Page 12 - Petroleum and Gas Field Processing

Figure 1 An outline of the processing surface field operations.

mostly as emulsified water. The presence of this salt water presents serious
corrosion and scaling problems in transportation and refinery operations.
Water remaining in the oil is known as the basic sediments and water
(BS&W). A maximum of 1% BS&W and in some cases less than 0.5%
BS&W is acceptable. The limit on the salt content of the remnant water in
oils is usually in the range of 10 to 15 PTB (pounds of salt per thousand
barrels of oil). If these specifications are not met, then further treatment of
the oil leaving the separator will be needed. Such treatment involves
emulsion treatment/dehydration and desalting processes.
After oil treating, there may be a need to stabilize the crude oil to
optimize the oil recovery and reduce its volatility. Some produced crude oils
contain hydrogen sulfide and other sulfur products. When it contains more
than 400 ppm of H 2 S gas, the oil is classified as sour crude. Sour crude oils

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