The drilling phase of any exploration program requires the greatest interaction between an exploration company and the contractors. It is essential that the relationship starts on a sound footing and that contracts clearly establish the duties and responsibilities of each party.
The following issues affect the safety of operations and must be made clear to all parties:
• methods of communication between exploration company personnel and the contractor’s personnel
• appointment of people to be accountable for safety on the site
• standard of competency-based training required for both principal and contractor personnel
• statements of minimum acceptable safety standards to be applied on the site.
• the need for all equipment to be suitably designed, maintained and operated to allow the work to be done safely and productively
• the need for equipment and systems audits, either jointly or separately, and how any necessary corrective action can be implemented
• the need for good accident and incident reporting procedures.
These issues should be detailed either in the contract or in joint operating procedures. For greater detail on contractual requirements, refer to Section 4, Contractor relationships.
The subject of exploration drilling safety includes all matters previously mentioned in this Minerals exploration safety guidance note, as well as substantial issues related to the actual operation of drill rigs. It is beyond the scope of this guidance note to provide anything but the minimum of guidance on safe drilling operations. Contractors must develop their own detailed standard work procedures.
In the past decade industry training advisory bodies have been established to assist with the introduction of national competencies for a broad range of skills in the workplace. These competencies were developed by the resource industries and the drilling industry. It is expected that workers will be given the necessary training to achieve the competencies appropriate to their work in order to improve safety and general skill levels in exploration.
Competencies are available for operation of equipment, blasting, maintenance, general safety and management practices. To fulfil the expectation of those responsible for safety and management in exploration, workers must be:
• trained by an authorised trainer
• able to access training material and operator manuals
• able to obtain national competencies in a reasonable period of time
• encouraged to access a trainer and assessor
• instructed not to undertake tasks without the appropriate authorisation.
Industry associations, the drilling industry training committee and the advisory bodies can all assist with identification of resources to provide training information. Obtaining a competency increases a person’s credibility and adds value to the workforce.
Under Queensland mining safety and health legislation all persons must be competent and records kept of training and assessment. Licensing and training may also be required in accordance with the Queensland Water Act 2000 for those persons required to drill in certain groundwater situations. Relevant legislation must be checked.
Moving rigs and vehicles
The size and complexity of the vehicle and drill rig fleet will depend on the exploration program being undertaken. It will vary from a single 4WD vehicle fitted with a small auger drill and all its necessary equipment, to large truck-mounted multi-purpose rigs with rod trucks, compressors, pumps and service vehicles.
General principles involved in moving drill rigs:
• Only authorised people should drive or control any vehicle or drill rig.
• Extreme caution is required when moving around power lines, bridges overhanging branches, steep roads, soft shoulders and in wet slippery conditions.
• Bystanders must be well clear when equipment is moved.
• Drill masts must be lowered for rig moves.
• Vehicles must not be left idling on slopes or loose ground.
• All loads must be secure and checked before moving.
Overhead or underground power lines
Overhead power lines are a major hazard for operators of mobile drill rigs and other high support equipment. Electricity regulations and rail safety documents stipulate clearance requirements for lines of particular voltages, and this information should always be included in induction programs. Management of these hazards needs to include:
• thorough site inspection before access to identify the location of power supply
• identification of authorised or recognised crossing points
• knowledge of the overall height of the vehicle or equipment (sticker in cab)
• knowledge of the height of the line above the ground (check with surveyor)
• establishment of new access close to power poles to maximise clearance
• provision of power line warning signs
• confirmation of the electrical hazard management procedures at site induction
• understanding of basic rescue warnings for power contact
• current first aid skills in cardio-pulmonary resuscitation and basic life support
• up-to-date details of electricity supply control office.
Drill operators need to remember that the height of the rig may change as the equipment is driven up slopes, such as at occupational/private rail crossings. Even though the rig clears the warning bars before the crossing, it may still contact the power conductor. Operators should be aware of rural power supply systems using single lines as the single line may be difficult to see, has a long span, and may be lower than expected.
Many accidents around drill sites can be attributed to poor site layout and poor housekeeping. Others can be attributed to inadequate site planning and preparation. Environmental issues may have a major impact on site layout, but these issues should be considered in conjunction with safe operations.
Sites should be assessed jointly by exploration company and drilling contractor representatives well in advance of rig moves to discuss potential problems. This is particularly important for holes with difficult access or collar positions. Points that must be considered when planning and preparing a drill site include:
• provision of good access for support trucks and service vehicles, particularly if the rig will operate at night
• identification and assessment of potential hazards such as power lines, flood paths, unstable ground and fire before earthworks begin
• identification and clearance of dangerous trees and branches
• the need for special work platforms in steep terrain
• the need for safety barriers to prevent crews from falling off platforms, down steep slopes or into old open-cut mines
• drainage requirements for the site and access tracks
• provision of clear escape routes in case of an emergency.
Precautions to be taken when rigging up include:
• making sure the site will take the weight of the rig and ancillary equipment before moving on to it
• clearing away debris and loose rocks, and cut tree stumps to ground level
• re-checking for power lines, underground cables, gas pipelines, water pipes, etc.
• making sure that the rig is stable and cannot move. Jacks must be placed on a sound foundation
• checking that equipment cannot snag on overhead branches
• arranging for safe disposal of excess water, drilling fluids, fuels and lubricants
• planning the position of auxiliary equipment such as rod trucks, compressors, pumps, etc. so that they can be accessed safely
• making sure fuels, muds, lubricants, etc. are conveniently and safely stored
• establishing firefighting and emergency equipment
• erecting any necessary barricades to prevent access by the public
• providing adequate weather protection for drill crews
• carrying out a planned audit of the site and drilling equipment before drilling to ensure that all equipment is in a safe condition and site hazards have been controlled.
Poor housekeeping is a major source of minor accidents around drill sites, such as trips, falls, cuts and sprains. Neat tidy sites are usually safe sites.
A tidy drill site improves safety
Good housekeeping involves:
• keeping platforms and working areas clean and safe underfoot
• making sure drilling fluids and water are channelled away from the hole, collar and around the rig. Muddy or slippery walkways, working platforms and ladders cause slips, falls and inefficient work practices
• stacking rods and casing in an orderly manner, preferably on racks, trestles or trucks. Place stops to prevent them rolling off
• keeping tools on tool racks when not being used
• keeping all tools, wrenches, rod clamps clean and free of dirt or grease. Discard worn wrenches and rod clamps
• providing rubbish disposal facilities
• keeping engines free from grease, dirt, oil, spilled fuel and accumulated leaves, twigs and other flammable material
• providing adequate sanitary facilities.
Only experienced people or those undergoing supervised training should be allowed around operating drill rigs. An operating site is no place for spectators or inexperienced visitors. Each drilling contractor should develop their own standard work procedures for drilling. The following factors should be considered:
• Only experienced trained people should operate drilling equipment.
• One person must be appointed to take charge of day-to-day operations and be accountable for safety on site.
• Nobody should be allowed on site without adequate personal protective equipment.
• Rig controls should be operated from a stable and convenient position, not from where it is difficult to reach the controls.
• The condition of all winches, ropes, hoisting plugs and clamps should be checked before raising or lowering rods, casing or drill pipes.
• Care should be taken when rods, casing or drill pipes are being raised or lowered. Make sure that the hoist plug or rotation head sub is correctly screwed in before taking the weight.
• Rods or casing must be firmly set in clamps before attempting to break a joint. Hands should be kept clear of hoist cables and plugs when uncoupling rods.
• Retaining tools such as rod safety clamps and rod spanners should be operated carefully to avoid contact with rotating rods.
• Never place any part of body between stilsons, tongs or break-out spanners and the mast or drill frame. On larger rigs, keep off the drilling platform when using automatic break-out tools.
• Do not use compressed air to pump core out of inner tubes as this can create a projectile. If pumping is required, use only water or mud, and exercise care.
• Never hand-carry tools up and down ladders or the drill rig mast; use a bag.
• Nobody should be on a mast while the rig is operating.
• Any person working on the mast or on the working platform must have and use a safety belt or harness.
• Maintenance must not be carried out while machinery is moving, and all guards on belts, chains and gears must be replaced after removal for maintenance.
• All high pressure pipes and fittings should be adequate for their purpose and hoses should be suitably restrained in case of breakage.
Untidy sites lead to accidents
After recent fatal accidents involving contact with rotating drill rods, several drilling manufacturers and operators have designed means of isolating the driller from the rotating rods. Those devices include Glindemann and Kitching’s Safety Rod, in which the drill rod rotates inside a static rod, and KL Drill Rig Services Drill Rod Guard, which consists of a three-piece guard that activates as the drill head descends. As such devices are developed, they should be installed on relevant rigs.
Natural gases encountered during drilling
Drilling associated with coal seams and petroleum will virtually always encounter gases in the strata. Some gases (methane) will be explosive within a certain range while other gases (hydrogen sulphide) will be toxic, even in very low concentrations. Increased carbon dioxide levels may be accompanied by reduced oxygen concentrations and become toxic at higher levels. If a hazard analysis of the operation identifies a risk, you may need to consider:
• inclusion of gas management in induction (blow-out preventers and extraction/venting procedures)
• a method of gas monitoring and warning
• extension of safety exclusion zones around the drill rig
• recognition and treatment of gas-related illness
• removal or treatment of ignition sources (electrical wiring, exhaust outlets, flame)
• general training for knowledge of gases.
Summary of gases
If borehole logging or other industrial activities that use radioactive substances are taking place near where you work, exercise caution before approaching the area. Requirements for radioactive probes are covered in section 17 of this guidance note. Any accident involving a radioactive substance must be dealt with by a trained radiation safety officer. Important points include:
• proceed with caution to treat any injured person
• stay clear of the area
• wait to be invited to a radiation work area
• follow the instruction of the radiation safety officer.
Compressors, pumps and high pressure equipment
All high pressure equipment, including receivers, pipes, fittings, pumps and hoses, must be suitable for the purpose for which they are used. Compressed air and hydraulic fluid are powerful energy sources and must be treated with respect. As drilling equipment becomes more sophisticated, the use of hydraulic components increases. The increased demand for faster drilling and larger holes means compressors are getting bigger and air pressures higher.
Some points to consider are:
• check and securely fix air hoses before applying pressure
• fit restraints on air hose connections to prevent whipping in the event of a coupling or hose failure
• construct and maintain air receivers and all pressure vessels in accordance with the relevant Australian Standard
• fit high pressure water pump and air compressors with pressure relief valves
• regularly examine all pressure system components for suitability and condition.
Substandard components should be changed immediately. Even so-called non-flammable hydraulic oils can burn easily when sprayed under pressure through a leaking hose or pipe on to hot components such as an engine exhaust.
Fatigue associated with driving long distances is well advertised and understood by most drivers. It is less well understood in the exploration industry, even though exploration workers have traditionally worked long hours, often coupled with extended rosters and field duties. Australian environmental conditions in association with these extended work hours are not conducive to simple control measures for fatigue management and additional risk factors may need to be considered.
Exploration managers should consider:
• roster length in relation to work hours
• remote locations and associated extensive travel
• after work and break activities
• physical demands and fitness for work
• break length between field roster periods
• education programs for the worker and family to gain a better understanding of fatigue
• alternative travel methods at the end of a roster.
All workers need to be consulted on the most appropriate roster structure. A roster that suits a local workforce may be inappropriate for exploration workers who live long distances from their workplace and are required to travel by road.
Heat and dehydration
Recognition of heat conditions is taught in basic first aid but it is important to prevent the likelihood of heat illness. Although not always possible, organisation of work at cooler times of the day can help eliminate or reduce the incidence of a heat-generated illness. Heat conditions have killed exploration workers, so control is important.
Actions that can be taken by individual workers include:
• providing at least 5 litres of cool water per person per eight-hour shift
• controlling the intake of alcohol in the eight hours before start of the shift
• wearing cotton clothing that covers as much skin as possible
• wearing a hat and a shade on a safety helmet
• wearing UV protection sunglasses
• applying sunscreen to exposed skin
• being hydrated before starting work and drinking regularly during work
• drinking some fluids (fruit juice) other than water to help restore salts
• eating normally to replace salts
• not waiting until you are thirsty before you drink—it may be too late
• providing shade during rest breaks and at other times, if the work process allows
• checking urine colour frequently during the day (the lighter the better)
• looking after co-workers to ensure that they are drinking enough fluid.
Drill Sites And Drilling | |