Archive for November, 2009

Reciprocating Compressor Troubleshooting – Unloader failure

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pneumatically operated, automated unloaders. A mal-functioning unloader remains in an open position and thus reduces the capacity of the compressor. To identify this problem, proceed as follows: • Set the compressor to run at a constant speed. • Close the suspect unloader pocket and note the effect on the engine’s fuel gas manifold pressure. • […]

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Reciprocating Compressor Troubleshooting – Evaluating lost compression horse power


The first step in troubleshooting reciprocating compressors is to quantify the extent of the problem. How much compression work has actually been lost? An approximate rule of thumb is: Inserting the data from the El Gringo operation in the above equation I found: HP (current) = 90 (1100/850 – 1) .520/ 520 = 2JL9 HP […]

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Flooding Dehydrator Tower – Plugged Tray

Drying towers in natural gas service can become rapidly fouled with drilling mud or formation and frac sand. The sand appears in the wellhead gas when the rate of gas production becomes excessive, and the sand is thus sucked out of the formation and into the well’s tubing. Drilling mud is found in natural gas […]

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Flooding Dehydrator Tower – Fouling vs Flooding

A distillation column can flood due to dry damage, undersized liquid downcomers, high liquid level in the bottom of the tower, foulcommonly encountered in natural gas conditioning. The troubleshooter should first check for flooding due to excessive vapor velocities. The following correlation may be used for trayed columns 2 feet or more in diameter with […]

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Glycol Dehydrator – Flooding Dehydrator Tower

The field supervisor’s first indication of a flooded contactor tower is usually a report of excessive glycol loss. A check of a lowpoint bleeder on the gas pipeline downstream of the tower will show glycol. After refilling the glycol reboiler, the level in the reboiler gauge glass noticeably decreases after a few hours. This is […]

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Glycol Dehydrator – Leaking Feed-Effluent Exchanger

The hot glycol from the reboiler is cooled by heat exchange with the wet glycol from the contactor. This heat transfer typically takes place in a double-pipe or plate-type exchanger. On one of the double-pipe heat exchangers, I noticed that the reboiled glycol was being cooled to a rather low temperature. I suspected that this […]

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Glycol Dehydrator – Glycol Regeration Temperature

The gas exiting the top of the contactor in Figure 6-1 can be assumed to be in equilibrium with the reboiled—i.e., dry—glycol. The higher the glycol reboiler temperature, the dryer the glycol. The dryer the glycol, the dryer the treated natural gas. For most of the year in El Gringo, critical control of the glycol […]

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