Separators: 2021 #10

True statements about oil and gas separators include (select any that apply):
__ Typically, oil must have less than 1% (by volume) water and gas less than 1 lbm water/MMscf to meet saleable pipeline specifications.
__ Typically, the four stages of depressurization are high pressure (HP), intermediate pressure (IP), free water knockout (FWKO), and the degasser/bulk oil treater (BOT) combination.
__ Bulk water is removed in the FWKO and final dewatering is accomplished in the BOT.
__ Staged separation (depressurization) is required to maximize the liquid hydrocarbon volumes.
__ Water may be removed in the HP and/or IP vessels.
__ The BOT is typically an electrostatic treater.
__ Sometimes the BOT will include a degassing section, eliminating the need for a separate degasser.
__ Typical deepwater platform pressures are 1,500, 700, 250, and 50 psig for the HP, IP, FWKO, and degasser stages, respectively.
__The terms “stage separator “and “trap” refer to a non-conventional oil/gas separator.
__ A flash chamber (trap or vessel) normally refers to a conventional oil/gas separator operated at high pressure, with the liquid from a higher-pressure separator being partially vaporized or “flashed” into it.
__ An expansion vessel is the first-stage separator or a low-temperature or cold-separation unit.
__ A gas scrubber is similar to an oil/gas separator. Usually, it handles fluid that contains less liquid than that produced from oil/gas wells.
__ Gas scrubbers are normally used in compressor trains, gas gathering, sales, and distribution lines, where they are required to handle slugs or heads of liquid.

Click the button for the answer, along with commentary and SPE references sourced. Note that the provided SPE Reference Guide will not help at all on these types of problems. Feel free to ask questions in the comment box below.

__ Typically, oil must have less than 1% (by volume) water and gas less than 5 lbm water/MMscf to meet saleable pipeline specifications. (HS3 P13)
 X  The four stages of depressurization are high pressure (HP), intermediate pressure (IP), free water knockout (FWKO), and the degasser/bulk oil treater (BOT) combination. (HS3 P13)
 X  Bulk water is removed in the third stage, FWKO, and final dewatering is accomplished in the BOT. (HS3 P13)
 X  Staged separation is required to maximize the liquid hydrocarbon volumes. (HS3 P13)
 X  Water may be removed in the HP and/or IP vessels. (HS3 P13)
 X  The BOT is typically an electrostatic treater; sometimes , the BOT will include a degassing section, eliminating the need for a separate degasser vessel. (HS3 P13)
 X  Typical deepwater platform pressures are 1,500, 700, 250, and 50 psig for the HP, IP, FWKO, and degasser stages, respectively. (HS3 P13).
__ The terms “oil/gas separator,” “separator,” “stage separator, “and “trap” refer to a conventional oil/gas separator. (HS3 P14)
__ A flash chamber (trap or vessel) normally refers to a conventional oil/gas separator operated at low pressure, with the liquid from a higher-pressure separator being partially vaporized or “flashed” into it. (HS3 P14) (HS3 P14)
 X  An expansion vessel is the first-stage separator or a low-temperature or cold-separation unit. This vessel may be equipped with a heating coil to melt hydrates, or a hydrate -preventing liquid (such as glycol) may be injected into the well fluid just before expansion into this vessel. (HS3 P14)
 X  Gas scrubbers usually handles fluid that contains less liquid than that produced from oi/gas wells. (HS3 P15)
__ Gas scrubbers are normally used in compressor trains, gas gathering, sales, and distribution lines, where they are not required to handle slugs or heads of liquid. (HS3 P15)