Wellhead Surface Equipment
Surface Equipment – Wellhead Flash Gas Recovery
For each barrel of natural gasoline condensate collected in storage, roughly 1,300,000 BTU’s worth of gas is flashed-off from the low pressure three phase separator. This assumes that the high pressure separator is operating at 1000 psig and the low pressure separator is running at 50 psig. In addition to being environmentally reprehensible, this venting [...]
10Oct2009 | admin | Comments Off | ContinuedSurface Equipment – Orifice Meter
Permitting a wellhead meter to read high robs your employer. The royalty and severance tax payments made by the lease operator are based on the meter readings. Pulsations in the meter run (such as those induced by wellhead reciprocating compressors) will invaribly cause the meter to read high. Occasionally, field personnel install a smaller orifice [...]
10Oct2009 | admin | Comments Off | ContinuedSurface Equipment – Brine Tank
If the interface level controller on the low pressure, three phase separator malfunctions, a well’s entire production of natural gasoline may wind up in an open top brine holding tank. Of course, losses in hydrocarbons will be accelerated due to evaporation. More importantly, the lease operator may lose all the well’s condensate. It can happen [...]
10Oct2009 | admin | Comments Off | ContinuedSurface Equipment – Condensate Tank
Maintaining the low pressure separator at too high a pressure can cause the natural gasoline condensate holding tank to over-pressure. As a rough approximation, about half a mole of gas is vented from a condensate tank for each barrel of condensate collected. This gas evolution rate is based on a 65 psig low pressure separator [...]
10Oct2009 | admin | Comments Off | ContinuedSurface Equipment – Low Pressure Three Phase Separator
The high pressure liquid flows into the low pressure separator. Typically the low pressure vessel operates at 30 to 60 psig. Below 20 psig, there will not be enough pressure to push the accumulated liquids into adjacent tanks. Above 60 psig, natural gasoline condensate will generate excessive vapors when it is introduced to a storage [...]
10Oct2009 | admin | Comments Off | ContinuedSurface Equipment – High Pressure Separator
To prevent metering difficulties, and to reduce corrosion and pressure drop in downstream piping, liquids are removed from wellhead gas. Water plus natural gasoline condensate are drawn off as a mixed phase. Gas flows out of the separator, through the sales meter, and into the collection (i.e. lateral) piping. The two main problems associated with [...]
10Oct2009 | admin | Comments Off | ContinuedSurface Equipment – Heater Operation
Why are there two chokes shown in figure 3—2. Certainly, gas flow could be controlled with a single choke. One reason is that the erosion of the choke is reduced by limiting the pressure drop through a single restriction. Note the pressure profile between the wellhead and high pressure separator shown in figure 3-1. The [...]
10Oct2009 | admin | Comments Off | Continued