Introduction
Natural gas is said to be cleaner than other natural source of energy such as coal and oil. However, the gas fields present unique hazardous challenges. Gas fields operators need to understand that each gas field has its own unique hazards, apart from the common hazards. The awareness of the worker about the safety and health hazards is paramount such that it will help the gas field works to actively participate in the enhancement of health and safety standards at gas field locations. Such hazards include damage to the physical environment as well as health and safety hazards. Dangerous gases emitted in the gas fields may be inhaled by workers and as such poses health risks to these workers. Accidents such as slipping or tripping in the gas fields pose are the safety hazards that workers are exposed to (Energy Justice Network 2011). Because of the high level of hazards posed by the entire process, there is a need to have efficient safety measures and solutions to cab this menace. The process a number of processes and stages. Each of these stages needs its own safety methods. The drilling process involves methods such as BOP while the refining process involves the absorption column to remove co2 from natural gas. The drilling and processing of natural gas involves complicate equipment that may be prone to accidents. Other safety hazards include faulty equipments as well as poor storage of these equipments (Aird 2008). Gas has to be transported and this is another area that is prone to hazards connected to pipeline transportation systems. There are risks involved in each of the hazard control methods and engineers always do have counter measures. Importantly, engineers do ensure that hazards are managed efficiently as the significance of any accidents occurring would be too severe. Thus different methods will be explained on how to manage gas filed hazards.
Gas well control
Gas well control is a well managed process that controls the hazard that may result from unexpected high pressures occurring in the process of drilling natural gas. In any natural gas site there is usually need to have effective and efficient measure to control such hazards. If such measures are not put into place there may be gas well blowout that causes serious ecological hazards, damage to the natural environment, injuries and death. One of the methods used in gas well control is the Blow Out Prevention, commonly known as BOP (Lyons and Plisga 2005). This method uses very large valve that automatically closes and prevent an upsurge of gases in case the pipeline experiences high pressures. Blow Out Preventers are installed after casing and cementing of the has been done in a rig (Aird 2008)There are two of such types of valves that can be used in the process. The ram-type BOP completely seals the gas pipes incase of an upsurge of pressure by compressing the gas pipes from both sides. This way the gas well is completely sealed and as such the gases cannot escape to the surface of the earth to cause any harm. The annular BOP is a hydraulic type of preventer that uses pistons to stop the flow of gases. The pistons react hydraulically by pushing up plate strategically placed above them. This sees the compression of the gas pipe (Lyons 2008). There have been innovations lately to improve on these BOPs so as to increases on their efficiency. Other than BOPs, it is important to train gas filed crew on how to monitor the rig process and identify potential hazards and take necessary prevention measures before a catastrophe happens (Aird 2008).
There are other methods to control gas drilling hazards such as the dump and pump method. This method has been found to be less efficient and more expensive. It also has a limited application in the process. As such better methods of drilling such as the dual gradient drilling have been developed. This method is much more useful in close surface gas exploration and drilling. It is most efficient as it reduces the amount of mud used in the process as well as ensuring the that use of chemical additives is only an option (Schubert and Elieff 2009). This method involves two types of gradients. The first type of gradient starts at the sea level. This is the sea level gradient. The ground level gradient begins at the sea bed level. This type of mechanism has only one type of pressure gradient and as such forms the fracture as well as the pore pressure. Drilling is controlled between these two pressures (Myers 2008).
Gas refinery process
There are a number of hazards associated with the gas refinery process. The hazards are dived into two broad categories. They are occupational hazards as well as health related hazards. Occupational hazards and accidents can occur due to the high flammability of gases involved in the process. Physical contact or even the inhalation of gasses such as carbon dioxide methane and as such other gasses can cause serious injuries and risks to gas miners. Other occupational hazards include high level of temperature in the tunnels as well as accidents from gas field machines. Health problems may occur if the miner inhales harmful gases such as methane (Argonne National Laboratory 1990)
There are various methods developed to ensure that the hazards emanating from this process are well handled. The gas absorption column, CAG, is one of them. The methods involve a system made up of a number of columns of gas pipes. These columns are intended to absorb carbon dioxide or even ammonia. These two gases are contained in an aqueous solution that does flow down the columns of pipes. The CAG functions as follows. The gases are absorbed from the system through two processes: chemical or physical. The chemical process involves the situation whereby carbon dioxide reacts chemically with other chemical elements deliberately put in the liquids found in the columns. In many cases carbon dioxide is reacted with caustic soda. The physical process is very similar with the chemical process but is less effective. As such the chemical process is preferred to the physical process as it endures high level accuracy and also reduces the risks associated with these hazards (Eterigho and Olutoye 2008).
Other methods of managing gas hazards include the catalyst regeneration method. In this method the amount of carbon dioxide is reduced by burning the mixture of gases in special types of boilers. After burning the gases, carbon dioxide is released and then taken care off by cyclones. Other methods include the gas incinerator that removes excess waste of dangerous gases such as hydrogen sulphide. This method is used in absence off such methods as Beavon and the Wellman-Lord processes. The refinery process also includes storage of such gases. Thus it means that the hazard that is caused by such gases is reduced by use of floater either put at the top of the storage tanks or fixed at the roofs of such tanks. This floater reduces the vapor space and as such stored gases cannot be released to the environment (Argonne National Laboratory 1990). Furthermore the crew working at gas field must have the necessary apparels such as gas masks, gloves, overalls and any other fir safety clothing (Aird 2008).
Hazards associate with drilling equipments
In the process of preparing natural gas, very little mount of gas can flow out naturally and therefore engineers have to develop very expensive equipment for use by miners (Bureau of Labor Statistic 2010). The use of these machines involves a number of hazards especially accidents oriented. Such hazards include faulty equipment, poor storage of such equipment as well as worn out equipment (Airs 2008). There are a number of hazards control methods associated with this equipments. Preliminary methods include the installation on the location cementing and cement batch mixer. When drilling a hazard can have a defect or an accident in the casing pipes. These cement mixers and pumps are used together with added storage for mud in such a way that it controls the rate of mixing mud and as such reduces the pressure on the surface. As such the casing is not subjected to any unnecessary pressure and thus the risk of hazard is reduced (Tarr and Flak n.d.). To ensure that the casings are prevented from any hazard they casings are reinforced by the use of a casing shoe. This is special type of a steel collar that is embedded at the bottom of the casing. It is supposed to prevent the casing from any corrosion and abrasive activities on the casing (Ministry of Natural Resources 2011). Another hazard control measure is the Depth Perforation Control Log. This is used in a gas well and after the well has been cased. The well is perforated using a casing reinforced by the casing shoe together with a sensor that uses gamma rays. The PDC logs help the engineers to identify the depth of these cased collars and as such determine the pressures in the gas pipes (Gow and Gow 2005). Other methods include securing stairways by installing guard rails, properly storing drilling equipment and ensuring the the crew is at safe distant from hoisting equipment (Aird 2008).
Choosing safe pipelines pipeline transport of gas
The most efficient way to transport gas is thorough the use of pipelines. Pipelines provide the best way for safe transport of gases. Pipelines are also reliable as they do have very minimal interruptions as compared to road transport. They can also be used to transport gas to far off places faster as well as being economical and means of transport. Due to the reduced cost of transportation as well as time needed to transport gas from one point to another, pipelines thus become the most efficient methods. Furthermore pipelines also do not consume large amounts of energy as compared to the other sources of transport (Goodland 2005). Despite its high ratings in terms of safety, this transport method is prone to a number of hazards. The hazards can be caused by human, technological, environmental or natural causes. This will thus lead to physical or functional damage of the infrastructure. As such the result will be gas leaked that may have devastating effects. In severe cases the pipeline can burst and the effects are even bigger as compared with hazards x=caused by leaks. Sometime the materials used in the construction of the pipe may be substandard. Such pipes are easily damaged. The soil sounding the pipeline may have high permeability the gas in transit will easily leak into the soil and into the ecosystem (Bersani, Citro, Gagliard, Sacile and Tomasoni n.d). There are however a number of measures to mitigate the occurrence of these hazards. The priority issue in this case is constant repair of pipelines. Gas pipelines are subject to constant monitoring to check for possible damage. The material used in such method is highly hardened steel that can handle the optimum allowed operation pressure. An alternative method is use of a bypass. An alternative pipeline is branching is constructed parallel to the damaged gas pipeline (Pluvinage and Elwany 2007). other risk management practices includes determining the safest depth to bury the pipes as well as controlling the gas pressure at inlets and outlets. Other measures include prohibit any human activities near the areas the gas pipe pass (Rodrigues 2010).
HAZOP
To ensure that the safety standards are met and maintained there has to be a hazard and operability study. The purpose of this study is to ensure that any impending hazard potential in current as well as future infrastructural mechanism is identified. In case of failure of the hazard management process, a hazard has a high probability of concurrence. Any hazard that can happen can lead to severed consequences both to the natural environment as well as the people in the vicinity. In this case The team to do a HAZOP would include engendering operation and health personnel. The team must establish priority in managing of risk and hazards posed (IoMosaic Corp 2002).
Health and safety management: Methods
Processing of natural presents a number of health as well as safety hazards to miners. These hazards are brought about by the nature of the working environment. The safety of miners is always put to risk because of the depth of the tunnels as well as the complicated equipment they work with. Their health is also put at risk as a result of the corrosive and poisonous nature of gasses in the tunnels. As such there ought to be efficient measures to meet health and safety hazards. The most effective way to meet these risks is through proper ventilation of mines and tunnels. The law requires that every mine should be properly ventilated to reduce the exposure of the miners to these gases to the bare minimum. Other than ventilations there are other methods used to contain dust particles that contain dangerous gases. These include sprinkling and spraying water at regular intervals in the mines. This ensures that most of the dust particles diffuse in water and thus un-inhalable. Furthermore the law in many countries that have natural gas mines require that every miner must have a respirator. Respirators are breath apparatus used by miner’s and contains only safe air. This ensures that miners cannot be exposed to dangerous gases. To ensure that the safety of miners is guaranteed, mines are designed in such a way that they have sufficient slopes, entries, exits as well as safe roofs and floors. The roofs are supported by strong pillars to reduce chances of caving in. tunnels are designed in such a way that they allow fro machines to pass without causing injuries to miners (Karmis 2001).
Conclusion
The management of health and safety hazards in gas field is an every day affair. It involves a series of measures at both individual and management level. Awareness needs to be created to the gas field crew on the need not to compromise on any safety measure. Gas field management should establish safety guideline to be followed. Among the necessary safety measures in place, the moist important gas field safety measures is carrying out routine inspection of gas filed equipment to ensure that it is in proper functioning form. Furthermore the gas filed crew should be regular trained to empower them to be more actively involved in enduring that gas fields are safe working places. This means that hazard management is matter of priority in gas field and all parties involved have an equal responsibility
Reference list
Aird, P. 2008. The wee land rig handbook: an introduction to safer land based drilling operations. Web.
Argonne National Laboratory. 1990. Environmental consequences of, and control processes for, energy technologies. New Jersey: Noyes Data Corp.
Bersani, C., Citro, L., Gagliardi, V., Sacile, R. and Tomasoni, M. n.d. Accident occurrence evaluation in the pipeline transport of dangerous goods. Web.
Bureau of Labor Statistic. 2010. Occupational outlook handbook. Washington: GPO
Elieff, A. and Schubert, J. 2009. Dual gradient drilling will control shallow hazards in deepwater environments.
Energy Justice Network. 2011. Natural gas health and environmental hazards.
Goodland, R. 2005. Oil and gas pipelines Social and Environmental Impact Assessment: State of the Art. Web.
Gow, S. and Gow, A . 2005 roughnecks, rock bits and rigs: the evolution of oil well drilling technology in Alberta, 1883-1970. Alberta: University of Calgary Press
ioMosaic Corporation. 2002. Iomosaic statement of qualification: process hazard analysis. Web.
Karmis, M. 2001. Mine health and safety management. Colorado: Society for Mining Metallurgy And Exploration Inc
Lyons, W. 2008. Air and gas drilling manual. Oxford: Gulf Professional Publishing
Lyons W. and Plisga, G. 2005. Standard handbook of petroleum and natural gas engineering. Oxford: Gulf professional publishing:
Ministry Of Natural Resources. 2011. Glossary. Web.
Myers, G. 2008. Ultra deep water riserless mud circulation with dual gradient drilling. Web.
OLUTOYE, M. and ETERIGHO, E. 2008. Modeling of a gas absorption column fo CO2-NaOH system under unsteady-state regime. Leonardo Electronic Journal o Practices and Technologies. Web.
Pluvinage, G. and, Elwany, M. 2007. Safety, reliability and risks associated with water, oil and gas pipelines. Dordrecht: Springer
Rodrigues, R. 2010. Pipeline risk management. Web.
Tarr, A. and Flak L. n.d. Underground blowouts. 2011. Web.