Saltwater disposal . Because of severe and long-term consequences to 

 vegetation and soil, salt water disposal facilities require frequent checking 

 to prevent mishaps. Salt water is usually collected in tanks or pits so that 

 particulate matter may settle out and oil may be skimmed off. After a long 

 period, the tank may have to be cleaned due to the collection of sediment. 

 The sediment is often piled nearby and may be hauled away or used as fill. 

 The skimmed oil is periodically returned to the separator system for reprocess- 

 ing. When it is impractical to skim the oil from the surface, it can be 

 burned. This is often the case on remote production sites that are only 

 partially automated. On some production facilities, a pilot light is on 

 constantly and when the floating oil and wax contacts the flame, it ignites 

 and burns. The brine is withdrawn from the pit below the water surface for 

 disposal or further treatment. 



Settling does not remove all particulate matter, and therefore filters 

 may be used. These may be in-line pressure filters or trickle filters. In- 

 line filters have elements that must be periodically changed. Trickle filters 

 depend upon slow percolation of water through a sequence of materials from 

 clay to gravel. Trickle filters are periodically maintained by back-flushing 

 and collection of the coagulated floe. On occasion the upper layers of a 

 trickle filter must be removed and recharged. The by-products of trickle 

 filter cleaning are removed from the equipment and disposed as solid wastes. 



Water quality standards for surface or subsurface disposal may mandate 



chemical or physical treatment of brine. Chemicals may need replenishing 



since they are used up during treatment. Frequently used chemicals include 

 chlorine, coagulants, and lime. 



The actual disposal of the brine depends on the magnitude of brine produc- 

 tion. Some wells or fields may produce very little brine. Thus, brine disposal 

 is a small problem handled by production personnel. Other fields, however, 

 may produce considerably more brine than crude. This is particularly true in 

 older fields where production is declining as the resource is depleted. 

 Consequently, the brine problem becomes a major element of production management. 



Some of the steps described above may be circumvented if a closed brine 

 system is used. For such a system to operate, the brine must be fairly clean 

 and remain unexposed to air. This system may be used when the brine is being 

 returned to the same formation from which it came. 



Spill and leak cleanup. Spills and leaks are the result of equipment 

 failure, improper operation of equipment, or human error. In many instances 

 automatic devices are used to control failures in equipment. Gas flowlines 

 often have automatic valves that shut if the pressure is above or below prese- 

 lected threshold values, or they at least have pressure detectors that signal 

 malfunctions. 



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