Safety in the Oil and Gas Industry - Assignment Example

Safety within the oil and gas industry Name Institution Question 2 A The HAZID carried out notes these operations The HAZID considers the depositing refrigerated vessels in a single containment tank, propelling of LPG through a vaporizer, LPG vaporization under suitable temperatures, driving the LPG into road tankers, transfer of LPG into pressurized storage tank, and the relocation of LPG into barges for exportation. Potential hazards studied include The natural hazards: these are dangers caused by Mother Nature. For instance earthquakes, lightening, floods, extreme weather (snow), tsunami, landslides, and tidal currents. Material hazards: these are caused by material that is used in the subsea system. The LPG, dry chemical powders, diesel oil, lubricants used, methanol, and nitrogen are among material hazards. External hazards: these involve hazards that are in the environment where the subsea system is constructed. They include illegal migrants, fishing vessels, oil spillages, and passing sea vessels. Loss of effectiveness hazards: these involve loss of material supply for running of the system. For instance, loss of power supply, loss of diesel supply, and loss of nitrogen supply. Threats incurred while transferring pipeline to single containment tanks which involves collision, leakage, and overpressure on the transfer system, fires, third party activity, and vehicle impact. Reduce ability to contain or control the gas, malfunctioning of loading arm, spillages, manual operations, and impact when anchoring, and risks against personnel are among hazards associated with the task of unloading ships and filling barges. Risks involved in pump and vaporizer areas which include fire, vapor cloud explosion, and poor maintenance procedures. Risks taking place in the refrigerated and pressurized storage vessels such as rollover, leakages, over and under pressure, tank start up and external fires may occur. Leakages may take place while pumping LPG into vaporizer and risks related with vaporization such leakages, and overpressure could also take place. These are some of the hazards the subsea system may face in the course of its operation. The following safeguards are already present Hazard Description Causes/Description Impacts Safety measures Recommendation Weather that is extreme .example Typhoon Strong winds Strong storm waves Affect moorage and process of offloading. Construction may be affected by the high winds. The design of the facility should be based on that of standard National Indonesia; height-10m, average time-4s, returns period-50 years. Training on the process of moor and offloading in critical conditions. Incorporating the jetty design of a standard higher than the waves Tsunami This is when the tidal waves are greater than the normal. Amenities and constructions may be ruined by the high waves and the floods experienced. Culmination of the process of LPG transfers by cargos due to warnings of Tsunamis. Ensuring proper drainage of storm water. Instructions and procedures of LPG transportation should adhere with tsunami warnings. Heavy rain and flooding Flooding causes destruction of constructions and other facilities. Water enters into electrical equipment. Ensuring good drainage. Use of IP satisfied equipment. lightening Causes power interruptions. Effect on instrumentation and control as a result of power surge Ignition from the ships vent at the back. Injuries and even death Cargo operation to be shut down through given procedures. Instrumentation system in case of failure it guarantees safety. Vent stack is designed based on radiation effect. Ensuring the impacts of power due to lightning in specification of motor drives equipment. landslide As a result of heavy rains Destroys piping, tanks and related facilities like control rooms Undertaking geotechnical studies on maintenance and design levels Having a layout that is clear on the routing of pipe racks not to be the rock cut base Seasonal variation in salinity The weather varies and changes over time as from November to march is wet and from June to September is dry. This is a result of a substantial precipitation. This may impact on the density of sea water affecting the LPG carrier and the loading arms operations. Consider variation of salinity in loading arm design and jetty design Earthquake May damage facilities Lack of containment may result to leakages Designing structures that are earthquake resistant .in this case the piping and jetty equipment. Designing buildings in Indonesian standards Tidal currents This may affect the ships ability to moor Affect the transfer of LPG Attention on the maximum form of the current in the design basis Mooring stalled if the current is high Fishing vessels in the java sea Existence of fishing vessel in the safety zone Refrigerated ship collide with fishing vessel and this adds ignition from ship when moored Creating a zone of safety Passing/Drifting vessels Vessels collide and power loss maybe experienced Destruction on the jetty and ship while moored Loss of containment due to destruction in pipes Availability of tugboats in the process of mooring Separation of jetty and valves at the ship end Jetty design to hold a certain load. Seek navigation aids, guard boats, lights and buoys Partaking marine traffic impact study from collision of vessels and when drifting Fast boats used by illegal immigrants reaching the terminals Insecurity may be experienced Improve security on the terminal Spillage of oil in the sea Sinking or collusion experienced by moving vessels There may be spill ignition with effect on jetty Water contamination Rapid transition as a result of spill Ensuring emergency response LPG Highly flammable Formation of explosive air vapor mixture In crowded areas may result to cloud ignition Contact with fluid causes cold burns Health complications as result of inhalation Application of safety systems especially detection and alarm systems Operating procedures which call for safety Nitrogen Helps to purge and in the loading arm process Used in storage tanks in controlled places like Asphyxiation tanks Ensuring use of safety procedures Dry chemical procedures Applied during fire fighting In case of inhalation may be hazardous Ensure proper safety procedures lubricants Proper maintenance of machinery Can lead to contamination of spillage Area around with user equipment Diesel oil used in firing water pumps in machine maintenance and generation of emergency power production Can be a cause of fire Safety procedures being applied Methanol Help to unfreeze valves as well as the flanges Can result in a fire Ensuring safety measures are in place Power supply losses Breakdown of terminals Operation such as offloading may fail Use of UPS and emergency generators used by crucial systems Ensuring UPS works well eventually Loss of nitrogen supply Crucial in the process of purging and arm loading Causes a lot of delay in offloading completion Entrance of moisture or gas into loading arm and equipment involved in purging Supply of nitrogen never exhausting Improved procedures Loss in supply of diesel Important in the process of usage in fire water pumps Important in maintenance of equipment and power production Influence on emergency reactions Storage of diesel immediately its delivered Loss of containment during offloading operation Drips experienced from spoilt joints in offloading arms. Corrosion may also cause leakages Leakage can also be in swivel joints Extreme weather leads to closure of offloading systems Fire may be caused due to spill of liquid Swivel joints may be assumed to just produce few spillages Cold spills in connection areas may influence the ships diverse areas Ensuring operations go us planned Fix detection systems, emergency offloading and carrying out frequent inspection Availability of fire water monitors Systems that ensures spill is controlled Counter the effects of cold spillage by designing resistant loading systems Loading arm failure Design may be faulty In anchoring process may not be good enough Cause fire or cold liquid spill Fire curbing system in place Emergency offloading Facilitating shutdown when need arises System that controls spillage available Fire on the ship while being moored Ignition on the ship due to spillage Radiation may affect individuals and facilities Install fire protection system Tugboat used to fight fire Spill on the ship while moored Spillage in the connecting areas of the ship May lead to break out of fire Installing systems that control spillage and ESD system Impact while mooring Unrealistic operation speed may influence jetty by LPG carrier in the mooring operation Destruction is suffered in the jetty structure and may lead to damages piping Fenders made to hold just a certain capacity of load Supervision must be carried out on the mooring operation Focus on speed checks and limits in the mooring operations Question 2 b The first scenario was that of a puddle of a flammable chemical, a burning puddle or pool fire. The main risks associated with this scenario are thermal radiation and downwind effects of the fire byproducts. The thermal radiation risk can be modeled using ALOHA, but the software is ineffective ant modeling the effect of the byproducts in the downwind. The diameter of the puddle was derive using the formular bellow; Whereby, D stands the burning pool’s diameter in M Q stands for the gas release rate in kg/s. b denotes the mass burning tempo (it is equivalent to LPG 0.11 kg/m2.s on the surface while on waters it stands at 0.22 kg/m2.s.) For this case, it was assumed that the spillages take place in the water. Therefore, the mass burning tempo is 0.22 kg/m2.s Q the rate of release is determined as follows Therefore when calculating the diameters of the poodle the above figure will be substituted in the diameter formula as follows: Therefore, the Diameter of the burning pool is 81.84m The spill occurs from the transfer arms from the ship transfer arms for duration of 5 minute at full rate of offloading. To determine the volume of the pool the rate of transfer is multiplied by the duration of the releases. As noted above, the duration is estimated to be five minutes The refrigerated ships take 12 hours to offload through two arms. These means that it takes 12 hours to offload 50,000 te through the two arms. Each arm offloads on average 25,000 te at full offload speed. The rate of offload will be amount/duration =25,000te/12hrs/60mins= 34.722te/min Therefore, in five minutes the spill from a single arm is 34.722te/min *5 mins= 173.61te From both arms =173.61*2 = 347.22 te 1 cubic meter = 2.41 metric tones Therefor the amount released by the arms in 5 hours will be = 347.22 te/2.41 = 144.0746887=144.075m3 Although reliable, ALOHA calculations are heavily disadvantage by the applications inability to compute figures beyond 220 tones. As a result, as a result conversion into cubic meter was intended to generate a smaller figure that could work with ALOHA. Based on the above calculation, ALOHA gave the following threat zones at 2.0 kw/(sq m), 5.0 kw/(sq m) and 10.0 kw/sq m). Based on the depicted danger zones in the ALOHA simulation above the distance between the jetty used by the unloading ships and the jetty used by the barges should be about 500 meters to prevent injuries on the personnel. The distance reduces the lethality of in case of spills and fires. It also reduces the change of 2nd degree burns for thermal radiation originating for the pool fire among the personnel working on the barge jet. Similarly, the workers are shielded from the negative effects of flashfires. The second scenario was the pool fire and flashfire from a butane release within the bund from the refrigerated storage reservoir filling line. For this second scenario, a burning puddle will be used as the basis of a pool fire and flashfire. Although the diameter of the pool with be determined using the diameter formula used in the first scenario, there will be a change in the mass burning rate since in the second scenario the spill occurs over land. Therefore the diameter will be computer as follows. Since it is assumed to occur due to a release from the transfer line to the bund, the pool will likely be formed between the bund and the tank since the pool has a particular diameter its volume will be easily computed as follows. i. The bund’s volume = The Maximum mass capacity multiplied by the density The maximum mass capacity = 50,000 te *110% = 55, 000 te The density of butane = 604 kg/m3 Therefore, the volume will be 55,000 *1000 kg/te * 604 kg/m3 = 91059.6m3 ii. The area will be calculated by Volume/Height = (Dbund2-Dtank2) for annulus Since the height is 5m The area will be 91059.6m3/5m = 18211.92m2 Based on the above calculations 163.67m is the diameter of the bund while the diameter is 60 m. Therefore the maximum diameter of the size of the puddle that can form in the bund is given by the different between the two. This is (Dbund - Dtank)/2 = (163.67m-60m)/2 = 51.84 m. Based on this diameter it is clear the mass of the puddle spilled in the bund will be more than 220 tones, which will be greater than what ALOHA can use. Therefore, the release rate will be assumed to be similar to that of the release from ship transfer arms for duration of five minutes which resulted in a volume of 144.075m3. Based on these volume and diameter the ALOHA modeling is as indicated below. The modeling indicates the threat zones at 2.0 kw/(sq m), 5.0 kw/(sq m) and 10.0 kw/sq m) for the bund puddle pool fire. The second model provides the threat of flash fire from evaporating cloud at 10% LEL and at 60% LEL. Relaying on the estimated danger zones the control room has to be located about 310 meters way for the bund which will make it 300 meters away from the thermal radiation zone. In addition, the control room should not be located in the direct of the wind since the flammable threat zone for a flash fire originating from a flammable cloud from the bund spill goes up to 641 meters from the source. For the people working outside the on the platform, there is increased lethality of second degree burns. In this regard, it is necessary to use PPE in addition to the provision of the necessary first aid measures. On a bright note, the bund could be helpful in containing the fire and thus decrease its extent. Conversely, the barges jetties and the ship out not to be position vertically in the same line with the loading arms as a way of protecting them from the dangerous threat zones as a result the loading arms of the ship out to be about 320 meters in length. The storage tanks should be at least 315 meters away from the puddle to reduce the chance of the butane stored in the tanks from heating which can easily leady to BLEVE. The third scenario assume that a rapture of pressurized butane loading and transfer line results in jet fires and flash fires for a duration of 25 minutes with the full transfer/loading rate. The flash fire is certainly a product of an evaporating poodle. The diameter of this poodle will be computed as follows Transfer line barges: The rate of release is same as loading rate hence; Q = (2000te by 1hr by 1000kg) divided by 4hr by 3600s by 1te = 138.8 kg/s. The puddle mass is then determined using the multiplication of release rate by the duration of the release The puddle’s mass = 138.8 kg/s by 60s by 15min = 125,000kg. The figure below shows the threat areas for the fire because of the rupture of the barges of the transfer: Transfer line facilitating transfers to road tankers: The rate of release is equivalent rate of the loading process which equals: The puddle’s mass is computed through the multiplying the rate of release by the duration of the release (15 mins). The puddle’s mass is = 13.8 kg/s * 60s * 15 min = 12420 kg. The danger zone for the flash fires resulting in the road tanker transfer lines rupture is a shown below: The butane spheres loading line: Release and loading rate will equivalent Mass of the pool is found by multiplication of the release rate by release time Hence the pool’s mass =. Dangers from rupture of flash fires of the spheres loading line are as indicate Modeling for three line jet fires takes the following shape: The diameter of the lines is determined from the equation: Release rate = Where A is the area of the hole (m²). Therefore, The pipe length is assumed to be 100 meters. The end of the tank which is unbroken is linked to an immeasurable tank and the piping is even. The pressure of the pipe the butane pressure which when kept in liquid form is 2 atm. The butane is in gaseous state. The temperature of the pipe is 20 C and the pipes rupture shows that the opening size is same as the pipe’s diameter. Danger zones from rupture of the transfer line to barges are as indicated below: Based on the release rate, the flame extent is computed as follows: Loading lanes to butane sphere Release and loading rate are equal so; Diameter of the lines is then computed from the following equation The assumptions that the pipe length for this case is 150 meters, that the uninterrupted terminus of the pipe is linked to an immeasurable reservoir and with a smooth piping, the pressure of the pipe was expected to be same as that of liquid butane which is 2 atm, the temperature of the pipe was 20C, and that the pipes rupture indicates that the apertures size is same as the pipes diameter. These were among assumptions considered. The following figure shows the dangers regions for the jet fire because of the rupture of the butane spheres loading line: Based on the release rate, the flame extent could be computed as indicated below; m denotes the rate of release which was computed in the flash fire computation which is equivalent to 111.1 kg/s From the threat zones above, the road tankers are the most likely to be affected by flash fires. This is because there is no better place to place the tanker as the terminal does not help in shielding it from risk of exposure. The 121m allocated for the barges jetty is to keep them away from risk of catching fires. ALOHA models the jet fire relying only on details provided by the pipe. The model ignores the release rate and time when the distance could be more than 45m. Therefore, workers who handle butane spheres are exposed to fire deaths if they operate in distances between 19m. Additionally they are also prone to 2nd degree death within a distance of 30m. Direct jet fires emanating from transfer lines could affect road tankers. The release rate and the road tanker spacing were among issues considered while calculating the flame length. Time of the release has to be thoroughly checked and reduced to reduce risk of exposure to fires. The fourth scenario presumed that an evaporating puddle would cause a formation a vapor cloud explosion. The affected area would be congested area of 20m by 10m. The mass of the puddle is computed as follows: The rate of release is already established in the third scenario above as Q = 111.1 kg/s Thus the diameter will be established as follows While the puddle’s mass with established as follows; Based on these figure the modeling of the danger zone by ALOHA is as follows; The following steps are followed in calculating the threat zone ϸ is the vapor density which equals 2.45 kg/m³ Stochiometric concentration in air is 0.03 Heat of combustion (f) butane equals 49700 KJ/kg The following graph has strength index equivalent to 7 and overpressure of 0.24 bar: P is the atmospheric pressure equivalent to 0.1 * 10³ KPa E is burning energy equivalent to 3.65 * 10ᵟ KJ R is denote the cloud’s radius (m) R is also the energy combustion less the scaled distance that is equivalent to 1.4m The distance from the control room to the congested area is 167m indicating no serious exposure to injury or glass shatters. However, people operating within a distance of 53m close to the congested region could easily get harmed. The fifth scenario saw a reservoir source taken from the model BLEVE. Here the reservoir is spherical in shape, with a diameter of 25 m, stored at 20C and has a carriage of 4000 te. The threat areas for BLEV are as follows: Based on the modeling by the ALOHA application the layout of the facility should be as follows Question 2 C The least distance between the proposed residential development in the south and the pant should be about 4.5 kilometers. This distance is necessary to protect the residential areas and the people who will reside on the northern part of the residential areas from flash fires resulting from the BLEVE. This maximum reach of the thermal radiation form the BLEVE is project to by around 4.2 kilometer. Therefore, a distance of 4.5 kilometers ensures a buffer zone of about 0.3 kilometer between the furthest reach of the BLEVE radiation and the residential area. Thus it protects the residents and their property from the thermal radiation. Question 2 d One area where the safety of the terminal could be looked into is during the process of loading and unloading. The nature of the arm should be suitable for safe operations to avoid accidents and spillages. For instance, the arm has to be made of low temperature carbon steel. Furthermore, it should be fitted with emergency release coupling (ERC) and a twin ball valve which allows the ship to readily drift when incidences of fire occur. External environmental factors such as the tide range and wind conditions have to be looked into while picking a suitable arm for the terminal. The arm also has to fit with an emergency shutdown procedure that could be used in case of accidents. This could be added as an additional precautionary measure. Communication is key in the operation of any successful operation so there has to be proper channels of information sharing put in place for use during the loading and offloading. Another safety measure has to be taken in the selection of material with which the terminal will be made up of. The composition of the terminal contributes enormously towards the safety of the whole terminal. 9 percent nickel steel has to be selected as the material for development of the inner cylindrical container of the storage tank. The outer tank which surrounds the inner tank should be composed of carbon steel and has to hold an insulation material in its annular space. The refrigerated butane tank and pressurized tanks have to be equipped with a controller, sensor and quality alarm systems. This helps prevent overfilling in the tank since when the tank is filled it will automatically be sensed and stopped. The pressure tanks have to be placed with safety valves to take note of exceeding pressure. Importantly, the personnel employed have to have qualified through adequate training. Since the terminal is an area that is exposed to hazards, the staff has to meet the desired criteria to operate the machinery. A simple case of ignorance or mistake could easily lead to accidents which are hugely hazardous. Question 2 e Emergency response plan for overfill of the butane tank Since the whole terminal is fitted with an alarm system, the leak when noticed will automatically trigger an alarm. From the sound of the alarm, the general manager who is in charge of the terminal will then start the emergency response plan which will take the following steps. Firstly, the important personnel will be alerted. An evacuation process should then take place due to the fact that the area is at risk of fire followed by the stopping of the loading of offloading works by shutting the inlet valve. The area should then be closed down and only specialized personnel allowed in while securing areas close to the tank. Anything that could lead to ignition or excess heat has to be eliminated since the gas may have already leaked out. All nearby drainages and areas of waste disposal have to be covered up. Once the drainages are protected, the area of release should be slowly and carefully ventilated to allow passage of the potentially explosive gas into the atmosphere. The concentration of butane released into the atmosphere has to be checked to know its extent. Then in the final steps while cleaning the spill, the personnel have to put on protective gear to avoid getting into contact with the risky gas. Then the release has to be reported to the relevant authorities at once. The first personnel to reach the alarm must activate the emergency shutdown system (ESD) and notify the person in charge of the terminal. Then the operator in charge or general manager has to quickly go to the area of danger and access the extent of damage then quickly estimate the amount of response needed. This is to ascertain if more help will be required to deal with the problem or if the personnel available can adequately deal with it. The personnel in charge has to then activate the emergency response plan. The general manager should be busy working on the communications with the main control unit. While at this, the chief operator has to be in charge at the site of the accident ensuring that everything is under control. The workers who were on duty then will clean up the spill taking into account its extent of danger under the supervision of the chief operator who in turn will report to the general manager on the progress of the clean-up. Finally, the general manager has to take control of the terminal again. The recovery process has to be initiated then the matter reported to the relevant authorities. What would follow would be an investigation into the incident later. Reference Chang, K. Kim, S. & Kim, S. (2013) Subsea System Reliability and Risk Management. The 2013 World Congress on Advances in Structural Engineering and Mechanics (ASEM13), Jeju Korea, September 8-12, 2013. Chang, K., Lee, D., Nam, K., & Jung, S. (2009). Risk assessments for high integrity pressure protection system by using layer of protection analysis. In C . G. Soares, R. Bri, & S. Martorell. Eds. Reliability Risk and Safety Theory and Applications. CRC Press Read More