site Pack — P&ID, Walkdown Layout, Isolation DiagramsOffshore only

🔐 ISSOW Permit to Work — NS-17 Pressure OperationsRaised on platform

Reflects real UKCS practice: P&ID and TRA are platform-held. ~80% of North Sea uses ISSOW (Wikipedia, 2012).

Mobilisation timeline

Job package review complete15 Aug — 17:00

Technical queries submitted15 Aug — 18:00

Equipment inspection complete15 Aug — 14:00

Mobilisation truck departs Aberdeen17 Aug — 06:00

Helicopter departure17 Aug — 10:00

Estimated platform arrival17 Aug — 11:30

Pre-job meeting with Caledonia Ops Rep18 Aug — 06:30

Planned operations start18 Aug — 10:00

Equipment register

NS-17 pre-mobilisation inspection — Aberdeen base

How to use this registerCross-reference the visible condition from the equipment photographs with the records below. Determine READY / NOT READY / CONDITIONAL for each asset before authorising the mobilisation manifest.

Asset	Rated WP	Cal / cert due	Last inspection	Status
PT-14 Pressure transducer ⚠️ Calibration expired 02/08/2026 — 12 days ago	15,000 psi	02/08/2026 EXPIRED	15/02/2026	NOT READY
H-118 HP hose assembly ⚠️ Rated 7,500 psi — job requires 10,000 psi minimum 👁️ Wear marks visible at end fitting — see photograph	7,500 psi	01/12/2026	01/06/2026	NOT READY
P-204 HP pump unit ⚠️ Open maintenance item: vibration flag — no close-out entry	10,500 psi	01/03/2027	01/03/2026	CONDITIONAL
CU-08 Control unit	—	01/02/2027	01/08/2026	READY
PRV-22 Pressure relief valve ✓ Set 10,500 psi — within limits	15,000 psi	01/06/2027	01/06/2026	READY
PT-22 Spare pressure transducer ✓ Replacement for PT-14	15,000 psi	01/09/2027	01/08/2026	READY
H-224 Spare HP hose assembly ✓ Replacement for H-118 — rated 15,000 psi	15,000 psi	01/11/2026	01/05/2026	READY
RST-01 Return strainer ⚠️ Inspection overdue — last cleaned 14/03/2026 (5 months ago) 📋 Previous job report: basket cleaning recommended before next operation	—	OVERDUE	14/03/2026	CHECK

HSE — Job Safety Analysis

NS-17 / NP-04 · Northern Pioneer platform · Pre-job

Hose routed across primary egress route

Consequence: trip injury; emergency exit blocked during evacuation

Initial risk: 9 — MediumControl: Re-route hose clear of walkwayResidual: 3 — Low

PRV discharge pointed toward occupied area

Consequence: serious injury from high-pressure release into manned zone

Initial risk: 8 — MediumControl: Redirect PRV discharge to safe zoneResidual: 2 — Low

Equipment skid within 1m of deck edge — no toe-board or restraint

Consequence: equipment over side; dropped object risk to personnel below

Initial risk: 8 — MediumControl: Fit toe-board; secure skid with chainResidual: 2 — Low

Worker visible in zone marked RESTRICTED DURING PRESSURISATION

Consequence: unauthorised personnel in hazard zone during live pressure operations

Initial risk: 10 — Medium-HighControl: Physical barrier + verbal instruction before pressurisationResidual: 2 — Low

GO / GO WITH CONTROLS / NO-GO decision

Live operations — NP-04

Reading the monitoring screen · Alarm state: 14:37:22

Pump pressure

7,340 psi

Equipment limit: 7,500 psi

Wellhead pressure

7,180 psi

MAWHP: 10,000 psi

Strainer ΔP

96 psi ⚠️

Limit: 50 psi — EXCEEDED

Return rate

36 bpm

Range: 38–45 bpm — LOW

Temperature

77 °C

Limit: 85°C

Pump speed

1,420 rpm

Constant since 11:00

What to noticePump speed has been constant at 1,420 rpm since operations started. ΔP has climbed from 18 psi to 96 psi — independently of pump speed. Flow rate has fallen from 41 bpm to 36 bpm while pump effort is unchanged. Constant pump speed + rising ΔP + falling flow = surface-side restriction, not a downhole event.

Pre-alarm history — console history view (14:22 → 14:37)This is the monitoring screen scrolled back. Pump speed was constant at 1,420 rpm throughout every row.

Time	PP (psi)	WHP (psi)	ΔP (psi)	Flow (bpm)	Pump rpm
14:22	6,980	6,750	34	40	1,420
14:23	7,010	6,770	38	39	1,420
14:24	7,040	6,800	42	39	1,420
14:25	7,080	6,830	46	38	1,420
14:26	7,100	6,860	51 ↑	38	1,420
14:27	7,140	6,900	57	37	1,420
14:28	7,180	6,940	63	37	1,420
14:29	7,220	6,980	68	37	1,420
14:30	7,260	7,020	73	36	1,420
14:31	7,290	7,060	79	36	1,420
14:32	7,310	7,100	84	36	1,420
14:33	7,320	7,130	88	35	1,420
14:34	7,330	7,150	91	35	1,420
14:35	7,335	7,165	93	35	1,420
14:36	7,338	7,175	95	35	1,420
14:37	7,340	7,180	96 ⚠️	36	1,420

Anomaly QC — classify what the screen is showingFour anomalies were flagged during the operation. Classify each as Real operational behaviour, Instrument error, or Data gap.

13:44:01 — Pump pressure: 23,000 psi then immediately 6,900 psi

Single reading. Pump speed unchanged. No other parameter affected. Instant return to previous value.

Real behaviourInstrument errorData gap

14:02:17 — Same timestamp with two different pressure readings

6,920 psi and 6,851 psi both appear at 14:02:17. Minor variation in other parameters.

Real behaviourInstrument errorData quality issue

13:11–13:13 — Pump pressure blank for 3 consecutive readings

All other parameters continued logging normally during this 3-minute period.

Real behaviourInstrument errorData gap

Temperature — consistent +3°C above trend from 14:22, gradual and sustained

Not a spike. A gradual, consistent upward drift over 15+ minutes.

Real behaviourInstrument errorData gap

Technical queries — NS-17

Formal information requests raised before mobilisation

When to raise a TQRaise a Technical Query when information required to plan or execute the job safely is missing. Do not assume a value. Do not proceed without confirmation.

TQ-001 — MASP not stated in client programme

Closed

MASP for NP-04 has not been provided in the current revision of the client programme. This value is required before the operating procedure can be finalised and before mobilisation can be authorised. Request confirmation of MASP at the wellhead measurement point.

Response — James Reid, 14 Aug 2026: MASP confirmed as 5,000 psi at the surface measurement point. Procedure to be updated accordingly before issue.

TQ-002 — Approved operating procedure not included in initial package

Closed

The approved operating procedure NSWSL-NS17-PROC-001 has not been released with the initial job package. This document is required before the pre-job meeting. Request confirmation of issue date.

Response — James Reid, 15 Aug 2026: Procedure finalised following MASP confirmation. NSWSL-NS17-PROC-001 Rev A issued — see Programme documents.

Subject Query

Daily report — NS-17

18 Aug 2026 · NP-04 · Northern Pioneer

CP1 — 11:00

PP: 6,940 psi

All normal

CP2 — 12:30

PP: 6,960 psi

All normal

CP3 — 13:45

ΔP: 42 psi

ΔP approaching limit

CP4 — 14:30

ΔP: 73 psi

ΔP above limit

Operational observations Abnormal events and anomalies