OFC Operating Range
- Beam Pump (Rod Pumped Wells)
- Minimum Prime Mover HP: 15-20
- Beam Pump Size > =114
- Gas volumes from 10-300 mcf
- Fluid volumes to 50 bpd
- Working pressure to 200 psig
- Suction pressure from 30” Hg to 100 psig
- Corrosive environment OK
At a typical installation of an Oil Flow Compressor (OFC®) on an oil well, the OFC® receives gas from the casing head into the suction (input) flex hose of the OFC®. The OFC® discharges the gas through the discharge (output) flex hose of the OFC® into the flow line or gas sales line.
Figure 1 is representative of a typical well-head configuration. Under normal operation, pumped oil exits the tubing through OV-1 (Oil Valve 1) and CV-2 (Check Valve 2), and enters the flow line to the separator. Casing-gas exits the casing head through GV-1 (Gas Valve 1) and CV-1 (Check Valve 1), and enters the same flow line to join the oil to the separator. The secondary gas valve GV-2 is normally closed, or is connected to a pressure gauge that indicates the casing-head gas pressure.
When an OFC® is installed at a well-site, nothing changes with regard to the oil flow through OV-1 and CV-2. However, with regard to casing-head gas flow, piping is connected to GV-2 as shown. The gas valves GV-2, GV-4 and GV-5 are installed in the piping configuration in order that the function of the OFC® can be removed from the well head operation. For example, an operator may desire to inject chemicals down the casing annulus without the chemicals being drawn into and through the OFC®. No harm would occur to the OFC®, but the well would not experience the effects of the injection.
When the OFC® function is active at the well, gas valve GV-1 is closed and GV-2 is open. This forces all the casing-head gas to enter the OFC® via GV-2. Gas valves GV-3 and GV-5 are open, and GV-4 is closed. Gas flows from the casing head, through GV-2 and GV-3 into the OFC®.
The discharged gas from the OFC® passes through GV-5 and CV-3 and enters the same flow line to the separator. During this configuration, the OFC® has isolated the well head from the down stream flow line. Therefore, the casing-head gas pressure can be reduced to the capacity of the OFC® (even into vacuum ranges), while the flow-line pressure remains higher. The higher flow-line pressure has no effect on the casing-head gas pressure, and therefore on the down-hole back pressure on the oil formation. The back pressure (hydrostatic) is now only a function of the OFC®.
In Figure 2, GV-3 and GV-5 are closed, and GV-4 is open. During the pumping motion of the walking beam, gas within the OFC® merely circulates internally. If desired by an operator, GV-1 can be reopened in order to keep the casing-head gas pressure no greater than the flow-line pressure.
When the OFC® function is again desired to be active, GV-3 and GV-5 are opened, and GV-4 and GV-1 are closed.