This article describe the key Safety standards in Drilling Operations;
1 Personnel
Work shall be restricted in all areas below other work being carried out at higher levels.
Work vests shall be worn by all personnel working over or near water, and where there are no guard rails in elevated positions. A safety belt and lifeline shall be worn by all personnel working above the first girt of the mast. The lifeline shall be secured to both the belt and the structure.
Personnel shall not be raised or lowered by the catlines, nor shall they "ride the elevator".
All tools and materials shall be raised to work platforms by a hand line, toolbag, or other means. Both hands shall be free when climbing ladders.
All safety belts, lifelines, stop chutes, and the Derrickman's emergency breathing apparatus shall be tested at regular intervals. The tests shall be included in the fortnightly inspection report.
Eye protection shall be worn at all times.
2 Floors And Work Platforms
Guard rails and toe boards shall be fitted round the work platforms wherever possible.
Walkways, staircases and platforms shall have non-slip surfaces. All openings shall be properly guarded and sign posted in English and Norwegian, or suitably covered.
Work platforms shall be erected on the mast for all personnel to stand on while working with equipment in or on the mast.
Work platforms shall be inspected before and after work for loose tools and materials, and a high standard of housekeeping shall be maintained at all times.
3 Safety Of Drilling Equipment
3.1 General
All the Drilling Contractors drilling equipment shall be included in the Contractor's maintenance system. The equipment shall be inspected in the fortnightly inspection report. Company drilling equipment shall also be maintained by the Drilling Contractor.
All certificates or copies thereof shall be available on board, and no equipment shall be used after the expiry date of such certificates.
Guards over moving parts of machinery shall not be removed while the machinery remains connected to a power source. Machinery with remote controls shall be isolated locally, the means of isolation shall be locked, and a warning notice posted.
All newly repaired or maintained equipment shall be commissioned by an authorised person.
All downhole equipment and other equipment (as necessary) shall be rated for the test pressures to be applied.
3.2 Iron Roughneck, Power Tongs, Tongs
In cases where the iron roughneck cannot be utilised, two rig tongs shall be used for making-up/breaking-out connections.
The rotary clutch shall not be engaged while the drillpipe tongs are latched round any piece of equipment or drillpipe in the rotary.
Floormen shall always:
- Keep their hands clear of the tong latch, the tong jaws, and the gap between the tongs and pipe.
- Observe swinging tongs to prevent being pushed into a hazardous position.
- Wear eye protection when changing tong dies.
Power tongs shall have a working safety device to prevent them operating whilst the gates or guards are open.
Spinning chain is not allowed in any circumstances.
When replacing and repairing snublines, it shall be verified that the length of the snubline remains correct.
3.3 Hoists
All hoists shall be marked with their Safe Working Load (SWL), and this shall be visible at all times.
The Weight Indicator shall be visible to the Driller at all times.
Wirelines shall be checked in the fortnightly inspection report. After the maximum allowed ton mileage the lines shall be slipped or slipped and cut.
Lines shall always have sufficient wrap on the drum to prevent the load being applied directly to the fastening clamps.
When greasing the crown and block, the Driller shall stay at the brake throughout the operation.
Use of the catline is prohibited.
3.4 Stop Chutes
Stop Chutes are a safety block with auto stopping device. They shall be available to provide a safe escape from masts and other places where work has to be carried out at heights.
The landing point of the Stop Chute shall be kept clear of obstructions.
Various types are available, and an appropriate model shall be used and adjusted for each situation.
3.5 Elevators And Slips
The use of power slips is recommended.
The elevator shall be removed when the drillstring is stuck, and the kelly or topdrive used to loosen the pipe. Jarring with the elevator can be dangerous. If this is done, tie the latch of the elevator.
Single joint elevators shall be used for picking up casing and tubing.
The elevator shall be used for picking up drillpipe from the Catwalk machine.
Operators shall:
- Ensure the elevator latch closes all the way when picking up pipe.
- Never catch the elevator bails. The back handle shall be used to pull the elevator away from the pipe.
- Keep their feet clear of the handles of the slips.
3.6 Stabbing Board
A log of the checks and maintenance of the stabbing board shall be kept as part of the drilling unit maintenance system. All ropes shall be checked regularly, and routine lubrication shall be carried out.
Whenever the stabbing board has not been used for 14 days or more, the ropes and lubrication system shall be completely checked, the stabbing board examined and all its motions tested.
The designated Stabbing Board Operator shall be trained in the operation of the equipment, and shall check it independently as soon as possible after coming on board.
3.7 Pipe Handling
Mechanical handling of drill pipe and tubulars (i.e. "Iron rough neck" and remote operated pipe racking) is a compulsory requirement for operations on the Norwegian Continental Shelf (NCS).
3.8 Drawworks
The drawworks "crown-o-matic" (crown block protection device), shall be tested (and recorded on the IADC report) each shift, and each time the drill line has been slipped or cut.
The Driller shall be at the controls whenever work is being carried out on the drawworks. A wok permit is also necessary for this work.
The rat-hole and mouse-hole shall be covered when not in use, unless the protective casing extends above the level of the rig floor.
The guards over the drum and rotary table gears shall always be in place when the machinery is in use.
3.9 High Pressure Equipment
Detailed information on Safety requirements for pressure testing is given in the "Safety Procedure Manual".
All equipment shall be pressure tested after repairs and maintenance in addition to routine tests.
All pressure lines shall be secured. All temporary pressure hoses shall be protected from damage.
All hoses and lines shall be vented to atmosphere before they are disconnected.
Rotary hoses shall be properly secured at both ends, with the standpipe end secured to the mast and the goose neck end to swivel.
It is a basic safety requirement that all equipment (e.g. wellhead equipment and choke manifolds etc.) shall be designed, operated and maintained to eliminate the possibility of discharges, and the potential of creating an explosive atmosphere during normal operations.
In this context, production test equipment shall conform to operational requirements and also meet the criteria governing its use in hazardous zones.
Personnel should not be in the vicinity of the pumps in the drilling unit and the fluid ends of pumps and hoses when high circulating/test pressures are being used.
3.10 Mud Pumping/ Mixing
Detailed information on use and handling of mud chemicals is given in the "Safety Procedure Manual".
The emergency stop switch in the pump room shall be locked shut and a warning notice posted while work is in progress on the mud pump.
Reset type relief valves are preferred. If shear pin type relief valves are fitted, guards shall be fitted to prevent sections of the sheared pin flying off if the valve(s) relieves.
Guards shall be in place over all moving parts of the equipment.
4 Safety Of Specific Drilling Operations
4.1 General
The following general precautions shall be observed at all times:
- No smoking outside the accommodation.
- Always use safety glasses outside the accomodation
- Never break off a drilling stand with the pump on.
- Never stand on the rotary table during drilling.
- Never place a hand on top of a pipe when adding pipe.
- Always keep hand tools in good working condition.
- Always keep the workplace tidy and clean.
- Always use Permits to Work as required for non routine operations.
- Check for H2S and petroleum vapours whenever gas is suspected.
- Wear the appropriate protective clothing for the operations being carried out.
4.2 Well Logging
Detailed safety procedures for electric wireline logging are given in the Drilling Manual.
4.3 Cementing
Detailed information on use and handling of cementing chemicals is given in the "Safety Procedure Manual".
All equipment shall be designed for the operation and test pressure it will be subjected to in the operations.
All personnel working on cement mixing shall wear the appropriate protective clothing, as detailed on the toxicological data sheets and in the Chemical Product Index. The cement room should be well ventilated.
The pipelines from the cement pump to the wellhead shall be tested before cement mixing commences.
4.4 Blow-out Prevention
Detailed information on blow-out prevention is given in the "Pressure Control Manual".
4.5 Production Testing
Paragraph 5.4.4 gives detailed information regarding safety during production testing. As it is necessary to carry out various safety procedures, it is important to refer to Paragraph 5.4.4 prior to commencing production testing operations.
4.6 Well Servicing
Well swabbing is prohibited.
The following precautions shall be observed when well acidising, (refer also to Para 5.4.4):
- Have the minimum personnel on the drill floor, wearing the appropriate protective clothing.
- Ensure fresh water is available for washing down protective equipment and personnel.
- Pressure test all piping and connections before use.
- Wash all equipment thoroughly with fresh water on completion of acidising.
4.7 Concurrent Operations
Detailed safety procedures for concurrent operations are given in Chapter 5.6 of this Manual.
5 Hazardous Zones
Discharges give rise to Hazardous Zones depending on the frequency of discharge and the ventilation available. Wherever there is a risk of explosion, all potential sources of ignition, principally electrical equipment, shall be adequately protected, isolated, or removed.
Hazardous zones are also established when explosives operations are in progress. Paragraph 7.9 details the procedures and precautions required.
The Senior Drilling Supervisor is responsible for ensuring that the requirements to Zone Classification within the drilling unit are being implemented. The Offshore Installation Manager shall ensure that all precautions are taken, and warning notices are posted for work in Hazardous Zones.
The Zones are classified as follows:
- Zone 0 - Area with an explosive atmosphere continuously or for long periods.
- Zone 1 - Area where an explosive atmosphere must be expected occasionally during normal operations.
- Zone 2 - Area where an explosive atmosphere occurs only exceptionally and for short periods of time.
The types of discharge giving rise to explosion risk are:
- Continual Discharge - taking place either continuously, or for short periods at a high frequency.
- Primary Discharge - Expected to take place intermittently or occasionally during normal operations.
- Secondary Discharge - Not expected to take place during normal operations. If discharges take place, they will be both infrequent and of short duration.
The Hazardous zones that shall be implemented are determined by the ventilation available, and can be determined from the following table:
- Continual Discharge
- With all types of ventilation, zones 0, 1 and 2 required
- Primary Discharge
- with natural or mechanical ventilation, zones 1 and 2 required.
- With no ventilation, zones 0, 1 and 2 required.
- Secondary Discharge
- With natural or mechanical ventilation, zone 2 required.
- With no ventilation, zones 1 and 2 required.