15.6.1 Safety System Overrides
Overriding of Station Fire Detection2 system when undertaking welding in new construction areas is sometimes necessary to avoid a station trip caused by the “ultra violet (UV)”
radiation released during the welding operation. There are three separate cases depending on the location of the Work:
Work more than 50 m from a Process Facility
The work is being done more than 50m away from the Process Facility, so a Permit is not normally required. However, if a request for Safety System Override is to be raised in conjunction with PR-1001c then a permit will be required or the area completely shielded from the detectors at the station.
Work within 50 m of an Operating Facility
In this case a Permit is required for work in a Hydrocarbon Area. The Permit should have an Override request form attached to it. The station operator (Area Authority) will implement the override in conjunction with PR-1001c – Temporary Override of Safeguarding Systems and will log this in his Override Log and use the Permit Location Board to indicate the Fire Detection Overrides that he has put in place. He will only validate the Permit after he has overridden the System. When the Permit is suspended he will reinstate the Fire Detection System.
Permit Work on an Adjacent Facility
This case relates to a situation where two facilities although physically close, are under the control of separate Area Authorities, e.g. Fahud MLPS, Water Injection and NOCS Plants.
Work within one area requires a Permit Validated by the Area for the location of the work. The Permit should additionally state on the Override request form attached to it, the requirements for Fire Detection System overrides on the adjacent facility.
The Area Authority for the adjacent facility will sign the Permit as the Other Affected Custodian, log the overrides in his override Log and use the Permit Location Board to indicate the Overrides that he has put in place.
The Area Authority for the area where the work is being done, will only Validate the Permit when he has received confirmation that the overrides are in place.
When the Permit is suspended he will tell the other Area Authority to remove the System overrides.
2 Refer to PR-1001c – Temporary Override of Safeguarding Systems for more details.
15.6.2 Installation, Replacement and Optimisation of Beam Pumps Installation of New Beam Pumps
This work can be done using a Class B Permit, provided the appropriate lifting precautions are specified in the Job HSE Plan, and a lifting plan in place. The work involves the following:
1. Pressure testing, and tying in the flow line at the well end requires a Class B Permit.
2. Welding cable tray supports requires a Class B Permit (unless the well is in a Process Facility, when a Class A Permit is required.) However if the electric cables are laid in a standard position, this could be done away from the site before the pump is placed in position and would then not require a Permit.
3. The above activities can all be done on one Class B Permit, Activities 1.1, 6.7 and 10.2.
4. The next job is tying in the flow line at the manifold end; this should be a separate Class B Permit, Activity 6.2, which may be combined with Activity 10.2 to complete the commissioning of the pump.
Replacement of Beam Pumps
Replacement of existing beam pumps after a well workover is to be Class B work, Activity 6.2 Beam Pump Optimisation Work
This work is to be Class B work, Activity 6.7.
Flowline Leaks
Where the Area Authority and Responsible Supervisor classify the leak as minor, it is to be isolated and a Class B Permit Activity 6.7 raised for a clamping repair only. No hot work of any sort is to be included in this type of clamped repair.
Beam Pump Stuffing Box Repairs
These are to be done under a Class B Permit Activity 6.7.
15.6.3 Well Cellar Entries
These require a Confined Space Entry Certificate to accompany the Class B Permit. Any Authorised Gas Tester may do gas testing. A separate gas test is to be conducted at each entry and recorded on the Confined Space Entry Certificate or Additional Gas Test Record sheet.
However for Operations Checks activity 2.3 applies.
A local procedure should be produced and in place, approved and signed by the Production Coordinator.
A Job HSE Plan must be produced, and a TRIC completed for each entry.
The electronic Job HSE Plan tool will be amended; however, in the meantime the hazard and controls listed below should be used as guidance when preparing for the activity.
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Hazard: Poisonous Insects / Reptiles
Visually inspect the cellar for reptiles and signs of poisonous insects.
In cases where the cellar is partially filled with sand, try poking the sand surface with a long stick to check for reptiles.
Hazard: Life Threatening Atmosphere
A minimum of two persons is required for this work.
Respiratory protection type ... (specify type) to be worn
Tests for oxygen and/or harmful gases/fumes are to be undertaken
Only trained and competent persons to carry out the task operate equipment or handle the substances involved.
Each person to carry an operational personal gas detector capable of measuring Hydrocarbon, H2S and Oxygen.
15.6.4 Replacement of Relief Valves
Although this is a routine job, it involves breaching a pressurised hydrocarbon system. It therefore requires a Class B Permit Activity 6.2. It may also require Activity 5.1.
A number of relief valves may be listed on a single Permit if the hazards are identical for all.
If a number of relief valves are listed on a single Permit a method statement for the activity shall be attached detailing the sequence etc.
The Permit will be cancelled when all the relief valves in the work pack have been replaced.
15.6.5 Tank and Vessel Entries
Where a number of tasks are to be done within a tank or vessel by the same work party, it is not necessary to raise a separate Permit for each task (see 3.5.4 of the PTW Manual.). A Class A Permit Activity 2.1 is to be raised for the entry, with the additional Activities on it (e.g.
6.3 and 6.6 for blasting and painting.) To ensure the correct precautions are highlighted for each Activity, a combined Job HSE Plan is to be raised covering all of the work within the tank or vessel.
If someone outside the work party requires access to the tank, they are to be considered part of the work party for the duration of the inspection. They are to work under the control of the Permit Holder.
15.6.6 Use of Vacuum Tankers and Delivery Trucks Vacuum Tanker Discharge of Hydrocarbons
Some Stations have a connection from the Oil-Saver Pit to a point external to the fence. The tanker discharges into an open funnel with a pit underneath the funnel and the whole area is effectively a Zone 1 Area. A gas test needs to be performed before the vehicle enters the area with continuous gas monitoring during discharge. The work requires a Class B Permit Activity 6.12. If a non-drip connection is used and the tanker remains outside the hazardous area then the work does not require a Permit.
Use of a Suction Tanker
If the vehicle enters an operating facility to empty a pit of hydrocarbons, a Class B Permit Activity 6.13 is required. If the tanker is collecting hazardous chemicals/substances then a Class B Permit, Activity 4.1 should be used.
Delivery of Liquid or Solid Stores by Vehicle to a Station
Vehicle entry to an operating facility normally requires a Class B Permit Activity 6.7.
However, if the vehicle entry is only for the delivery of operational stores, and the vehicle is under the Area Authority's direction throughout, then the delivery does not normally require a Permit or an Access Authorisation form. The following conditions shall be met for a Permit not to be required:
The delivery of goods should be planned and known to the Area Authority.
Offloading is in a safe, non-hazardous, area away from hydrocarbon and electrical facilities.
The Operator/Area Authority shall directly control the access and movement of the vehicle.
15.6.7 Trenching Using Hand Tools and Power Tools
Excavation or Trenching using manual Hand Tools down to a depth of 300 mm does not normally require a Permit. The exception to this being in those Areas or Stations where there are no documented details of buried services, in this case the excavation is to be treated similar to a mechanised excavation. Mechanised excavations are to follow PDO Procedures for Excavation in Operational Areas and a Class B Permit Activity 12.1 is to be used for all excavations using mechanised or power tools.
15.6.8 Radiography
All radiography (x-ray and gamma sources) performed outside engineer enclosures requires a Class B permit (Activity 4.2) and attachment of a completed Radiography Certificate Appendix 8, Job HSE plan and Sketch of the Controlled Area (7.5 us/h) boundary distances.
In addition where radiography is to be carried out in a process area, or close to process facilities, the safety systems and any nucleonic level measurement should be inhibited through the approved route.
15.6.9 Instrumentation Work
Resetting of trips following a station trip comes under the heading of fault finding and does not require a Permit.
Installation of new equipment not tied into the existing safety/protection systems comes under Activity 6.7, and requires a Class B Permit.
Work that interfaces with existing protection/safety systems e.g. remedial or modification work on existing systems or tie in of new systems requires a Permit Activity 5.1 for ESD and Fire & Gas systems, (Class A for Process Facilities, Class B for Hydrocarbon Areas). Activity 5.2 for Process Control and Machinery Control and Surveillance (Class B).
15.6.10 Maintenance of Diesel Engines in Remote Locations
Routine maintenance such as filter & oil changes and adjustments comes under the heading of routine plant checks and does not require a Permit. However, any test runs on the equipment will require a permit.
15.6.11 Routine Strainer Cleaning
Although this involves unbolting joints on Hydrocarbon lines, it is a standard maintenance job and the strainers are isolated, depressurised and drained before work starts. Where the Station Operator is doing this, or is in attendance, it is a routine watch keeping operation which does not require a Permit.
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When it is being done by a contractor, unaccompanied by the Station Operator, and requires vehicle access for the suction tanker to remove spillage, a Class B Permit Activity 6.7 will be required.
15.6.12 Changing of Filters (Air and Lube Oil)
Where the equipment is fitted with dual filters and has change over facilities between the filters, the work of changing the "Off Line" filter is classed as an Operational Routine and does not require a Permit.
15.6.13 Plant Condition Monitoring and Integrity Checks
Routine checking of the Rotating Equipment Condition Monitoring systems involves the use of a 'Micro-Log Data Collector' in Hazardous Areas. Pipeline wall thickness checking is also being performed with ultra sonic equipment in Hazardous Areas. Since these equipments are not certified for use in Hazardous Areas, their use falls under Activity 11.2 which means that Gas Testing precautions should be applied.
15.6.14 Air Conditioning Maintenance
Regular Air Conditioning maintenance in Production Stations involves cleaning out filters and vacuuming out dust from the condenser units. This involves working within the control building and also using non-certified electrical equipment outside the control room within the plant fence. The maintenance staffs isolate the system at the main switch and places a notice on the switch.
So long as the work is in a non-hazardous area then the work does not require a Permit.
However a No Permit Job Form and TRIC are required. For hazardous areas, the work requires a Class B Permit, Activity 6.7. When preparing the work the applicant should check with the Responsible Supervisor or Area Authority to ensure that the location is indeed in a non-hazardous area.
15.6.15 Remote Site Working
Work at a remote site can be managed from a different Production Station from the one the system flows to. The Outside Work section of the Permit Location Board will be used to show this work e.g. Work to remove sand from a Station' Well cellar is required however, 'B-Station' is not open but 'B-Station' is open; the Permit can therefore be issued from 'C-Station'. This situation only applies when the nature of the work does not directly affect the station process. When Permit work is to take place inside the station, the station must be under the control of a fully licensed Area Authority based at the station.
15.6.16 Wireline and Well Services
Well Engineering operations that are performed by a dedicated well engineering crew who operate under an approved PTW system which include job safety controls etc. do not necessarily require a PDO Permit to Work, if the well has been formally handed over to the Well Engineering crew via the Well Location Custodianship Transfer Form. This transfer mechanism, together with the responsibilities of the Well Engineering crew, are described in procedure PR-1098, and while the well is under transfer no work other than Well Engineering work should be done. It is the responsibility of the Well Engineering Supervisor to ensure all controls within the Job HSE plan are in place and monitored. The well should be isolated by Operations, under a mechanical isolation certificate, and attached to the WLCTF or PTW system. Any requirement to flow the well should be captured under a De-isolation for Test (DFT).
Activities that can be carried out under a WLCTF and those to be carried out under PDO PTW system are clearly defined in PR-1098.
There are certain cases when Well Engineering can isolate the flowline to carry out work. This is described in section 7.7.1
15.6.17 Hand and Spray Painting Process Plant
Painting of process plant requires a Class B Permit.
Painting in Areas controlled by Electrical Departments
Painting in Areas controlled by Electrical Departments requires a Class B Permit Buildings
Painting of buildings located in process or electrical areas may involve working inside as well as outside a Facility fence. Inside the fence, the work will require a Class B Permit. Outside the fence, the work does not necessarily require a Permit. However a ‘No Permit Job Form’, Job HSE Plan and TRIC must be completed.