Onshore facilities

Onshore or offshore gas plants are designed for either LNG rejection and gas injection, or LNG rejection and transmission for sale. In the case of offshore plants, onshore facilities further process the natural gas before transmission for sale. In either case, natural gas must be treated and then refrigerated to make rejection of heavy hydrocarbons possible. In plants where natural gas is treated for sale purposes, water and hydrocarbon dew points of the gas must also be controlled. 

The requirements of both PSM and SEMP are, from a practical standpoint, identical and thus, SEMP can easily be applied to onshore facilities as well as offshore facilities. The basic concepts of SEMP are as follows ... 

The required power for production facilities is either generated on site by engine- or turbine-driven generator units or purchased from a local utility company. For onshore facilities the power is generally purchased from a utility. However, if the facility is at a remote location where there... 

There has much analysis in the petroleum industry as what is the prudent spacing table to use in the layout of an onshore facility. Attempts have even been made to compare the spacing tables used by individuals companies. This would provide a consolidated table the entire industry could apply. Although such an idea is admirable, there are several obstacles in achieving such a goal. 

For exposed buildings at onshore facilities, heavy monlithic concrete construction is used. Entranceways are provided with heavy blast resistance doors, that do not face the exposed area. 

Areas of the North and South Atlantic, and North and South Pacific present continual extreme and hostile ambient conditions that make survival exposed to such conditions a very limited probability with adequate protection measures. In these locations the probability of survival is increased with the provision of a fixed safe refuge rather than the provision of an immediate means of escape. For offshore facilities historical evidence indicates that both helicopter and lifeboat mechanism may be unavailable in some catastrophic incidents. Remote onshore facilities may also experience severe winter conditions that also render this philosophy applicable. 

For onshore facilities, water may be supplied from local public water mains, storage tanks, lakes and rivers. In these cases a conventional horizontal pump is used. The preferred design for onshore fire water pumps is a horizontal centrifugal type with a relatively flat performance curve (i.e., pressure versus quantity). The discharge pressure is determined by the minimum residual pressure required at the most remote location of the facility flowing its highest practical demand with allowances added for piping friction losses. 

All fixed fire suppression system control valves should be located out of the fire hazard area but still within reach of manual activation. For high hazard areas (such as offshore facilities), dual feeds to fire suppression systems should be considered from opposite areas. For onshore facilities, firewater isolation valve handles should not be contained within a valve pit or a below grade enclosure within the vicinity of hydrocarbon process facilities, since heavy process vapors travel from the process and may settle inside. 

Hydrants should be considered as a backup water supply source to monitors and fixed fire suppression systems. Hydrants should be located on the ring main at intervals to suitably direct water on the fire hazard with a fire hose. Hydrants monitors and hose reels should be placed a minimum of 15 meters (50 ft.) from the hazard they protect for onshore facilities. Hydrants in process areas should be located so that any portion of a process unit can be reached from at least two opposite directions with the use of 76 meters (250 ft), hose lines if the approach is made from the upwind side of the fire. Offshore hydrants are located at the main accessways at the edge of the platform for each module. Normal access into a location should not be impeded by the placement of monitors or hydrants. This is especially important for heavy crane access during maintenance and turnaround activities. 

Offshore facilities are dramatically different from onshore facilities because instead of being spread out the equipment is segregated essentially into compartments or separated into a complex of platforms. Offshore facilities pose critical questions of personnel evacuation and the possibility of total asset destruction if prudent risk assessments are not performed. A through analysis of both life safety and asset protection measures must be undertaken. These analyses should be commensurate with the level of risk a particular facility represents, either in personnel exposed or financial loss. An unmanned wellhead platform might only require the review of wellhead shut-in, flowline protection and platform ship collisions to be effective, while manned drilling and production platforms may require the most extensive analysis. 

Spill Prevention, Control, and Countermeasures (SPCC) 1974 Encourages pollution prevention and cleanup of waters by requiring plans from onshore facilities that can potentially discharge oil and other pollutants in harmful quantities into or on U.S. navigable waters... 

Oil Pollution Prevention Non-Transportation-Related Onshore Facilities... 

Within the broad reporting categories of vessels (tankers and barges) and facilities (pipelines, tanks batteries, and other onshore facilities) in the period 1984—1993, numbers of reported spill incidents were roughly equivalent 42,000 incidents from vessels and 38,000 from facilities. Over this period, the vessels spilled a much larger cumulative amount of oil 45 million gallons from vessels versus 15 million gallons for facilities. Major incidents can dominate these totals. Two vessel spills account for around one-third of the vessel totals. 

Minerals Management Service (MMS) (2006). Impact Assessment cf Onshore Facilities from Hurricanes Katrina and Rita. United States Department of the Interior. 

On onshore facilities, the people who are not actually at work go home. Therefore, in the event of a serious accident, they cannot be killed—the number of affected people is limited to those who are on duty. For example, the explosion at the chemical plant in Hixborough, England, in the year 1974 was very bad 28 men died. But the accident occurred on a weekend had it occurred during the middle of a working day the death toll would have been higher—much higher. (The number of... 

Companies in the United States pay particular attention to the OSHA recordable rate. Onshore facilities are required to report this number anyway, so it provides a reliable means of comparing different organizations with one another. 

Much of the information will be stored at onshore facilities. However, the safety-critical information that onboard personnel may need—often in a hurry—should be identified. Information of this type should probably be available in hard copy format, since, during an emergency, it is more than likely that normal electronic data management system will not be functioning properly. 

In addition to the duties imposed on licensees and owners of onshore facilities by individual provisions in these regulations, they are also responsible for seeing to it that the operator complies with the requirements stipulated in the health, safety and environment legislation. 

Offshore installations and onshore facilities. These include exploration and production installations, including FPSOs, MODUs,... 

Currently, the majority of PW generated worldwide at onshore facilities is re-injected into the soil in disposal wells and therefore, the treatment facilities are mostly designed to remove dispersed oil and grease (O G) and suspended solids (SS) to avoid formation plugging. The main treatment objective is to reduce O G to acceptable levels and mitigate toxicity impacts on aquatic fauna and flora. As a consequence, the PW treatment methods applied in the petroleum industry are historically limited to physical separation technologies such as API separators, coalescers or hydro-cyclones. These technologies are. 

The Norwegian Ministry of Petroleum and Energy (in white paper no. 38) defines lO as Use of information technology to change work processes to achieve improved decisions, remote control of processes and equipment, and to relocatefunctions and personnel to a remote installation or an onshore facility . 

The radical improvement in safety over a period of 20 years that was noted in Figure 1.1 is repeated for these onshore facilities. 

SEMP is very similar to the Process Safety Management standard (OSHA 1992) issued for onshore facilities in 1992 and which was widely hailed as being a good example of a performance-based, nonprescriptive standard. SEMP provided the basis of the SEMS rule, which was then supplemented by SEMS II. Therefore the combination of SEMS and SEMS II does create a performance-based system, although different in detail and application from the Safety Case approach. 

In the previous two chapters it was noted that offshore safety management has much in common with other process industries, particularly onshore facilities such as refineries, pipelines, and chemical plants. However, each industry does have its unique safety issues and problems. For example, a chemical plant will often either manufacture or use highly toxic compounds that have to be handled with special... 

Offshore facilities use chemicals such as methanol and monoethylene glycol for hydrate removal. Although these chemicals are toxic and flammable, they are much less hazardous than many of the chemicals found in a typical chemical plant or refinery. Moreover, the quantities used offshore are quite small compared with a typical onshore facility. Generally the chemicals are supplied in tote tanks that are offloaded from a supply boat and stored on a dedicated section of the deck. 

The oil and gas that are produced at the platform can be delivered to onshore facilities through subsea pipelines. Issues to be considered with regard to these pipelines include the following ... 

Regarding cost, a rule of thumb for onshore facilities is that each change processed through the MOC system has a direct administrative cost of around US 1500, with associated implementation costs of at least US 1 million for a 400-person facility. 

Onshore facilities also need to consider the impact of noise on the local community. 

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